1/*
2 * Brute Force & Ignorance (BFI) demuxer
3 * Copyright (c) 2008 Sisir Koppaka
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file libavformat/bfi.c
24 * @brief Brute Force & Ignorance (.bfi) file demuxer
25 * @author Sisir Koppaka ( sisir.koppaka at gmail dot com )
26 * @sa http://wiki.multimedia.cx/index.php?title=BFI
27 */
28
29#include "libavutil/intreadwrite.h"
30#include "avformat.h"
31
32typedef struct BFIContext {
33    int nframes;
34    int audio_frame;
35    int video_frame;
36    int video_size;
37    int avflag;
38} BFIContext;
39
40static int bfi_probe(AVProbeData * p)
41{
42    /* Check file header */
43    if (AV_RL32(p->buf) == MKTAG('B', 'F', '&', 'I'))
44        return AVPROBE_SCORE_MAX;
45    else
46        return 0;
47}
48
49static int bfi_read_header(AVFormatContext * s, AVFormatParameters * ap)
50{
51    BFIContext *bfi = s->priv_data;
52    ByteIOContext *pb = s->pb;
53    AVStream *vstream;
54    AVStream *astream;
55    int fps, chunk_header;
56
57    /* Initialize the video codec... */
58    vstream = av_new_stream(s, 0);
59    if (!vstream)
60        return AVERROR(ENOMEM);
61
62    /* Initialize the audio codec... */
63    astream = av_new_stream(s, 0);
64    if (!astream)
65        return AVERROR(ENOMEM);
66
67    /* Set the total number of frames. */
68    url_fskip(pb, 8);
69    chunk_header           = get_le32(pb);
70    bfi->nframes           = get_le32(pb);
71    get_le32(pb);
72    get_le32(pb);
73    get_le32(pb);
74    fps                    = get_le32(pb);
75    url_fskip(pb, 12);
76    vstream->codec->width  = get_le32(pb);
77    vstream->codec->height = get_le32(pb);
78
79    /*Load the palette to extradata */
80    url_fskip(pb, 8);
81    vstream->codec->extradata      = av_malloc(768);
82    vstream->codec->extradata_size = 768;
83    get_buffer(pb, vstream->codec->extradata,
84               vstream->codec->extradata_size);
85
86    astream->codec->sample_rate = get_le32(pb);
87
88    /* Set up the video codec... */
89    av_set_pts_info(vstream, 32, 1, fps);
90    vstream->codec->codec_type = CODEC_TYPE_VIDEO;
91    vstream->codec->codec_id   = CODEC_ID_BFI;
92    vstream->codec->pix_fmt    = PIX_FMT_PAL8;
93
94    /* Set up the audio codec now... */
95    astream->codec->codec_type      = CODEC_TYPE_AUDIO;
96    astream->codec->codec_id        = CODEC_ID_PCM_U8;
97    astream->codec->channels        = 1;
98    astream->codec->bits_per_coded_sample = 8;
99    astream->codec->bit_rate        =
100        astream->codec->sample_rate * astream->codec->bits_per_coded_sample;
101    url_fseek(pb, chunk_header - 3, SEEK_SET);
102    av_set_pts_info(astream, 64, 1, astream->codec->sample_rate);
103    return 0;
104}
105
106
107static int bfi_read_packet(AVFormatContext * s, AVPacket * pkt)
108{
109    BFIContext *bfi = s->priv_data;
110    ByteIOContext *pb = s->pb;
111    int ret, audio_offset, video_offset, chunk_size, audio_size = 0;
112    if (bfi->nframes == 0 || url_feof(pb)) {
113        return AVERROR(EIO);
114    }
115
116    /* If all previous chunks were completely read, then find a new one... */
117    if (!bfi->avflag) {
118        uint32_t state = 0;
119        while(state != MKTAG('S','A','V','I')){
120            if (url_feof(pb))
121                return AVERROR(EIO);
122            state = 256*state + get_byte(pb);
123        }
124        /* Now that the chunk's location is confirmed, we proceed... */
125        chunk_size      = get_le32(pb);
126        get_le32(pb);
127        audio_offset    = get_le32(pb);
128        get_le32(pb);
129        video_offset    = get_le32(pb);
130        audio_size      = video_offset - audio_offset;
131        bfi->video_size = chunk_size - video_offset;
132
133        //Tossing an audio packet at the audio decoder.
134        ret = av_get_packet(pb, pkt, audio_size);
135        if (ret < 0)
136            return ret;
137
138        pkt->pts          = bfi->audio_frame;
139        bfi->audio_frame += ret;
140    }
141
142    else {
143
144        //Tossing a video packet at the video decoder.
145        ret = av_get_packet(pb, pkt, bfi->video_size);
146        if (ret < 0)
147            return ret;
148
149        pkt->pts          = bfi->video_frame;
150        bfi->video_frame += ret / bfi->video_size;
151
152        /* One less frame to read. A cursory decrement. */
153        bfi->nframes--;
154    }
155
156    bfi->avflag       = !bfi->avflag;
157    pkt->stream_index = bfi->avflag;
158    return ret;
159}
160
161AVInputFormat bfi_demuxer = {
162    "bfi",
163    NULL_IF_CONFIG_SMALL("Brute Force & Ignorance"),
164    sizeof(BFIContext),
165    bfi_probe,
166    bfi_read_header,
167    bfi_read_packet,
168};
169