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 "libavutil/intreadwrite.h"

#include "avformat.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 (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(ENOMEM);

            /* 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 = AVMEDIA_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(ENOMEM);

            st->codec->codec_type = AVMEDIA_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(EIO);

        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(EIO);

        }

        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(EIO);

        }

        pkt->stream_index = thp->audio_stream_index;

        thp->audiosize = 0;

        thp->frame++;

    }

    return 0;

}

AVInputFormat thp_demuxer = {

    "thp",

    NULL_IF_CONFIG_SMALL("THP"),

    sizeof(ThpDemuxContext),

    thp_probe,

    thp_read_header,

    thp_read_packet

};