PeerStreamer

/*

 * THP Demuxer

 * Copyright (c) 2007 Marco Gerards.

 *

 * 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 "allformats.h"

typedef struct ThpDemuxContext {

    int              version;

    int              first_frame;

    int              first_framesz;

    int              last_frame;

    int              compoff;

    int              framecnt;

    AVRational       fps;

    int              frame;

    int              next_frame;

    int              next_framesz;

    int              video_stream_index;

    int              audio_stream_index;

    int              compcount;

    unsigned char    components[16];

    AVStream*        vst;

    int              has_audio;

    int              audiosize;

} ThpDemuxContext;

static int thp_probe(AVProbeData *p)

{

    /* check file header */

    if (p->buf_size < 4)

        return 0;

    if (AV_RL32(p->buf) == MKTAG('T', 'H', 'P', '\0'))

        return AVPROBE_SCORE_MAX;

    else

        return 0;

}

static int thp_read_header(AVFormatContext *s,

                           AVFormatParameters *ap)

{

  ThpDemuxContext *thp = s->priv_data;

  AVStream *st;

  ByteIOContext *pb = &s->pb;

  int i;

  /* Read the file header.  */

                         get_be32(pb); /* Skip Magic.  */

  thp->version         = get_be32(pb);

                         get_be32(pb); /* Max buf size.  */

                         get_be32(pb); /* Max samples.  */

  thp->fps             = av_d2q(av_int2flt(get_be32(pb)), INT_MAX);

  thp->framecnt        = get_be32(pb);

  thp->first_framesz   = get_be32(pb);

                         get_be32(pb); /* Data size.  */

  thp->compoff         = get_be32(pb);

                         get_be32(pb); /* offsetDataOffset.  */

  thp->first_frame     = get_be32(pb);

  thp->last_frame      = get_be32(pb);

  thp->next_framesz    = thp->first_framesz;

  thp->next_frame      = thp->first_frame;

  /* Read the component structure.  */

  url_fseek (pb, thp->compoff, SEEK_SET);

  thp->compcount       = get_be32(pb);

  /* Read the list of component types.  */

  get_buffer(pb, thp->components, 16);

  for (i = 0; i < thp->compcount; i++) {

      if (thp->components[i] == 0) {

          if (thp->vst != 0)

             break;

          /* Video component.  */

          st = av_new_stream(s, 0);

          if (!st)

             return AVERROR_NOMEM;

          /* The denominator and numerator are switched because 1/fps

             is required.  */

          av_set_pts_info(st, 64, thp->fps.den, thp->fps.num);

          st->codec->codec_type = CODEC_TYPE_VIDEO;

          st->codec->codec_id = CODEC_ID_THP;

          st->codec->codec_tag = 0;  /* no fourcc */

          st->codec->width = get_be32(pb);

          st->codec->height = get_be32(pb);

          st->codec->sample_rate = av_q2d(thp->fps);

          thp->vst = st;

          thp->video_stream_index = st->index;

          if (thp->version == 0x11000)

             get_be32(pb); /* Unknown.  */

        }

      else if (thp->components[i] == 1) {

          if (thp->has_audio != 0)

              break;

          /* Audio component.  */

          st = av_new_stream(s, 0);

          if (!st)

              return AVERROR_NOMEM;

          st->codec->codec_type = CODEC_TYPE_AUDIO;

          st->codec->codec_id = CODEC_ID_ADPCM_THP;

          st->codec->codec_tag = 0;  /* no fourcc */

          st->codec->channels    = get_be32(pb); /* numChannels.  */

          st->codec->sample_rate = get_be32(pb); /* Frequency.  */

          av_set_pts_info(st, 64, 1, st->codec->sample_rate);

          thp->audio_stream_index = st->index;

          thp->has_audio = 1;

      }

    }

  return 0;

}

static int thp_read_packet(AVFormatContext *s,

                            AVPacket *pkt)

{

    ThpDemuxContext *thp = s->priv_data;

    ByteIOContext *pb = &s->pb;

    int size;

    int ret;

    if (thp->audiosize == 0) {

    /* Terminate when last frame is reached.  */

    if (thp->frame >= thp->framecnt)

       return AVERROR_IO;

    url_fseek(pb, thp->next_frame, SEEK_SET);

    /* Locate the next frame and read out its size.  */

    thp->next_frame += thp->next_framesz;

    thp->next_framesz = get_be32(pb);

                        get_be32(pb); /* Previous total size.  */

    size              = get_be32(pb); /* Total size of this frame.  */

    /* Store the audiosize so the next time this function is called,

       the audio can be read.  */

    if (thp->has_audio)

        thp->audiosize = get_be32(pb); /* Audio size.  */

    else

        thp->frame++;

    ret = av_get_packet(pb, pkt, size);

    if (ret != size) {

       av_free_packet(pkt);

       return AVERROR_IO;

    }

    pkt->stream_index = thp->video_stream_index;

    }

    else {

        ret = av_get_packet(pb, pkt, thp->audiosize);

        if (ret != thp->audiosize) {

            av_free_packet(pkt);

            return AVERROR_IO;

        }

        pkt->stream_index = thp->audio_stream_index;

        thp->audiosize = 0;

        thp->frame++;

    }

    return 0;

}

AVInputFormat thp_demuxer = {

    "thp",

    "THP",

    sizeof(ThpDemuxContext),

    thp_probe,

    thp_read_header,

    thp_read_packet

};