/* * Copyright (C) 2024 Niklas Haas * Copyright (C) 2001-2011 Michael Niedermayer * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef SWSCALE_SWSCALE_H #define SWSCALE_SWSCALE_H /** * @file * @ingroup libsws * external API header */ #include #include "libavutil/avutil.h" #include "libavutil/frame.h" #include "libavutil/log.h" #include "libavutil/pixfmt.h" #include "version_major.h" #ifndef HAVE_AV_CONFIG_H /* When included as part of the ffmpeg build, only include the major version * to avoid unnecessary rebuilds. When included externally, keep including * the full version information. */ #include "version.h" #endif /** * @defgroup libsws libswscale * Color conversion and scaling library. * * @{ * * Return the LIBSWSCALE_VERSION_INT constant. */ unsigned swscale_version(void); /** * Return the libswscale build-time configuration. */ const char *swscale_configuration(void); /** * Return the libswscale license. */ const char *swscale_license(void); /** * Get the AVClass for SwsContext. It can be used in combination with * AV_OPT_SEARCH_FAKE_OBJ for examining options. * * @see av_opt_find(). */ const AVClass *sws_get_class(void); /****************************** * Flags and quality settings * ******************************/ typedef enum SwsDither { SWS_DITHER_NONE = 0, /* disable dithering */ SWS_DITHER_AUTO, /* auto-select from preset */ SWS_DITHER_BAYER, /* ordered dither matrix */ SWS_DITHER_ED, /* error diffusion */ SWS_DITHER_A_DITHER, /* arithmetic addition */ SWS_DITHER_X_DITHER, /* arithmetic xor */ SWS_DITHER_NB, /* not part of the ABI */ } SwsDither; typedef enum SwsAlphaBlend { SWS_ALPHA_BLEND_NONE = 0, SWS_ALPHA_BLEND_UNIFORM, SWS_ALPHA_BLEND_CHECKERBOARD, SWS_ALPHA_BLEND_NB, /* not part of the ABI */ } SwsAlphaBlend; typedef enum SwsFlags { /** * Scaler selection options. Only one may be active at a time. */ SWS_FAST_BILINEAR = 1 << 0, ///< fast bilinear filtering SWS_BILINEAR = 1 << 1, ///< bilinear filtering SWS_BICUBIC = 1 << 2, ///< 2-tap cubic B-spline SWS_X = 1 << 3, ///< experimental SWS_POINT = 1 << 4, ///< nearest neighbor SWS_AREA = 1 << 5, ///< area averaging SWS_BICUBLIN = 1 << 6, ///< bicubic luma, bilinear chroma SWS_GAUSS = 1 << 7, ///< gaussian approximation SWS_SINC = 1 << 8, ///< unwindowed sinc SWS_LANCZOS = 1 << 9, ///< 3-tap sinc/sinc SWS_SPLINE = 1 << 10, ///< cubic Keys spline /** * Return an error on underspecified conversions. Without this flag, * unspecified fields are defaulted to sensible values. */ SWS_STRICT = 1 << 11, /** * Emit verbose log of scaling parameters. */ SWS_PRINT_INFO = 1 << 12, /** * Perform full chroma upsampling when upscaling to RGB. * * For example, when converting 50x50 yuv420p to 100x100 rgba, setting this flag * will scale the chroma plane from 25x25 to 100x100 (4:4:4), and then convert * the 100x100 yuv444p image to rgba in the final output step. * * Without this flag, the chroma plane is instead scaled to 50x100 (4:2:2), * with a single chroma sample being reused for both of the horizontally * adjacent RGBA output pixels. */ SWS_FULL_CHR_H_INT = 1 << 13, /** * Perform full chroma interpolation when downscaling RGB sources. * * For example, when converting a 100x100 rgba source to 50x50 yuv444p, setting * this flag will generate a 100x100 (4:4:4) chroma plane, which is then * downscaled to the required 50x50. * * Without this flag, the chroma plane is instead generated at 50x100 (dropping * every other pixel), before then being downscaled to the required 50x50 * resolution. */ SWS_FULL_CHR_H_INP = 1 << 14, /** * Force bit-exact output. This will prevent the use of platform-specific * optimizations that may lead to slight difference in rounding, in favor * of always maintaining exact bit output compatibility with the reference * C code. * * Note: It is recommended to set both of these flags simultaneously. */ SWS_ACCURATE_RND = 1 << 18, SWS_BITEXACT = 1 << 19, /** * Deprecated flags. */ SWS_DIRECT_BGR = 1 << 15, ///< This flag has no effect SWS_ERROR_DIFFUSION = 1 << 23, ///< Set `SwsContext.dither` instead } SwsFlags; typedef enum SwsIntent { SWS_INTENT_PERCEPTUAL = 0, ///< Perceptual tone mapping SWS_INTENT_RELATIVE_COLORIMETRIC = 1, ///< Relative colorimetric clipping SWS_INTENT_SATURATION = 2, ///< Saturation mapping SWS_INTENT_ABSOLUTE_COLORIMETRIC = 3, ///< Absolute colorimetric clipping SWS_INTENT_NB, ///< not part of the ABI } SwsIntent; /*********************************** * Context creation and management * ***********************************/ /** * Main external API structure. New fields can be added to the end with * minor version bumps. Removal, reordering and changes to existing fields * require a major version bump. sizeof(SwsContext) is not part of the ABI. */ typedef struct SwsContext { const AVClass *av_class; /** * Private data of the user, can be used to carry app specific stuff. */ void *opaque; /** * Bitmask of SWS_*. See `SwsFlags` for details. */ unsigned flags; /** * Extra parameters for fine-tuning certain scalers. */ double scaler_params[2]; /** * How many threads to use for processing, or 0 for automatic selection. */ int threads; /** * Dither mode. */ SwsDither dither; /** * Alpha blending mode. See `SwsAlphaBlend` for details. */ SwsAlphaBlend alpha_blend; /** * Use gamma correct scaling. */ int gamma_flag; /** * Deprecated frame property overrides, for the legacy API only. * * Ignored by sws_scale_frame() when used in dynamic mode, in which * case all properties are instead taken from the frame directly. */ int src_w, src_h; ///< Width and height of the source frame int dst_w, dst_h; ///< Width and height of the destination frame int src_format; ///< Source pixel format int dst_format; ///< Destination pixel format int src_range; ///< Source is full range int dst_range; ///< Destination is full range int src_v_chr_pos; ///< Source vertical chroma position in luma grid / 256 int src_h_chr_pos; ///< Source horizontal chroma position int dst_v_chr_pos; ///< Destination vertical chroma position int dst_h_chr_pos; ///< Destination horizontal chroma position /** * Desired ICC intent for color space conversions. */ int intent; /* Remember to add new fields to graph.c:opts_equal() */ } SwsContext; /** * Allocate an empty SwsContext and set its fields to default values. */ SwsContext *sws_alloc_context(void); /** * Free the context and everything associated with it, and write NULL * to the provided pointer. */ void sws_free_context(SwsContext **ctx); /*************************** * Supported frame formats * ***************************/ /** * Test if a given pixel format is supported. * * @param output If 0, test if compatible with the source/input frame; * otherwise, with the destination/output frame. * @param format The format to check. * * @return A positive integer if supported, 0 otherwise. */ int sws_test_format(enum AVPixelFormat format, int output); /** * Test if a given color space is supported. * * @param output If 0, test if compatible with the source/input frame; * otherwise, with the destination/output frame. * @param colorspace The colorspace to check. * * @return A positive integer if supported, 0 otherwise. */ int sws_test_colorspace(enum AVColorSpace colorspace, int output); /** * Test if a given set of color primaries is supported. * * @param output If 0, test if compatible with the source/input frame; * otherwise, with the destination/output frame. * @param primaries The color primaries to check. * * @return A positive integer if supported, 0 otherwise. */ int sws_test_primaries(enum AVColorPrimaries primaries, int output); /** * Test if a given color transfer function is supported. * * @param output If 0, test if compatible with the source/input frame; * otherwise, with the destination/output frame. * @param trc The color transfer function to check. * * @return A positive integer if supported, 0 otherwise. */ int sws_test_transfer(enum AVColorTransferCharacteristic trc, int output); /** * Helper function to run all sws_test_* against a frame, as well as testing * the basic frame properties for sanity. Ignores irrelevant properties - for * example, AVColorSpace is not checked for RGB frames. */ int sws_test_frame(const AVFrame *frame, int output); /** * Like `sws_scale_frame`, but without actually scaling. It will instead * merely initialize internal state that *would* be required to perform the * operation, as well as returning the correct error code for unsupported * frame combinations. * * @param ctx The scaling context. * @param dst The destination frame to consider. * @param src The source frame to consider. * @return 0 on success, a negative AVERROR code on failure. */ int sws_frame_setup(SwsContext *ctx, const AVFrame *dst, const AVFrame *src); /******************** * Main scaling API * ********************/ /** * Check if a given conversion is a noop. Returns a positive integer if * no operation needs to be performed, 0 otherwise. */ int sws_is_noop(const AVFrame *dst, const AVFrame *src); /** * Scale source data from `src` and write the output to `dst`. * * This function can be used directly on an allocated context, without setting * up any frame properties or calling `sws_init_context()`. Such usage is fully * dynamic and does not require reallocation if the frame properties change. * * Alternatively, this function can be called on a context that has been * explicitly initialized. However, this is provided only for backwards * compatibility. In this usage mode, all frame properties must be correctly * set at init time, and may no longer change after initialization. * * @param ctx The scaling context. * @param dst The destination frame. The data buffers may either be already * allocated by the caller or left clear, in which case they will * be allocated by the scaler. The latter may have performance * advantages - e.g. in certain cases some (or all) output planes * may be references to input planes, rather than copies. * @param src The source frame. If the data buffers are set to NULL, then * this function behaves identically to `sws_frame_setup`. * @return >= 0 on success, a negative AVERROR code on failure. */ int sws_scale_frame(SwsContext *c, AVFrame *dst, const AVFrame *src); /************************* * Legacy (stateful) API * *************************/ #define SWS_SRC_V_CHR_DROP_MASK 0x30000 #define SWS_SRC_V_CHR_DROP_SHIFT 16 #define SWS_PARAM_DEFAULT 123456 #define SWS_MAX_REDUCE_CUTOFF 0.002 #define SWS_CS_ITU709 1 #define SWS_CS_FCC 4 #define SWS_CS_ITU601 5 #define SWS_CS_ITU624 5 #define SWS_CS_SMPTE170M 5 #define SWS_CS_SMPTE240M 7 #define SWS_CS_DEFAULT 5 #define SWS_CS_BT2020 9 /** * Return a pointer to yuv<->rgb coefficients for the given colorspace * suitable for sws_setColorspaceDetails(). * * @param colorspace One of the SWS_CS_* macros. If invalid, * SWS_CS_DEFAULT is used. */ const int *sws_getCoefficients(int colorspace); // when used for filters they must have an odd number of elements // coeffs cannot be shared between vectors typedef struct SwsVector { double *coeff; ///< pointer to the list of coefficients int length; ///< number of coefficients in the vector } SwsVector; // vectors can be shared typedef struct SwsFilter { SwsVector *lumH; SwsVector *lumV; SwsVector *chrH; SwsVector *chrV; } SwsFilter; /** * Return a positive value if pix_fmt is a supported input format, 0 * otherwise. */ int sws_isSupportedInput(enum AVPixelFormat pix_fmt); /** * Return a positive value if pix_fmt is a supported output format, 0 * otherwise. */ int sws_isSupportedOutput(enum AVPixelFormat pix_fmt); /** * @param[in] pix_fmt the pixel format * @return a positive value if an endianness conversion for pix_fmt is * supported, 0 otherwise. */ int sws_isSupportedEndiannessConversion(enum AVPixelFormat pix_fmt); /** * Initialize the swscaler context sws_context. * * This function is considered deprecated, and provided only for backwards * compatibility with sws_scale() and sws_start_frame(). The preferred way to * use libswscale is to set all frame properties correctly and call * sws_scale_frame() directly, without explicitly initializing the context. * * @return zero or positive value on success, a negative value on * error */ av_warn_unused_result int sws_init_context(SwsContext *sws_context, SwsFilter *srcFilter, SwsFilter *dstFilter); /** * Free the swscaler context swsContext. * If swsContext is NULL, then does nothing. */ void sws_freeContext(SwsContext *swsContext); /** * Allocate and return an SwsContext. You need it to perform * scaling/conversion operations using sws_scale(). * * @param srcW the width of the source image * @param srcH the height of the source image * @param srcFormat the source image format * @param dstW the width of the destination image * @param dstH the height of the destination image * @param dstFormat the destination image format * @param flags specify which algorithm and options to use for rescaling * @param param extra parameters to tune the used scaler * For SWS_BICUBIC param[0] and [1] tune the shape of the basis * function, param[0] tunes f(1) and param[1] f´(1) * For SWS_GAUSS param[0] tunes the exponent and thus cutoff * frequency * For SWS_LANCZOS param[0] tunes the width of the window function * @return a pointer to an allocated context, or NULL in case of error * @note this function is to be removed after a saner alternative is * written */ SwsContext *sws_getContext(int srcW, int srcH, enum AVPixelFormat srcFormat, int dstW, int dstH, enum AVPixelFormat dstFormat, int flags, SwsFilter *srcFilter, SwsFilter *dstFilter, const double *param); /** * Scale the image slice in srcSlice and put the resulting scaled * slice in the image in dst. A slice is a sequence of consecutive * rows in an image. Requires a context that has been previously * been initialized with sws_init_context(). * * Slices have to be provided in sequential order, either in * top-bottom or bottom-top order. If slices are provided in * non-sequential order the behavior of the function is undefined. * * @param c the scaling context previously created with * sws_getContext() * @param srcSlice the array containing the pointers to the planes of * the source slice * @param srcStride the array containing the strides for each plane of * the source image * @param srcSliceY the position in the source image of the slice to * process, that is the number (counted starting from * zero) in the image of the first row of the slice * @param srcSliceH the height of the source slice, that is the number * of rows in the slice * @param dst the array containing the pointers to the planes of * the destination image * @param dstStride the array containing the strides for each plane of * the destination image * @return the height of the output slice */ int sws_scale(SwsContext *c, const uint8_t *const srcSlice[], const int srcStride[], int srcSliceY, int srcSliceH, uint8_t *const dst[], const int dstStride[]); /** * Initialize the scaling process for a given pair of source/destination frames. * Must be called before any calls to sws_send_slice() and sws_receive_slice(). * Requires a context that has been previously been initialized with * sws_init_context(). * * This function will retain references to src and dst, so they must both use * refcounted buffers (if allocated by the caller, in case of dst). * * @param c The scaling context * @param dst The destination frame. * * The data buffers may either be already allocated by the caller or * left clear, in which case they will be allocated by the scaler. * The latter may have performance advantages - e.g. in certain cases * some output planes may be references to input planes, rather than * copies. * * Output data will be written into this frame in successful * sws_receive_slice() calls. * @param src The source frame. The data buffers must be allocated, but the * frame data does not have to be ready at this point. Data * availability is then signalled by sws_send_slice(). * @return 0 on success, a negative AVERROR code on failure * * @see sws_frame_end() */ int sws_frame_start(SwsContext *c, AVFrame *dst, const AVFrame *src); /** * Finish the scaling process for a pair of source/destination frames previously * submitted with sws_frame_start(). Must be called after all sws_send_slice() * and sws_receive_slice() calls are done, before any new sws_frame_start() * calls. * * @param c The scaling context */ void sws_frame_end(SwsContext *c); /** * Indicate that a horizontal slice of input data is available in the source * frame previously provided to sws_frame_start(). The slices may be provided in * any order, but may not overlap. For vertically subsampled pixel formats, the * slices must be aligned according to subsampling. * * @param c The scaling context * @param slice_start first row of the slice * @param slice_height number of rows in the slice * * @return a non-negative number on success, a negative AVERROR code on failure. */ int sws_send_slice(SwsContext *c, unsigned int slice_start, unsigned int slice_height); /** * Request a horizontal slice of the output data to be written into the frame * previously provided to sws_frame_start(). * * @param c The scaling context * @param slice_start first row of the slice; must be a multiple of * sws_receive_slice_alignment() * @param slice_height number of rows in the slice; must be a multiple of * sws_receive_slice_alignment(), except for the last slice * (i.e. when slice_start+slice_height is equal to output * frame height) * * @return a non-negative number if the data was successfully written into the output * AVERROR(EAGAIN) if more input data needs to be provided before the * output can be produced * another negative AVERROR code on other kinds of scaling failure */ int sws_receive_slice(SwsContext *c, unsigned int slice_start, unsigned int slice_height); /** * Get the alignment required for slices. Requires a context that has been * previously been initialized with sws_init_context(). * * @param c The scaling context * @return alignment required for output slices requested with sws_receive_slice(). * Slice offsets and sizes passed to sws_receive_slice() must be * multiples of the value returned from this function. */ unsigned int sws_receive_slice_alignment(const SwsContext *c); /** * @param c the scaling context * @param dstRange flag indicating the while-black range of the output (1=jpeg / 0=mpeg) * @param srcRange flag indicating the while-black range of the input (1=jpeg / 0=mpeg) * @param table the yuv2rgb coefficients describing the output yuv space, normally ff_yuv2rgb_coeffs[x] * @param inv_table the yuv2rgb coefficients describing the input yuv space, normally ff_yuv2rgb_coeffs[x] * @param brightness 16.16 fixed point brightness correction * @param contrast 16.16 fixed point contrast correction * @param saturation 16.16 fixed point saturation correction * * @return A negative error code on error, non negative otherwise. * If `LIBSWSCALE_VERSION_MAJOR < 7`, returns -1 if not supported. */ int sws_setColorspaceDetails(SwsContext *c, const int inv_table[4], int srcRange, const int table[4], int dstRange, int brightness, int contrast, int saturation); /** * @return A negative error code on error, non negative otherwise. * If `LIBSWSCALE_VERSION_MAJOR < 7`, returns -1 if not supported. */ int sws_getColorspaceDetails(SwsContext *c, int **inv_table, int *srcRange, int **table, int *dstRange, int *brightness, int *contrast, int *saturation); /** * Allocate and return an uninitialized vector with length coefficients. */ SwsVector *sws_allocVec(int length); /** * Return a normalized Gaussian curve used to filter stuff * quality = 3 is high quality, lower is lower quality. */ SwsVector *sws_getGaussianVec(double variance, double quality); /** * Scale all the coefficients of a by the scalar value. */ void sws_scaleVec(SwsVector *a, double scalar); /** * Scale all the coefficients of a so that their sum equals height. */ void sws_normalizeVec(SwsVector *a, double height); void sws_freeVec(SwsVector *a); SwsFilter *sws_getDefaultFilter(float lumaGBlur, float chromaGBlur, float lumaSharpen, float chromaSharpen, float chromaHShift, float chromaVShift, int verbose); void sws_freeFilter(SwsFilter *filter); /** * Check if context can be reused, otherwise reallocate a new one. * * If context is NULL, just calls sws_getContext() to get a new * context. Otherwise, checks if the parameters are the ones already * saved in context. If that is the case, returns the current * context. Otherwise, frees context and gets a new context with * the new parameters. * * Be warned that srcFilter and dstFilter are not checked, they * are assumed to remain the same. */ SwsContext *sws_getCachedContext(SwsContext *context, int srcW, int srcH, enum AVPixelFormat srcFormat, int dstW, int dstH, enum AVPixelFormat dstFormat, int flags, SwsFilter *srcFilter, SwsFilter *dstFilter, const double *param); /** * Convert an 8-bit paletted frame into a frame with a color depth of 32 bits. * * The output frame will have the same packed format as the palette. * * @param src source frame buffer * @param dst destination frame buffer * @param num_pixels number of pixels to convert * @param palette array with [256] entries, which must match color arrangement (RGB or BGR) of src */ void sws_convertPalette8ToPacked32(const uint8_t *src, uint8_t *dst, int num_pixels, const uint8_t *palette); /** * Convert an 8-bit paletted frame into a frame with a color depth of 24 bits. * * With the palette format "ABCD", the destination frame ends up with the format "ABC". * * @param src source frame buffer * @param dst destination frame buffer * @param num_pixels number of pixels to convert * @param palette array with [256] entries, which must match color arrangement (RGB or BGR) of src */ void sws_convertPalette8ToPacked24(const uint8_t *src, uint8_t *dst, int num_pixels, const uint8_t *palette); /** * @} */ #endif /* SWSCALE_SWSCALE_H */