summaryrefslogtreecommitdiff
path: root/libavformat/bfi.c
blob: 99371bd4c091355bbfa8953e7b40b2c751a3ceca (plain)
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
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
/*
 * Brute Force & Ignorance (BFI) demuxer
 * Copyright (c) 2008 Sisir Koppaka
 *
 * 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
 * @brief Brute Force & Ignorance (.bfi) file demuxer
 * @author Sisir Koppaka ( sisir.koppaka at gmail dot com )
 * @see http://wiki.multimedia.cx/index.php?title=BFI
 */

#include "libavutil/channel_layout.h"
#include "libavutil/intreadwrite.h"
#include "avformat.h"
#include "internal.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)
{
    BFIContext *bfi = s->priv_data;
    AVIOContext *pb = s->pb;
    AVStream *vstream;
    AVStream *astream;
    int fps, chunk_header;

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

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

    /* Set the total number of frames. */
    avio_skip(pb, 8);
    chunk_header           = avio_rl32(pb);
    bfi->nframes           = avio_rl32(pb);
    avio_rl32(pb);
    avio_rl32(pb);
    avio_rl32(pb);
    fps                    = avio_rl32(pb);
    avio_skip(pb, 12);
    vstream->codecpar->width  = avio_rl32(pb);
    vstream->codecpar->height = avio_rl32(pb);

    /*Load the palette to extradata */
    avio_skip(pb, 8);
    vstream->codecpar->extradata      = av_malloc(768);
    vstream->codecpar->extradata_size = 768;
    avio_read(pb, vstream->codecpar->extradata,
              vstream->codecpar->extradata_size);

    astream->codecpar->sample_rate = avio_rl32(pb);

    /* Set up the video codec... */
    avpriv_set_pts_info(vstream, 32, 1, fps);
    vstream->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
    vstream->codecpar->codec_id   = AV_CODEC_ID_BFI;
    vstream->codecpar->format     = AV_PIX_FMT_PAL8;

    /* Set up the audio codec now... */
    astream->codecpar->codec_type      = AVMEDIA_TYPE_AUDIO;
    astream->codecpar->codec_id        = AV_CODEC_ID_PCM_U8;
    astream->codecpar->channels        = 1;
    astream->codecpar->channel_layout  = AV_CH_LAYOUT_MONO;
    astream->codecpar->bits_per_coded_sample = 8;
    astream->codecpar->bit_rate        =
        astream->codecpar->sample_rate * astream->codecpar->bits_per_coded_sample;
    avio_seek(pb, chunk_header - 3, SEEK_SET);
    avpriv_set_pts_info(astream, 64, 1, astream->codecpar->sample_rate);
    return 0;
}


static int bfi_read_packet(AVFormatContext * s, AVPacket * pkt)
{
    BFIContext *bfi = s->priv_data;
    AVIOContext *pb = s->pb;
    int ret, audio_offset, video_offset, chunk_size, audio_size = 0;
    if (bfi->nframes == 0 || pb->eof_reached) {
        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 (pb->eof_reached)
                return AVERROR(EIO);
            state = 256*state + avio_r8(pb);
        }
        /* Now that the chunk's location is confirmed, we proceed... */
        chunk_size      = avio_rl32(pb);
        avio_rl32(pb);
        audio_offset    = avio_rl32(pb);
        avio_rl32(pb);
        video_offset    = avio_rl32(pb);
        audio_size      = video_offset - audio_offset;
        bfi->video_size = chunk_size - video_offset;
        if (audio_size < 0 || bfi->video_size < 0) {
            av_log(s, AV_LOG_ERROR, "Invalid audio/video offsets or chunk size\n");
            return AVERROR_INVALIDDATA;
        }

        //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 if (bfi->video_size > 0) {

        //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--;
    } else {
        /* Empty video packet */
        ret = AVERROR(EAGAIN);
    }

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

AVInputFormat ff_bfi_demuxer = {
    .name           = "bfi",
    .long_name      = NULL_IF_CONFIG_SMALL("Brute Force & Ignorance"),
    .priv_data_size = sizeof(BFIContext),
    .read_probe     = bfi_probe,
    .read_header    = bfi_read_header,
    .read_packet    = bfi_read_packet,
};