PeerStreamer

/*

 * Bink demuxer

 * Copyright (c) 2008-2010 Peter Ross (pross@xvid.org)

 * Copyright (c) 2009 Daniel Verkamp (daniel@drv.nu)

 *

 * This file is part of Libav.

 *

 * Libav 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.

 *

 * Libav 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 Libav; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

/**

 * @file

 * Bink demuxer

 *

 * Technical details here:

 *  http://wiki.multimedia.cx/index.php?title=Bink_Container

 */

#include "libavutil/intreadwrite.h"

#include "avformat.h"

enum BinkAudFlags {

    BINK_AUD_16BITS = 0x4000, ///< prefer 16-bit output

    BINK_AUD_STEREO = 0x2000,

    BINK_AUD_USEDCT = 0x1000,

};

#define BINK_EXTRADATA_SIZE     1

#define BINK_MAX_AUDIO_TRACKS   256

#define BINK_MAX_WIDTH          7680

#define BINK_MAX_HEIGHT         4800

typedef struct {

    uint32_t file_size;

    uint32_t num_audio_tracks;

    int current_track;      ///< audio track to return in next packet

    int64_t video_pts;

    int64_t audio_pts[BINK_MAX_AUDIO_TRACKS];

    uint32_t remain_packet_size;

} BinkDemuxContext;

static int probe(AVProbeData *p)

{

    const uint8_t *b = p->buf;

    if ( b[0] == 'B' && b[1] == 'I' && b[2] == 'K' &&

        (b[3] == 'b' || b[3] == 'f' || b[3] == 'g' || b[3] == 'h' || b[3] == 'i') &&

        AV_RL32(b+8) > 0 &&  // num_frames

        AV_RL32(b+20) > 0 && AV_RL32(b+20) <= BINK_MAX_WIDTH &&

        AV_RL32(b+24) > 0 && AV_RL32(b+24) <= BINK_MAX_HEIGHT &&

        AV_RL32(b+28) > 0 && AV_RL32(b+32) > 0)  // fps num,den

        return AVPROBE_SCORE_MAX;

    return 0;

}

static int read_header(AVFormatContext *s, AVFormatParameters *ap)

{

    BinkDemuxContext *bink = s->priv_data;

    AVIOContext *pb = s->pb;

    uint32_t fps_num, fps_den;

    AVStream *vst, *ast;

    unsigned int i;

    uint32_t pos, next_pos;

    uint16_t flags;

    int keyframe;

    vst = av_new_stream(s, 0);

    if (!vst)

        return AVERROR(ENOMEM);

    vst->codec->codec_tag = avio_rl32(pb);

    bink->file_size = avio_rl32(pb) + 8;

    vst->duration   = avio_rl32(pb);

    if (vst->duration > 1000000) {

        av_log(s, AV_LOG_ERROR, "invalid header: more than 1000000 frames\n");

        return AVERROR(EIO);

    }

    if (avio_rl32(pb) > bink->file_size) {

        av_log(s, AV_LOG_ERROR,

               "invalid header: largest frame size greater than file size\n");

        return AVERROR(EIO);

    }

    avio_skip(pb, 4);

    vst->codec->width  = avio_rl32(pb);

    vst->codec->height = avio_rl32(pb);

    fps_num = avio_rl32(pb);

    fps_den = avio_rl32(pb);

    if (fps_num == 0 || fps_den == 0) {

        av_log(s, AV_LOG_ERROR, "invalid header: invalid fps (%d/%d)\n", fps_num, fps_den);

        return AVERROR(EIO);

    }

    av_set_pts_info(vst, 64, fps_den, fps_num);

    vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;

    vst->codec->codec_id   = CODEC_ID_BINKVIDEO;

    vst->codec->extradata  = av_mallocz(4 + FF_INPUT_BUFFER_PADDING_SIZE);

    vst->codec->extradata_size = 4;

    avio_read(pb, vst->codec->extradata, 4);

    bink->num_audio_tracks = avio_rl32(pb);

    if (bink->num_audio_tracks > BINK_MAX_AUDIO_TRACKS) {

        av_log(s, AV_LOG_ERROR,

               "invalid header: more than "AV_STRINGIFY(BINK_MAX_AUDIO_TRACKS)" audio tracks (%d)\n",

               bink->num_audio_tracks);

        return AVERROR(EIO);

    }

    if (bink->num_audio_tracks) {

        avio_skip(pb, 4 * bink->num_audio_tracks);

        for (i = 0; i < bink->num_audio_tracks; i++) {

            ast = av_new_stream(s, 1);

            if (!ast)

                return AVERROR(ENOMEM);

            ast->codec->codec_type  = AVMEDIA_TYPE_AUDIO;

            ast->codec->codec_tag   = vst->codec->codec_tag;

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

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

            flags = avio_rl16(pb);

            ast->codec->codec_id = flags & BINK_AUD_USEDCT ?

                                   CODEC_ID_BINKAUDIO_DCT : CODEC_ID_BINKAUDIO_RDFT;

            ast->codec->channels = flags & BINK_AUD_STEREO ? 2 : 1;

        }

        for (i = 0; i < bink->num_audio_tracks; i++)

            s->streams[i + 1]->id = avio_rl32(pb);

    }

    /* frame index table */

    next_pos = avio_rl32(pb);

    for (i = 0; i < vst->duration; i++) {

        pos = next_pos;

        if (i == vst->duration - 1) {

            next_pos = bink->file_size;

            keyframe = 0;

        } else {

            next_pos = avio_rl32(pb);

            keyframe = pos & 1;

        }

        pos &= ~1;

        next_pos &= ~1;

        if (next_pos <= pos) {

            av_log(s, AV_LOG_ERROR, "invalid frame index table\n");

            return AVERROR(EIO);

        }

        av_add_index_entry(vst, pos, i, next_pos - pos, 0,

                           keyframe ? AVINDEX_KEYFRAME : 0);

    }

    avio_skip(pb, 4);

    bink->current_track = -1;

    return 0;

}

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

{

    BinkDemuxContext *bink = s->priv_data;

    AVIOContext *pb = s->pb;

    int ret;

    if (bink->current_track < 0) {

        int index_entry;

        AVStream *st = s->streams[0]; // stream 0 is video stream with index

        if (bink->video_pts >= st->duration)

            return AVERROR(EIO);

        index_entry = av_index_search_timestamp(st, bink->video_pts,

                                                AVSEEK_FLAG_ANY);

        if (index_entry < 0) {

            av_log(s, AV_LOG_ERROR,

                   "could not find index entry for frame %"PRId64"\n",

                   bink->video_pts);

            return AVERROR(EIO);

        }

        bink->remain_packet_size = st->index_entries[index_entry].size;

        bink->current_track = 0;

    }

    while (bink->current_track < bink->num_audio_tracks) {

        uint32_t audio_size = avio_rl32(pb);

        if (audio_size > bink->remain_packet_size - 4) {

            av_log(s, AV_LOG_ERROR,

                   "frame %"PRId64": audio size in header (%u) > size of packet left (%u)\n",

                   bink->video_pts, audio_size, bink->remain_packet_size);

            return AVERROR(EIO);

        }

        bink->remain_packet_size -= 4 + audio_size;

        bink->current_track++;

        if (audio_size >= 4) {

            /* get one audio packet per track */

            if ((ret = av_get_packet(pb, pkt, audio_size)) < 0)

                return ret;

            pkt->stream_index = bink->current_track;

            pkt->pts = bink->audio_pts[bink->current_track - 1];

            /* Each audio packet reports the number of decompressed samples

               (in bytes). We use this value to calcuate the audio PTS */

            if (pkt->size >= 4)

                bink->audio_pts[bink->current_track -1] +=

                    AV_RL32(pkt->data) / (2 * s->streams[bink->current_track]->codec->channels);

            return 0;

        } else {

            avio_skip(pb, audio_size);

        }

    }

    /* get video packet */

    if ((ret = av_get_packet(pb, pkt, bink->remain_packet_size)) < 0)

        return ret;

    pkt->stream_index = 0;

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

    pkt->flags |= AV_PKT_FLAG_KEY;

    /* -1 instructs the next call to read_packet() to read the next frame */

    bink->current_track = -1;

    return 0;

}

static int read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)

{

    BinkDemuxContext *bink = s->priv_data;

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

    if (!s->pb->seekable)

        return -1;

    /* seek to the first frame */

    avio_seek(s->pb, vst->index_entries[0].pos, SEEK_SET);

    bink->video_pts = 0;

    memset(bink->audio_pts, 0, sizeof(bink->audio_pts));

    bink->current_track = -1;

    return 0;

}

AVInputFormat ff_bink_demuxer = {

    "bink",

    NULL_IF_CONFIG_SMALL("Bink"),

    sizeof(BinkDemuxContext),

    probe,

    read_header,

    read_packet,

    NULL,

    read_seek,

};