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
24 * @brief Brute Force & Ignorance (.bfi) file demuxer
25 * @author Sisir Koppaka ( sisir.koppaka at gmail dot com )
26 * @see http://wiki.multimedia.cx/index.php?title=BFI
27 */
28
29 #include "libavutil/channel_layout.h"
30 #include "libavutil/intreadwrite.h"
31 #include "avformat.h"
32 #include "internal.h"
33
34 typedef struct BFIContext {
35 int nframes;
36 int audio_frame;
37 int video_frame;
38 int video_size;
39 int avflag;
40 } BFIContext;
41
bfi_probe(const AVProbeData * p)42 static int bfi_probe(const AVProbeData * p)
43 {
44 /* Check file header */
45 if (AV_RL32(p->buf) == MKTAG('B', 'F', '&', 'I'))
46 return AVPROBE_SCORE_MAX;
47 else
48 return 0;
49 }
50
bfi_read_header(AVFormatContext * s)51 static int bfi_read_header(AVFormatContext * s)
52 {
53 BFIContext *bfi = s->priv_data;
54 AVIOContext *pb = s->pb;
55 AVStream *vstream;
56 AVStream *astream;
57 int ret, fps, chunk_header;
58
59 /* Initialize the video codec... */
60 vstream = avformat_new_stream(s, NULL);
61 if (!vstream)
62 return AVERROR(ENOMEM);
63
64 /* Initialize the audio codec... */
65 astream = avformat_new_stream(s, NULL);
66 if (!astream)
67 return AVERROR(ENOMEM);
68
69 /* Set the total number of frames. */
70 avio_skip(pb, 8);
71 chunk_header = avio_rl32(pb);
72 if (chunk_header < 3)
73 return AVERROR_INVALIDDATA;
74
75 bfi->nframes = avio_rl32(pb);
76 if (bfi->nframes < 0)
77 return AVERROR_INVALIDDATA;
78 avio_rl32(pb);
79 avio_rl32(pb);
80 avio_rl32(pb);
81 fps = avio_rl32(pb);
82 avio_skip(pb, 12);
83 vstream->codecpar->width = avio_rl32(pb);
84 vstream->codecpar->height = avio_rl32(pb);
85
86 /*Load the palette to extradata */
87 avio_skip(pb, 8);
88 ret = ff_get_extradata(s, vstream->codecpar, pb, 768);
89 if (ret < 0)
90 return ret;
91
92 astream->codecpar->sample_rate = avio_rl32(pb);
93 if (astream->codecpar->sample_rate <= 0) {
94 av_log(s, AV_LOG_ERROR, "Invalid sample rate %d\n", astream->codecpar->sample_rate);
95 return AVERROR_INVALIDDATA;
96 }
97
98 /* Set up the video codec... */
99 avpriv_set_pts_info(vstream, 32, 1, fps);
100 vstream->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
101 vstream->codecpar->codec_id = AV_CODEC_ID_BFI;
102 vstream->codecpar->format = AV_PIX_FMT_PAL8;
103 vstream->nb_frames =
104 vstream->duration = bfi->nframes;
105
106 /* Set up the audio codec now... */
107 astream->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
108 astream->codecpar->codec_id = AV_CODEC_ID_PCM_U8;
109 astream->codecpar->channels = 1;
110 astream->codecpar->channel_layout = AV_CH_LAYOUT_MONO;
111 astream->codecpar->bits_per_coded_sample = 8;
112 astream->codecpar->bit_rate =
113 (int64_t)astream->codecpar->sample_rate * astream->codecpar->bits_per_coded_sample;
114 avio_seek(pb, chunk_header - 3, SEEK_SET);
115 avpriv_set_pts_info(astream, 64, 1, astream->codecpar->sample_rate);
116 return 0;
117 }
118
119
bfi_read_packet(AVFormatContext * s,AVPacket * pkt)120 static int bfi_read_packet(AVFormatContext * s, AVPacket * pkt)
121 {
122 BFIContext *bfi = s->priv_data;
123 AVIOContext *pb = s->pb;
124 int ret, audio_offset, video_offset, chunk_size, audio_size = 0;
125 if (bfi->nframes == 0 || avio_feof(pb)) {
126 return AVERROR_EOF;
127 }
128
129 /* If all previous chunks were completely read, then find a new one... */
130 if (!bfi->avflag) {
131 uint32_t state = 0;
132 while(state != MKTAG('S','A','V','I')){
133 if (avio_feof(pb))
134 return AVERROR(EIO);
135 state = 256*state + avio_r8(pb);
136 }
137 /* Now that the chunk's location is confirmed, we proceed... */
138 chunk_size = avio_rl32(pb);
139 avio_rl32(pb);
140 audio_offset = avio_rl32(pb);
141 avio_rl32(pb);
142 video_offset = avio_rl32(pb);
143 audio_size = video_offset - audio_offset;
144 bfi->video_size = chunk_size - video_offset;
145 if (audio_size < 0 || bfi->video_size < 0) {
146 av_log(s, AV_LOG_ERROR, "Invalid audio/video offsets or chunk size\n");
147 return AVERROR_INVALIDDATA;
148 }
149
150 //Tossing an audio packet at the audio decoder.
151 ret = av_get_packet(pb, pkt, audio_size);
152 if (ret < 0)
153 return ret;
154
155 pkt->pts = bfi->audio_frame;
156 bfi->audio_frame += ret;
157 } else if (bfi->video_size > 0) {
158
159 //Tossing a video packet at the video decoder.
160 ret = av_get_packet(pb, pkt, bfi->video_size);
161 if (ret < 0)
162 return ret;
163
164 pkt->pts = bfi->video_frame;
165 bfi->video_frame += ret / bfi->video_size;
166
167 /* One less frame to read. A cursory decrement. */
168 bfi->nframes--;
169 } else {
170 /* Empty video packet */
171 ret = AVERROR(EAGAIN);
172 }
173
174 bfi->avflag = !bfi->avflag;
175 pkt->stream_index = bfi->avflag;
176 return ret;
177 }
178
179 AVInputFormat ff_bfi_demuxer = {
180 .name = "bfi",
181 .long_name = NULL_IF_CONFIG_SMALL("Brute Force & Ignorance"),
182 .priv_data_size = sizeof(BFIContext),
183 .read_probe = bfi_probe,
184 .read_header = bfi_read_header,
185 .read_packet = bfi_read_packet,
186 };
187