PeerStreamer

/*

 * Bitmap Brothers JV demuxer

 * Copyright (c) 2005, 2011 Peter Ross <pross@xvid.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

 */

/**

 * @file

 * Bitmap Brothers JV demuxer

 * @author Peter Ross <pross@xvid.org>

 */

#include "libavutil/intreadwrite.h"

#include "avformat.h"

#define JV_PREAMBLE_SIZE 5

typedef struct {

    int audio_size;    /** audio packet size (bytes) */

    int video_size;    /** video packet size (bytes) */

    int palette_size;  /** palette size (bytes) */

    int video_type;    /** per-frame video compression type */

} JVFrame;

typedef struct {

    JVFrame *frames;

    enum {

        JV_AUDIO = 0,

        JV_VIDEO,

        JV_PADDING

    } state;

    int64_t pts;

} JVDemuxContext;

#define MAGIC " Compression by John M Phillips Copyright (C) 1995 The Bitmap Brothers Ltd."

static int read_probe(AVProbeData *pd)

{

    if (pd->buf[0] == 'J' && pd->buf[1] == 'V' &&

        !memcmp(pd->buf + 4, MAGIC, FFMIN(strlen(MAGIC), pd->buf_size - 4)))

        return AVPROBE_SCORE_MAX;

    return 0;

}

static int read_header(AVFormatContext *s,

                       AVFormatParameters *ap)

{

    JVDemuxContext *jv = s->priv_data;

    AVIOContext *pb = s->pb;

    AVStream *vst, *ast;

    int64_t audio_pts = 0;

    int64_t offset;

    int i;

    avio_skip(pb, 80);

    ast = av_new_stream(s, 0);

    vst = av_new_stream(s, 1);

    if (!ast || !vst)

        return AVERROR(ENOMEM);

    vst->codec->codec_type  = CODEC_TYPE_VIDEO;

    vst->codec->codec_id    = CODEC_ID_JV;

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

    vst->codec->width       = avio_rl16(pb);

    vst->codec->height      = avio_rl16(pb);

    vst->nb_frames          =

    ast->nb_index_entries   = avio_rl16(pb);

    av_set_pts_info(vst, 64, avio_rl16(pb), 1000);

    avio_skip(pb, 4);

    ast->codec->codec_type  = CODEC_TYPE_AUDIO;

    ast->codec->codec_id    = CODEC_ID_PCM_U8;

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

    ast->codec->sample_rate = avio_rl16(pb);

    ast->codec->channels    = 1;

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

    avio_skip(pb, 10);

    ast->index_entries = av_malloc(ast->nb_index_entries * sizeof(*ast->index_entries));

    if (!ast->index_entries)

        return AVERROR(ENOMEM);

    jv->frames = av_malloc(ast->nb_index_entries * sizeof(JVFrame));

    if (!jv->frames)

        return AVERROR(ENOMEM);

    offset = 0x68 + ast->nb_index_entries * 16;

    for(i = 0; i < ast->nb_index_entries; i++) {

        AVIndexEntry *e   = ast->index_entries + i;

        JVFrame      *jvf = jv->frames + i;

        /* total frame size including audio, video, palette data and padding */

        e->size         = avio_rl32(pb);

        e->timestamp    = i;

        e->pos          = offset;

        offset         += e->size;

        jvf->audio_size = avio_rl32(pb);

        jvf->video_size = avio_rl32(pb);

        jvf->palette_size = avio_r8(pb) ? 768 : 0;

        jvf->video_size = FFMIN(FFMAX(jvf->video_size, 0),

                                INT_MAX - JV_PREAMBLE_SIZE - jvf->palette_size);

        if (avio_r8(pb))

             av_log(s, AV_LOG_WARNING, "unsupported audio codec\n");

        jvf->video_type = avio_r8(pb);

        avio_skip(pb, 1);

        e->timestamp = jvf->audio_size ? audio_pts : AV_NOPTS_VALUE;

        audio_pts += jvf->audio_size;

        e->flags = jvf->video_type != 1 ? AVINDEX_KEYFRAME : 0;

    }

    jv->state = JV_AUDIO;

    return 0;

}

static int read_packet(AVFormatContext *s, AVPacket *pkt)

{

    JVDemuxContext *jv = s->priv_data;

    AVIOContext *pb = s->pb;

    AVStream *ast = s->streams[0];

    while (!url_feof(s->pb) && jv->pts < ast->nb_index_entries) {

        const AVIndexEntry *e   = ast->index_entries + jv->pts;

        const JVFrame      *jvf = jv->frames + jv->pts;

        switch(jv->state) {

        case JV_AUDIO:

            jv->state++;

            if (jvf->audio_size ) {

                if (av_get_packet(s->pb, pkt, jvf->audio_size) < 0)

                    return AVERROR(ENOMEM);

                pkt->stream_index = 0;

                pkt->pts          = e->timestamp;

                pkt->flags       |= PKT_FLAG_KEY;

                return 0;

            }

        case JV_VIDEO:

            jv->state++;

            if (jvf->video_size || jvf->palette_size) {

                int size = jvf->video_size + jvf->palette_size;

                if (av_new_packet(pkt, size + JV_PREAMBLE_SIZE))

                    return AVERROR(ENOMEM);

                AV_WL32(pkt->data, jvf->video_size);

                pkt->data[4]      = jvf->video_type;

                if (avio_read(pb, pkt->data + JV_PREAMBLE_SIZE, size) < 0)

                    return AVERROR(EIO);

                pkt->size         = size + JV_PREAMBLE_SIZE;

                pkt->stream_index = 1;

                pkt->pts          = jv->pts;

                if (jvf->video_type != 1)

                    pkt->flags |= PKT_FLAG_KEY;

                return 0;

            }

        case JV_PADDING:

            avio_skip(pb, FFMAX(e->size - jvf->audio_size - jvf->video_size

                                        - jvf->palette_size, 0));

            jv->state = JV_AUDIO;

            jv->pts++;

        }

    }

    return AVERROR(EIO);

}

static int read_seek(AVFormatContext *s, int stream_index,

                     int64_t ts, int flags)

{

    JVDemuxContext *jv = s->priv_data;

    AVStream *ast = s->streams[0];

    int i;

    if (flags & (AVSEEK_FLAG_BYTE|AVSEEK_FLAG_FRAME))

        return AVERROR_NOTSUPP;

    switch(stream_index) {

    case 0:

        i = av_index_search_timestamp(ast, ts, flags);

        break;

    case 1:

        i = ts;

        break;

    default:

        return 0;

    }

    if (i < 0 || i >= ast->nb_index_entries)

        return 0;

    jv->state = JV_AUDIO;

    jv->pts   = i;

    avio_seek(s->pb, ast->index_entries[i].pos, SEEK_SET);

    return 0;

}

AVInputFormat ff_jv_demuxer = {

    .name           = "jv",

    .long_name      = NULL_IF_CONFIG_SMALL("Bitmap Brothers JV"),

    .priv_data_size = sizeof(JVDemuxContext),

    .read_probe     = read_probe,

    .read_header    = read_header,

    .read_packet    = read_packet,

    .read_seek      = read_seek,

};