text: /*
   * AVI muxer
   * Copyright (c) 2000 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
   */
  
  //#define DEBUG
  
  #include "avformat.h"
  #include "internal.h"
  #include "avi.h"
  #include "avio_internal.h"
  #include "riff.h"
  #include "mpegts.h"
  #include "libavformat/avlanguage.h"
  #include "libavutil/avstring.h"
  #include "libavutil/intreadwrite.h"
  #include "libavutil/dict.h"
  #include "libavutil/avassert.h"
  #include "libavutil/timestamp.h"
  #include "libavutil/pixdesc.h"
  #include "libavcodec/raw.h"
  
  /*
   * TODO:
   *  - fill all fields if non streamed (nb_frames for example)
   */
  
  typedef struct AVIIentry {
      unsigned int flags, pos, len;
  } AVIIentry;
  
  #define AVI_INDEX_CLUSTER_SIZE 16384
  
  typedef struct AVIIndex {
      int64_t     indx_start;
      int         entry;
      int         ents_allocated;
      AVIIentry** cluster;
  } AVIIndex;
  
  typedef struct {
      int64_t riff_start, movi_list, odml_list;
      int64_t frames_hdr_all;
      int riff_id;
  } AVIContext;
  
  typedef struct  {
      int64_t frames_hdr_strm;
      int64_t audio_strm_length;
      int packet_count;
      int entry;
      int max_size;
  
      AVIIndex indexes;
  } AVIStream;
  
  static inline AVIIentry *avi_get_ientry(AVIIndex *idx, int ent_id)
  {
      int cl = ent_id / AVI_INDEX_CLUSTER_SIZE;
      int id = ent_id % AVI_INDEX_CLUSTER_SIZE;
      return &idx->cluster[cl][id];
  }
  
  static int64_t avi_start_new_riff(AVFormatContext *s, AVIOContext *pb,
                                    const char *riff_tag, const char *list_tag)
  {
      AVIContext *avi = s->priv_data;
      int64_t loff;
      int i;
  
      avi->riff_id++;
      for (i = 0; i < s->nb_streams; i++) {
          AVIStream *avist = s->streams[i]->priv_data;
          avist->indexes.entry = 0;
      }
  
      avi->riff_start = ff_start_tag(pb, "RIFF");
      ffio_wfourcc(pb, riff_tag);
      loff = ff_start_tag(pb, "LIST");
      ffio_wfourcc(pb, list_tag);
      return loff;
  }
  
  static char *avi_stream2fourcc(char *tag, int index, enum AVMediaType type)
  {
      tag[0] = '0' + index / 10;
      tag[1] = '0' + index % 10;
      if (type == AVMEDIA_TYPE_VIDEO) {
          tag[2] = 'd';
          tag[3] = 'c';
      } else if (type == AVMEDIA_TYPE_SUBTITLE) {
          // note: this is not an official code
          tag[2] = 's';
          tag[3] = 'b';
      } else {
          tag[2] = 'w';
          tag[3] = 'b';
      }
      tag[4] = '\0';
      return tag;
  }
  
  static int avi_write_counters(AVFormatContext *s, int riff_id)
  {
      AVIOContext *pb = s->pb;
      AVIContext *avi = s->priv_data;
      int n, au_byterate, au_ssize, au_scale, nb_frames = 0;
      int64_t file_size;
      AVCodecContext *stream;
  
      file_size = avio_tell(pb);
      for (n = 0; n < s->nb_streams; n++) {
          AVIStream *avist = s->streams[n]->priv_data;
  
          av_assert0(avist->frames_hdr_strm);
          stream = s->streams[n]->codec;
          avio_seek(pb, avist->frames_hdr_strm, SEEK_SET);
          ff_parse_specific_params(s->streams[n], &au_byterate, &au_ssize, &au_scale);
          if (au_ssize == 0)
              avio_wl32(pb, avist->packet_count);
          else
              avio_wl32(pb, avist->audio_strm_length / au_ssize);
          if (stream->codec_type == AVMEDIA_TYPE_VIDEO)
              nb_frames = FFMAX(nb_frames, avist->packet_count);
      }
      if (riff_id == 1) {
          av_assert0(avi->frames_hdr_all);
          avio_seek(pb, avi->frames_hdr_all, SEEK_SET);
          avio_wl32(pb, nb_frames);
      }
      avio_seek(pb, file_size, SEEK_SET);
  
      return 0;
  }
  
  static int avi_write_header(AVFormatContext *s)
  {
      AVIContext *avi = s->priv_data;
      AVIOContext *pb = s->pb;
      int bitrate, n, i, nb_frames, au_byterate, au_ssize, au_scale;
      AVCodecContext *video_enc;
      AVStream *video_st = NULL;
      int64_t list1, list2, strh, strf;
      AVDictionaryEntry *t = NULL;
      int padding;
  
      if (s->nb_streams > AVI_MAX_STREAM_COUNT) {
          av_log(s, AV_LOG_ERROR, "AVI does not support >%d streams\n",
                 AVI_MAX_STREAM_COUNT);
          return AVERROR(EINVAL);
      }
  
      for (n = 0; n < s->nb_streams; n++) {
          s->streams[n]->priv_data = av_mallocz(sizeof(AVIStream));
          if (!s->streams[n]->priv_data)
              return AVERROR(ENOMEM);
      }
  
      /* header list */
      avi->riff_id = 0;
      list1 = avi_start_new_riff(s, pb, "AVI ", "hdrl");
  
      /* avi header */
      ffio_wfourcc(pb, "avih");
      avio_wl32(pb, 14 * 4);
      bitrate = 0;
  
      video_enc = NULL;
      for (n = 0; n < s->nb_streams; n++) {
          AVCodecContext *codec = s->streams[n]->codec;
          bitrate += codec->bit_rate;
          if (codec->codec_type == AVMEDIA_TYPE_VIDEO) {
              video_enc = codec;
              video_st = s->streams[n];
          }
      }
  
      nb_frames = 0;
  
      // TODO: should be avg_frame_rate
      if (video_st)
          avio_wl32(pb, (uint32_t) (INT64_C(1000000) * video_st->time_base.num /
                                    video_st->time_base.den));
      else
          avio_wl32(pb, 0);
      avio_wl32(pb, bitrate / 8); /* XXX: not quite exact */
      avio_wl32(pb, 0); /* padding */
      if (!pb->seekable)
          avio_wl32(pb, AVIF_TRUSTCKTYPE | AVIF_ISINTERLEAVED);  /* flags */
      else
          avio_wl32(pb, AVIF_TRUSTCKTYPE | AVIF_HASINDEX | AVIF_ISINTERLEAVED);  /* flags */
      avi->frames_hdr_all = avio_tell(pb); /* remember this offset to fill later */
      avio_wl32(pb, nb_frames); /* nb frames, filled later */
      avio_wl32(pb, 0); /* initial frame */
      avio_wl32(pb, s->nb_streams); /* nb streams */
      avio_wl32(pb, 1024 * 1024); /* suggested buffer size */
      if (video_enc) {
          avio_wl32(pb, video_enc->width);
          avio_wl32(pb, video_enc->height);
      } else {
          avio_wl32(pb, 0);
          avio_wl32(pb, 0);
      }
      avio_wl32(pb, 0); /* reserved */
      avio_wl32(pb, 0); /* reserved */
      avio_wl32(pb, 0); /* reserved */
      avio_wl32(pb, 0); /* reserved */
  
      /* stream list */
      for (i = 0; i < n; i++) {
          AVStream *st = s->streams[i];
          AVCodecContext *enc = st->codec;
          AVIStream *avist = st->priv_data;
          list2 = ff_start_tag(pb, "LIST");
          ffio_wfourcc(pb, "strl");
  
          /* stream generic header */
          strh = ff_start_tag(pb, "strh");
          switch (enc->codec_type) {
          case AVMEDIA_TYPE_SUBTITLE:
              // XSUB subtitles behave like video tracks, other subtitles
              // are not (yet) supported.
              if (enc->codec_id != AV_CODEC_ID_XSUB) {
                  av_log(s, AV_LOG_ERROR,
                         "Subtitle streams other than DivX XSUB are not supported by the AVI muxer.\n");
                  return AVERROR_PATCHWELCOME;
              }
          case AVMEDIA_TYPE_VIDEO:
              ffio_wfourcc(pb, "vids");
              break;
          case AVMEDIA_TYPE_AUDIO:
              ffio_wfourcc(pb, "auds");
              break;
  //      case AVMEDIA_TYPE_TEXT:
  //          ffio_wfourcc(pb, "txts");
  //          break;
          case AVMEDIA_TYPE_DATA:
              ffio_wfourcc(pb, "dats");
              break;
          }
          if (enc->codec_type == AVMEDIA_TYPE_VIDEO ||
              enc->codec_id == AV_CODEC_ID_XSUB)
              avio_wl32(pb, enc->codec_tag);
          else
              avio_wl32(pb, 1);
          avio_wl32(pb, 0); /* flags */
          avio_wl16(pb, 0); /* priority */
          avio_wl16(pb, 0); /* language */
          avio_wl32(pb, 0); /* initial frame */
  
          ff_parse_specific_params(st, &au_byterate, &au_ssize, &au_scale);
  
          if (   enc->codec_type == AVMEDIA_TYPE_VIDEO
              && enc->codec_id != AV_CODEC_ID_XSUB
              && au_byterate > LLN(1000)*au_scale) {
              au_byterate = 600;
              au_scale    = 1;
          }
          avpriv_set_pts_info(st, 64, au_scale, au_byterate);
          if (enc->codec_id == AV_CODEC_ID_XSUB)
              au_scale = au_byterate = 0;
  
          avio_wl32(pb, au_scale); /* scale */
          avio_wl32(pb, au_byterate); /* rate */
  
          avio_wl32(pb, 0); /* start */
          /* remember this offset to fill later */
          avist->frames_hdr_strm = avio_tell(pb);
          if (!pb->seekable)
              /* FIXME: this may be broken, but who cares */
              avio_wl32(pb, AVI_MAX_RIFF_SIZE);
          else
              avio_wl32(pb, 0);  /* length, XXX: filled later */
  
          /* suggested buffer size, is set to largest chunk size in avi_write_trailer */
          if (enc->codec_type == AVMEDIA_TYPE_VIDEO)
              avio_wl32(pb, 1024 * 1024);
          else if (enc->codec_type == AVMEDIA_TYPE_AUDIO)
              avio_wl32(pb, 12 * 1024);
          else
              avio_wl32(pb, 0);
          avio_wl32(pb, -1); /* quality */
          avio_wl32(pb, au_ssize); /* sample size */
          avio_wl32(pb, 0);
          avio_wl16(pb, enc->width);
          avio_wl16(pb, enc->height);
          ff_end_tag(pb, strh);
  
          if (enc->codec_type != AVMEDIA_TYPE_DATA) {
              int ret;
              enum AVPixelFormat pix_fmt;
  
              strf = ff_start_tag(pb, "strf");
              switch (enc->codec_type) {
              case AVMEDIA_TYPE_SUBTITLE:
                  /* XSUB subtitles behave like video tracks, other subtitles
                   * are not (yet) supported. */
                  if (enc->codec_id != AV_CODEC_ID_XSUB)
                      break;
              case AVMEDIA_TYPE_VIDEO:
                  /* WMP expects RGB 5:5:5 rawvideo in avi to have bpp set to 16. */
                  if (  !enc->codec_tag
                      && enc->codec_id == AV_CODEC_ID_RAWVIDEO
                      && enc->pix_fmt == AV_PIX_FMT_RGB555LE
                      && enc->bits_per_coded_sample == 15)
                      enc->bits_per_coded_sample = 16;
                  ff_put_bmp_header(pb, enc, ff_codec_bmp_tags, 0, 0);
                  pix_fmt = avpriv_find_pix_fmt(avpriv_pix_fmt_bps_avi,
                                                enc->bits_per_coded_sample);
                  if (   !enc->codec_tag
                      && enc->codec_id == AV_CODEC_ID_RAWVIDEO
                      && enc->pix_fmt != pix_fmt
                      && enc->pix_fmt != AV_PIX_FMT_NONE)
                      av_log(s, AV_LOG_ERROR, "%s rawvideo cannot be written to avi, output file will be unreadable\n",
                            av_get_pix_fmt_name(enc->pix_fmt));
                  break;
              case AVMEDIA_TYPE_AUDIO:
                  if ((ret = ff_put_wav_header(pb, enc, 0)) < 0)
                      return ret;
                  break;
              default:
                  av_log(s, AV_LOG_ERROR,
                      "Invalid or not supported codec type '%s' found in the input\n",
                      (char *)av_x_if_null(av_get_media_type_string(enc->codec_type), "?"));
                  return AVERROR(EINVAL);
              }
              ff_end_tag(pb, strf);
              if ((t = av_dict_get(st->metadata, "title", NULL, 0))) {
                  ff_riff_write_info_tag(s->pb, "strn", t->value);
                  t = NULL;
              }
              if (enc->codec_id == AV_CODEC_ID_XSUB
              && (t = av_dict_get(s->streams[i]->metadata, "language", NULL, 0))) {
                  const char* langstr = av_convert_lang_to(t->value, AV_LANG_ISO639_1);
                  t = NULL;
                  if (langstr) {
                      char* str = av_asprintf("Subtitle - %s-xx;02", langstr);
                      ff_riff_write_info_tag(s->pb, "strn", str);
                      av_free(str);
                  }
              }
          }
  
          if (pb->seekable) {
              unsigned char tag[5];
              int j;
  
              /* Starting to lay out AVI OpenDML master index.
               * We want to make it JUNK entry for now, since we'd
               * like to get away without making AVI an OpenDML one
               * for compatibility reasons. */
              avist->indexes.entry      = avist->indexes.ents_allocated = 0;
              avist->indexes.indx_start = ff_start_tag(pb, "JUNK");
              avio_wl16(pb, 4);   /* wLongsPerEntry */
              avio_w8(pb, 0);     /* bIndexSubType (0 == frame index) */
              avio_w8(pb, 0);     /* bIndexType (0 == AVI_INDEX_OF_INDEXES) */
              avio_wl32(pb, 0);   /* nEntriesInUse (will fill out later on) */
              ffio_wfourcc(pb, avi_stream2fourcc(tag, i, enc->codec_type));
                                  /* dwChunkId */
              avio_wl64(pb, 0);   /* dwReserved[3] */
              // avio_wl32(pb, 0);   /* Must be 0.    */
              for (j = 0; j < AVI_MASTER_INDEX_SIZE * 2; j++)
                  avio_wl64(pb, 0);
              ff_end_tag(pb, avist->indexes.indx_start);
          }
  
          if (enc->codec_type == AVMEDIA_TYPE_VIDEO   &&
              st->sample_aspect_ratio.num > 0 &&
              st->sample_aspect_ratio.den > 0) {
              int vprp       = ff_start_tag(pb, "vprp");
  			AVRational dar = av_mul_q(st->sample_aspect_ratio,
                                        (AVRational) { enc->width,
                                                       enc->height });
  			int num, den;
              av_reduce(&num, &den, dar.num, dar.den, 0xFFFF);
  
              avio_wl32(pb, 0); // video format   = unknown
              avio_wl32(pb, 0); // video standard = unknown
              // TODO: should be avg_frame_rate
              avio_wl32(pb, lrintf(1.0 / av_q2d(st->time_base)));
              avio_wl32(pb, enc->width);
              avio_wl32(pb, enc->height);
              avio_wl16(pb, den);
              avio_wl16(pb, num);
              avio_wl32(pb, enc->width);
              avio_wl32(pb, enc->height);
              avio_wl32(pb, 1); // progressive FIXME
  
              avio_wl32(pb, enc->height);
              avio_wl32(pb, enc->width);
              avio_wl32(pb, enc->height);
              avio_wl32(pb, enc->width);
              avio_wl32(pb, 0);
              avio_wl32(pb, 0);
  
              avio_wl32(pb, 0);
              avio_wl32(pb, 0);
              ff_end_tag(pb, vprp);
          }
  
          ff_end_tag(pb, list2);
      }
  
      if (pb->seekable) {
          /* AVI could become an OpenDML one, if it grows beyond 2Gb range */
          avi->odml_list = ff_start_tag(pb, "JUNK");
          ffio_wfourcc(pb, "odml");
          ffio_wfourcc(pb, "dmlh");
          avio_wl32(pb, 248);
          for (i = 0; i < 248; i += 4)
              avio_wl32(pb, 0);
          ff_end_tag(pb, avi->odml_list);
      }
  
      ff_end_tag(pb, list1);
  
      ff_riff_write_info(s);
  
  
      padding = s->metadata_header_padding;
      if (padding < 0)
          padding = 1016;
  
      /* some padding for easier tag editing */
      if (padding) {
          list2 = ff_start_tag(pb, "JUNK");
          for (i = padding; i > 0; i -= 4)
              avio_wl32(pb, 0);
          ff_end_tag(pb, list2);
      }
  
      avi->movi_list = ff_start_tag(pb, "LIST");
      ffio_wfourcc(pb, "movi");
  
      avio_flush(pb);
  
      return 0;
  }
  
  static int avi_write_ix(AVFormatContext *s)
  {
      AVIOContext *pb = s->pb;
      AVIContext *avi = s->priv_data;
      char tag[5];
      char ix_tag[] = "ix00";
      int i, j;
  
      av_assert0(pb->seekable);
  
      if (avi->riff_id > AVI_MASTER_INDEX_SIZE) {
          av_log(s, AV_LOG_ERROR, "Invalid riff index %d > %d\n",
                 avi->riff_id, AVI_MASTER_INDEX_SIZE);
          return AVERROR(EINVAL);
      }
  
      for (i = 0; i < s->nb_streams; i++) {
          AVIStream *avist = s->streams[i]->priv_data;
          int64_t ix, pos;
  
          avi_stream2fourcc(tag, i, s->streams[i]->codec->codec_type);
          ix_tag[3] = '0' + i;
  
          /* Writing AVI OpenDML leaf index chunk */
          ix = avio_tell(pb);
          ffio_wfourcc(pb, ix_tag);      /* ix?? */
          avio_wl32(pb, avist->indexes.entry * 8 + 24);
          /* chunk size */
          avio_wl16(pb, 2);           /* wLongsPerEntry */
          avio_w8(pb, 0);             /* bIndexSubType (0 == frame index) */
          avio_w8(pb, 1);             /* bIndexType (1 == AVI_INDEX_OF_CHUNKS) */
          avio_wl32(pb, avist->indexes.entry);
          /* nEntriesInUse */
          ffio_wfourcc(pb, tag);         /* dwChunkId */
          avio_wl64(pb, avi->movi_list); /* qwBaseOffset */
          avio_wl32(pb, 0);              /* dwReserved_3 (must be 0) */
  
          for (j = 0; j < avist->indexes.entry; j++) {
              AVIIentry *ie = avi_get_ientry(&avist->indexes, j);
              avio_wl32(pb, ie->pos + 8);
              avio_wl32(pb, ((uint32_t) ie->len & ~0x80000000) |
                            (ie->flags & 0x10 ? 0 : 0x80000000));
          }
          avio_flush(pb);
          pos = avio_tell(pb);
  
          /* Updating one entry in the AVI OpenDML master index */
          avio_seek(pb, avist->indexes.indx_start - 8, SEEK_SET);
          ffio_wfourcc(pb, "indx");             /* enabling this entry */
          avio_skip(pb, 8);
          avio_wl32(pb, avi->riff_id);          /* nEntriesInUse */
          avio_skip(pb, 16 * avi->riff_id);
          avio_wl64(pb, ix);                    /* qwOffset */
          avio_wl32(pb, pos - ix);              /* dwSize */
          avio_wl32(pb, avist->indexes.entry);  /* dwDuration */
  
          avio_seek(pb, pos, SEEK_SET);
      }
      return 0;
  }
  
  static int avi_write_idx1(AVFormatContext *s)
  {
      AVIOContext *pb = s->pb;
      AVIContext *avi = s->priv_data;
      int64_t idx_chunk;
      int i;
      char tag[5];
  
      if (pb->seekable) {
          AVIStream *avist;
          AVIIentry *ie = 0, *tie;
          int empty, stream_id = -1;
  
          idx_chunk = ff_start_tag(pb, "idx1");
          for (i = 0; i < s->nb_streams; i++) {
              avist        = s->streams[i]->priv_data;
              avist->entry = 0;
          }
  
          do {
              empty = 1;
              for (i = 0; i < s->nb_streams; i++) {
                  avist = s->streams[i]->priv_data;
                  if (avist->indexes.entry <= avist->entry)
                      continue;
  
                  tie = avi_get_ientry(&avist->indexes, avist->entry);
                  if (empty || tie->pos < ie->pos) {
                      ie        = tie;
                      stream_id = i;
                  }
                  empty = 0;
              }
              if (!empty) {
                  avist = s->streams[stream_id]->priv_data;
                  avi_stream2fourcc(tag, stream_id,
                                    s->streams[stream_id]->codec->codec_type);
                  ffio_wfourcc(pb, tag);
                  avio_wl32(pb, ie->flags);
                  avio_wl32(pb, ie->pos);
                  avio_wl32(pb, ie->len);
                  avist->entry++;
              }
          } while (!empty);
          ff_end_tag(pb, idx_chunk);
  
          avi_write_counters(s, avi->riff_id);
      }
      return 0;
  }
  
  static int avi_write_packet(AVFormatContext *s, AVPacket *pkt)
  {
      unsigned char tag[5];
      unsigned int flags = 0;
      const int stream_index = pkt->stream_index;
      int size               = pkt->size;
      AVIContext *avi     = s->priv_data;
      AVIOContext *pb     = s->pb;
      AVIStream *avist    = s->streams[stream_index]->priv_data;
      AVCodecContext *enc = s->streams[stream_index]->codec;
  
      if (enc->codec_id == AV_CODEC_ID_H264 && enc->codec_tag == MKTAG('H','2','6','4')) {
          int ret = ff_check_h264_startcode(s, s->streams[stream_index], pkt);
          if (ret < 0)
              return ret;
      }
  	av_dlog(s, "dts:%s packet_count:%d stream_index:%d\n", av_ts2str(pkt->dts), avist->packet_count, stream_index);
  	while (enc->block_align == 0 && pkt->dts != AV_NOPTS_VALUE &&
             pkt->dts > avist->packet_count && enc->codec_id != AV_CODEC_ID_XSUB && avist->packet_count) {
          AVPacket empty_packet;
  
          if (pkt->dts - avist->packet_count > 60000) {
              av_log(s, AV_LOG_ERROR, "Too large number of skipped frames %"PRId64" > 60000\n", pkt->dts - avist->packet_count);
              return AVERROR(EINVAL);
          }
  
          av_init_packet(&empty_packet);
          empty_packet.size         = 0;
          empty_packet.data         = NULL;
          empty_packet.stream_index = stream_index;
          avi_write_packet(s, &empty_packet);
  		av_dlog(s, "dup dts:%s packet_count:%d\n", av_ts2str(pkt->dts), avist->packet_count);
  	}
      avist->packet_count++;
  
      // Make sure to put an OpenDML chunk when the file size exceeds the limits
      if (pb->seekable &&
          (avio_tell(pb) - avi->riff_start > AVI_MAX_RIFF_SIZE)) {
          avi_write_ix(s);
          ff_end_tag(pb, avi->movi_list);
  
          if (avi->riff_id == 1)
              avi_write_idx1(s);
  
          ff_end_tag(pb, avi->riff_start);
          avi->movi_list = avi_start_new_riff(s, pb, "AVIX", "movi");
      }
  
      avi_stream2fourcc(tag, stream_index, enc->codec_type);
      if (pkt->flags & AV_PKT_FLAG_KEY)
          flags = 0x10;
      if (enc->codec_type == AVMEDIA_TYPE_AUDIO)
          avist->audio_strm_length += size;
  
      if (s->pb->seekable) {
          AVIIndex *idx = &avist->indexes;
          int cl = idx->entry / AVI_INDEX_CLUSTER_SIZE;
          int id = idx->entry % AVI_INDEX_CLUSTER_SIZE;
          if (idx->ents_allocated <= idx->entry) {
              idx->cluster = av_realloc_f(idx->cluster, sizeof(void*), cl+1);
              if (!idx->cluster) {
                  idx->ents_allocated = 0;
                  idx->entry          = 0;
                  return AVERROR(ENOMEM);
              }
              idx->cluster[cl] =
                  av_malloc(AVI_INDEX_CLUSTER_SIZE * sizeof(AVIIentry));
              if (!idx->cluster[cl])
                  return AVERROR(ENOMEM);
              idx->ents_allocated += AVI_INDEX_CLUSTER_SIZE;
          }
  
          idx->cluster[cl][id].flags = flags;
          idx->cluster[cl][id].pos   = avio_tell(pb) - avi->movi_list;
          idx->cluster[cl][id].len   = size;
          avist->max_size = FFMAX(avist->max_size, size);
          idx->entry++;
      }
  
      avio_write(pb, tag, 4);
      avio_wl32(pb, size);
      avio_write(pb, pkt->data, size);
      if (size & 1)
          avio_w8(pb, 0);
  
      return 0;
  }
  
  static int avi_write_trailer(AVFormatContext *s)
  {
      AVIContext *avi = s->priv_data;
      AVIOContext *pb = s->pb;
      int res = 0;
      int i, j, n, nb_frames;
      int64_t file_size;
  
      if (pb->seekable) {
          if (avi->riff_id == 1) {
              ff_end_tag(pb, avi->movi_list);
              res = avi_write_idx1(s);
              ff_end_tag(pb, avi->riff_start);
          } else {
              avi_write_ix(s);
              ff_end_tag(pb, avi->movi_list);
              ff_end_tag(pb, avi->riff_start);
  
              file_size = avio_tell(pb);
              avio_seek(pb, avi->odml_list - 8, SEEK_SET);
              ffio_wfourcc(pb, "LIST"); /* Making this AVI OpenDML one */
              avio_skip(pb, 16);
  
              for (n = nb_frames = 0; n < s->nb_streams; n++) {
                  AVCodecContext *stream = s->streams[n]->codec;
                  AVIStream *avist       = s->streams[n]->priv_data;
  
                  if (stream->codec_type == AVMEDIA_TYPE_VIDEO) {
                      if (nb_frames < avist->packet_count)
                          nb_frames = avist->packet_count;
                  } else {
                      if (stream->codec_id == AV_CODEC_ID_MP2 ||
                          stream->codec_id == AV_CODEC_ID_MP3)
                          nb_frames += avist->packet_count;
                  }
              }
              avio_wl32(pb, nb_frames);
              avio_seek(pb, file_size, SEEK_SET);
  
              avi_write_counters(s, avi->riff_id);
          }
      }
  
      for (i = 0; i < s->nb_streams; i++) {
          AVIStream *avist = s->streams[i]->priv_data;
          for (j = 0; j < avist->indexes.ents_allocated / AVI_INDEX_CLUSTER_SIZE; j++)
              av_freep(&avist->indexes.cluster[j]);
          av_freep(&avist->indexes.cluster);
          avist->indexes.ents_allocated = avist->indexes.entry = 0;
          if (pb->seekable) {
              avio_seek(pb, avist->frames_hdr_strm + 4, SEEK_SET);
              avio_wl32(pb, avist->max_size);
          }
      }
  
      return res;
  }
  
  AVOutputFormat ff_avi_muxer = {
  	.name           = "avi",
      .long_name      = NULL_IF_CONFIG_SMALL("AVI (Audio Video Interleaved)"),
      .mime_type      = "video/x-msvideo",
      .extensions     = "avi",
      .priv_data_size = sizeof(AVIContext),
      .audio_codec    = CONFIG_LIBMP3LAME ? AV_CODEC_ID_MP3 : AV_CODEC_ID_AC3,
      .video_codec    = AV_CODEC_ID_MPEG4,
      .write_header   = avi_write_header,
      .write_packet   = avi_write_packet,
      .write_trailer  = avi_write_trailer,
      .codec_tag      = (const AVCodecTag * const []) {
          ff_codec_bmp_tags, ff_codec_wav_tags, 0
      },
  };
  