FFmpeg Formats Documentation

3.5.1 Syntax ¶

The script is a text file in extended-ASCII, with one directive per line. Empty lines, leading spaces and lines starting with ’#’ are ignored. The following directive is recognized:

file path

Path to a file to read; special characters and spaces must be escaped with backslash or single quotes.

All subsequent file-related directives apply to that file.

ffconcat version 1.0

Identify the script type and version.

To make FFmpeg recognize the format automatically, this directive must appear exactly as is (no extra space or byte-order-mark) on the very first line of the script.

duration dur

Duration of the file. This information can be specified from the file; specifying it here may be more efficient or help if the information from the file is not available or accurate.

If the duration is set for all files, then it is possible to seek in the whole concatenated video.

inpoint timestamp

In point of the file. When the demuxer opens the file it instantly seeks to the specified timestamp. Seeking is done so that all streams can be presented successfully at In point.

This directive works best with intra frame codecs, because for non-intra frame ones you will usually get extra packets before the actual In point and the decoded content will most likely contain frames before In point too.

For each file, packets before the file In point will have timestamps less than the calculated start timestamp of the file (negative in case of the first file), and the duration of the files (if not specified by the duration directive) will be reduced based on their specified In point.

Because of potential packets before the specified In point, packet timestamps may overlap between two concatenated files.

outpoint timestamp

Out point of the file. When the demuxer reaches the specified decoding timestamp in any of the streams, it handles it as an end of file condition and skips the current and all the remaining packets from all streams.

Out point is exclusive, which means that the demuxer will not output packets with a decoding timestamp greater or equal to Out point.

This directive works best with intra frame codecs and formats where all streams are tightly interleaved. For non-intra frame codecs you will usually get additional packets with presentation timestamp after Out point therefore the decoded content will most likely contain frames after Out point too. If your streams are not tightly interleaved you may not get all the packets from all streams before Out point and you may only will be able to decode the earliest stream until Out point.

The duration of the files (if not specified by the duration directive) will be reduced based on their specified Out point.

file_packet_metadata key=value

Metadata of the packets of the file. The specified metadata will be set for each file packet. You can specify this directive multiple times to add multiple metadata entries. This directive is deprecated, use file_packet_meta instead.

file_packet_meta key value

Metadata of the packets of the file. The specified metadata will be set for each file packet. You can specify this directive multiple times to add multiple metadata entries.

option key value

Option to access, open and probe the file. Can be present multiple times.

stream

Introduce a stream in the virtual file. All subsequent stream-related directives apply to the last introduced stream. Some streams properties must be set in order to allow identifying the matching streams in the subfiles. If no streams are defined in the script, the streams from the first file are copied.

exact_stream_id id

Set the id of the stream. If this directive is given, the string with the corresponding id in the subfiles will be used. This is especially useful for MPEG-PS (VOB) files, where the order of the streams is not reliable.

stream_meta key value

Metadata for the stream. Can be present multiple times.

stream_codec value

Codec for the stream.

stream_extradata hex_string

Extradata for the string, encoded in hexadecimal.

chapter id start end

Add a chapter. id is an unique identifier, possibly small and consecutive.

3.5.2 Options ¶

This demuxer accepts the following option:

safe

If set to 1, reject unsafe file paths and directives. A file path is considered safe if it does not contain a protocol specification and is relative and all components only contain characters from the portable character set (letters, digits, period, underscore and hyphen) and have no period at the beginning of a component.

If set to 0, any file name is accepted.

The default is 1.

auto_convert

If set to 1, try to perform automatic conversions on packet data to make the streams concatenable. The default is 1.

Currently, the only conversion is adding the h264_mp4toannexb bitstream filter to H.264 streams in MP4 format. This is necessary in particular if there are resolution changes.

segment_time_metadata

If set to 1, every packet will contain the lavf.concat.start_time and the lavf.concat.duration packet metadata values which are the start_time and the duration of the respective file segments in the concatenated output expressed in microseconds. The duration metadata is only set if it is known based on the concat file. The default is 0.

3.5.3 Examples ¶

• Use absolute filenames and include some comments:

  # my first filename
  file /mnt/share/file-1.wav
  # my second filename including whitespace
  file '/mnt/share/file 2.wav'
  # my third filename including whitespace plus single quote
  file '/mnt/share/file 3'\''.wav'
  

• Allow for input format auto-probing, use safe filenames and set the duration of the first file:

  ffconcat version 1.0
  
  file file-1.wav
  duration 20.0
  
  file subdir/file-2.wav
  

3.6.1 Options ¶

This demuxer accepts the following option:

cenc_decryption_key

16-byte key, in hex, to decrypt files encrypted using ISO Common Encryption (CENC/AES-128 CTR; ISO/IEC 23001-7).

3.7.1 Background ¶

DVD-Video is not a directly accessible, linear container format in the traditional sense. Instead, it allows for complex and programmatic playback of carefully muxed MPEG-PS streams that are stored in headerless VOB files. To the end-user, these streams are known simply as "titles", but the actual logical playback sequence is defined by one or more "PGCs", or Program Group Chains, within the title. The PGC is in turn comprised of multiple "PGs", or Programs", which are the actual video segments (and for a typical video feature, sequentially ordered). The PGC structure, along with stream layout and metadata, are stored in IFO files that need to be parsed. PGCs can be thought of as playlists in easier terms.

An actual DVD player relies on user GUI interaction via menus and an internal VM to drive the direction of demuxing. Generally, the user would either navigate (via menus) or automatically be redirected to the PGC of their choice. During this process and the subsequent playback, the DVD player’s internal VM also maintains a state and executes instructions that can create jumps to different sectors during playback. This is why libdvdnav is involved, as a linear read of the MPEG-PS blobs on the disc (VOBs) is not enough to produce the right sequence in many cases.

There are many other DVD structures (a long subject) that will not be discussed here. NAV packets, in particular, are handled by this demuxer to build accurate timing but not emitted as a stream. For a good high-level understanding, refer to: https://code.videolan.org/videolan/libdvdnav/-/blob/master/doc/dvd_structures

3.7.2 Options ¶

This demuxer accepts the following options:

title int

The title number to play. Must be set if pgc and pg are not set. Not applicable to menus. Default is 0 (auto), which currently only selects the first available title (title 1) and notifies the user about the implications.

chapter_start int

The chapter, or PTT (part-of-title), number to start at. Not applicable to menus. Default is 1.

chapter_end int

The chapter, or PTT (part-of-title), number to end at. Not applicable to menus. Default is 0, which is a special value to signal end at the last possible chapter.

angle int

The video angle number, referring to what is essentially an additional video stream that is composed from alternate frames interleaved in the VOBs. Not applicable to menus. Default is 1.

region int

The region code to use for playback. Some discs may use this to default playback at a particular angle in different regions. This option will not affect the region code of a real DVD drive, if used as an input. Not applicable to menus. Default is 0, "world".

menu bool

Demux menu assets instead of navigating a title. Requires exact coordinates of the menu (menu_lu, menu_vts, pgc, pg). Default is false.

menu_lu int

The menu language to demux. In DVD, menus are grouped by language. Default is 0, the first language unit.

menu_vts int

The VTS where the menu lives, or 0 if it is a VMG menu (root-level). Default is 0, VMG menu.

pgc int

The entry PGC to start playback, in conjunction with pg. Alternative to setting title. Chapter markers are not supported at this time. Must be explicitly set for menus. Default is 0, automatically resolve from value of title.

pg int

The entry PG to start playback, in conjunction with pgc. Alternative to setting title. Chapter markers are not supported at this time. Default is 0, automatically resolve from value of title, or start from the beginning (PG 1) of the menu.

preindex bool

Enable this to have accurate chapter (PTT) markers and duration measurement, which requires a slow second pass read in order to index the chapter marker timestamps from NAV packets. This is non-ideal extra work for real optical drives. It is recommended and faster to use this option with a backup of the DVD structure stored on a hard drive. Not compatible with pgc and pg. Not applicable to menus. Default is 0, false.

trim bool

Skip padding cells (i.e. cells shorter than 1 second) from the beginning. There exist many discs with filler segments at the beginning of the PGC, often with junk data intended for controlling a real DVD player’s buffering speed and with no other material data value. Not applicable to menus. Default is 1, true.

3.7.3 Examples ¶

• Open title 3 from a given DVD structure:

  ffmpeg -f dvdvideo -title 3 -i <path to DVD> ...
  

• Open chapters 3-6 from title 1 from a given DVD structure:

  ffmpeg -f dvdvideo -chapter_start 3 -chapter_end 6 -title 1 -i <path to DVD> ...
  

• Open only chapter 5 from title 1 from a given DVD structure:

  ffmpeg -f dvdvideo -chapter_start 5 -chapter_end 5 -title 1 -i <path to DVD> ...
  

• Demux menu with language 1 from VTS 1, PGC 1, starting at PG 1:

  ffmpeg -f dvdvideo -menu 1 -menu_lu 1 -menu_vts 1 -pgc 1 -pg 1 -i <path to DVD> ...
  

3.8.1 Options ¶

merge_alpha bool

Normally the VP6 alpha channel (if exists) is returned as a secondary video stream, by setting this option you can make the demuxer return a single video stream which contains the alpha channel in addition to the ordinary video.

3.13.1 Examples ¶

• Use ffmpeg for creating a video from the images in the file sequence img-001.jpeg, img-002.jpeg, ..., assuming an input frame rate of 10 frames per second:

  ffmpeg -framerate 10 -i 'img-%03d.jpeg' out.mkv
  

• As above, but start by reading from a file with index 100 in the sequence:

  ffmpeg -framerate 10 -start_number 100 -i 'img-%03d.jpeg' out.mkv
  

• Read images matching the "*.png" glob pattern , that is all the files terminating with the ".png" suffix:

  ffmpeg -framerate 10 -pattern_type glob -i "*.png" out.mkv
  

3.17.1 Options ¶

This demuxer accepts the following options:

enable_drefs

Enable loading of external tracks, disabled by default. Enabling this can theoretically leak information in some use cases.

use_absolute_path

Allows loading of external tracks via absolute paths, disabled by default. Enabling this poses a security risk. It should only be enabled if the source is known to be non-malicious.

seek_streams_individually

When seeking, identify the closest point in each stream individually and demux packets in that stream from identified point. This can lead to a different sequence of packets compared to demuxing linearly from the beginning. Default is true.

ignore_editlist

Ignore any edit list atoms. The demuxer, by default, modifies the stream index to reflect the timeline described by the edit list. Default is false.

advanced_editlist

Modify the stream index to reflect the timeline described by the edit list. ignore_editlist must be set to false for this option to be effective. If both ignore_editlist and this option are set to false, then only the start of the stream index is modified to reflect initial dwell time or starting timestamp described by the edit list. Default is true.

ignore_chapters

Don’t parse chapters. This includes GoPro ’HiLight’ tags/moments. Note that chapters are only parsed when input is seekable. Default is false.

use_mfra_for

For seekable fragmented input, set fragment’s starting timestamp from media fragment random access box, if present.

Following options are available:

‘auto’

Auto-detect whether to set mfra timestamps as PTS or DTS (default)

‘dts’

Set mfra timestamps as DTS

‘pts’

Set mfra timestamps as PTS

‘0’

Don’t use mfra box to set timestamps

use_tfdt

For fragmented input, set fragment’s starting timestamp to baseMediaDecodeTime from the tfdt box. Default is enabled, which will prefer to use the tfdt box to set DTS. Disable to use the earliest_presentation_time from the sidx box. In either case, the timestamp from the mfra box will be used if it’s available and use_mfra_for is set to pts or dts.

export_all

Export unrecognized boxes within the udta box as metadata entries. The first four characters of the box type are set as the key. Default is false.

export_xmp

Export entire contents of XMP_ box and uuid box as a string with key xmp. Note that if export_all is set and this option isn’t, the contents of XMP_ box are still exported but with key XMP_. Default is false.

activation_bytes

4-byte key required to decrypt Audible AAX and AAX+ files. See Audible AAX subsection below.

audible_fixed_key

Fixed key used for handling Audible AAX/AAX+ files. It has been pre-set so should not be necessary to specify.

decryption_key

16-byte key, in hex, to decrypt files encrypted using ISO Common Encryption (CENC/AES-128 CTR; ISO/IEC 23001-7).

max_stts_delta

Very high sample deltas written in a trak’s stts box may occasionally be intended but usually they are written in error or used to store a negative value for dts correction when treated as signed 32-bit integers. This option lets the user set an upper limit, beyond which the delta is clamped to 1. Values greater than the limit if negative when cast to int32 are used to adjust onward dts.

Unit is the track time scale. Range is 0 to UINT_MAX. Default is UINT_MAX - 48000*10 which allows up to a 10 second dts correction for 48 kHz audio streams while accommodating 99.9% of uint32 range.

interleaved_read

Interleave packets from multiple tracks at demuxer level. For badly interleaved files, this prevents playback issues caused by large gaps between packets in different tracks, as MOV/MP4 do not have packet placement requirements. However, this can cause excessive seeking on very badly interleaved files, due to seeking between tracks, so disabling it may prevent I/O issues, at the expense of playback.

3.17.2 Audible AAX ¶

Audible AAX files are encrypted M4B files, and they can be decrypted by specifying a 4 byte activation secret.

ffmpeg -activation_bytes 1CEB00DA -i test.aax -vn -c:a copy output.mp4

3.21.1 Examples ¶

• Render CC to ASS using the built-in decoder:

  ffmpeg -i CC.rcwt.bin CC.ass
  

  Note that if your output appears to be empty, you may have to manually set the decoder’s data_field option to pick the desired CC substream.

• Convert an RCWT backup to Scenarist (SCC) format:

  ffmpeg -i CC.rcwt.bin -c:s copy CC.scc
  

  Note that the SCC format does not support all of the possible CC extensions that can be stored in RCWT (such as EIA-708).

4.1.1 Examples ¶

• Store raw video frames with the ‘rawvideo’ muxer using ffmpeg:

  ffmpeg -f lavfi -i testsrc -t 10 -s hd1080p testsrc.yuv
  

  Since the rawvideo muxer do not store the information related to size and format, this information must be provided when demuxing the file:

  ffplay -video_size 1920x1080 -pixel_format rgb24 -f rawvideo testsrc.rgb
  

4.3.1 Options ¶

muxrate rate

Set user-defined mux rate expressed as a number of bits/s. If not specied the automatically computed mux rate is employed. Default value is 0.

preload delay

Set initial demux-decode delay in microseconds. Default value is 500000.

4.4.1 Fragmentation ¶

The ‘mov’, ‘mp4’, and ‘ismv’ muxers support fragmentation. Normally, a MOV/MP4 file has all the metadata about all packets stored in one location.

This data is usually written at the end of the file, but it can be moved to the start for better playback by adding +faststart to the -movflags, or using the qt-faststart tool).

A fragmented file consists of a number of fragments, where packets and metadata about these packets are stored together. Writing a fragmented file has the advantage that the file is decodable even if the writing is interrupted (while a normal MOV/MP4 is undecodable if it is not properly finished), and it requires less memory when writing very long files (since writing normal MOV/MP4 files stores info about every single packet in memory until the file is closed). The downside is that it is less compatible with other applications.

Fragmentation is enabled by setting one of the options that define how to cut the file into fragments:

frag_duration

frag_size

min_frag_duration

movflags +frag_keyframe

movflags +frag_custom

If more than one condition is specified, fragments are cut when one of the specified conditions is fulfilled. The exception to this is the option min_frag_duration, which has to be fulfilled for any of the other conditions to apply.

4.4.2 Options ¶

brand brand_string

Override major brand.

empty_hdlr_name bool

Enable to skip writing the name inside a hdlr box. Default is false.

encryption_key key

set the media encryption key in hexadecimal format

encryption_kid kid

set the media encryption key identifier in hexadecimal format

encryption_scheme scheme

configure the encryption scheme, allowed values are ‘none’, and ‘cenc-aes-ctr’

frag_duration duration

Create fragments that are duration microseconds long.

frag_interleave number

Interleave samples within fragments (max number of consecutive samples, lower is tighter interleaving, but with more overhead. It is set to 0 by default.

frag_size size

create fragments that contain up to size bytes of payload data

iods_audio_profile profile

specify iods number for the audio profile atom (from -1 to 255), default is -1

iods_video_profile profile

specify iods number for the video profile atom (from -1 to 255), default is -1

ism_lookahead num_entries

specify number of lookahead entries for ISM files (from 0 to 255), default is 0

min_frag_duration duration

do not create fragments that are shorter than duration microseconds long

moov_size bytes

Reserves space for the moov atom at the beginning of the file instead of placing the moov atom at the end. If the space reserved is insufficient, muxing will fail.

mov_gamma gamma

specify gamma value for gama atom (as a decimal number from 0 to 10), default is 0.0, must be set together with + movflags

movflags flags

Set various muxing switches. The following flags can be used:

‘cmaf’

write CMAF (Common Media Application Format) compatible fragmented MP4 output

‘dash’

write DASH (Dynamic Adaptive Streaming over HTTP) compatible fragmented MP4 output

‘default_base_moof’

Similarly to the ‘omit_tfhd_offset’ flag, this flag avoids writing the absolute base_data_offset field in tfhd atoms, but does so by using the new default-base-is-moof flag instead. This flag is new from 14496-12:2012. This may make the fragments easier to parse in certain circumstances (avoiding basing track fragment location calculations on the implicit end of the previous track fragment).

‘delay_moov’

delay writing the initial moov until the first fragment is cut, or until the first fragment flush

‘disable_chpl’

Disable Nero chapter markers (chpl atom). Normally, both Nero chapters and a QuickTime chapter track are written to the file. With this option set, only the QuickTime chapter track will be written. Nero chapters can cause failures when the file is reprocessed with certain tagging programs, like mp3Tag 2.61a and iTunes 11.3, most likely other versions are affected as well.

‘faststart’

Run a second pass moving the index (moov atom) to the beginning of the file. This operation can take a while, and will not work in various situations such as fragmented output, thus it is not enabled by default.

‘frag_custom’

Allow the caller to manually choose when to cut fragments, by calling av_write_frame(ctx, NULL) to write a fragment with the packets written so far. (This is only useful with other applications integrating libavformat, not from ffmpeg.)

‘frag_discont’

signal that the next fragment is discontinuous from earlier ones

‘frag_every_frame’

fragment at every frame

‘frag_keyframe’

start a new fragment at each video keyframe

‘global_sidx’

write a global sidx index at the start of the file

‘isml’

create a live smooth streaming feed (for pushing to a publishing point)

‘negative_cts_offsets’

Enables utilization of version 1 of the CTTS box, in which the CTS offsets can be negative. This enables the initial sample to have DTS/CTS of zero, and reduces the need for edit lists for some cases such as video tracks with B-frames. Additionally, eases conformance with the DASH-IF interoperability guidelines.

This option is implicitly set when writing ‘ismv’ (Smooth Streaming) files.

‘omit_tfhd_offset’

Do not write any absolute base_data_offset in tfhd atoms. This avoids tying fragments to absolute byte positions in the file/streams.

‘prefer_icc’

If writing colr atom prioritise usage of ICC profile if it exists in stream packet side data.

‘rtphint’

add RTP hinting tracks to the output file

‘separate_moof’

Write a separate moof (movie fragment) atom for each track. Normally, packets for all tracks are written in a moof atom (which is slightly more efficient), but with this option set, the muxer writes one moof/mdat pair for each track, making it easier to separate tracks.

‘skip_sidx’

Skip writing of sidx atom. When bitrate overhead due to sidx atom is high, this option could be used for cases where sidx atom is not mandatory. When the ‘global_sidx’ flag is enabled, this option is ignored.

‘skip_trailer’

skip writing the mfra/tfra/mfro trailer for fragmented files

‘use_metadata_tags’

use mdta atom for metadata

‘write_colr’

write colr atom even if the color info is unspecified. This flag is experimental, may be renamed or changed, do not use from scripts.

‘write_gama’

write deprecated gama atom

‘hybrid_fragmented’

For recoverability - write the output file as a fragmented file. This allows the intermediate file to be read while being written (in particular, if the writing process is aborted uncleanly). When writing is finished, the file is converted to a regular, non-fragmented file, which is more compatible and allows easier and quicker seeking.

If writing is aborted, the intermediate file can manually be remuxed to get a regular, non-fragmented file of what had been written into the unfinished file.

movie_timescale scale

Set the timescale written in the movie header box (mvhd). Range is 1 to INT_MAX. Default is 1000.

rtpflags flags

Add RTP hinting tracks to the output file.

The following flags can be used:

‘h264_mode0’

use mode 0 for H.264 in RTP

‘latm’

use MP4A-LATM packetization instead of MPEG4-GENERIC for AAC

‘rfc2190’

use RFC 2190 packetization instead of RFC 4629 for H.263

‘send_bye’

send RTCP BYE packets when finishing

‘skip_rtcp’

do not send RTCP sender reports

skip_iods bool

skip writing iods atom (default value is true)

use_editlist bool

use edit list (default value is auto)

use_stream_ids_as_track_ids bool

use stream ids as track ids (default value is false)

video_track_timescale scale

Set the timescale used for video tracks. Range is 0 to INT_MAX. If set to 0, the timescale is automatically set based on the native stream time base. Default is 0.

write_btrt bool

Force or disable writing bitrate box inside stsd box of a track. The box contains decoding buffer size (in bytes), maximum bitrate and average bitrate for the track. The box will be skipped if none of these values can be computed. Default is -1 or auto, which will write the box only in MP4 mode.

write_prft option

Write producer time reference box (PRFT) with a specified time source for the NTP field in the PRFT box. Set value as ‘wallclock’ to specify timesource as wallclock time and ‘pts’ to specify timesource as input packets’ PTS values.

write_tmcd bool

Specify on to force writing a timecode track, off to disable it and auto to write a timecode track only for mov and mp4 output (default).

Setting value to ‘pts’ is applicable only for a live encoding use case, where PTS values are set as as wallclock time at the source. For example, an encoding use case with decklink capture source where video_pts and audio_pts are set to ‘abs_wallclock’.

4.4.3 Examples ¶

• Push Smooth Streaming content in real time to a publishing point on IIS with the ‘ismv’ muxer using ffmpeg:

  ffmpeg -re <normal input/transcoding options> -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)
  

4.6.1 Options ¶

write_crc bool

when enabled, write a CRC checksum for each packet to the output, default is false

4.7.1 Options ¶

write_id3v2 bool

Enable to write ID3v2.4 tags at the start of the stream. Default is disabled.

write_apetag bool

Enable to write APE tags at the end of the stream. Default is disabled.

write_mpeg2 bool

Enable to set MPEG version bit in the ADTS frame header to 1 which indicates MPEG-2. Default is 0, which indicates MPEG-4.

4.9.1 Options ¶

write_id3v2 bool

Enable ID3v2 tags writing when set to 1. Default is 0 (disabled).

id3v2_version bool

Select ID3v2 version to write. Currently only version 3 and 4 (aka. ID3v2.3 and ID3v2.4) are supported. The default is version 4.

4.10.1 Options ¶

type type

Set file type.

type accepts the following values:

‘tun’

Set file type as music. Must have a sample rate of 22050 Hz.

‘pcm’

Set file type as sfx.

‘auto’

Set file type as per output file extension. .pcm results in type pcm else type tun is set. (default)

4.14.1 Options ¶

final_delay delay

Force a delay expressed in seconds after the last frame of each repetition. Default value is 0.0.

plays repetitions

specify how many times to play the content, 0 causes an infinte loop, with 1 there is no loop

4.14.2 Examples ¶

• Use ffmpeg to generate an APNG output with 2 repetitions, and with a delay of half a second after the first repetition:

  ffmpeg -i INPUT -final_delay 0.5 -plays 2 out.apng
  

4.15.1 Options ¶

version_major version

override file major version, specified as an integer, default value is 2

version_minor version

override file minor version, specified as an integer, default value is 1

name name

Embed file name into file, if not specified use the output file name. The name is truncated to 8 characters.

4.16.1 Options ¶

skip_rate_check bool

skip sample rate check (default is false)

loop bool

set loop flag (default is false)

reverb boolean

set reverb flag (default is true)

4.17.1 Options ¶

packet_size size

Set the muxer packet size as a number of bytes. By tuning this setting you may reduce data fragmentation or muxer overhead depending on your source. Default value is 3200, minimum is 100, maximum is 64Ki.

4.18.1 Options ¶

ignore_readorder bool

Write dialogue events immediately, even if they are out-of-order, default is false, otherwise they are cached until the expected time event is found.

4.19.1 Options ¶

loopstart start

Specify loop start position expressesd in milliseconds, from -1 to INT_MAX, in case -1 is set then no loop is specified (default -1) and the loopend value is ignored.

loopend end

Specify loop end position expressed in milliseconds, from 0 to INT_MAX, default is 0, in case 0 is set it assumes the total stream duration.

4.21.1 Options ¶

flipped_raw_rgb bool

If set to true, store positive height for raw RGB bitmaps, which indicates bitmap is stored bottom-up. Note that this option does not flip the bitmap which has to be done manually beforehand, e.g. by using the ‘vflip’ filter. Default is false and indicates bitmap is stored top down.

reserve_index_space size

Reserve the specified amount of bytes for the OpenDML master index of each stream within the file header. By default additional master indexes are embedded within the data packets if there is no space left in the first master index and are linked together as a chain of indexes. This index structure can cause problems for some use cases, e.g. third-party software strictly relying on the OpenDML index specification or when file seeking is slow. Reserving enough index space in the file header avoids these problems.

The required index space depends on the output file size and should be about 16 bytes per gigabyte. When this option is omitted or set to zero the necessary index space is guessed.

Default value is 0.

write_channel_mask bool

Write the channel layout mask into the audio stream header.

This option is enabled by default. Disabling the channel mask can be useful in specific scenarios, e.g. when merging multiple audio streams into one for compatibility with software that only supports a single audio stream in AVI (see the "amerge" section in the ffmpeg-filters manual).

4.22.1 Options ¶

loop count

number of times to loop an animated AVIF, 0 specify an infinite loop, default is 0

movie_timescale timescale

Set the timescale written in the movie header box (mvhd). Range is 1 to INT_MAX. Default is 1000.

4.27.1 Options ¶

algorithm version

Select version of algorithm to fingerprint with. Range is 0 to 4. Version 3 enables silence detection. Default is 1.

fp_format format

Format to output the fingerprint as. Accepts the following options:

‘base64’

Base64 compressed fingerprint (default)

‘compressed’

Binary compressed fingerprint

‘raw’

Binary raw fingerprint

silence_threshold threshold

Threshold for detecting silence. Range is from -1 to 32767, where -1 disables silence detection. Silence detection can only be used with version 3 of the algorithm.

Silence detection must be disabled for use with the AcoustID service. Default is -1.

4.28.1 Examples ¶

• Use ffmpeg to compute the CRC of the input, and store it in the file out.crc:

  ffmpeg -i INPUT -f crc out.crc
  

• Use ffmpeg to print the CRC to stdout with the command:

  ffmpeg -i INPUT -f crc -
  

• You can select the output format of each frame with ffmpeg by specifying the audio and video codec and format. For example, to compute the CRC of the input audio converted to PCM unsigned 8-bit and the input video converted to MPEG-2 video, use the command:

  ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc -
  

4.29.1 Options ¶

adaptation_sets adaptation_sets

Assign streams to adaptation sets, specified in the MPD manifest AdaptationSets section.

An adaptation set contains a set of one or more streams accessed as a single subset, e.g. corresponding streams encoded at different size selectable by the user depending on the available bandwidth, or to different audio streams with a different language.

Each adaptation set is specified with the syntax:

id=index,streams=streams

where index must be a numerical index, and streams is a sequence of ,-separated stream indices. Multiple adaptation sets can be specified, separated by spaces.

To map all video (or audio) streams to an adaptation set, v (or a) can be used as stream identifier instead of IDs.

When no assignment is defined, this defaults to an adaptation set for each stream.

The following optional fields can also be specified:

descriptor

Define the descriptor as defined by ISO/IEC 23009-1:2014/Amd.2:2015.

For example:

<SupplementalProperty schemeIdUri=\"urn:mpeg:dash:srd:2014\" value=\"0,0,0,1,1,2,2\"/>

The descriptor string should be a self-closing XML tag.

frag_duration

Override the global fragment duration specified with the frag_duration option.

frag_type

Override the global fragment type specified with the frag_type option.

seg_duration

Override the global segment duration specified with the seg_duration option.

trick_id

Mark an adaptation set as containing streams meant to be used for Trick Mode for the referenced adaptation set.

A few examples of possible values for the adaptation_sets option follow:

id=0,seg_duration=2,frag_duration=1,frag_type=duration,streams=v id=1,seg_duration=2,frag_type=none,streams=a

id=0,seg_duration=2,frag_type=none,streams=0 id=1,seg_duration=10,frag_type=none,trick_id=0,streams=1

dash_segment_type type

Set DASH segment files type.

Possible values:

‘auto’

The dash segment files format will be selected based on the stream codec. This is the default mode.

‘mp4’

the dash segment files will be in ISOBMFF/MP4 format

‘webm’

the dash segment files will be in WebM format

extra_window_size size

Set the maximum number of segments kept outside of the manifest before removing from disk.

format_options options_list

Set container format (mp4/webm) options using a :-separated list of key=value parameters. Values containing : special characters must be escaped.

frag_duration duration

Set the length in seconds of fragments within segments, fractional value can also be set.

frag_type type

Set the type of interval for fragmentation.

Possible values:

‘auto’

set one fragment per segment

‘every_frame’

fragment at every frame

‘duration’

fragment at specific time intervals

‘pframes’

fragment at keyframes and following P-Frame reordering (Video only, experimental)

global_sidx bool

Write global SIDX atom. Applicable only for single file, mp4 output, non-streaming mode.

hls_master_name file_name

HLS master playlist name. Default is master.m3u8.

hls_playlist bool

Generate HLS playlist files. The master playlist is generated with filename specified by the hls_master_name option. One media playlist file is generated for each stream with filenames media_0.m3u8, media_1.m3u8, etc.

http_opts http_opts

Specify a list of :-separated key=value options to pass to the underlying HTTP protocol. Applicable only for HTTP output.

http_persistent bool

Use persistent HTTP connections. Applicable only for HTTP output.

http_user_agent user_agent

Override User-Agent field in HTTP header. Applicable only for HTTP output.

ignore_io_errors bool

Ignore IO errors during open and write. Useful for long-duration runs with network output. This is disabled by default.

index_correction bool

Enable or disable segment index correction logic. Applicable only when use_template is enabled and use_timeline is disabled. This is disabled by default.

When enabled, the logic monitors the flow of segment indexes. If a streams’s segment index value is not at the expected real time position, then the logic corrects that index value.

Typically this logic is needed in live streaming use cases. The network bandwidth fluctuations are common during long run streaming. Each fluctuation can cause the segment indexes fall behind the expected real time position.

init_seg_name init_name

DASH-templated name to use for the initialization segment. Default is init-stream$RepresentationID$.$ext$. $ext$ is replaced with the file name extension specific for the segment format.

ldash bool

Enable Low-latency Dash by constraining the presence and values of some elements. This is disabled by default.

lhls bool

Enable Low-latency HLS (LHLS). Add #EXT-X-PREFETCH tag with current segment’s URI. hls.js player folks are trying to standardize an open LHLS spec. The draft spec is available at https://github.com/video-dev/hlsjs-rfcs/blob/lhls-spec/proposals/0001-lhls.md.

This option tries to comply with the above open spec. It enables streaming and hls_playlist options automatically. This is an experimental feature.

Note: This is not Apple’s version LHLS. See https://datatracker.ietf.org/doc/html/draft-pantos-hls-rfc8216bis

master_m3u8_publish_rate segment_intervals_count

Publish master playlist repeatedly every after specified number of segment intervals.

max_playback_rate rate

Set the maximum playback rate indicated as appropriate for the purposes of automatically adjusting playback latency and buffer occupancy during normal playback by clients.

media_seg_name segment_name

DASH-templated name to use for the media segments. Default is chunk-stream$RepresentationID$-$Number%05d$.$ext$. $ext$ is replaced with the file name extension specific for the segment format.

method method

Use the given HTTP method to create output files. Generally set to PUT or POST.

min_playback_rate rate

Set the minimum playback rate indicated as appropriate for the purposes of automatically adjusting playback latency and buffer occupancy during normal playback by clients.

mpd_profile flags

Set one or more MPD manifest profiles.

Possible values:

‘dash’

MPEG-DASH ISO Base media file format live profile

‘dvb_dash’

DVB-DASH profile

Default value is dash.

remove_at_exit bool

Enable or disable removal of all segments when finished. This is disabled by default.

seg_duration duration

Set the segment length in seconds (fractional value can be set). The value is treated as average segment duration when the use_template option is enabled and the use_timeline option is disabled and as minimum segment duration for all the other use cases.

Default value is 5.

single_file bool

Enable or disable storing all segments in one file, accessed using byte ranges. This is disabled by default.

The name of the single file can be specified with the single_file_name option, if not specified assume the basename of the manifest file with the output format extension.

single_file_name file_name

DASH-templated name to use for the manifest baseURL element. Imply that the single_file option is set to true. In the template, $ext$ is replaced with the file name extension specific for the segment format.

streaming bool

Enable or disable chunk streaming mode of output. In chunk streaming mode, each frame will be a moof fragment which forms a chunk. This is disabled by default.

target_latency target_latency

Set an intended target latency in seconds for serving (fractional value can be set). Applicable only when the streaming and write_prft options are enabled. This is an informative fields clients can use to measure the latency of the service.

timeout timeout

Set timeout for socket I/O operations expressed in seconds (fractional value can be set). Applicable only for HTTP output.

update_period period

Set the MPD update period, for dynamic content. The unit is second. If set to 0, the period is automatically computed.

Default value is 0.

use_template bool

Enable or disable use of SegmentTemplate instead of SegmentList in the manifest. This is enabled by default.

use_timeline bool

Enable or disable use of SegmentTimeline within the SegmentTemplate manifest section. This is enabled by default.

utc_timing_url url

URL of the page that will return the UTC timestamp in ISO format, for example https://time.akamai.com/?iso

window_size size

Set the maximum number of segments kept in the manifest, discard the oldest one. This is useful for live streaming.

If the value is 0, all segments are kept in the manifest. Default value is 0.

write_prft write_prft

Write Producer Reference Time elements on supported streams. This also enables writing prft boxes in the underlying muxer. Applicable only when the utc_url option is enabled. It is set to auto by default, in which case the muxer will attempt to enable it only in modes that require it.

4.29.2 Example ¶

Generate a DASH output reading from an input source in realtime using ffmpeg.

Two multimedia streams are generated from the input file, both containing a video stream encoded through ‘libx264’, and an audio stream encoded with ‘libfdk_aac’. The first multimedia stream contains video with a bitrate of 800k and audio at the default rate, the second with video scaled to 320x170 pixels at 300k and audio resampled at 22005 Hz.

The window_size option keeps only the latest 5 segments with the default duration of 5 seconds.

ffmpeg -re -i <input> -map 0 -map 0 -c:a libfdk_aac -c:v libx264 \
-b:v:0 800k -profile:v:0 main \
-b:v:1 300k -s:v:1 320x170 -profile:v:1 baseline -ar:a:1 22050 \
-bf 1 -keyint_min 120 -g 120 -sc_threshold 0 -b_strategy 0 \
-use_timeline 1 -use_template 1 -window_size 5 \
-adaptation_sets "id=0,streams=v id=1,streams=a" \
-f dash /path/to/out.mpd

4.30.1 Example ¶

Use ffmpeg to mux input audio to a ‘5.1’ channel layout resampled at 96000Hz:

ffmpeg -i INPUT -af aresample=96000,pan=5.1 slow.302

For ffmpeg versions before 7.0 you might have to use the ‘asetnsamples’ filter to limit the muxed packet size, because this format does not support muxing packets larger than 65535 bytes (3640 samples). For newer ffmpeg versions audio is automatically packetized to 36000 byte (2000 sample) packets.

4.31.1 Example ¶

Use ffmpeg to convert the input:

ffmpeg -i INPUT -s:v 720x480 -pix_fmt yuv411p -r 29.97 -ac 2 -ar 48000 -y out.dv

4.32.1 Example ¶

Use ffmpeg to extract metadata from an input file to a metadata.ffmeta file in ‘ffmetadata’ format:

ffmpeg -i INPUT -f ffmetadata metadata.ffmeta

4.33.1 Options ¶

attempt_recovery bool

If failure occurs, attempt to recover the output. This is especially useful when used with network output, since it makes it possible to restart streaming transparently. By default this option is set to false.

drop_pkts_on_overflow bool

If set to true, in case the fifo queue fills up, packets will be dropped rather than blocking the encoder. This makes it possible to continue streaming without delaying the input, at the cost of omitting part of the stream. By default this option is set to false, so in such cases the encoder will be blocked until the muxer processes some of the packets and none of them is lost.

fifo_format format_name

Specify the format name. Useful if it cannot be guessed from the output name suffix.

format_opts options

Specify format options for the underlying muxer. Muxer options can be specified as a list of key=value pairs separated by ’:’.

max_recovery_attempts count

Set maximum number of successive unsuccessful recovery attempts after which the output fails permanently. By default this option is set to 0 (unlimited).

queue_size size

Specify size of the queue as a number of packets. Default value is 60.

recover_any_error bool

If set to true, recovery will be attempted regardless of type of the error causing the failure. By default this option is set to false and in case of certain (usually permanent) errors the recovery is not attempted even when the attempt_recovery option is set to true.

recovery_wait_streamtime bool

If set to false, the real time is used when waiting for the recovery attempt (i.e. the recovery will be attempted after the time specified by the recovery_wait_time option).

If set to true, the time of the processed stream is taken into account instead (i.e. the recovery will be attempted after discarding the packets corresponding to the recovery_wait_time option).

By default this option is set to false.

recovery_wait_time duration

Specify waiting time in seconds before the next recovery attempt after previous unsuccessful recovery attempt. Default value is 5.

restart_with_keyframe bool

Specify whether to wait for the keyframe after recovering from queue overflow or failure. This option is set to false by default.

timeshift duration

Buffer the specified amount of packets and delay writing the output. Note that the value of the queue_size option must be big enough to store the packets for timeshift. At the end of the input the fifo buffer is flushed at realtime speed.

4.33.2 Example ¶

Use ffmpeg to stream to an RTMP server, continue processing the stream at real-time rate even in case of temporary failure (network outage) and attempt to recover streaming every second indefinitely:

ffmpeg -re -i ... -c:v libx264 -c:a aac -f fifo -fifo_format flv \
  -drop_pkts_on_overflow 1 -attempt_recovery 1 -recovery_wait_time 1 \
  -map 0:v -map 0:a rtmp://example.com/live/stream_name

4.37.1 Options ¶

write_header bool

write the file header if set to true, default is true

4.37.2 Example ¶

Use ffmpeg to store the audio stream from an input file, together with several pictures used with ‘attached_pic’ disposition:

ffmpeg -i INPUT -i pic1.png -i pic2.jpg -map 0:a -map 1 -map 2 -disposition:v attached_pic OUTPUT

4.38.1 Options ¶

flvflags flags

Possible values:

‘aac_seq_header_detect’

Place AAC sequence header based on audio stream data.

‘no_sequence_end’

Disable sequence end tag.

‘no_metadata’

Disable metadata tag.

‘no_duration_filesize’

Disable duration and filesize in metadata when they are equal to zero at the end of stream. (Be used to non-seekable living stream).

‘add_keyframe_index’

Used to facilitate seeking; particularly for HTTP pseudo streaming.

4.39.1 Examples ¶

For example to compute the CRC of the audio and video frames in INPUT, converted to raw audio and video packets, and store it in the file out.crc:

ffmpeg -i INPUT -f framecrc out.crc

To print the information to stdout, use the command:

ffmpeg -i INPUT -f framecrc -

With ffmpeg, you can select the output format to which the audio and video frames are encoded before computing the CRC for each packet by specifying the audio and video codec. For example, to compute the CRC of each decoded input audio frame converted to PCM unsigned 8-bit and of each decoded input video frame converted to MPEG-2 video, use the command:

ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -

See also the crc muxer.

4.40.1 Examples ¶

To compute the SHA-256 hash of the audio and video frames in INPUT, converted to raw audio and video packets, and store it in the file out.sha256:

ffmpeg -i INPUT -f framehash out.sha256

To print the information to stdout, using the MD5 hash function, use the command:

ffmpeg -i INPUT -f framehash -hash md5 -

See also the hash muxer.

4.41.1 Examples ¶

To compute the MD5 hash of the audio and video frames in INPUT, converted to raw audio and video packets, and store it in the file out.md5:

ffmpeg -i INPUT -f framemd5 out.md5

To print the information to stdout, use the command:

ffmpeg -i INPUT -f framemd5 -

See also the framehash and md5 muxers.

4.42.1 Options ¶

loop bool

Set the number of times to loop the output. Use -1 for no loop, 0 for looping indefinitely (default).

final_delay delay

Force the delay (expressed in centiseconds) after the last frame. Each frame ends with a delay until the next frame. The default is -1, which is a special value to tell the muxer to re-use the previous delay. In case of a loop, you might want to customize this value to mark a pause for instance.

4.42.2 Example ¶

Encode a gif looping 10 times, with a 5 seconds delay between the loops:

ffmpeg -i INPUT -loop 10 -final_delay 500 out.gif

Note 1: if you wish to extract the frames into separate GIF files, you need to force the image2 muxer:

ffmpeg -i INPUT -c:v gif -f image2 "out%d.gif"

4.44.1 Examples ¶

To compute the SHA-256 hash of the input converted to raw audio and video, and store it in the file out.sha256:

ffmpeg -i INPUT -f hash out.sha256

To print an MD5 hash to stdout use the command:

ffmpeg -i INPUT -f hash -hash md5 -

See also the framehash muxer.

4.45.1 Options ¶

extra_window_size int

number of fragments kept outside of the manifest before removing from disk

min_frag_duration microseconds

minimum fragment duration (in microseconds), default value is 1 second (10000000)

remove_at_exit bool

remove all fragments when finished when set to true

window_size int

number of fragments kept in the manifest, if set to a value different from 0. By default all segments are kept in the output directory.

4.45.2 Example ¶

Use ffmpeg to generate HDS files to the output.hds directory in real-time rate:

ffmpeg -re -i INPUT -f hds -b:v 200k output.hds

4.46.1 Options ¶

hls_init_time duration

Set the initial target segment length. Default value is 0.

duration must be a time duration specification, see the Time duration section in the ffmpeg-utils(1) manual.

Segment will be cut on the next key frame after this time has passed on the first m3u8 list. After the initial playlist is filled, ffmpeg will cut segments at duration equal to hls_time.

hls_time duration

Set the target segment length. Default value is 2.

duration must be a time duration specification, see the Time duration section in the ffmpeg-utils(1) manual. Segment will be cut on the next key frame after this time has passed.

hls_list_size size

Set the maximum number of playlist entries. If set to 0 the list file will contain all the segments. Default value is 5.

hls_delete_threshold size

Set the number of unreferenced segments to keep on disk before hls_flags delete_segments deletes them. Increase this to allow continue clients to download segments which were recently referenced in the playlist. Default value is 1, meaning segments older than hls_list_size+1 will be deleted.

hls_start_number_source source

Start the playlist sequence number (#EXT-X-MEDIA-SEQUENCE) according to the specified source. Unless hls_flags single_file is set, it also specifies source of starting sequence numbers of segment and subtitle filenames. In any case, if hls_flags append_list is set and read playlist sequence number is greater than the specified start sequence number, then that value will be used as start value.

It accepts the following values:

generic (default)

Set the start numbers according to the start_number option value.

epoch

Set the start number as the seconds since epoch (1970-01-01 00:00:00).

epoch_us

Set the start number as the microseconds since epoch (1970-01-01 00:00:00).

datetime

Set the start number based on the current date/time as YYYYmmddHHMMSS. e.g. 20161231235759.

start_number number

Start the playlist sequence number (#EXT-X-MEDIA-SEQUENCE) from the specified number when hls_start_number_source value is generic. (This is the default case.) Unless hls_flags single_file is set, it also specifies starting sequence numbers of segment and subtitle filenames. Default value is 0.

hls_allow_cache bool

Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments.

hls_base_url baseurl

Append baseurl to every entry in the playlist. Useful to generate playlists with absolute paths.

Note that the playlist sequence number must be unique for each segment and it is not to be confused with the segment filename sequence number which can be cyclic, for example if the wrap option is specified.

hls_segment_filename filename

Set the segment filename. Unless the hls_flags option is set with ‘single_file’, filename is used as a string format with the segment number appended.

For example:

ffmpeg -i in.nut -hls_segment_filename 'file%03d.ts' out.m3u8

will produce the playlist, out.m3u8, and segment files: file000.ts, file001.ts, file002.ts, etc.

filename may contain a full path or relative path specification, but only the file name part without any path will be contained in the m3u8 segment list. Should a relative path be specified, the path of the created segment files will be relative to the current working directory. When strftime_mkdir is set, the whole expanded value of filename will be written into the m3u8 segment list.

When var_stream_map is set with two or more variant streams, the filename pattern must contain the string "%v", and this string will be expanded to the position of variant stream index in the generated segment file names.

For example:

ffmpeg -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
  -map 0:v -map 0:a -map 0:v -map 0:a -f hls -var_stream_map "v:0,a:0 v:1,a:1" \
  -hls_segment_filename 'file_%v_%03d.ts' out_%v.m3u8

will produce the playlists segment file sets: file_0_000.ts, file_0_001.ts, file_0_002.ts, etc. and file_1_000.ts, file_1_001.ts, file_1_002.ts, etc.

The string "%v" may be present in the filename or in the last directory name containing the file, but only in one of them. (Additionally, %v may appear multiple times in the last sub-directory or filename.) If the string %v is present in the directory name, then sub-directories are created after expanding the directory name pattern. This enables creation of segments corresponding to different variant streams in subdirectories.

For example:

ffmpeg -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
  -map 0:v -map 0:a -map 0:v -map 0:a -f hls -var_stream_map "v:0,a:0 v:1,a:1" \
  -hls_segment_filename 'vs%v/file_%03d.ts' vs%v/out.m3u8

will produce the playlists segment file sets: vs0/file_000.ts, vs0/file_001.ts, vs0/file_002.ts, etc. and vs1/file_000.ts, vs1/file_001.ts, vs1/file_002.ts, etc.

strftime bool

Use strftime() on filename to expand the segment filename with localtime. The segment number is also available in this mode, but to use it, you need to set ‘second_level_segment_index’ in the hls_flag and %%d will be the specifier.

For example:

ffmpeg -i in.nut -strftime 1 -hls_segment_filename 'file-%Y%m%d-%s.ts' out.m3u8

will produce the playlist, out.m3u8, and segment files: file-20160215-1455569023.ts, file-20160215-1455569024.ts, etc. Note: On some systems/environments, the %s specifier is not available. See strftime() documentation.

For example:

ffmpeg -i in.nut -strftime 1 -hls_flags second_level_segment_index -hls_segment_filename 'file-%Y%m%d-%%04d.ts' out.m3u8

will produce the playlist, out.m3u8, and segment files: file-20160215-0001.ts, file-20160215-0002.ts, etc.

strftime_mkdir bool

Used together with strftime, it will create all subdirectories which are present in the expanded values of option hls_segment_filename.

For example:

ffmpeg -i in.nut -strftime 1 -strftime_mkdir 1 -hls_segment_filename '%Y%m%d/file-%Y%m%d-%s.ts' out.m3u8

will create a directory 201560215 (if it does not exist), and then produce the playlist, out.m3u8, and segment files: 20160215/file-20160215-1455569023.ts, 20160215/file-20160215-1455569024.ts, etc.

For example:

ffmpeg -i in.nut -strftime 1 -strftime_mkdir 1 -hls_segment_filename '%Y/%m/%d/file-%Y%m%d-%s.ts' out.m3u8

will create a directory hierarchy 2016/02/15 (if any of them do not exist), and then produce the playlist, out.m3u8, and segment files: 2016/02/15/file-20160215-1455569023.ts, 2016/02/15/file-20160215-1455569024.ts, etc.

hls_segment_options options_list

Set output format options using a :-separated list of key=value parameters. Values containing : special characters must be escaped.

hls_key_info_file key_info_file

Use the information in key_info_file for segment encryption. The first line of key_info_file specifies the key URI written to the playlist. The key URL is used to access the encryption key during playback. The second line specifies the path to the key file used to obtain the key during the encryption process. The key file is read as a single packed array of 16 octets in binary format. The optional third line specifies the initialization vector (IV) as a hexadecimal string to be used instead of the segment sequence number (default) for encryption. Changes to key_info_file will result in segment encryption with the new key/IV and an entry in the playlist for the new key URI/IV if hls_flags periodic_rekey is enabled.

Key info file format:

key URI
key file path
IV (optional)

Example key URIs:

http://server/file.key
/path/to/file.key
file.key

Example key file paths:

file.key
/path/to/file.key

Example IV:

0123456789ABCDEF0123456789ABCDEF

Key info file example:

http://server/file.key
/path/to/file.key
0123456789ABCDEF0123456789ABCDEF

Example shell script:

#!/bin/sh
BASE_URL=${1:-'.'}
openssl rand 16 > file.key
echo $BASE_URL/file.key > file.keyinfo
echo file.key >> file.keyinfo
echo $(openssl rand -hex 16) >> file.keyinfo
ffmpeg -f lavfi -re -i testsrc -c:v h264 -hls_flags delete_segments \
  -hls_key_info_file file.keyinfo out.m3u8

hls_enc bool

Enable (1) or disable (0) the AES128 encryption. When enabled every segment generated is encrypted and the encryption key is saved as playlist name.key.

hls_enc_key key

Specify a 16-octet key to encrypt the segments, by default it is randomly generated.

hls_enc_key_url keyurl

If set, keyurl is prepended instead of baseurl to the key filename in the playlist.

hls_enc_iv iv

Specify the 16-octet initialization vector for every segment instead of the autogenerated ones.

hls_segment_type flags

Possible values:

‘mpegts’

Output segment files in MPEG-2 Transport Stream format. This is compatible with all HLS versions.

‘fmp4’

Output segment files in fragmented MP4 format, similar to MPEG-DASH. fmp4 files may be used in HLS version 7 and above.

hls_fmp4_init_filename filename

Set filename for the fragment files header file, default filename is init.mp4.

When strftime is enabled, filename is expanded to the segment filename with localtime.

For example:

ffmpeg -i in.nut -hls_segment_type fmp4 -strftime 1 -hls_fmp4_init_filename "%s_init.mp4" out.m3u8

will produce init like this 1602678741_init.mp4.

hls_fmp4_init_resend bool

Resend init file after m3u8 file refresh every time, default is 0.

When var_stream_map is set with two or more variant streams, the filename pattern must contain the string "%v", this string specifies the position of variant stream index in the generated init file names. The string "%v" may be present in the filename or in the last directory name containing the file. If the string is present in the directory name, then sub-directories are created after expanding the directory name pattern. This enables creation of init files corresponding to different variant streams in subdirectories.

hls_flags flags

Possible values:

‘single_file’

If this flag is set, the muxer will store all segments in a single MPEG-TS file, and will use byte ranges in the playlist. HLS playlists generated with this way will have the version number 4.

For example:

ffmpeg -i in.nut -hls_flags single_file out.m3u8

will produce the playlist, out.m3u8, and a single segment file, out.ts.

‘delete_segments’

Segment files removed from the playlist are deleted after a period of time equal to the duration of the segment plus the duration of the playlist.

‘append_list’

Append new segments into the end of old segment list, and remove the #EXT-X-ENDLIST from the old segment list.

‘round_durations’

Round the duration info in the playlist file segment info to integer values, instead of using floating point. If there are no other features requiring higher HLS versions be used, then this will allow ffmpeg to output a HLS version 2 m3u8.

‘discont_start’

Add the #EXT-X-DISCONTINUITY tag to the playlist, before the first segment’s information.

‘omit_endlist’

Do not append the EXT-X-ENDLIST tag at the end of the playlist.

‘periodic_rekey’

The file specified by hls_key_info_file will be checked periodically and detect updates to the encryption info. Be sure to replace this file atomically, including the file containing the AES encryption key.

‘independent_segments’

Add the #EXT-X-INDEPENDENT-SEGMENTS tag to playlists that has video segments and when all the segments of that playlist are guaranteed to start with a key frame.

‘iframes_only’

Add the #EXT-X-I-FRAMES-ONLY tag to playlists that has video segments and can play only I-frames in the #EXT-X-BYTERANGE mode.

‘split_by_time’

Allow segments to start on frames other than key frames. This improves behavior on some players when the time between key frames is inconsistent, but may make things worse on others, and can cause some oddities during seeking. This flag should be used with the hls_time option.

‘program_date_time’

Generate EXT-X-PROGRAM-DATE-TIME tags.

‘second_level_segment_index’

Make it possible to use segment indexes as %%d in the hls_segment_filename option expression besides date/time values when strftime option is on. To get fixed width numbers with trailing zeroes, %%0xd format is available where x is the required width.

‘second_level_segment_size’

Make it possible to use segment sizes (counted in bytes) as %%s in hls_segment_filename option expression besides date/time values when strftime is on. To get fixed width numbers with trailing zeroes, %%0xs format is available where x is the required width.

‘second_level_segment_duration’

Make it possible to use segment duration (calculated in microseconds) as %%t in hls_segment_filename option expression besides date/time values when strftime is on. To get fixed width numbers with trailing zeroes, %%0xt format is available where x is the required width.

For example:

ffmpeg -i sample.mpeg \
   -f hls -hls_time 3 -hls_list_size 5 \
   -hls_flags second_level_segment_index+second_level_segment_size+second_level_segment_duration \
   -strftime 1 -strftime_mkdir 1 -hls_segment_filename "segment_%Y%m%d%H%M%S_%%04d_%%08s_%%013t.ts" stream.m3u8

will produce segments like this: segment_20170102194334_0003_00122200_0000003000000.ts, segment_20170102194334_0004_00120072_0000003000000.ts etc.

‘temp_file’

Write segment data to filename.tmp and rename to filename only once the segment is complete.

A webserver serving up segments can be configured to reject requests to *.tmp to prevent access to in-progress segments before they have been added to the m3u8 playlist.

This flag also affects how m3u8 playlist files are created. If this flag is set, all playlist files will be written into a temporary file and renamed after they are complete, similarly as segments are handled. But playlists with file protocol and with hls_playlist_type type other than ‘vod’ are always written into a temporary file regardless of this flag.

Master playlist files specified with master_pl_name, if any, with file protocol, are always written into temporary file regardless of this flag if master_pl_publish_rate value is other than zero.

hls_playlist_type type

If type is ‘event’, emit #EXT-X-PLAYLIST-TYPE:EVENT in the m3u8 header. This forces hls_list_size to 0; the playlist can only be appended to.

If type is ‘vod’, emit #EXT-X-PLAYLIST-TYPE:VOD in the m3u8 header. This forces hls_list_size to 0; the playlist must not change.

method method

Use the given HTTP method to create the hls files.

For example:

ffmpeg -re -i in.ts -f hls -method PUT http://example.com/live/out.m3u8

will upload all the mpegts segment files to the HTTP server using the HTTP PUT method, and update the m3u8 files every refresh times using the same method. Note that the HTTP server must support the given method for uploading files.

http_user_agent agent

Override User-Agent field in HTTP header. Applicable only for HTTP output.

var_stream_map stream_map

Specify a map string defining how to group the audio, video and subtitle streams into different variant streams. The variant stream groups are separated by space.

Expected string format is like this "a:0,v:0 a:1,v:1 ....". Here a:, v:, s: are the keys to specify audio, video and subtitle streams respectively. Allowed values are 0 to 9 (limited just based on practical usage).

When there are two or more variant streams, the output filename pattern must contain the string "%v": this string specifies the position of variant stream index in the output media playlist filenames. The string "%v" may be present in the filename or in the last directory name containing the file. If the string is present in the directory name, then sub-directories are created after expanding the directory name pattern. This enables creation of variant streams in subdirectories.

A few examples follow.

• Create two hls variant streams. The first variant stream will contain video stream of bitrate 1000k and audio stream of bitrate 64k and the second variant stream will contain video stream of bitrate 256k and audio stream of bitrate 32k. Here, two media playlist with file names out_0.m3u8 and out_1.m3u8 will be created.

  ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
    -map 0:v -map 0:a -map 0:v -map 0:a -f hls -var_stream_map "v:0,a:0 v:1,a:1" \
    http://example.com/live/out_%v.m3u8
  

• If you want something meaningful text instead of indexes in result names, you may specify names for each or some of the variants. The following example will create two hls variant streams as in the previous one. But here, the two media playlist with file names out_my_hd.m3u8 and out_my_sd.m3u8 will be created.

  ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
    -map 0:v -map 0:a -map 0:v -map 0:a -f hls -var_stream_map "v:0,a:0,name:my_hd v:1,a:1,name:my_sd" \
    http://example.com/live/out_%v.m3u8
  

• Create three hls variant streams. The first variant stream will be a video only stream with video bitrate 1000k, the second variant stream will be an audio only stream with bitrate 64k and the third variant stream will be a video only stream with bitrate 256k. Here, three media playlist with file names out_0.m3u8, out_1.m3u8 and out_2.m3u8 will be created.

  ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k \
    -map 0:v -map 0:a -map 0:v -f hls -var_stream_map "v:0 a:0 v:1" \
    http://example.com/live/out_%v.m3u8
  

• Create the variant streams in subdirectories. Here, the first media playlist is created at http://example.com/live/vs_0/out.m3u8 and the second one at http://example.com/live/vs_1/out.m3u8.

  ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
    -map 0:v -map 0:a -map 0:v -map 0:a -f hls -var_stream_map "v:0,a:0 v:1,a:1" \
    http://example.com/live/vs_%v/out.m3u8
  

• Create two audio only and two video only variant streams. In addition to the #EXT-X-STREAM-INF tag for each variant stream in the master playlist, the #EXT-X-MEDIA tag is also added for the two audio only variant streams and they are mapped to the two video only variant streams with audio group names ’aud_low’ and ’aud_high’. By default, a single hls variant containing all the encoded streams is created.

  ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k -b:v:1 3000k  \
    -map 0:a -map 0:a -map 0:v -map 0:v -f hls \
    -var_stream_map "a:0,agroup:aud_low a:1,agroup:aud_high v:0,agroup:aud_low v:1,agroup:aud_high" \
    -master_pl_name master.m3u8 \
    http://example.com/live/out_%v.m3u8
  

• Create two audio only and one video only variant streams. In addition to the #EXT-X-STREAM-INF tag for each variant stream in the master playlist, the #EXT-X-MEDIA tag is also added for the two audio only variant streams and they are mapped to the one video only variant streams with audio group name ’aud_low’, and the audio group have default stat is NO or YES. By default, a single hls variant containing all the encoded streams is created.

  ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k \
    -map 0:a -map 0:a -map 0:v -f hls \
    -var_stream_map "a:0,agroup:aud_low,default:yes a:1,agroup:aud_low v:0,agroup:aud_low" \
    -master_pl_name master.m3u8 \
    http://example.com/live/out_%v.m3u8
  

• Create two audio only and one video only variant streams. In addition to the #EXT-X-STREAM-INF tag for each variant stream in the master playlist, the #EXT-X-MEDIA tag is also added for the two audio only variant streams and they are mapped to the one video only variant streams with audio group name ’aud_low’, and the audio group have default stat is NO or YES, and one audio have and language is named ENG, the other audio language is named CHN. By default, a single hls variant containing all the encoded streams is created.

  ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k \
    -map 0:a -map 0:a -map 0:v -f hls \
    -var_stream_map "a:0,agroup:aud_low,default:yes,language:ENG a:1,agroup:aud_low,language:CHN v:0,agroup:aud_low" \
    -master_pl_name master.m3u8 \
    http://example.com/live/out_%v.m3u8
  

• Create a single variant stream. Add the #EXT-X-MEDIA tag with TYPE=SUBTITLES in the master playlist with webvtt subtitle group name ’subtitle’. Make sure the input file has one text subtitle stream at least.

  ffmpeg -y -i input_with_subtitle.mkv \
   -b:v:0 5250k -c:v h264 -pix_fmt yuv420p -profile:v main -level 4.1 \
   -b:a:0 256k \
   -c:s webvtt -c:a mp2 -ar 48000 -ac 2 -map 0:v -map 0:a:0 -map 0:s:0 \
   -f hls -var_stream_map "v:0,a:0,s:0,sgroup:subtitle" \
   -master_pl_name master.m3u8 -t 300 -hls_time 10 -hls_init_time 4 -hls_list_size \
   10 -master_pl_publish_rate 10 -hls_flags \
   delete_segments+discont_start+split_by_time ./tmp/video.m3u8
  

cc_stream_map cc_stream_map

Map string which specifies different closed captions groups and their attributes. The closed captions stream groups are separated by space.

Expected string format is like this "ccgroup:<group name>,instreamid:<INSTREAM-ID>,language:<language code> ....". ’ccgroup’ and ’instreamid’ are mandatory attributes. ’language’ is an optional attribute.

The closed captions groups configured using this option are mapped to different variant streams by providing the same ’ccgroup’ name in the var_stream_map string.

For example:

ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
  -a53cc:0 1 -a53cc:1 1 \
  -map 0:v -map 0:a -map 0:v -map 0:a -f hls \
  -cc_stream_map "ccgroup:cc,instreamid:CC1,language:en ccgroup:cc,instreamid:CC2,language:sp" \
  -var_stream_map "v:0,a:0,ccgroup:cc v:1,a:1,ccgroup:cc" \
  -master_pl_name master.m3u8 \
  http://example.com/live/out_%v.m3u8

will add two #EXT-X-MEDIA tags with TYPE=CLOSED-CAPTIONS in the master playlist for the INSTREAM-IDs ’CC1’ and ’CC2’. Also, it will add CLOSED-CAPTIONS attribute with group name ’cc’ for the two output variant streams.

If var_stream_map is not set, then the first available ccgroup in cc_stream_map is mapped to the output variant stream.

For example:

ffmpeg -re -i in.ts -b:v 1000k -b:a 64k -a53cc 1 -f hls \
  -cc_stream_map "ccgroup:cc,instreamid:CC1,language:en" \
  -master_pl_name master.m3u8 \
  http://example.com/live/out.m3u8

this will add #EXT-X-MEDIA tag with TYPE=CLOSED-CAPTIONS in the master playlist with group name ’cc’, language ’en’ (english) and INSTREAM-ID ’CC1’. Also, it will add CLOSED-CAPTIONS attribute with group name ’cc’ for the output variant stream.

master_pl_name name

Create HLS master playlist with the given name.

For example:

ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 http://example.com/live/out.m3u8

creates an HLS master playlist with name master.m3u8 which is published at http://example.com/live/.

master_pl_publish_rate count

Publish master play list repeatedly every after specified number of segment intervals.

For example:

ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 \
-hls_time 2 -master_pl_publish_rate 30 http://example.com/live/out.m3u8

creates an HLS master playlist with name master.m3u8 and keeps publishing it repeatedly every after 30 segments i.e. every after 60s.

http_persistent bool

Use persistent HTTP connections. Applicable only for HTTP output.

timeout timeout

Set timeout for socket I/O operations. Applicable only for HTTP output.

ignore_io_errors bool

Ignore IO errors during open, write and delete. Useful for long-duration runs with network output.

headers headers

Set custom HTTP headers, can override built in default headers. Applicable only for HTTP output.

4.50.1 Options ¶

frame_pts bool

If set to 1, expand the filename with the packet PTS (presentation time stamp). Default value is 0.

start_number count

Start the sequence from the specified number. Default value is 1.

update bool

If set to 1, the filename will always be interpreted as just a filename, not a pattern, and the corresponding file will be continuously overwritten with new images. Default value is 0.

strftime bool

If set to 1, expand the filename with date and time information from strftime(). Default value is 0.

atomic_writing bool

Write output to a temporary file, which is renamed to target filename once writing is completed. Default is disabled.

protocol_opts options_list

Set protocol options as a :-separated list of key=value parameters. Values containing the : special character must be escaped.

4.50.2 Examples ¶

• Use ffmpeg for creating a sequence of files img-001.jpeg, img-002.jpeg, ..., taking one image every second from the input video:

  ffmpeg -i in.avi -vsync cfr -r 1 -f image2 'img-%03d.jpeg'
  

  Note that with ffmpeg, if the format is not specified with the -f option and the output filename specifies an image file format, the image2 muxer is automatically selected, so the previous command can be written as:

  ffmpeg -i in.avi -vsync cfr -r 1 'img-%03d.jpeg'
  

  Note also that the pattern must not necessarily contain "%d" or "%0Nd", for example to create a single image file img.jpeg from the start of the input video you can employ the command:

  ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg
  

• The strftime option allows you to expand the filename with date and time information. Check the documentation of the strftime() function for the syntax.

  To generate image files from the strftime() "%Y-%m-%d_%H-%M-%S" pattern, the following ffmpeg command can be used:

  ffmpeg -f v4l2 -r 1 -i /dev/video0 -f image2 -strftime 1 "%Y-%m-%d_%H-%M-%S.jpg"
  

• Set the file name with current frame’s PTS:

  ffmpeg -f v4l2 -r 1 -i /dev/video0 -copyts -f image2 -frame_pts true %d.jpg
  

• Publish contents of your desktop directly to a WebDAV server every second:

  ffmpeg -f x11grab -framerate 1 -i :0.0 -q:v 6 -update 1 -protocol_opts method=PUT http://example.com/desktop.jpg
  

4.56.1 Metadata ¶

The following metadata tags are converted to the format corresponding metadata:

title

album

artist

author

creator

encoder

encoder_version

If ‘encoder_version’ is not explicitly set, it is automatically set to the libavformat version.

4.57.1 Metadata ¶

The recognized metadata settings in this muxer are:

title

Set title name provided to a single track. This gets mapped to the FileDescription element for a stream written as attachment.

language

Specify the language of the track in the Matroska languages form.

The language can be either the 3 letters bibliographic ISO-639-2 (ISO 639-2/B) form (like "fre" for French), or a language code mixed with a country code for specialities in languages (like "fre-ca" for Canadian French).

stereo_mode

Set stereo 3D video layout of two views in a single video track.

The following values are recognized:

‘mono’

video is not stereo

‘left_right’

Both views are arranged side by side, Left-eye view is on the left

‘bottom_top’

Both views are arranged in top-bottom orientation, Left-eye view is at bottom

‘top_bottom’

Both views are arranged in top-bottom orientation, Left-eye view is on top

‘checkerboard_rl’

Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first

‘checkerboard_lr’

Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first

‘row_interleaved_rl’

Each view is constituted by a row based interleaving, Right-eye view is first row

‘row_interleaved_lr’

Each view is constituted by a row based interleaving, Left-eye view is first row

‘col_interleaved_rl’

Both views are arranged in a column based interleaving manner, Right-eye view is first column

‘col_interleaved_lr’

Both views are arranged in a column based interleaving manner, Left-eye view is first column

‘anaglyph_cyan_red’

All frames are in anaglyph format viewable through red-cyan filters

‘right_left’

Both views are arranged side by side, Right-eye view is on the left

‘anaglyph_green_magenta’

All frames are in anaglyph format viewable through green-magenta filters

‘block_lr’

Both eyes laced in one Block, Left-eye view is first

‘block_rl’

Both eyes laced in one Block, Right-eye view is first

For example a 3D WebM clip can be created using the following command line:

ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm

4.57.2 Options ¶

reserve_index_space size

By default, this muxer writes the index for seeking (called cues in Matroska terms) at the end of the file, because it cannot know in advance how much space to leave for the index at the beginning of the file. However for some use cases – e.g. streaming where seeking is possible but slow – it is useful to put the index at the beginning of the file.

If this option is set to a non-zero value, the muxer will reserve size bytes of space in the file header and then try to write the cues there when the muxing finishes. If the reserved space does not suffice, no Cues will be written, the file will be finalized and writing the trailer will return an error. A safe size for most use cases should be about 50kB per hour of video.

Note that cues are only written if the output is seekable and this option will have no effect if it is not.

cues_to_front bool

If set, the muxer will write the index at the beginning of the file by shifting the main data if necessary. This can be combined with reserve_index_space in which case the data is only shifted if the initially reserved space turns out to be insufficient.

This option is ignored if the output is unseekable.

cluster_size_limit size

Store at most the provided amount of bytes in a cluster.

If not specified, the limit is set automatically to a sensible hardcoded fixed value.

cluster_time_limit duration

Store at most the provided number of milliseconds in a cluster.

If not specified, the limit is set automatically to a sensible hardcoded fixed value.

dash bool

Create a WebM file conforming to WebM DASH specification. By default it is set to false.

dash_track_number index

Track number for the DASH stream. By default it is set to 1.

live bool

Write files assuming it is a live stream. By default it is set to false.

allow_raw_vfw bool

Allow raw VFW mode. By default it is set to false.

flipped_raw_rgb bool

If set to true, store positive height for raw RGB bitmaps, which indicates bitmap is stored bottom-up. Note that this option does not flip the bitmap which has to be done manually beforehand, e.g. by using the ‘vflip’ filter. Default is false and indicates bitmap is stored top down.

write_crc32 bool

Write a CRC32 element inside every Level 1 element. By default it is set to true. This option is ignored for WebM.

default_mode mode

Control how the FlagDefault of the output tracks will be set. It influences which tracks players should play by default. The default mode is ‘passthrough’.

‘infer’

Every track with disposition default will have the FlagDefault set. Additionally, for each type of track (audio, video or subtitle), if no track with disposition default of this type exists, then the first track of this type will be marked as default (if existing). This ensures that the default flag is set in a sensible way even if the input originated from containers that lack the concept of default tracks.

‘infer_no_subs’

This mode is the same as infer except that if no subtitle track with disposition default exists, no subtitle track will be marked as default.

‘passthrough’

In this mode the FlagDefault is set if and only if the AV_DISPOSITION_DEFAULT flag is set in the disposition of the corresponding stream.

4.58.1 Examples ¶

• To compute the MD5 hash of the input converted to raw audio and video, and store it in the file out.md5:

  ffmpeg -i INPUT -f md5 out.md5
  

• To print the MD5 hash to stdout:

  ffmpeg -i INPUT -f md5 -
  

4.62.1 Options ¶

The muxer options are:

mpegts_transport_stream_id integer

Set the ‘transport_stream_id’. This identifies a transponder in DVB. Default is 0x0001.

mpegts_original_network_id integer

Set the ‘original_network_id’. This is unique identifier of a network in DVB. Its main use is in the unique identification of a service through the path ‘Original_Network_ID, Transport_Stream_ID’. Default is 0x0001.

mpegts_service_id integer

Set the ‘service_id’, also known as program in DVB. Default is 0x0001.

mpegts_service_type integer

Set the program ‘service_type’. Default is digital_tv. Accepts the following options:

‘hex_value’

Any hexadecimal value between 0x01 and 0xff as defined in ETSI 300 468.

‘digital_tv’

Digital TV service.

‘digital_radio’

Digital Radio service.

‘teletext’

Teletext service.

‘advanced_codec_digital_radio’

Advanced Codec Digital Radio service.

‘mpeg2_digital_hdtv’

MPEG2 Digital HDTV service.

‘advanced_codec_digital_sdtv’

Advanced Codec Digital SDTV service.

‘advanced_codec_digital_hdtv’

Advanced Codec Digital HDTV service.

mpegts_pmt_start_pid integer

Set the first PID for PMTs. Default is 0x1000, minimum is 0x0020, maximum is 0x1ffa. This option has no effect in m2ts mode where the PMT PID is fixed 0x0100.

mpegts_start_pid integer

Set the first PID for elementary streams. Default is 0x0100, minimum is 0x0020, maximum is 0x1ffa. This option has no effect in m2ts mode where the elementary stream PIDs are fixed.

mpegts_m2ts_mode boolean

Enable m2ts mode if set to 1. Default value is -1 which disables m2ts mode.

muxrate integer

Set a constant muxrate. Default is VBR.

pes_payload_size integer

Set minimum PES packet payload in bytes. Default is 2930.

mpegts_flags flags

Set mpegts flags. Accepts the following options:

‘resend_headers’

Reemit PAT/PMT before writing the next packet.

‘latm’

Use LATM packetization for AAC.

‘pat_pmt_at_frames’

Reemit PAT and PMT at each video frame.

‘system_b’

Conform to System B (DVB) instead of System A (ATSC).

‘initial_discontinuity’

Mark the initial packet of each stream as discontinuity.

‘nit’

Emit NIT table.

‘omit_rai’

Disable writing of random access indicator.

mpegts_copyts boolean

Preserve original timestamps, if value is set to 1. Default value is -1, which results in shifting timestamps so that they start from 0.

omit_video_pes_length boolean

Omit the PES packet length for video packets. Default is 1 (true).

pcr_period integer

Override the default PCR retransmission time in milliseconds. Default is -1 which means that the PCR interval will be determined automatically: 20 ms is used for CBR streams, the highest multiple of the frame duration which is less than 100 ms is used for VBR streams.

pat_period duration

Maximum time in seconds between PAT/PMT tables. Default is 0.1.

sdt_period duration

Maximum time in seconds between SDT tables. Default is 0.5.

nit_period duration

Maximum time in seconds between NIT tables. Default is 0.5.

tables_version integer

Set PAT, PMT, SDT and NIT version (default 0, valid values are from 0 to 31, inclusively). This option allows updating stream structure so that standard consumer may detect the change. To do so, reopen output AVFormatContext (in case of API usage) or restart ffmpeg instance, cyclically changing tables_version value:

ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
...
ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111
ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
...

4.62.2 Example ¶

ffmpeg -i file.mpg -c copy \
     -mpegts_original_network_id 0x1122 \
     -mpegts_transport_stream_id 0x3344 \
     -mpegts_service_id 0x5566 \
     -mpegts_pmt_start_pid 0x1500 \
     -mpegts_start_pid 0x150 \
     -metadata service_provider="Some provider" \
     -metadata service_name="Some Channel" \
     out.ts

4.63.1 Options ¶

The muxer options are:

store_user_comments bool

Set if user comments should be stored if available or never. IRT D-10 does not allow user comments. The default is thus to write them for mxf and mxf_opatom but not for mxf_d10

4.67.1 Examples ¶

• Extract Closed Captions to RCWT using lavfi:

  ffmpeg -f lavfi -i "movie=INPUT.mkv[out+subcc]" -map 0:s:0 -c:s copy -f rcwt CC.rcwt.bin
  

4.68.1 Options ¶

The segment muxer supports the following options:

increment_tc 1|0

if set to 1, increment timecode between each segment If this is selected, the input need to have a timecode in the first video stream. Default value is 0.

reference_stream specifier

Set the reference stream, as specified by the string specifier. If specifier is set to auto, the reference is chosen automatically. Otherwise it must be a stream specifier (see the “Stream specifiers” chapter in the ffmpeg manual) which specifies the reference stream. The default value is auto.

segment_format format

Override the inner container format, by default it is guessed by the filename extension.

segment_format_options options_list

Set output format options using a :-separated list of key=value parameters. Values containing the : special character must be escaped.

segment_list name

Generate also a listfile named name. If not specified no listfile is generated.

segment_list_flags flags

Set flags affecting the segment list generation.

It currently supports the following flags:

‘cache’

Allow caching (only affects M3U8 list files).

‘live’

Allow live-friendly file generation.

segment_list_size size

Update the list file so that it contains at most size segments. If 0 the list file will contain all the segments. Default value is 0.

segment_list_entry_prefix prefix

Prepend prefix to each entry. Useful to generate absolute paths. By default no prefix is applied.

segment_list_type type

Select the listing format.

The following values are recognized:

‘flat’

Generate a flat list for the created segments, one segment per line.

‘csv, ext’

Generate a list for the created segments, one segment per line, each line matching the format (comma-separated values):

segment_filename,segment_start_time,segment_end_time

segment_filename is the name of the output file generated by the muxer according to the provided pattern. CSV escaping (according to RFC4180) is applied if required.

segment_start_time and segment_end_time specify the segment start and end time expressed in seconds.

A list file with the suffix ".csv" or ".ext" will auto-select this format.

‘ext’ is deprecated in favor or ‘csv’.

‘ffconcat’

Generate an ffconcat file for the created segments. The resulting file can be read using the FFmpeg concat demuxer.

A list file with the suffix ".ffcat" or ".ffconcat" will auto-select this format.

‘m3u8’

Generate an extended M3U8 file, version 3, compliant with http://tools.ietf.org/id/draft-pantos-http-live-streaming.

A list file with the suffix ".m3u8" will auto-select this format.

If not specified the type is guessed from the list file name suffix.

segment_time time

Set segment duration to time, the value must be a duration specification. Default value is "2". See also the segment_times option.

Note that splitting may not be accurate, unless you force the reference stream key-frames at the given time. See the introductory notice and the examples below.

min_seg_duration time

Set minimum segment duration to time, the value must be a duration specification. This prevents the muxer ending segments at a duration below this value. Only effective with segment_time. Default value is "0".

segment_atclocktime 1|0

If set to "1" split at regular clock time intervals starting from 00:00 o’clock. The time value specified in segment_time is used for setting the length of the splitting interval.

For example with segment_time set to "900" this makes it possible to create files at 12:00 o’clock, 12:15, 12:30, etc.

Default value is "0".

segment_clocktime_offset duration

Delay the segment splitting times with the specified duration when using segment_atclocktime.

For example with segment_time set to "900" and segment_clocktime_offset set to "300" this makes it possible to create files at 12:05, 12:20, 12:35, etc.

Default value is "0".

segment_clocktime_wrap_duration duration

Force the segmenter to only start a new segment if a packet reaches the muxer within the specified duration after the segmenting clock time. This way you can make the segmenter more resilient to backward local time jumps, such as leap seconds or transition to standard time from daylight savings time.

Default is the maximum possible duration which means starting a new segment regardless of the elapsed time since the last clock time.

segment_time_delta delta

Specify the accuracy time when selecting the start time for a segment, expressed as a duration specification. Default value is "0".

When delta is specified a key-frame will start a new segment if its PTS satisfies the relation:

PTS >= start_time - time_delta

This option is useful when splitting video content, which is always split at GOP boundaries, in case a key frame is found just before the specified split time.

In particular may be used in combination with the ffmpeg option force_key_frames. The key frame times specified by force_key_frames may not be set accurately because of rounding issues, with the consequence that a key frame time may result set just before the specified time. For constant frame rate videos a value of 1/(2*frame_rate) should address the worst case mismatch between the specified time and the time set by force_key_frames.

segment_times times

Specify a list of split points. times contains a list of comma separated duration specifications, in increasing order. See also the segment_time option.

segment_frames frames

Specify a list of split video frame numbers. frames contains a list of comma separated integer numbers, in increasing order.

This option specifies to start a new segment whenever a reference stream key frame is found and the sequential number (starting from 0) of the frame is greater or equal to the next value in the list.

segment_wrap limit

Wrap around segment index once it reaches limit.

segment_start_number number

Set the sequence number of the first segment. Defaults to 0.

strftime 1|0

Use the strftime function to define the name of the new segments to write. If this is selected, the output segment name must contain a strftime function template. Default value is 0.

break_non_keyframes 1|0

If enabled, allow segments to start on frames other than keyframes. This improves behavior on some players when the time between keyframes is inconsistent, but may make things worse on others, and can cause some oddities during seeking. Defaults to 0.

reset_timestamps 1|0

Reset timestamps at the beginning of each segment, so that each segment will start with near-zero timestamps. It is meant to ease the playback of the generated segments. May not work with some combinations of muxers/codecs. It is set to 0 by default.

initial_offset offset

Specify timestamp offset to apply to the output packet timestamps. The argument must be a time duration specification, and defaults to 0.

write_empty_segments 1|0

If enabled, write an empty segment if there are no packets during the period a segment would usually span. Otherwise, the segment will be filled with the next packet written. Defaults to 0.

Make sure to require a closed GOP when encoding and to set the GOP size to fit your segment time constraint.

4.68.2 Examples ¶

• Remux the content of file in.mkv to a list of segments out-000.nut, out-001.nut, etc., and write the list of generated segments to out.list:

  ffmpeg -i in.mkv -codec hevc -flags +cgop -g 60 -map 0 -f segment -segment_list out.list out%03d.nut
  

• Segment input and set output format options for the output segments:

  ffmpeg -i in.mkv -f segment -segment_time 10 -segment_format_options movflags=+faststart out%03d.mp4
  

• Segment the input file according to the split points specified by the segment_times option:

  ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 out%03d.nut
  

• Use the ffmpeg force_key_frames option to force key frames in the input at the specified location, together with the segment option segment_time_delta to account for possible roundings operated when setting key frame times.

  ffmpeg -i in.mkv -force_key_frames 1,2,3,5,8,13,21 -codec:v mpeg4 -codec:a pcm_s16le -map 0 \
  -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 -segment_time_delta 0.05 out%03d.nut
  

  In order to force key frames on the input file, transcoding is required.

• Segment the input file by splitting the input file according to the frame numbers sequence specified with the segment_frames option:

  ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_frames 100,200,300,500,800 out%03d.nut
  

• Convert the in.mkv to TS segments using the libx264 and aac encoders:

  ffmpeg -i in.mkv -map 0 -codec:v libx264 -codec:a aac -f ssegment -segment_list out.list out%03d.ts
  

• Segment the input file, and create an M3U8 live playlist (can be used as live HLS source):

  ffmpeg -re -i in.mkv -codec copy -map 0 -f segment -segment_list playlist.m3u8 \
  -segment_list_flags +live -segment_time 10 out%03d.mkv
  

4.70.1 Examples ¶

To compute the SHA-256 hash of the input converted to raw audio and video, and store it in the file out.sha256:

ffmpeg -i INPUT -f streamhash out.sha256

To print an MD5 hash to stdout use the command:

ffmpeg -i INPUT -f streamhash -hash md5 -

See also the hash and framehash muxers.

4.71.1 Options ¶

use_fifo bool

If set to 1, slave outputs will be processed in separate threads using the fifo muxer. This allows to compensate for different speed/latency/reliability of outputs and setup transparent recovery. By default this feature is turned off.

fifo_options

Options to pass to fifo pseudo-muxer instances. See fifo.

Muxer options can be specified for each slave by prepending them as a list of key=value pairs separated by ’:’, between square brackets. If the options values contain a special character or the ’:’ separator, they must be escaped; note that this is a second level escaping.

The following special options are also recognized:

f

Specify the format name. Required if it cannot be guessed from the output URL.

bsfs[/spec]

Specify a list of bitstream filters to apply to the specified output.

It is possible to specify to which streams a given bitstream filter applies, by appending a stream specifier to the option separated by /. spec must be a stream specifier (see Format stream specifiers).

If the stream specifier is not specified, the bitstream filters will be applied to all streams in the output. This will cause that output operation to fail if the output contains streams to which the bitstream filter cannot be applied e.g. h264_mp4toannexb being applied to an output containing an audio stream.

Options for a bitstream filter must be specified in the form of opt=value.

Several bitstream filters can be specified, separated by ",".

use_fifo bool

This allows to override tee muxer use_fifo option for individual slave muxer.

fifo_options

This allows to override tee muxer fifo_options for individual slave muxer. See fifo.

select

Select the streams that should be mapped to the slave output, specified by a stream specifier. If not specified, this defaults to all the mapped streams. This will cause that output operation to fail if the output format does not accept all mapped streams.

You may use multiple stream specifiers separated by commas (,) e.g.: a:0,v

onfail

Specify behaviour on output failure. This can be set to either abort (which is default) or ignore. abort will cause whole process to fail in case of failure on this slave output. ignore will ignore failure on this output, so other outputs will continue without being affected.

4.71.2 Examples ¶

• Encode something and both archive it in a WebM file and stream it as MPEG-TS over UDP:

  ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
    "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
  

• As above, but continue streaming even if output to local file fails (for example local drive fills up):

  ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
    "[onfail=ignore]archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
  

• Use ffmpeg to encode the input, and send the output to three different destinations. The dump_extra bitstream filter is used to add extradata information to all the output video keyframes packets, as requested by the MPEG-TS format. The select option is applied to out.aac in order to make it contain only audio packets.

  ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
         -f tee "[bsfs/v=dump_extra=freq=keyframe]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac"
  

• As above, but select only stream a:1 for the audio output. Note that a second level escaping must be performed, as ":" is a special character used to separate options.

  ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
         -f tee "[bsfs/v=dump_extra=freq=keyframe]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac"
  

4.72.1 Options ¶

This muxer supports the following options:

chunk_start_index

Index of the first chunk (defaults to 0).

header

Filename of the header where the initialization data will be written.

audio_chunk_duration

Duration of each audio chunk in milliseconds (defaults to 5000).

4.72.2 Example ¶

ffmpeg -f v4l2 -i /dev/video0 \
       -f alsa -i hw:0 \
       -map 0:0 \
       -c:v libvpx-vp9 \
       -s 640x360 -keyint_min 30 -g 30 \
       -f webm_chunk \
       -header webm_live_video_360.hdr \
       -chunk_start_index 1 \
       webm_live_video_360_%d.chk \
       -map 1:0 \
       -c:a libvorbis \
       -b:a 128k \
       -f webm_chunk \
       -header webm_live_audio_128.hdr \
       -chunk_start_index 1 \
       -audio_chunk_duration 1000 \
       webm_live_audio_128_%d.chk

4.73.1 Options ¶

This muxer supports the following options:

adaptation_sets

This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding audio and video streams. Any number of adaptation sets can be added using this option.

live

Set this to 1 to create a live stream DASH Manifest. Default: 0.

chunk_start_index

Start index of the first chunk. This will go in the ‘startNumber’ attribute of the ‘SegmentTemplate’ element in the manifest. Default: 0.

chunk_duration_ms

Duration of each chunk in milliseconds. This will go in the ‘duration’ attribute of the ‘SegmentTemplate’ element in the manifest. Default: 1000.

utc_timing_url

URL of the page that will return the UTC timestamp in ISO format. This will go in the ‘value’ attribute of the ‘UTCTiming’ element in the manifest. Default: None.

time_shift_buffer_depth

Smallest time (in seconds) shifting buffer for which any Representation is guaranteed to be available. This will go in the ‘timeShiftBufferDepth’ attribute of the ‘MPD’ element. Default: 60.

minimum_update_period

Minimum update period (in seconds) of the manifest. This will go in the ‘minimumUpdatePeriod’ attribute of the ‘MPD’ element. Default: 0.

4.73.2 Example ¶

ffmpeg -f webm_dash_manifest -i video1.webm \
       -f webm_dash_manifest -i video2.webm \
       -f webm_dash_manifest -i audio1.webm \
       -f webm_dash_manifest -i audio2.webm \
       -map 0 -map 1 -map 2 -map 3 \
       -c copy \
       -f webm_dash_manifest \
       -adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \
       manifest.xml