libavformat/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(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 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->codec->width = avio_rl32(pb);
79  vstream->codec->height = avio_rl32(pb);
80 
81  /*Load the palette to extradata */
82  avio_skip(pb, 8);
83  vstream->codec->extradata = av_malloc(768);
84  vstream->codec->extradata_size = 768;
85  avio_read(pb, vstream->codec->extradata,
86  vstream->codec->extradata_size);
87 
88  astream->codec->sample_rate = avio_rl32(pb);
89 
90  /* Set up the video codec... */
91  avpriv_set_pts_info(vstream, 32, 1, fps);
93  vstream->codec->codec_id = AV_CODEC_ID_BFI;
94  vstream->codec->pix_fmt = AV_PIX_FMT_PAL8;
95  vstream->nb_frames =
96  vstream->duration = bfi->nframes;
97 
98  /* Set up the audio codec now... */
100  astream->codec->codec_id = AV_CODEC_ID_PCM_U8;
101  astream->codec->channels = 1;
103  astream->codec->bits_per_coded_sample = 8;
104  astream->codec->bit_rate =
105  astream->codec->sample_rate * astream->codec->bits_per_coded_sample;
106  avio_seek(pb, chunk_header - 3, SEEK_SET);
107  avpriv_set_pts_info(astream, 64, 1, astream->codec->sample_rate);
108  return 0;
109 }
110 
111 
113 {
114  BFIContext *bfi = s->priv_data;
115  AVIOContext *pb = s->pb;
116  int ret, audio_offset, video_offset, chunk_size, audio_size = 0;
117  if (bfi->nframes == 0 || url_feof(pb)) {
118  return AVERROR_EOF;
119  }
120 
121  /* If all previous chunks were completely read, then find a new one... */
122  if (!bfi->avflag) {
123  uint32_t state = 0;
124  while(state != MKTAG('S','A','V','I')){
125  if (url_feof(pb))
126  return AVERROR(EIO);
127  state = 256*state + avio_r8(pb);
128  }
129  /* Now that the chunk's location is confirmed, we proceed... */
130  chunk_size = avio_rl32(pb);
131  avio_rl32(pb);
132  audio_offset = avio_rl32(pb);
133  avio_rl32(pb);
134  video_offset = avio_rl32(pb);
135  audio_size = video_offset - audio_offset;
136  bfi->video_size = chunk_size - video_offset;
137 
138  //Tossing an audio packet at the audio decoder.
139  ret = av_get_packet(pb, pkt, audio_size);
140  if (ret < 0)
141  return ret;
142 
143  pkt->pts = bfi->audio_frame;
144  bfi->audio_frame += ret;
145  }
146 
147  else {
148 
149  //Tossing a video packet at the video decoder.
150  ret = av_get_packet(pb, pkt, bfi->video_size);
151  if (ret < 0)
152  return ret;
153 
154  pkt->pts = bfi->video_frame;
155  bfi->video_frame += bfi->video_size ? ret / bfi->video_size : 1;
156 
157  /* One less frame to read. A cursory decrement. */
158  bfi->nframes--;
159  }
160 
161  bfi->avflag = !bfi->avflag;
162  pkt->stream_index = bfi->avflag;
163  return ret;
164 }
165 
167  .name = "bfi",
168  .long_name = NULL_IF_CONFIG_SMALL("Brute Force & Ignorance"),
169  .priv_data_size = sizeof(BFIContext),
173 };
const char * s
Definition: avisynth_c.h:668
Bytestream IO Context.
Definition: avio.h:68
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.
static int64_t audio_size
Definition: ffmpeg.c:126
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:199
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:256
Format I/O context.
Definition: avformat.h:944
8 bit with PIX_FMT_RGB32 palette
Definition: pixfmt.h:79
static AVPacket pkt
Definition: demuxing.c:56
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
#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.
int bits_per_coded_sample
bits per sample/pixel from the demuxer (needed for huffyuv).
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:478
AVInputFormat ff_bfi_demuxer
static int bfi_read_packet(AVFormatContext *s, AVPacket *pkt)
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:579
struct BFIContext BFIContext
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
static int bfi_probe(AVProbeData *p)
uint64_t channel_layout
Audio channel layout.
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:469
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:662
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:336
int bit_rate
the average bitrate
audio channel layout utility functions
static int read_probe(AVProbeData *pd)
ret
Definition: avfilter.c:821
int width
picture width / height.
#define AV_RL32
static int bfi_read_header(AVFormatContext *s)
int url_feof(AVIOContext *s)
feof() equivalent for AVIOContext.
Definition: aviobuf.c:280
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:517
Stream structure.
Definition: avformat.h:643
NULL
Definition: eval.c:55
enum AVMediaType codec_type
enum AVCodecID codec_id
int sample_rate
samples per second
AVIOContext * pb
I/O context.
Definition: avformat.h:977
static int read_packet(AVFormatContext *ctx, AVPacket *pkt)
Definition: libcdio.c:114
void * av_malloc(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:73
This structure contains the data a format has to probe a file.
Definition: avformat.h:334
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFilterBuffer 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.Buffer references ownership and permissions
static uint32_t state
Definition: trasher.c:27
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:696
#define AVPROBE_SCORE_MAX
maximum score, half of that is used for file-extension-based detection
Definition: avformat.h:340
Main libavformat public API header.
int64_t nb_frames
number of frames in this stream if known or 0
Definition: avformat.h:698
int channels
number of audio channels
void * priv_data
Format private data.
Definition: avformat.h:964
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:461
#define AV_CH_LAYOUT_MONO
#define MKTAG(a, b, c, d)
Definition: common.h:282
This structure stores compressed data.
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...