FFmpeg
mpc8.c
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1 /*
2  * Musepack SV8 demuxer
3  * Copyright (c) 2007 Konstantin Shishkov
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 #include "libavcodec/get_bits.h"
23 #include "libavcodec/unary.h"
24 #include "apetag.h"
25 #include "avformat.h"
26 #include "internal.h"
27 #include "avio_internal.h"
28 
29 /// Two-byte MPC tag
30 #define MKMPCTAG(a, b) ((a) | ((b) << 8))
31 
32 #define TAG_MPCK MKTAG('M','P','C','K')
33 
34 /// Reserved MPC tags
36  TAG_STREAMHDR = MKMPCTAG('S','H'),
37  TAG_STREAMEND = MKMPCTAG('S','E'),
38 
40 
42  TAG_SEEKTABLE = MKMPCTAG('S','T'),
43 
45  TAG_ENCINFO = MKMPCTAG('E','I'),
46 };
47 
48 static const int mpc8_rate[8] = { 44100, 48000, 37800, 32000, -1, -1, -1, -1 };
49 
50 typedef struct MPCContext {
51  int ver;
52  int64_t header_pos;
53  int64_t samples;
54 
55  int64_t apetag_start;
56 } MPCContext;
57 
58 static inline int64_t bs_get_v(const uint8_t **bs)
59 {
60  uint64_t v = 0;
61  int br = 0;
62  int c;
63 
64  do {
65  c = **bs; (*bs)++;
66  v <<= 7;
67  v |= c & 0x7F;
68  br++;
69  if (br > 10)
70  return -1;
71  } while (c & 0x80);
72 
73  return v - br;
74 }
75 
76 static int mpc8_probe(const AVProbeData *p)
77 {
78  const uint8_t *bs = p->buf + 4;
79  const uint8_t *bs_end = bs + p->buf_size;
80  int64_t size;
81 
82  if (p->buf_size < 16)
83  return 0;
84  if (AV_RL32(p->buf) != TAG_MPCK)
85  return 0;
86  while (bs < bs_end + 3) {
87  int header_found = (bs[0] == 'S' && bs[1] == 'H');
88  if (bs[0] < 'A' || bs[0] > 'Z' || bs[1] < 'A' || bs[1] > 'Z')
89  return 0;
90  bs += 2;
91  size = bs_get_v(&bs);
92  if (size < 2)
93  return 0;
94  if (size >= bs_end - bs + 2)
95  return AVPROBE_SCORE_EXTENSION - 1; // seems to be valid MPC but no header yet
96  if (header_found) {
97  if (size < 11 || size > 28)
98  return 0;
99  if (!AV_RL32(bs)) //zero CRC is invalid
100  return 0;
101  return AVPROBE_SCORE_MAX;
102  } else {
103  bs += size - 2;
104  }
105  }
106  return 0;
107 }
108 
109 static inline int64_t gb_get_v(GetBitContext *gb)
110 {
111  uint64_t v = 0;
112  int bits = 0;
113  while(get_bits1(gb) && bits < 64-7){
114  v <<= 7;
115  v |= get_bits(gb, 7);
116  bits += 7;
117  }
118  v <<= 7;
119  v |= get_bits(gb, 7);
120 
121  return v;
122 }
123 
124 static void mpc8_get_chunk_header(AVIOContext *pb, int *tag, int64_t *size)
125 {
126  int64_t pos;
127  pos = avio_tell(pb);
128  *tag = avio_rl16(pb);
129  *size = ffio_read_varlen(pb);
130  pos -= avio_tell(pb);
131  if (av_sat_add64(*size, pos) != (uint64_t)*size + pos) {
132  *size = -1;
133  } else
134  *size += pos;
135 }
136 
137 static void mpc8_parse_seektable(AVFormatContext *s, int64_t off)
138 {
139  MPCContext *c = s->priv_data;
140  int tag;
141  int64_t size, pos, ppos[2];
142  uint8_t *buf;
143  int i, t, seekd, ret;
144  GetBitContext gb;
145 
146  if (s->nb_streams == 0) {
147  av_log(s, AV_LOG_ERROR, "No stream added before parsing seek table\n");
148  return;
149  }
150 
151  avio_seek(s->pb, off, SEEK_SET);
152  mpc8_get_chunk_header(s->pb, &tag, &size);
153  if(tag != TAG_SEEKTABLE){
154  av_log(s, AV_LOG_ERROR, "No seek table at given position\n");
155  return;
156  }
157  if (size > INT_MAX/10 || size<=0) {
158  av_log(s, AV_LOG_ERROR, "Bad seek table size\n");
159  return;
160  }
162  return;
163  ret = avio_read(s->pb, buf, size);
164  if (ret != size) {
165  av_log(s, AV_LOG_ERROR, "seek table truncated\n");
166  av_free(buf);
167  return;
168  }
169  memset(buf+size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
170 
171  init_get_bits(&gb, buf, size * 8);
172  size = gb_get_v(&gb);
173  if(size > UINT_MAX/4 || size > c->samples/1152){
174  av_log(s, AV_LOG_ERROR, "Seek table is too big\n");
175  av_free(buf);
176  return;
177  }
178  seekd = get_bits(&gb, 4);
179  for(i = 0; i < 2; i++){
180  pos = gb_get_v(&gb) + c->header_pos;
181  ppos[1 - i] = pos;
182  av_add_index_entry(s->streams[0], pos, i, 0, 0, AVINDEX_KEYFRAME);
183  }
184  for(; i < size; i++){
185  if (get_bits_left(&gb) < 13) {
186  av_free(buf);
187  return;
188  }
189  t = get_unary(&gb, 1, 33) << 12;
190  t += get_bits(&gb, 12);
191  if(t & 1)
192  t = -(t & ~1);
193  pos = (t >> 1) + (uint64_t)ppos[0]*2 - ppos[1];
194  av_add_index_entry(s->streams[0], pos, (int64_t)i << seekd, 0, 0, AVINDEX_KEYFRAME);
195  ppos[1] = ppos[0];
196  ppos[0] = pos;
197  }
198  av_free(buf);
199 }
200 
201 static void mpc8_handle_chunk(AVFormatContext *s, int tag, int64_t chunk_pos, int64_t size)
202 {
203  AVIOContext *pb = s->pb;
204  int64_t pos, off;
205 
206  switch(tag){
207  case TAG_SEEKTBLOFF:
208  pos = avio_tell(pb) + size;
209  off = ffio_read_varlen(pb);
210  mpc8_parse_seektable(s, chunk_pos + off);
211  avio_seek(pb, pos, SEEK_SET);
212  break;
213  default:
214  avio_skip(pb, size);
215  }
216 }
217 
219 {
220  MPCContext *c = s->priv_data;
221  AVIOContext *pb = s->pb;
222  AVStream *st;
223  int tag = 0, ret;
224  int64_t size, pos;
225 
226  c->header_pos = avio_tell(pb);
227  if(avio_rl32(pb) != TAG_MPCK){
228  av_log(s, AV_LOG_ERROR, "Not a Musepack8 file\n");
229  return AVERROR_INVALIDDATA;
230  }
231 
232  while(!avio_feof(pb)){
233  pos = avio_tell(pb);
235  if (size < 0) {
236  av_log(s, AV_LOG_ERROR, "Invalid chunk length\n");
237  return AVERROR_INVALIDDATA;
238  }
239  if(tag == TAG_STREAMHDR)
240  break;
242  }
243  if(tag != TAG_STREAMHDR){
244  av_log(s, AV_LOG_ERROR, "Stream header not found\n");
245  return AVERROR_INVALIDDATA;
246  }
247  pos = avio_tell(pb);
248  avio_skip(pb, 4); //CRC
249  c->ver = avio_r8(pb);
250  if(c->ver != 8){
251  avpriv_report_missing_feature(s, "Stream version %d", c->ver);
252  return AVERROR_PATCHWELCOME;
253  }
254  c->samples = ffio_read_varlen(pb);
255  ffio_read_varlen(pb); //silence samples at the beginning
256 
257  st = avformat_new_stream(s, NULL);
258  if (!st)
259  return AVERROR(ENOMEM);
263 
264  if ((ret = ff_get_extradata(s, st->codecpar, pb, 2)) < 0)
265  return ret;
266 
267  st->codecpar->channels = (st->codecpar->extradata[1] >> 4) + 1;
268  st->codecpar->sample_rate = mpc8_rate[st->codecpar->extradata[0] >> 5];
269  avpriv_set_pts_info(st, 64, 1152 << (st->codecpar->extradata[1]&3)*2, st->codecpar->sample_rate);
270  st->start_time = 0;
271  st->duration = c->samples / (1152 << (st->codecpar->extradata[1]&3)*2);
272  size -= avio_tell(pb) - pos;
273  if (size > 0)
274  avio_skip(pb, size);
275 
276  if (pb->seekable & AVIO_SEEKABLE_NORMAL) {
277  int64_t pos = avio_tell(s->pb);
278  c->apetag_start = ff_ape_parse_tag(s);
279  avio_seek(s->pb, pos, SEEK_SET);
280  }
281 
282  return 0;
283 }
284 
286 {
287  MPCContext *c = s->priv_data;
288  int tag, ret;
289  int64_t pos, size;
290 
291  while(!avio_feof(s->pb)){
292  pos = avio_tell(s->pb);
293 
294  /* don't return bogus packets with the ape tag data */
295  if (c->apetag_start && pos >= c->apetag_start)
296  return AVERROR_EOF;
297 
298  mpc8_get_chunk_header(s->pb, &tag, &size);
299  if (size < 0 || size > INT_MAX)
300  return -1;
301  if(tag == TAG_AUDIOPACKET){
302  if ((ret = av_get_packet(s->pb, pkt, size)) < 0)
303  return ret;
304  pkt->stream_index = 0;
305  pkt->duration = 1;
306  return 0;
307  }
308  if(tag == TAG_STREAMEND)
309  return AVERROR_EOF;
311  }
312  return AVERROR_EOF;
313 }
314 
315 static int mpc8_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
316 {
317  AVStream *st = s->streams[stream_index];
318  int index = av_index_search_timestamp(st, timestamp, flags);
319 
320  if(index < 0) return -1;
321  if (avio_seek(s->pb, st->internal->index_entries[index].pos, SEEK_SET) < 0)
322  return -1;
324  return 0;
325 }
326 
327 
329  .name = "mpc8",
330  .long_name = NULL_IF_CONFIG_SMALL("Musepack SV8"),
331  .priv_data_size = sizeof(MPCContext),
336 };
AVCodecParameters::extradata
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: codec_par.h:74
get_bits_left
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:849
AVERROR
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
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4547
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
TAG_AUDIOPACKET
@ TAG_AUDIOPACKET
Definition: mpc8.c:39
ff_get_extradata
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:3386
TAG_ENCINFO
@ TAG_ENCINFO
Definition: mpc8.c:45
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:55
mpc8_read_seek
static int mpc8_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Definition: mpc8.c:315
apetag.h
index
fg index
Definition: ffmpeg_filter.c:170
mpc8_get_chunk_header
static void mpc8_get_chunk_header(AVIOContext *pb, int *tag, int64_t *size)
Definition: mpc8.c:124
AVStream::internal
AVStreamInternal * internal
An opaque field for libavformat internal usage.
Definition: avformat.h:1112
MPCContext
Definition: mpc.h:53
mpc8_read_packet
static int mpc8_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: mpc8.c:285
AVPacket::duration
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:387
AVProbeData::buf_size
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:444
mpc8_parse_seektable
static void mpc8_parse_seektable(AVFormatContext *s, int64_t off)
Definition: mpc8.c:137
init_get_bits
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:659
ff_ape_parse_tag
int64_t ff_ape_parse_tag(AVFormatContext *s)
Read and parse an APE tag.
Definition: apetag.c:108
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:31
AVINDEX_KEYFRAME
#define AVINDEX_KEYFRAME
Definition: avformat.h:811
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:453
get_bits
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:379
AVCodecParameters::channels
int channels
Audio only.
Definition: codec_par.h:166
read_seek
static int read_seek(AVFormatContext *ctx, int stream_index, int64_t timestamp, int flags)
Definition: libcdio.c:153
av_add_index_entry
int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp, int size, int distance, int flags)
Add an index entry into a sorted list.
Definition: utils.c:2044
GetBitContext
Definition: get_bits.h:61
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
AVStream::duration
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:922
avio_rl16
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:734
ff_mpc8_demuxer
AVInputFormat ff_mpc8_demuxer
Definition: mpc8.c:328
pkt
AVPacket * pkt
Definition: movenc.c:59
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:194
AVInputFormat
Definition: avformat.h:640
mpc8_read_header
static int mpc8_read_header(AVFormatContext *s)
Definition: mpc8.c:218
s
#define s(width, name)
Definition: cbs_vp9.c:257
TAG_SEEKTABLE
@ TAG_SEEKTABLE
Definition: mpc8.c:42
TAG_STREAMEND
@ TAG_STREAMEND
Definition: mpc8.c:37
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:645
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
bits
uint8_t bits
Definition: vp3data.h:141
AVIndexEntry::timestamp
int64_t timestamp
Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are...
Definition: avformat.h:805
get_bits.h
AVFormatContext
Format I/O context.
Definition: avformat.h:1231
internal.h
ff_update_cur_dts
void ff_update_cur_dts(AVFormatContext *s, AVStream *ref_st, int64_t timestamp)
Update cur_dts of all streams based on the given timestamp and AVStream.
Definition: utils.c:1958
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1038
read_header
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:527
NULL
#define NULL
Definition: coverity.c:32
AVERROR_PATCHWELCOME
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
read_probe
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
gb_get_v
static int64_t gb_get_v(GetBitContext *gb)
Definition: mpc8.c:109
get_bits1
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:498
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
MPCContext::samples
int64_t samples
Definition: mpc8.c:53
TAG_MPCK
#define TAG_MPCK
Definition: mpc8.c:32
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
AVPROBE_SCORE_EXTENSION
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:451
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:170
get_unary
static int get_unary(GetBitContext *gb, int stop, int len)
Get unary code of limited length.
Definition: unary.h:46
avio_rl32
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:750
AVIOContext
Bytestream IO Context.
Definition: avio.h:161
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
AVIOContext::seekable
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:260
TAG_SEEKTBLOFF
@ TAG_SEEKTBLOFF
Definition: mpc8.c:41
avpriv_set_pts_info
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:4993
size
int size
Definition: twinvq_data.h:10344
avpriv_report_missing_feature
void avpriv_report_missing_feature(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
avio_r8
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:624
AVStreamInternal::index_entries
AVIndexEntry * index_entries
Only used if the format does not support seeking natively.
Definition: internal.h:250
ffio_read_varlen
uint64_t ffio_read_varlen(AVIOContext *bc)
Definition: aviobuf.c:910
unary.h
i
int i
Definition: input.c:407
avio_internal.h
uint8_t
uint8_t
Definition: audio_convert.c:194
av_get_packet
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
tag
uint32_t tag
Definition: movenc.c:1611
ret
ret
Definition: filter_design.txt:187
read_packet
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
AVStream
Stream structure.
Definition: avformat.h:873
MPCContext::header_pos
int64_t header_pos
Definition: mpc8.c:52
avio_seek
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:253
pos
unsigned int pos
Definition: spdifenc.c:412
avformat.h
AV_INPUT_BUFFER_PADDING_SIZE
#define AV_INPUT_BUFFER_PADDING_SIZE
Definition: avcodec.h:215
AV_CODEC_ID_MUSEPACK8
@ AV_CODEC_ID_MUSEPACK8
Definition: codec_id.h:458
av_sat_add64
#define av_sat_add64
Definition: common.h:164
AV_RL32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:92
MKMPCTAG
#define MKMPCTAG(a, b)
Two-byte MPC tag.
Definition: mpc8.c:30
AVIO_SEEKABLE_NORMAL
#define AVIO_SEEKABLE_NORMAL
Seeking works like for a local file.
Definition: avio.h:40
MPCContext::apetag_start
int64_t apetag_start
Definition: mpc8.c:55
avio_read
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:633
AVIndexEntry::pos
int64_t pos
Definition: avformat.h:804
AVPacket::stream_index
int stream_index
Definition: packet.h:371
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:337
mpc8_handle_chunk
static void mpc8_handle_chunk(AVFormatContext *s, int tag, int64_t chunk_pos, int64_t size)
Definition: mpc8.c:201
AVCodecParameters::bits_per_coded_sample
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: codec_par.h:102
av_free
#define av_free(p)
Definition: tableprint_vlc.h:34
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
AVPacket
This structure stores compressed data.
Definition: packet.h:346
TAG_STREAMHDR
@ TAG_STREAMHDR
Definition: mpc8.c:36
TAG_REPLAYGAIN
@ TAG_REPLAYGAIN
Definition: mpc8.c:44
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
MPCContext::ver
int ver
Definition: mpc.c:40
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
AVStream::start_time
int64_t start_time
Decoding: pts of the first frame of the stream in presentation order, in stream time base.
Definition: avformat.h:912
mpc8_probe
static int mpc8_probe(const AVProbeData *p)
Definition: mpc8.c:76
bs_get_v
static int64_t bs_get_v(const uint8_t **bs)
Definition: mpc8.c:58
MPCPacketTags
MPCPacketTags
Reserved MPC tags.
Definition: mpc8.c:35
av_index_search_timestamp
int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags)
Get the index for a specific timestamp.
Definition: utils.c:2161
mpc8_rate
static const int mpc8_rate[8]
Definition: mpc8.c:48
avio_feof
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:364