/* Gstreamer
 * Copyright (C) <2011> Intel Corporation
 * Copyright (C) <2011> Collabora Ltd.
 * Copyright (C) <2011> Thibault Saunier <thibault.saunier@collabora.com>
 *
 * Some bits C-c,C-v'ed and s/4/3 from h264parse and videoparsers/h264parse.c:
 *    Copyright (C) <2010> Mark Nauwelaerts <mark.nauwelaerts@collabora.co.uk>
 *    Copyright (C) <2010> Collabora Multimedia
 *    Copyright (C) <2010> Nokia Corporation
 *
 *    (C) 2005 Michal Benes <michal.benes@itonis.tv>
 *    (C) 2008 Wim Taymans <wim.taymans@gmail.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

/**
 * Common code for NAL parsing from h264 and h265 parsers.
 */

#ifdef HAVE_CONFIG_H
#  include "config.h"
#endif

#include <gst/base/gstbytereader.h>
#include <gst/base/gstbitreader.h>
#include <gst/base/gstbitwriter.h>

typedef struct
{
  const guint8 *data;
  guint size;

  guint n_epb;                  /* Number of emulation prevention bytes */
  guint byte;                   /* Byte position */
  guint bits_in_cache;          /* bitpos in the cache of next bit */
  guint8 first_byte;
  guint32 epb_cache;            /* cache 3 bytes to check emulation prevention bytes */
  guint64 cache;                /* cached bytes */
} NalReader;

typedef struct
{
  GstBitWriter bw;

  guint nal_prefix_size;
  gboolean packetized;
} NalWriter;

G_GNUC_INTERNAL
void nal_reader_init (NalReader * nr, const guint8 * data, guint size);

G_GNUC_INTERNAL
gboolean nal_reader_read (NalReader * nr, guint nbits);

G_GNUC_INTERNAL
gboolean nal_reader_skip (NalReader * nr, guint nbits);

G_GNUC_INTERNAL
gboolean nal_reader_skip_long (NalReader * nr, guint nbits);

G_GNUC_INTERNAL
guint nal_reader_get_pos (const NalReader * nr);

G_GNUC_INTERNAL
guint nal_reader_get_remaining (const NalReader * nr);

G_GNUC_INTERNAL
guint nal_reader_get_epb_count (const NalReader * nr);

G_GNUC_INTERNAL
gboolean nal_reader_is_byte_aligned (NalReader * nr);

G_GNUC_INTERNAL
gboolean nal_reader_has_more_data (NalReader * nr);

#define NAL_READER_READ_BITS_H(bits) \
G_GNUC_INTERNAL \
gboolean nal_reader_get_bits_uint##bits (NalReader *nr, guint##bits *val, guint nbits)

NAL_READER_READ_BITS_H (8);
NAL_READER_READ_BITS_H (16);
NAL_READER_READ_BITS_H (32);

#define NAL_READER_PEEK_BITS_H(bits) \
G_GNUC_INTERNAL \
gboolean nal_reader_peek_bits_uint##bits (const NalReader *nr, guint##bits *val, guint nbits)

NAL_READER_PEEK_BITS_H (8);

G_GNUC_INTERNAL
gboolean nal_reader_get_ue (NalReader * nr, guint32 * val);

G_GNUC_INTERNAL
gboolean nal_reader_get_se (NalReader * nr, gint32 * val);

#define CHECK_ALLOWED_MAX_WITH_DEBUG(dbg, val, max) { \
  if (val > max) { \
    GST_WARNING ("value for '" dbg "' greater than max. value: %d, max %d", \
                     val, max); \
    goto error; \
  } \
}
#define CHECK_ALLOWED_MAX(val, max) \
  CHECK_ALLOWED_MAX_WITH_DEBUG (G_STRINGIFY (val), val, max)

#define CHECK_ALLOWED_WITH_DEBUG(dbg, val, min, max) { \
  if (val < min || val > max) { \
    GST_WARNING ("value for '" dbg "' not in allowed range. value: %d, range %d-%d", \
                     val, min, max); \
    goto error; \
  } \
}
#define CHECK_ALLOWED(val, min, max) \
  CHECK_ALLOWED_WITH_DEBUG (G_STRINGIFY (val), val, min, max)

#define READ_UINT8(nr, val, nbits) { \
  if (!nal_reader_get_bits_uint8 (nr, &val, nbits)) { \
    GST_WARNING ("failed to read uint8 for '" G_STRINGIFY (val) "', nbits: %d", nbits); \
    goto error; \
  } \
}

#define READ_UINT16(nr, val, nbits) { \
  if (!nal_reader_get_bits_uint16 (nr, &val, nbits)) { \
  GST_WARNING ("failed to read uint16 for '" G_STRINGIFY (val) "', nbits: %d", nbits); \
    goto error; \
  } \
}

#define READ_UINT32(nr, val, nbits) { \
  if (!nal_reader_get_bits_uint32 (nr, &val, nbits)) { \
  GST_WARNING ("failed to read uint32 for '" G_STRINGIFY (val) "', nbits: %d", nbits); \
    goto error; \
  } \
}

#define READ_UINT64(nr, val, nbits) { \
  if (!nal_reader_get_bits_uint64 (nr, &val, nbits)) { \
    GST_WARNING ("failed to read uint32 for '" G_STRINGIFY (val) "', nbits: %d", nbits); \
    goto error; \
  } \
}

#define READ_UE(nr, val) { \
  if (!nal_reader_get_ue (nr, &val)) { \
    GST_WARNING ("failed to read UE for '" G_STRINGIFY (val) "'"); \
    goto error; \
  } \
}

#define READ_UE_ALLOWED(nr, val, min, max) { \
  guint32 tmp; \
  READ_UE (nr, tmp); \
  CHECK_ALLOWED_WITH_DEBUG (G_STRINGIFY (val), tmp, min, max); \
  val = tmp; \
}

#define READ_UE_MAX(nr, val, max) { \
  guint32 tmp; \
  READ_UE (nr, tmp); \
  CHECK_ALLOWED_MAX_WITH_DEBUG (G_STRINGIFY (val), tmp, max); \
  val = tmp; \
}

#define READ_SE(nr, val) { \
  if (!nal_reader_get_se (nr, &val)) { \
    GST_WARNING ("failed to read SE for '" G_STRINGIFY (val) "'"); \
    goto error; \
  } \
}

#define READ_SE_ALLOWED(nr, val, min, max) { \
  gint32 tmp; \
  READ_SE (nr, tmp); \
  CHECK_ALLOWED_WITH_DEBUG (G_STRINGIFY (val), tmp, min, max); \
  val = tmp; \
}

G_GNUC_INTERNAL
gint scan_for_start_codes (const guint8 * data, guint size);

G_GNUC_INTERNAL
void nal_writer_init (NalWriter * nw, guint nal_prefix_size, gboolean packetized);

G_GNUC_INTERNAL
void nal_writer_reset (NalWriter * nw);

G_GNUC_INTERNAL
gboolean nal_writer_do_rbsp_trailing_bits (NalWriter * nw);

G_GNUC_INTERNAL
GstMemory * nal_writer_reset_and_get_memory (NalWriter * nw);

G_GNUC_INTERNAL
guint8 * nal_writer_reset_and_get_data (NalWriter * nw, guint32 * ret_size);

G_GNUC_INTERNAL
gboolean nal_writer_put_bits_uint8 (NalWriter * nw, guint8 value, guint nbits);

G_GNUC_INTERNAL
gboolean nal_writer_put_bits_uint16 (NalWriter * nw, guint16 value, guint nbits);

G_GNUC_INTERNAL
gboolean nal_writer_put_bits_uint32 (NalWriter * nw, guint32 value, guint nbits);

G_GNUC_INTERNAL
gboolean nal_writer_put_bytes (NalWriter * nw, const guint8 * data, guint nbytes);

G_GNUC_INTERNAL
gboolean nal_writer_put_ue (NalWriter * nw, guint32 value);

G_GNUC_INTERNAL
gboolean count_exp_golomb_bits (guint32 value, guint * leading_zeros, guint * rest);

#define WRITE_UINT8(nw, val, nbits) { \
  if (!nal_writer_put_bits_uint8 (nw, val, nbits)) { \
    GST_WARNING ("failed to write uint8 for '" G_STRINGIFY (val) "', nbits: %d", nbits); \
    goto error; \
  } \
}

#define WRITE_UINT16(nw, val, nbits) { \
  if (!nal_writer_put_bits_uint16 (nw, val, nbits)) { \
    GST_WARNING ("failed to write uint16 for '" G_STRINGIFY (val) "', nbits: %d", nbits); \
    goto error; \
  } \
}

#define WRITE_UINT32(nw, val, nbits) { \
  if (!nal_writer_put_bits_uint32 (nw, val, nbits)) { \
    GST_WARNING ("failed to write uint32 for '" G_STRINGIFY (val) "', nbits: %d", nbits); \
    goto error; \
  } \
}

#define WRITE_BYTES(nw, data, nbytes) { \
  if (!nal_writer_put_bytes (nw, data, nbytes)) { \
    GST_WARNING ("failed to write bytes for '" G_STRINGIFY (val) "', nbits: %d", nbytes); \
    goto error; \
  } \
}

#define WRITE_UE(nw, val) { \
  if (!nal_writer_put_ue (nw, val)) { \
    GST_WARNING ("failed to write ue for '" G_STRINGIFY (val) "'"); \
    goto error; \
  } \
}

static inline guint32 div_ceil (guint32 a, guint32 b)
{
  /* http://blog.pkh.me/p/36-figuring-out-round%2C-floor-and-ceil-with-integer-division.html */
  g_assert (b > 0);
  return a / b + (a % b > 0);
}