text: /*
   * AVS demuxer.
   * Copyright (c) 2006  Aurelien Jacobs <aurel@gnuage.org>
   *
   * 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 "avformat.h"
  #include "voc.h"
  
  
  typedef struct avs_format {
      VocDecContext voc;
      AVStream *st_video;
      AVStream *st_audio;
      int width;
      int height;
      int bits_per_sample;
      int fps;
      int nb_frames;
      int remaining_frame_size;
      int remaining_audio_size;
  } AvsFormat;
  
  typedef enum avs_block_type {
      AVS_NONE      = 0x00,
      AVS_VIDEO     = 0x01,
      AVS_AUDIO     = 0x02,
      AVS_PALETTE   = 0x03,
      AVS_GAME_DATA = 0x04,
  } AvsBlockType;
  
  static int avs_probe(AVProbeData * p)
  {
      const uint8_t *d;
  
      d = p->buf;
      if (d[0] == 'w' && d[1] == 'W' && d[2] == 0x10 && d[3] == 0)
          return 50;
  
      return 0;
  }
  
  static int avs_read_header(AVFormatContext * s, AVFormatParameters * ap)
  {
      AvsFormat *avs = s->priv_data;
  
      s->ctx_flags |= AVFMTCTX_NOHEADER;
  
      avio_skip(s->pb, 4);
      avs->width = avio_rl16(s->pb);
      avs->height = avio_rl16(s->pb);
      avs->bits_per_sample = avio_rl16(s->pb);
      avs->fps = avio_rl16(s->pb);
      avs->nb_frames = avio_rl32(s->pb);
      avs->remaining_frame_size = 0;
      avs->remaining_audio_size = 0;
  
      avs->st_video = avs->st_audio = NULL;
  
      if (avs->width != 318 || avs->height != 198)
          av_log(s, AV_LOG_ERROR, "This avs pretend to be %dx%d "
                 "when the avs format is supposed to be 318x198 only.\n",
                 avs->width, avs->height);
  
      return 0;
  }
  
  static int
  avs_read_video_packet(AVFormatContext * s, AVPacket * pkt,
                        AvsBlockType type, int sub_type, int size,
                        uint8_t * palette, int palette_size)
  {
      AvsFormat *avs = s->priv_data;
      int ret;
  
      ret = av_new_packet(pkt, size + palette_size);
      if (ret < 0)
          return ret;
  
      if (palette_size) {
          pkt->data[0] = 0x00;
          pkt->data[1] = 0x03;
          pkt->data[2] = palette_size & 0xFF;
          pkt->data[3] = (palette_size >> 8) & 0xFF;
          memcpy(pkt->data + 4, palette, palette_size - 4);
      }
  
      pkt->data[palette_size + 0] = sub_type;
      pkt->data[palette_size + 1] = type;
      pkt->data[palette_size + 2] = size & 0xFF;
      pkt->data[palette_size + 3] = (size >> 8) & 0xFF;
      ret = avio_read(s->pb, pkt->data + palette_size + 4, size - 4) + 4;
      if (ret < size) {
          av_free_packet(pkt);
          return AVERROR(EIO);
      }
  
      pkt->size = ret + palette_size;
      pkt->stream_index = avs->st_video->index;
      if (sub_type == 0)
          pkt->flags |= AV_PKT_FLAG_KEY;
  
      return 0;
  }
  
  static int avs_read_audio_packet(AVFormatContext * s, AVPacket * pkt)
  {
      AvsFormat *avs = s->priv_data;
      int ret, size;
  
      size = avio_tell(s->pb);
      ret = voc_get_packet(s, pkt, avs->st_audio, avs->remaining_audio_size);
      size = avio_tell(s->pb) - size;
      avs->remaining_audio_size -= size;
  
      if (ret == AVERROR(EIO))
          return 0;    /* this indicate EOS */
      if (ret < 0)
          return ret;
  
      pkt->stream_index = avs->st_audio->index;
      pkt->flags |= AV_PKT_FLAG_KEY;
  
      return size;
  }
  
  static int avs_read_packet(AVFormatContext * s, AVPacket * pkt)
  {
      AvsFormat *avs = s->priv_data;
      int sub_type = 0, size = 0;
      AvsBlockType type = AVS_NONE;
      int palette_size = 0;
      uint8_t palette[4 + 3 * 256];
      int ret;
  
      if (avs->remaining_audio_size > 0)
          if (avs_read_audio_packet(s, pkt) > 0)
              return 0;
  
      while (1) {
          if (avs->remaining_frame_size <= 0) {
              if (!avio_rl16(s->pb))    /* found EOF */
                  return AVERROR(EIO);
              avs->remaining_frame_size = avio_rl16(s->pb) - 4;
          }
  
          while (avs->remaining_frame_size > 0) {
              sub_type = avio_r8(s->pb);
              type = avio_r8(s->pb);
              size = avio_rl16(s->pb);
              avs->remaining_frame_size -= size;
  
              switch (type) {
              case AVS_PALETTE:
                  ret = avio_read(s->pb, palette, size - 4);
                  if (ret < size - 4)
                      return AVERROR(EIO);
                  palette_size = size;
                  break;
  
              case AVS_VIDEO:
                  if (!avs->st_video) {
                      avs->st_video = av_new_stream(s, AVS_VIDEO);
                      if (avs->st_video == NULL)
                          return AVERROR(ENOMEM);
                      avs->st_video->codec->codec_type = AVMEDIA_TYPE_VIDEO;
                      avs->st_video->codec->codec_id = CODEC_ID_AVS;
                      avs->st_video->codec->width = avs->width;
                      avs->st_video->codec->height = avs->height;
                      avs->st_video->codec->bits_per_coded_sample=avs->bits_per_sample;
                      avs->st_video->nb_frames = avs->nb_frames;
                      avs->st_video->codec->time_base = (AVRational) {
                      1, avs->fps};
                  }
                  return avs_read_video_packet(s, pkt, type, sub_type, size,
                                               palette, palette_size);
  
              case AVS_AUDIO:
                  if (!avs->st_audio) {
                      avs->st_audio = av_new_stream(s, AVS_AUDIO);
                      if (avs->st_audio == NULL)
                          return AVERROR(ENOMEM);
                      avs->st_audio->codec->codec_type = AVMEDIA_TYPE_AUDIO;
                  }
                  avs->remaining_audio_size = size - 4;
                  size = avs_read_audio_packet(s, pkt);
                  if (size != 0)
                      return size;
                  break;
  
              default:
                  avio_skip(s->pb, size - 4);
              }
          }
      }
  }
  
  static int avs_read_close(AVFormatContext * s)
  {
      return 0;
  }
  
  AVInputFormat ff_avs_demuxer = {
      "avs",
      NULL_IF_CONFIG_SMALL("AVS format"),
      sizeof(AvsFormat),
      avs_probe,
      avs_read_header,
      avs_read_packet,
      avs_read_close,
  };
  