bfi.c 4.88 KB
Newer Older
Sisir Koppaka's avatar
Sisir Koppaka committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161
/*
 * Brute Force & Ignorance (BFI) demuxer
 * Copyright (c) 2008 Sisir Koppaka
 *
 * 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 bfi.c
 * @brief Brute Force & Ignorance (.bfi) file demuxer
 * @author Sisir Koppaka ( sisir.koppaka at gmail dot com )
 * @sa http://wiki.multimedia.cx/index.php?title=BFI
 */

#include "avformat.h"

typedef struct BFIContext {
    int nframes;
    int audio_frame;
    int video_frame;
    int video_size;
    int avflag;
} BFIContext;

static int bfi_probe(AVProbeData * p)
{
    /* Check file header */
    if (AV_RL32(p->buf) == MKTAG('B', 'F', '&', 'I'))
        return AVPROBE_SCORE_MAX;
    else
        return 0;
}

static int bfi_read_header(AVFormatContext * s, AVFormatParameters * ap)
{
    BFIContext *bfi = s->priv_data;
    ByteIOContext *pb = s->pb;
    AVStream *vstream;
    AVStream *astream;
    int fps, chunk_header;

    /* Initialize the video codec... */
    vstream = av_new_stream(s, 0);
    if (!vstream)
        return AVERROR(ENOMEM);

    /* Initialize the audio codec... */
    astream = av_new_stream(s, 0);
    if (!astream)
        return AVERROR(ENOMEM);

    /* Set the total number of frames. */
    url_fskip(pb, 8);
    chunk_header           = get_le32(pb);
    bfi->nframes           = get_le32(pb);
    get_le32(pb);
    get_le32(pb);
    get_le32(pb);
    fps                    = get_le32(pb);
    url_fskip(pb, 12);
    vstream->codec->width  = get_le32(pb);
    vstream->codec->height = get_le32(pb);

    /*Load the palette to extradata */
    url_fskip(pb, 8);
    vstream->codec->extradata      = av_malloc(768);
    vstream->codec->extradata_size = 768;
    get_buffer(pb, vstream->codec->extradata,
               vstream->codec->extradata_size);

    astream->codec->sample_rate = get_le32(pb);

    /* Set up the video codec... */
    av_set_pts_info(vstream, 32, 1, fps);
    vstream->codec->codec_type = CODEC_TYPE_VIDEO;
    vstream->codec->codec_id   = CODEC_ID_BFI;
    vstream->codec->pix_fmt    = PIX_FMT_PAL8;

    /* Set up the audio codec now... */
    astream->codec->codec_type      = CODEC_TYPE_AUDIO;
    astream->codec->codec_id        = CODEC_ID_PCM_U8;
    astream->codec->channels        = 1;
    astream->codec->bits_per_sample = 8;
    astream->codec->bit_rate        =
        astream->codec->sample_rate * astream->codec->bits_per_sample;
    url_fseek(pb, chunk_header - 3, SEEK_SET);
    av_set_pts_info(astream, 64, 1, astream->codec->sample_rate);
    return 0;
}


static int bfi_read_packet(AVFormatContext * s, AVPacket * pkt)
{
    BFIContext *bfi = s->priv_data;
    ByteIOContext *pb = s->pb;
    int ret, audio_offset, video_offset, chunk_size, audio_size = 0;
    if (bfi->nframes == 0 || url_feof(pb)) {
        return AVERROR(EIO);
    }

    /* If all previous chunks were completely read, then find a new one... */
    if (!bfi->avflag) {
        uint32_t state = 0;
        while(state != MKTAG('S','A','V','I')){
            if (url_feof(pb))
                return AVERROR(EIO);
            state = 256*state + get_byte(pb);
        }
        /* Now that the chunk's location is confirmed, we proceed... */
        chunk_size      = get_le32(pb);
        get_le32(pb);
        audio_offset    = get_le32(pb);
        get_le32(pb);
        video_offset    = get_le32(pb);
        audio_size      = video_offset - audio_offset;
        bfi->video_size = chunk_size - video_offset;

        //Tossing an audio packet at the audio decoder.
        ret = av_get_packet(pb, pkt, audio_size);
        if (ret < 0)
            return ret;

        pkt->pts          = bfi->audio_frame;
        bfi->audio_frame += ret;
    }

    else {

        //Tossing a video packet at the video decoder.
        ret = av_get_packet(pb, pkt, bfi->video_size);
        if (ret < 0)
            return ret;

        pkt->pts          = bfi->video_frame;
        bfi->video_frame += ret / bfi->video_size;

        /* One less frame to read. A cursory decrement. */
        bfi->nframes--;
    }

    bfi->avflag       = !bfi->avflag;
    pkt->stream_index = bfi->avflag;
    return ret;
}

AVInputFormat bfi_demuxer = {
    "bfi",
162
    NULL_IF_CONFIG_SMALL("Brute Force & Ignorance"),
Sisir Koppaka's avatar
Sisir Koppaka committed
163 164 165 166 167
    sizeof(BFIContext),
    bfi_probe,
    bfi_read_header,
    bfi_read_packet,
};