FFmpeg
bfi.c
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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 
30 #include "libavutil/intreadwrite.h"
31 #include "avformat.h"
32 #include "internal.h"
33 
34 typedef struct BFIContext {
35  int nframes;
39  int avflag;
40 } BFIContext;
41 
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 
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  bfi->nframes = avio_rl32(pb);
73  avio_rl32(pb);
74  avio_rl32(pb);
75  avio_rl32(pb);
76  fps = avio_rl32(pb);
77  avio_skip(pb, 12);
78  vstream->codecpar->width = avio_rl32(pb);
79  vstream->codecpar->height = avio_rl32(pb);
80 
81  /*Load the palette to extradata */
82  avio_skip(pb, 8);
83  ret = ff_get_extradata(s, vstream->codecpar, pb, 768);
84  if (ret < 0)
85  return ret;
86 
87  astream->codecpar->sample_rate = avio_rl32(pb);
88  if (astream->codecpar->sample_rate <= 0) {
89  av_log(s, AV_LOG_ERROR, "Invalid sample rate %d\n", astream->codecpar->sample_rate);
90  return AVERROR_INVALIDDATA;
91  }
92 
93  /* Set up the video codec... */
94  avpriv_set_pts_info(vstream, 32, 1, fps);
96  vstream->codecpar->codec_id = AV_CODEC_ID_BFI;
97  vstream->codecpar->format = AV_PIX_FMT_PAL8;
98  vstream->nb_frames =
99  vstream->duration = bfi->nframes;
100 
101  /* Set up the audio codec now... */
104  astream->codecpar->channels = 1;
106  astream->codecpar->bits_per_coded_sample = 8;
107  astream->codecpar->bit_rate =
108  (int64_t)astream->codecpar->sample_rate * astream->codecpar->bits_per_coded_sample;
109  avio_seek(pb, chunk_header - 3, SEEK_SET);
110  avpriv_set_pts_info(astream, 64, 1, astream->codecpar->sample_rate);
111  return 0;
112 }
113 
114 
116 {
117  BFIContext *bfi = s->priv_data;
118  AVIOContext *pb = s->pb;
119  int ret, audio_offset, video_offset, chunk_size, audio_size = 0;
120  if (bfi->nframes == 0 || avio_feof(pb)) {
121  return AVERROR_EOF;
122  }
123 
124  /* If all previous chunks were completely read, then find a new one... */
125  if (!bfi->avflag) {
126  uint32_t state = 0;
127  while(state != MKTAG('S','A','V','I')){
128  if (avio_feof(pb))
129  return AVERROR(EIO);
130  state = 256*state + avio_r8(pb);
131  }
132  /* Now that the chunk's location is confirmed, we proceed... */
133  chunk_size = avio_rl32(pb);
134  avio_rl32(pb);
135  audio_offset = avio_rl32(pb);
136  avio_rl32(pb);
137  video_offset = avio_rl32(pb);
138  audio_size = video_offset - audio_offset;
139  bfi->video_size = chunk_size - video_offset;
140  if (audio_size < 0 || bfi->video_size < 0) {
141  av_log(s, AV_LOG_ERROR, "Invalid audio/video offsets or chunk size\n");
142  return AVERROR_INVALIDDATA;
143  }
144 
145  //Tossing an audio packet at the audio decoder.
146  ret = av_get_packet(pb, pkt, audio_size);
147  if (ret < 0)
148  return ret;
149 
150  pkt->pts = bfi->audio_frame;
151  bfi->audio_frame += ret;
152  } else if (bfi->video_size > 0) {
153 
154  //Tossing a video packet at the video decoder.
155  ret = av_get_packet(pb, pkt, bfi->video_size);
156  if (ret < 0)
157  return ret;
158 
159  pkt->pts = bfi->video_frame;
160  bfi->video_frame += ret / bfi->video_size;
161 
162  /* One less frame to read. A cursory decrement. */
163  bfi->nframes--;
164  } else {
165  /* Empty video packet */
166  ret = AVERROR(EAGAIN);
167  }
168 
169  bfi->avflag = !bfi->avflag;
170  pkt->stream_index = bfi->avflag;
171  return ret;
172 }
173 
175  .name = "bfi",
176  .long_name = NULL_IF_CONFIG_SMALL("Brute Force & Ignorance"),
177  .priv_data_size = sizeof(BFIContext),
181 };
#define NULL
Definition: coverity.c:32
Bytestream IO Context.
Definition: avio.h:161
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:4896
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3960
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:246
int video_frame
Definition: bfi.c:37
int audio_frame
Definition: bfi.c:36
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:334
Definition: bfi.c:34
static AVPacket pkt
Format I/O context.
Definition: avformat.h:1358
int width
Video only.
Definition: avcodec.h:4026
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:77
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4469
#define AVERROR_EOF
End of file.
Definition: error.h:55
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:310
uint64_t channel_layout
Audio only.
Definition: avcodec.h:4062
#define av_log(a,...)
int64_t bit_rate
The average bitrate of the encoded data (in bits per second).
Definition: avcodec.h:3989
int video_size
Definition: bfi.c:38
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
AVInputFormat ff_bfi_demuxer
Definition: bfi.c:174
static int bfi_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: bfi.c:115
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:772
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3956
static int bfi_probe(const AVProbeData *p)
Definition: bfi.c:42
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:641
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:448
audio channel layout utility functions
#define s(width, name)
Definition: cbs_vp9.c:257
static int bfi_read_header(AVFormatContext *s)
Definition: bfi.c:51
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:530
Stream structure.
Definition: avformat.h:881
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
int nframes
Definition: bfi.c:35
AVIOContext * pb
I/O context.
Definition: avformat.h:1400
int avflag
Definition: bfi.c:39
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:930
int sample_rate
Audio only.
Definition: avcodec.h:4070
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
Main libavformat public API header.
int ff_get_extradata(AVFormatContext *s, AVCodecParameters *par, AVIOContext *pb, int size)
Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end which is always set to 0 and f...
Definition: utils.c:3316
int64_t nb_frames
number of frames in this stream if known or 0
Definition: avformat.h:932
void * priv_data
Format private data.
Definition: avformat.h:1386
static struct @316 state
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: avcodec.h:4002
int channels
Audio only.
Definition: avcodec.h:4066
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:654
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1028
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:361
int stream_index
Definition: avcodec.h:1482
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
#define AV_CH_LAYOUT_MONO
#define MKTAG(a, b, c, d)
Definition: common.h:366
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:87
This structure stores compressed data.
Definition: avcodec.h:1457
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1473