text: /*
   * RAW demuxers
   * Copyright (c) 2001 Fabrice Bellard
   * Copyright (c) 2005 Alex Beregszaszi
   *
   * 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 "internal.h"
  #include "avio_internal.h"
  #include "rawdec.h"
  #include "libavutil/opt.h"
  #include "libavutil/parseutils.h"
  #include "libavutil/pixdesc.h"
  #include "libavutil/avassert.h"
  #include "libavutil/intreadwrite.h"
  
  #define RAW_PACKET_SIZE 1024
  
  int ff_raw_read_partial_packet(AVFormatContext *s, AVPacket *pkt)
  {
      int ret, size;
  
      size = RAW_PACKET_SIZE;
  
      if (av_new_packet(pkt, size) < 0)
          return AVERROR(ENOMEM);
  
      pkt->pos= avio_tell(s->pb);
      pkt->stream_index = 0;
      ret = ffio_read_partial(s->pb, pkt->data, size);
      if (ret < 0) {
          av_packet_unref(pkt);
          return ret;
      }
      av_shrink_packet(pkt, ret);
      return ret;
  }
  
  int ff_raw_audio_read_header(AVFormatContext *s)
  {
      AVStream *st = avformat_new_stream(s, NULL);
      if (!st)
          return AVERROR(ENOMEM);
      st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
      st->codec->codec_id = s->iformat->raw_codec_id;
      st->need_parsing = AVSTREAM_PARSE_FULL_RAW;
      st->start_time = 0;
      /* the parameters will be extracted from the compressed bitstream */
  
      return 0;
  }
  
  /* MPEG-1/H.263 input */
  int ff_raw_video_read_header(AVFormatContext *s)
  {
      AVStream *st;
      FFRawVideoDemuxerContext *s1 = s->priv_data;
      int ret = 0;
  
  
      st = avformat_new_stream(s, NULL);
      if (!st) {
          ret = AVERROR(ENOMEM);
          goto fail;
      }
  
      st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
      st->codec->codec_id = s->iformat->raw_codec_id;
      st->need_parsing = AVSTREAM_PARSE_FULL_RAW;
  
      st->codec->framerate = s1->framerate;
      st->codec->time_base = av_inv_q(s1->framerate);
      avpriv_set_pts_info(st, 64, 1, 1200000);
  
  fail:
      return ret;
  }
  
  int ff_raw_data_read_header(AVFormatContext *s)
  {
      AVStream *st = avformat_new_stream(s, NULL);
      if (!st)
          return AVERROR(ENOMEM);
      st->codec->codec_type = AVMEDIA_TYPE_DATA;
      st->codec->codec_id = s->iformat->raw_codec_id;
      st->start_time = 0;
      return 0;
  }
  
  /* Note: Do not forget to add new entries to the Makefile as well. */
  
  #define OFFSET(x) offsetof(FFRawVideoDemuxerContext, x)
  #define DEC AV_OPT_FLAG_DECODING_PARAM
  const AVOption ff_rawvideo_options[] = {
      { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, 0, DEC},
      { NULL },
  };
  
  #if CONFIG_DATA_DEMUXER
  AVInputFormat ff_data_demuxer = {
      .name           = "data",
      .long_name      = NULL_IF_CONFIG_SMALL("raw data"),
      .read_header    = ff_raw_data_read_header,
      .read_packet    = ff_raw_read_partial_packet,
      .raw_codec_id   = AV_CODEC_ID_NONE,
      .flags          = AVFMT_NOTIMESTAMPS,
  };
  #endif
  
  #if CONFIG_MJPEG_DEMUXER
  static int mjpeg_probe(AVProbeData *p)
  {
      int i;
      int state = -1;
      int nb_invalid = 0;
      int nb_frames = 0;
  
      for (i=0; i<p->buf_size-2; i++) {
          int c;
          if (p->buf[i] != 0xFF)
              continue;
          c = p->buf[i+1];
          switch (c) {
          case 0xD8:
              state = 0xD8;
              break;
          case 0xC0:
          case 0xC1:
          case 0xC2:
          case 0xC3:
          case 0xC5:
          case 0xC6:
          case 0xC7:
          case 0xF7:
              if (state == 0xD8) {
                  state = 0xC0;
              } else
                  nb_invalid++;
              break;
          case 0xDA:
              if (state == 0xC0) {
                  state = 0xDA;
              } else
                  nb_invalid++;
              break;
          case 0xD9:
              if (state == 0xDA) {
                  state = 0xD9;
                  nb_frames++;
              } else
                  nb_invalid++;
              break;
          default:
              if (  (c >= 0x02 && c <= 0xBF)
                  || c == 0xC8) {
                  nb_invalid++;
              }
          }
      }
  
      if (nb_invalid*4 + 1 < nb_frames) {
          static const char ct_jpeg[] = "\r\nContent-Type: image/jpeg\r\n";
          int i;
  
          for (i=0; i<FFMIN(p->buf_size - (int)sizeof(ct_jpeg), 100); i++)
              if (!memcmp(p->buf + i, ct_jpeg, sizeof(ct_jpeg) - 1))
                  return AVPROBE_SCORE_EXTENSION;
  
          if (nb_invalid == 0 && nb_frames > 2)
              return AVPROBE_SCORE_EXTENSION / 2;
          return AVPROBE_SCORE_EXTENSION / 4;
      }
  
      return 0;
  }
  
  FF_DEF_RAWVIDEO_DEMUXER2(mjpeg, "raw MJPEG video", mjpeg_probe, "mjpg,mjpeg,mpo", AV_CODEC_ID_MJPEG, AVFMT_GENERIC_INDEX|AVFMT_NOTIMESTAMPS)
  #endif
  