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
177
178
179
180
181
182
183
184
185
186
|
/*
* 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
* @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 "demux.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(const 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 ret, 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);
if (chunk_header < 3)
return AVERROR_INVALIDDATA;
bfi->nframes = avio_rl32(pb);
if (bfi->nframes < 0)
return AVERROR_INVALIDDATA;
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);
ret = ff_get_extradata(s, vstream->codecpar, pb, 768);
if (ret < 0)
return ret;
astream->codecpar->sample_rate = avio_rl32(pb);
if (astream->codecpar->sample_rate <= 0) {
av_log(s, AV_LOG_ERROR, "Invalid sample rate %d\n", astream->codecpar->sample_rate);
return AVERROR_INVALIDDATA;
}
/* 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;
vstream->nb_frames =
vstream->duration = bfi->nframes;
/* Set up the audio codec now... */
astream->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
astream->codecpar->codec_id = AV_CODEC_ID_PCM_U8;
astream->codecpar->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
astream->codecpar->bits_per_coded_sample = 8;
astream->codecpar->bit_rate =
(int64_t)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 || avio_feof(pb)) {
return AVERROR_EOF;
}
/* 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 (avio_feof(pb))
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;
}
const 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,
};
|
