text: /*
   * AVPacket functions for libavcodec
   * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
   *
   * 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
   */
  
  #include <string.h>
  
  #include "libavutil/avassert.h"
  #include "libavutil/common.h"
  #include "libavutil/internal.h"
  #include "libavutil/mathematics.h"
  #include "libavutil/mem.h"
  #include "avcodec.h"
  #include "bytestream.h"
  #include "internal.h"
  
  void av_init_packet(AVPacket *pkt)
  {
      pkt->pts                  = AV_NOPTS_VALUE;
      pkt->dts                  = AV_NOPTS_VALUE;
      pkt->pos                  = -1;
      pkt->duration             = 0;
  #if FF_API_CONVERGENCE_DURATION
  FF_DISABLE_DEPRECATION_WARNINGS
      pkt->convergence_duration = 0;
  FF_ENABLE_DEPRECATION_WARNINGS
  #endif
      pkt->flags                = 0;
      pkt->stream_index         = 0;
      pkt->buf                  = NULL;
      pkt->side_data            = NULL;
      pkt->side_data_elems      = 0;
  }
  
  AVPacket *av_packet_alloc(void)
  {
      AVPacket *pkt = av_mallocz(sizeof(AVPacket));
      if (!pkt)
          return pkt;
  
      av_packet_unref(pkt);
  
      return pkt;
  }
  
  void av_packet_free(AVPacket **pkt)
  {
      if (!pkt || !*pkt)
          return;
  
      av_packet_unref(*pkt);
      av_freep(pkt);
  }
  
  static int packet_alloc(AVBufferRef **buf, int size)
  {
      int ret;
      if (size < 0 || size >= INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE)
          return AVERROR(EINVAL);
  
      ret = av_buffer_realloc(buf, size + AV_INPUT_BUFFER_PADDING_SIZE);
      if (ret < 0)
          return ret;
  
      memset((*buf)->data + size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
  
      return 0;
  }
  
  int av_new_packet(AVPacket *pkt, int size)
  {
      AVBufferRef *buf = NULL;
      int ret = packet_alloc(&buf, size);
      if (ret < 0)
          return ret;
  
      av_init_packet(pkt);
      pkt->buf      = buf;
      pkt->data     = buf->data;
      pkt->size     = size;
  
      return 0;
  }
  
  void av_shrink_packet(AVPacket *pkt, int size)
  {
      if (pkt->size <= size)
          return;
      pkt->size = size;
      memset(pkt->data + size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
  }
  
  int av_grow_packet(AVPacket *pkt, int grow_by)
  {
      int new_size;
      av_assert0((unsigned)pkt->size <= INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE);
      if ((unsigned)grow_by >
          INT_MAX - (pkt->size + AV_INPUT_BUFFER_PADDING_SIZE))
          return -1;
  
      new_size = pkt->size + grow_by + AV_INPUT_BUFFER_PADDING_SIZE;
      if (pkt->buf) {
          size_t data_offset;
          uint8_t *old_data = pkt->data;
          if (pkt->data == NULL) {
              data_offset = 0;
              pkt->data = pkt->buf->data;
          } else {
              data_offset = pkt->data - pkt->buf->data;
              if (data_offset > INT_MAX - new_size)
                  return -1;
          }
  
          if (new_size + data_offset > pkt->buf->size) {
              int ret = av_buffer_realloc(&pkt->buf, new_size + data_offset);
              if (ret < 0) {
                  pkt->data = old_data;
                  return ret;
              }
              pkt->data = pkt->buf->data + data_offset;
          }
      } else {
          pkt->buf = av_buffer_alloc(new_size);
          if (!pkt->buf)
              return AVERROR(ENOMEM);
          if (pkt->size > 0)
              memcpy(pkt->buf->data, pkt->data, pkt->size);
          pkt->data = pkt->buf->data;
      }
      pkt->size += grow_by;
      memset(pkt->data + pkt->size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
  
      return 0;
  }
  
  int av_packet_from_data(AVPacket *pkt, uint8_t *data, int size)
  {
      if (size >= INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE)
          return AVERROR(EINVAL);
  
      pkt->buf = av_buffer_create(data, size + AV_INPUT_BUFFER_PADDING_SIZE,
                                  av_buffer_default_free, NULL, 0);
      if (!pkt->buf)
          return AVERROR(ENOMEM);
  
      pkt->data = data;
      pkt->size = size;
  
      return 0;
  }
  
  #if FF_API_AVPACKET_OLD_API
  FF_DISABLE_DEPRECATION_WARNINGS
  #define ALLOC_MALLOC(data, size) data = av_malloc(size)
  #define ALLOC_BUF(data, size)                \
  do {                                         \
      av_buffer_realloc(&pkt->buf, size);      \
      data = pkt->buf ? pkt->buf->data : NULL; \
  } while (0)
  
  #define DUP_DATA(dst, src, size, padding, ALLOC)                        \
      do {                                                                \
          void *data;                                                     \
          if (padding) {                                                  \
              if ((unsigned)(size) >                                      \
                  (unsigned)(size) + AV_INPUT_BUFFER_PADDING_SIZE)        \
                  goto failed_alloc;                                      \
              ALLOC(data, size + AV_INPUT_BUFFER_PADDING_SIZE);           \
          } else {                                                        \
              ALLOC(data, size);                                          \
          }                                                               \
          if (!data)                                                      \
              goto failed_alloc;                                          \
          memcpy(data, src, size);                                        \
          if (padding)                                                    \
              memset((uint8_t *)data + size, 0,                           \
                     AV_INPUT_BUFFER_PADDING_SIZE);                       \
          dst = data;                                                     \
      } while (0)
  
  /* Makes duplicates of data, side_data, but does not copy any other fields */
  static int copy_packet_data(AVPacket *pkt, const AVPacket *src, int dup)
  {
      pkt->data      = NULL;
      pkt->side_data = NULL;
      pkt->side_data_elems = 0;
      if (pkt->buf) {
          AVBufferRef *ref = av_buffer_ref(src->buf);
          if (!ref)
              return AVERROR(ENOMEM);
          pkt->buf  = ref;
          pkt->data = ref->data;
      } else {
          DUP_DATA(pkt->data, src->data, pkt->size, 1, ALLOC_BUF);
      }
      if (src->side_data_elems && dup) {
          pkt->side_data = src->side_data;
          pkt->side_data_elems = src->side_data_elems;
      }
      if (src->side_data_elems && !dup) {
          return av_copy_packet_side_data(pkt, src);
      }
      return 0;
  
  failed_alloc:
      av_packet_unref(pkt);
      return AVERROR(ENOMEM);
  }
  
  int av_copy_packet_side_data(AVPacket *pkt, const AVPacket *src)
  {
      if (src->side_data_elems) {
          int i;
          DUP_DATA(pkt->side_data, src->side_data,
                  src->side_data_elems * sizeof(*src->side_data), 0, ALLOC_MALLOC);
          if (src != pkt) {
              memset(pkt->side_data, 0,
                     src->side_data_elems * sizeof(*src->side_data));
          }
          for (i = 0; i < src->side_data_elems; i++) {
              DUP_DATA(pkt->side_data[i].data, src->side_data[i].data,
                      src->side_data[i].size, 1, ALLOC_MALLOC);
              pkt->side_data[i].size = src->side_data[i].size;
              pkt->side_data[i].type = src->side_data[i].type;
          }
      }
      pkt->side_data_elems = src->side_data_elems;
      return 0;
  
  failed_alloc:
      av_packet_unref(pkt);
      return AVERROR(ENOMEM);
  }
  
  int av_dup_packet(AVPacket *pkt)
  {
      AVPacket tmp_pkt;
  
      if (!pkt->buf && pkt->data) {
          tmp_pkt = *pkt;
          return copy_packet_data(pkt, &tmp_pkt, 1);
      }
      return 0;
  }
  
  int av_copy_packet(AVPacket *dst, const AVPacket *src)
  {
      *dst = *src;
      return copy_packet_data(dst, src, 0);
  }
  FF_ENABLE_DEPRECATION_WARNINGS
  #endif
  
  void av_packet_free_side_data(AVPacket *pkt)
  {
      int i;
      for (i = 0; i < pkt->side_data_elems; i++)
          av_freep(&pkt->side_data[i].data);
      av_freep(&pkt->side_data);
      pkt->side_data_elems = 0;
  }
  
  #if FF_API_AVPACKET_OLD_API
  FF_DISABLE_DEPRECATION_WARNINGS
  void av_free_packet(AVPacket *pkt)
  {
      if (pkt) {
          if (pkt->buf)
              av_buffer_unref(&pkt->buf);
          pkt->data            = NULL;
          pkt->size            = 0;
  
          av_packet_free_side_data(pkt);
      }
  }
  FF_ENABLE_DEPRECATION_WARNINGS
  #endif
  
  int av_packet_add_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
                              uint8_t *data, size_t size)
  {
      AVPacketSideData *tmp;
      int i, elems = pkt->side_data_elems;
  
      for (i = 0; i < elems; i++) {
          AVPacketSideData *sd = &pkt->side_data[i];
  
          if (sd->type == type) {
              av_free(sd->data);
              sd->data = data;
              sd->size = size;
              return 0;
          }
      }
  
      if ((unsigned)elems + 1 > AV_PKT_DATA_NB)
          return AVERROR(ERANGE);
  
      tmp = av_realloc(pkt->side_data, (elems + 1) * sizeof(*tmp));
      if (!tmp)
          return AVERROR(ENOMEM);
  
      pkt->side_data = tmp;
      pkt->side_data[elems].data = data;
      pkt->side_data[elems].size = size;
      pkt->side_data[elems].type = type;
      pkt->side_data_elems++;
  
      return 0;
  }
  
  
  uint8_t *av_packet_new_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
                                   int size)
  {
      int ret;
      uint8_t *data;
  
      if ((unsigned)size > INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE)
          return NULL;
      data = av_mallocz(size + AV_INPUT_BUFFER_PADDING_SIZE);
      if (!data)
          return NULL;
  
      ret = av_packet_add_side_data(pkt, type, data, size);
      if (ret < 0) {
          av_freep(&data);
          return NULL;
      }
  
      return data;
  }
  
  uint8_t *av_packet_get_side_data(const AVPacket *pkt, enum AVPacketSideDataType type,
                                   int *size)
  {
      int i;
  
      for (i = 0; i < pkt->side_data_elems; i++) {
          if (pkt->side_data[i].type == type) {
              if (size)
                  *size = pkt->side_data[i].size;
              return pkt->side_data[i].data;
          }
      }
      if (size)
          *size = 0;
      return NULL;
  }
  
  const char *av_packet_side_data_name(enum AVPacketSideDataType type)
  {
      switch(type) {
      case AV_PKT_DATA_PALETTE:                    return "Palette";
      case AV_PKT_DATA_NEW_EXTRADATA:              return "New Extradata";
      case AV_PKT_DATA_PARAM_CHANGE:               return "Param Change";
      case AV_PKT_DATA_H263_MB_INFO:               return "H263 MB Info";
      case AV_PKT_DATA_REPLAYGAIN:                 return "Replay Gain";
      case AV_PKT_DATA_DISPLAYMATRIX:              return "Display Matrix";
      case AV_PKT_DATA_STEREO3D:                   return "Stereo 3D";
      case AV_PKT_DATA_AUDIO_SERVICE_TYPE:         return "Audio Service Type";
      case AV_PKT_DATA_SKIP_SAMPLES:               return "Skip Samples";
      case AV_PKT_DATA_JP_DUALMONO:                return "JP Dual Mono";
      case AV_PKT_DATA_STRINGS_METADATA:           return "Strings Metadata";
      case AV_PKT_DATA_SUBTITLE_POSITION:          return "Subtitle Position";
      case AV_PKT_DATA_MATROSKA_BLOCKADDITIONAL:   return "Matroska BlockAdditional";
      case AV_PKT_DATA_WEBVTT_IDENTIFIER:          return "WebVTT ID";
      case AV_PKT_DATA_WEBVTT_SETTINGS:            return "WebVTT Settings";
      case AV_PKT_DATA_METADATA_UPDATE:            return "Metadata Update";
      case AV_PKT_DATA_MPEGTS_STREAM_ID:           return "MPEGTS Stream ID";
      case AV_PKT_DATA_MASTERING_DISPLAY_METADATA: return "Mastering display metadata";
      case AV_PKT_DATA_CONTENT_LIGHT_LEVEL:        return "Content light level metadata";
      case AV_PKT_DATA_SPHERICAL:                  return "Spherical Mapping";
      case AV_PKT_DATA_A53_CC:                     return "A53 Closed Captions";
      }
      return NULL;
  }
  
  #if FF_API_MERGE_SD_API
  
  #define FF_MERGE_MARKER 0x8c4d9d108e25e9feULL
  
  int av_packet_merge_side_data(AVPacket *pkt){
      if(pkt->side_data_elems){
          AVBufferRef *buf;
          int i;
          uint8_t *p;
          uint64_t size= pkt->size + 8LL + AV_INPUT_BUFFER_PADDING_SIZE;
          AVPacket old= *pkt;
          for (i=0; i<old.side_data_elems; i++) {
              size += old.side_data[i].size + 5LL;
          }
          if (size > INT_MAX)
              return AVERROR(EINVAL);
          buf = av_buffer_alloc(size);
          if (!buf)
              return AVERROR(ENOMEM);
          pkt->buf = buf;
          pkt->data = p = buf->data;
          pkt->size = size - AV_INPUT_BUFFER_PADDING_SIZE;
          bytestream_put_buffer(&p, old.data, old.size);
          for (i=old.side_data_elems-1; i>=0; i--) {
              bytestream_put_buffer(&p, old.side_data[i].data, old.side_data[i].size);
              bytestream_put_be32(&p, old.side_data[i].size);
              *p++ = old.side_data[i].type | ((i==old.side_data_elems-1)*128);
          }
          bytestream_put_be64(&p, FF_MERGE_MARKER);
          av_assert0(p-pkt->data == pkt->size);
          memset(p, 0, AV_INPUT_BUFFER_PADDING_SIZE);
          av_packet_unref(&old);
          pkt->side_data_elems = 0;
          pkt->side_data = NULL;
          return 1;
      }
      return 0;
  }
  
  int av_packet_split_side_data(AVPacket *pkt){
      if (!pkt->side_data_elems && pkt->size >12 && AV_RB64(pkt->data + pkt->size - 8) == FF_MERGE_MARKER){
          int i;
          unsigned int size;
          uint8_t *p;
  
          p = pkt->data + pkt->size - 8 - 5;
          for (i=1; ; i++){
              size = AV_RB32(p);
              if (size>INT_MAX - 5 || p - pkt->data < size)
                  return 0;
              if (p[4]&128)
                  break;
              if (p - pkt->data < size + 5)
                  return 0;
              p-= size+5;
          }
  
          if (i > AV_PKT_DATA_NB)
              return AVERROR(ERANGE);
  
          pkt->side_data = av_malloc_array(i, sizeof(*pkt->side_data));
          if (!pkt->side_data)
              return AVERROR(ENOMEM);
  
          p= pkt->data + pkt->size - 8 - 5;
          for (i=0; ; i++){
              size= AV_RB32(p);
              av_assert0(size<=INT_MAX - 5 && p - pkt->data >= size);
              pkt->side_data[i].data = av_mallocz(size + AV_INPUT_BUFFER_PADDING_SIZE);
              pkt->side_data[i].size = size;
              pkt->side_data[i].type = p[4]&127;
              if (!pkt->side_data[i].data)
                  return AVERROR(ENOMEM);
              memcpy(pkt->side_data[i].data, p-size, size);
              pkt->size -= size + 5;
              if(p[4]&128)
                  break;
              p-= size+5;
          }
          pkt->size -= 8;
          pkt->side_data_elems = i+1;
          return 1;
      }
      return 0;
  }
  #endif
  
  #if FF_API_MERGE_SD
  int ff_packet_split_and_drop_side_data(AVPacket *pkt){
      if (!pkt->side_data_elems && pkt->size >12 && AV_RB64(pkt->data + pkt->size - 8) == FF_MERGE_MARKER){
          int i;
          unsigned int size;
          uint8_t *p;
  
          p = pkt->data + pkt->size - 8 - 5;
          for (i=1; ; i++){
              size = AV_RB32(p);
              if (size>INT_MAX - 5 || p - pkt->data < size)
                  return 0;
              if (p[4]&128)
                  break;
              if (p - pkt->data < size + 5)
                  return 0;
              p-= size+5;
              if (i > AV_PKT_DATA_NB)
                  return 0;
          }
          pkt->size = p - pkt->data - size;
          av_assert0(pkt->size >= 0);
          return 1;
      }
      return 0;
  }
  #endif
  
  uint8_t *av_packet_pack_dictionary(AVDictionary *dict, int *size)
  {
      AVDictionaryEntry *t = NULL;
      uint8_t *data = NULL;
      *size = 0;
  
      if (!dict)
          return NULL;
  
      while ((t = av_dict_get(dict, "", t, AV_DICT_IGNORE_SUFFIX))) {
          const size_t keylen   = strlen(t->key);
          const size_t valuelen = strlen(t->value);
          const size_t new_size = *size + keylen + 1 + valuelen + 1;
          uint8_t *const new_data = av_realloc(data, new_size);
  
          if (!new_data)
              goto fail;
          data = new_data;
          if (new_size > INT_MAX)
              goto fail;
  
          memcpy(data + *size, t->key, keylen + 1);
          memcpy(data + *size + keylen + 1, t->value, valuelen + 1);
  
          *size = new_size;
      }
  
      return data;
  
  fail:
      av_freep(&data);
      *size = 0;
      return NULL;
  }
  
  int av_packet_unpack_dictionary(const uint8_t *data, int size, AVDictionary **dict)
  {
      const uint8_t *end = data + size;
      int ret = 0;
  
      if (!dict || !data || !size)
          return ret;
      if (size && end[-1])
          return AVERROR_INVALIDDATA;
      while (data < end) {
          const uint8_t *key = data;
          const uint8_t *val = data + strlen(key) + 1;
  
          if (val >= end || !*key)
              return AVERROR_INVALIDDATA;
  
          ret = av_dict_set(dict, key, val, 0);
          if (ret < 0)
              break;
          data = val + strlen(val) + 1;
      }
  
      return ret;
  }
  
  int av_packet_shrink_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
                                 int size)
  {
      int i;
  
      for (i = 0; i < pkt->side_data_elems; i++) {
          if (pkt->side_data[i].type == type) {
              if (size > pkt->side_data[i].size)
                  return AVERROR(ENOMEM);
              pkt->side_data[i].size = size;
              return 0;
          }
      }
      return AVERROR(ENOENT);
  }
  
  int av_packet_copy_props(AVPacket *dst, const AVPacket *src)
  {
      int i;
  
      dst->pts                  = src->pts;
      dst->dts                  = src->dts;
      dst->pos                  = src->pos;
      dst->duration             = src->duration;
  #if FF_API_CONVERGENCE_DURATION
  FF_DISABLE_DEPRECATION_WARNINGS
      dst->convergence_duration = src->convergence_duration;
  FF_ENABLE_DEPRECATION_WARNINGS
  #endif
      dst->flags                = src->flags;
      dst->stream_index         = src->stream_index;
  
      for (i = 0; i < src->side_data_elems; i++) {
           enum AVPacketSideDataType type = src->side_data[i].type;
           int size          = src->side_data[i].size;
           uint8_t *src_data = src->side_data[i].data;
           uint8_t *dst_data = av_packet_new_side_data(dst, type, size);
  
          if (!dst_data) {
              av_packet_free_side_data(dst);
              return AVERROR(ENOMEM);
          }
          memcpy(dst_data, src_data, size);
      }
  
      return 0;
  }
  
  void av_packet_unref(AVPacket *pkt)
  {
      av_packet_free_side_data(pkt);
      av_buffer_unref(&pkt->buf);
      av_init_packet(pkt);
      pkt->data = NULL;
      pkt->size = 0;
  }
  
  int av_packet_ref(AVPacket *dst, const AVPacket *src)
  {
      int ret;
  
      ret = av_packet_copy_props(dst, src);
      if (ret < 0)
          return ret;
  
      if (!src->buf) {
          ret = packet_alloc(&dst->buf, src->size);
          if (ret < 0)
              goto fail;
          if (src->size)
              memcpy(dst->buf->data, src->data, src->size);
  
          dst->data = dst->buf->data;
      } else {
          dst->buf = av_buffer_ref(src->buf);
          if (!dst->buf) {
              ret = AVERROR(ENOMEM);
              goto fail;
          }
          dst->data = src->data;
      }
  
      dst->size = src->size;
  
      return 0;
  fail:
      av_packet_free_side_data(dst);
      return ret;
  }
  
  AVPacket *av_packet_clone(const AVPacket *src)
  {
      AVPacket *ret = av_packet_alloc();
  
      if (!ret)
          return ret;
  
      if (av_packet_ref(ret, src))
          av_packet_free(&ret);
  
      return ret;
  }
  
  void av_packet_move_ref(AVPacket *dst, AVPacket *src)
  {
      *dst = *src;
      av_init_packet(src);
      src->data = NULL;
      src->size = 0;
  }
  
  void av_packet_rescale_ts(AVPacket *pkt, AVRational src_tb, AVRational dst_tb)
  {
      if (pkt->pts != AV_NOPTS_VALUE)
          pkt->pts = av_rescale_q(pkt->pts, src_tb, dst_tb);
      if (pkt->dts != AV_NOPTS_VALUE)
          pkt->dts = av_rescale_q(pkt->dts, src_tb, dst_tb);
      if (pkt->duration > 0)
          pkt->duration = av_rescale_q(pkt->duration, src_tb, dst_tb);
  #if FF_API_CONVERGENCE_DURATION
  FF_DISABLE_DEPRECATION_WARNINGS
      if (pkt->convergence_duration > 0)
          pkt->convergence_duration = av_rescale_q(pkt->convergence_duration, src_tb, dst_tb);
  FF_ENABLE_DEPRECATION_WARNINGS
  #endif
  }
  
  int ff_side_data_set_encoder_stats(AVPacket *pkt, int quality, int64_t *error, int error_count, int pict_type)
  {
      uint8_t *side_data;
      int side_data_size;
      int i;
  
      side_data = av_packet_get_side_data(pkt, AV_PKT_DATA_QUALITY_STATS, &side_data_size);
      if (!side_data) {
          side_data_size = 4+4+8*error_count;
          side_data = av_packet_new_side_data(pkt, AV_PKT_DATA_QUALITY_STATS,
                                              side_data_size);
      }
  
      if (!side_data || side_data_size < 4+4+8*error_count)
          return AVERROR(ENOMEM);
  
      AV_WL32(side_data   , quality  );
      side_data[4] = pict_type;
      side_data[5] = error_count;
      for (i = 0; i<error_count; i++)
          AV_WL64(side_data+8 + 8*i , error[i]);
  
      return 0;
  }
  