PeerStreamer

/*

 * id RoQ (.roq) File Demuxer

 * Copyright (c) 2003 The ffmpeg Project

 *

 * 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

 */

/**

 * @file

 * id RoQ format file demuxer

 * by Mike Melanson (melanson@pcisys.net)

 * for more information on the .roq file format, visit:

 *   http://www.csse.monash.edu.au/~timf/

 */

#include "libavutil/intreadwrite.h"

#include "avformat.h"

#define RoQ_MAGIC_NUMBER 0x1084

#define RoQ_CHUNK_PREAMBLE_SIZE 8

#define RoQ_AUDIO_SAMPLE_RATE 22050

#define RoQ_CHUNKS_TO_SCAN 30

#define RoQ_INFO           0x1001

#define RoQ_QUAD_CODEBOOK  0x1002

#define RoQ_QUAD_VQ        0x1011

#define RoQ_SOUND_MONO     0x1020

#define RoQ_SOUND_STEREO   0x1021

typedef struct RoqDemuxContext {

    int width;

    int height;

    int audio_channels;

    int video_stream_index;

    int audio_stream_index;

    int64_t video_pts;

    unsigned int audio_frame_count;

} RoqDemuxContext;

static int roq_probe(AVProbeData *p)

{

    if ((AV_RL16(&p->buf[0]) != RoQ_MAGIC_NUMBER) ||

        (AV_RL32(&p->buf[2]) != 0xFFFFFFFF))

        return 0;

    return AVPROBE_SCORE_MAX;

}

static int roq_read_header(AVFormatContext *s,

                           AVFormatParameters *ap)

{

    RoqDemuxContext *roq = s->priv_data;

    AVIOContext *pb = s->pb;

    int framerate;

    AVStream *st;

    unsigned char preamble[RoQ_CHUNK_PREAMBLE_SIZE];

    /* get the main header */

    if (avio_read(pb, preamble, RoQ_CHUNK_PREAMBLE_SIZE) !=

        RoQ_CHUNK_PREAMBLE_SIZE)

        return AVERROR(EIO);

    framerate = AV_RL16(&preamble[6]);

    /* init private context parameters */

    roq->width = roq->height = roq->audio_channels = roq->video_pts =

    roq->audio_frame_count = 0;

    roq->audio_stream_index = -1;

    st = av_new_stream(s, 0);

    if (!st)

        return AVERROR(ENOMEM);

    av_set_pts_info(st, 63, 1, framerate);

    roq->video_stream_index = st->index;

    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

    st->codec->codec_id = CODEC_ID_ROQ;

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

    return 0;

}

static int roq_read_packet(AVFormatContext *s,

                           AVPacket *pkt)

{

    RoqDemuxContext *roq = s->priv_data;

    AVIOContext *pb = s->pb;

    int ret = 0;

    unsigned int chunk_size;

    unsigned int chunk_type;

    unsigned int codebook_size;

    unsigned char preamble[RoQ_CHUNK_PREAMBLE_SIZE];

    int packet_read = 0;

    int64_t codebook_offset;

    while (!packet_read) {

        if (s->pb->eof_reached)

            return AVERROR(EIO);

        /* get the next chunk preamble */

        if ((ret = avio_read(pb, preamble, RoQ_CHUNK_PREAMBLE_SIZE)) !=

            RoQ_CHUNK_PREAMBLE_SIZE)

            return AVERROR(EIO);

        chunk_type = AV_RL16(&preamble[0]);

        chunk_size = AV_RL32(&preamble[2]);

        if(chunk_size > INT_MAX)

            return AVERROR_INVALIDDATA;

        switch (chunk_type) {

        case RoQ_INFO:

            if (!roq->width || !roq->height) {

                AVStream *st = s->streams[roq->video_stream_index];

                if (avio_read(pb, preamble, RoQ_CHUNK_PREAMBLE_SIZE) != RoQ_CHUNK_PREAMBLE_SIZE)

                    return AVERROR(EIO);

                st->codec->width  = roq->width  = AV_RL16(preamble);

                st->codec->height = roq->height = AV_RL16(preamble + 2);

                break;

            }

            /* don't care about this chunk anymore */

            avio_seek(pb, RoQ_CHUNK_PREAMBLE_SIZE, SEEK_CUR);

            break;

        case RoQ_QUAD_CODEBOOK:

            /* packet needs to contain both this codebook and next VQ chunk */

            codebook_offset = avio_tell(pb) - RoQ_CHUNK_PREAMBLE_SIZE;

            codebook_size = chunk_size;

            avio_seek(pb, codebook_size, SEEK_CUR);

            if (avio_read(pb, preamble, RoQ_CHUNK_PREAMBLE_SIZE) !=

                RoQ_CHUNK_PREAMBLE_SIZE)

                return AVERROR(EIO);

            chunk_size = AV_RL32(&preamble[2]) + RoQ_CHUNK_PREAMBLE_SIZE * 2 +

                codebook_size;

            /* rewind */

            avio_seek(pb, codebook_offset, SEEK_SET);

            /* load up the packet */

            ret= av_get_packet(pb, pkt, chunk_size);

            if (ret != chunk_size)

                return AVERROR(EIO);

            pkt->stream_index = roq->video_stream_index;

            pkt->pts = roq->video_pts++;

            packet_read = 1;

            break;

        case RoQ_SOUND_MONO:

        case RoQ_SOUND_STEREO:

            if (roq->audio_stream_index == -1) {

                AVStream *st = av_new_stream(s, 1);

                if (!st)

                    return AVERROR(ENOMEM);

                av_set_pts_info(st, 32, 1, RoQ_AUDIO_SAMPLE_RATE);

                roq->audio_stream_index = st->index;

                st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

                st->codec->codec_id = CODEC_ID_ROQ_DPCM;

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

                st->codec->channels = roq->audio_channels = chunk_type == RoQ_SOUND_STEREO ? 2 : 1;

                st->codec->sample_rate = RoQ_AUDIO_SAMPLE_RATE;

                st->codec->bits_per_coded_sample = 16;

                st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *

                    st->codec->bits_per_coded_sample;

                st->codec->block_align = st->codec->channels * st->codec->bits_per_coded_sample;

            }

        case RoQ_QUAD_VQ:

            /* load up the packet */

            if (av_new_packet(pkt, chunk_size + RoQ_CHUNK_PREAMBLE_SIZE))

                return AVERROR(EIO);

            /* copy over preamble */

            memcpy(pkt->data, preamble, RoQ_CHUNK_PREAMBLE_SIZE);

            if (chunk_type == RoQ_QUAD_VQ) {

                pkt->stream_index = roq->video_stream_index;

                pkt->pts = roq->video_pts++;

            } else {

                pkt->stream_index = roq->audio_stream_index;

                pkt->pts = roq->audio_frame_count;

                roq->audio_frame_count += (chunk_size / roq->audio_channels);

            }

            pkt->pos= avio_tell(pb);

            ret = avio_read(pb, pkt->data + RoQ_CHUNK_PREAMBLE_SIZE,

                chunk_size);

            if (ret != chunk_size)

                ret = AVERROR(EIO);

            packet_read = 1;

            break;

        default:

            av_log(s, AV_LOG_ERROR, "  unknown RoQ chunk (%04X)\n", chunk_type);

            return AVERROR_INVALIDDATA;

            break;

        }

    }

    return ret;

}

AVInputFormat ff_roq_demuxer = {

    "RoQ",

    NULL_IF_CONFIG_SMALL("id RoQ format"),

    sizeof(RoqDemuxContext),

    roq_probe,

    roq_read_header,

    roq_read_packet,

};