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  *size -= avio_tell(pb) - pos;
131 }
132 
133 static void mpc8_parse_seektable(AVFormatContext *s, int64_t off)
134 {
135  MPCContext *c = s->priv_data;
136  int tag;
137  int64_t size, pos, ppos[2];
138  uint8_t *buf;
139  int i, t, seekd, ret;
140  GetBitContext gb;
141 
142  if (s->nb_streams == 0) {
143  av_log(s, AV_LOG_ERROR, "No stream added before parsing seek table\n");
144  return;
145  }
146 
147  avio_seek(s->pb, off, SEEK_SET);
148  mpc8_get_chunk_header(s->pb, &tag, &size);
149  if(tag != TAG_SEEKTABLE){
150  av_log(s, AV_LOG_ERROR, "No seek table at given position\n");
151  return;
152  }
153  if (size > INT_MAX/10 || size<=0) {
154  av_log(s, AV_LOG_ERROR, "Bad seek table size\n");
155  return;
156  }
158  return;
159  ret = avio_read(s->pb, buf, size);
160  if (ret != size) {
161  av_log(s, AV_LOG_ERROR, "seek table truncated\n");
162  av_free(buf);
163  return;
164  }
166 
167  init_get_bits(&gb, buf, size * 8);
168  size = gb_get_v(&gb);
169  if(size > UINT_MAX/4 || size > c->samples/1152){
170  av_log(s, AV_LOG_ERROR, "Seek table is too big\n");
171  return;
172  }
173  seekd = get_bits(&gb, 4);
174  for(i = 0; i < 2; i++){
175  pos = gb_get_v(&gb) + c->header_pos;
176  ppos[1 - i] = pos;
177  av_add_index_entry(s->streams[0], pos, i, 0, 0, AVINDEX_KEYFRAME);
178  }
179  for(; i < size; i++){
180  if (get_bits_left(&gb) < 13) {
181  av_free(buf);
182  return;
183  }
184  t = get_unary(&gb, 1, 33) << 12;
185  t += get_bits(&gb, 12);
186  if(t & 1)
187  t = -(t & ~1);
188  pos = (t >> 1) + (uint64_t)ppos[0]*2 - ppos[1];
189  av_add_index_entry(s->streams[0], pos, (int64_t)i << seekd, 0, 0, AVINDEX_KEYFRAME);
190  ppos[1] = ppos[0];
191  ppos[0] = pos;
192  }
193  av_free(buf);
194 }
195 
196 static void mpc8_handle_chunk(AVFormatContext *s, int tag, int64_t chunk_pos, int64_t size)
197 {
198  AVIOContext *pb = s->pb;
199  int64_t pos, off;
200 
201  switch(tag){
202  case TAG_SEEKTBLOFF:
203  pos = avio_tell(pb);
204  off = ffio_read_varlen(pb);
205  if (pos > INT64_MAX - size || off < 0 || off > INT64_MAX - chunk_pos)
206  return;
207  pos += size;
208  mpc8_parse_seektable(s, chunk_pos + off);
209  avio_seek(pb, pos, SEEK_SET);
210  break;
211  default:
212  avio_skip(pb, size);
213  }
214 }
215 
217 {
218  MPCContext *c = s->priv_data;
219  AVIOContext *pb = s->pb;
220  AVStream *st;
221  int tag = 0;
222  int64_t size, pos;
223 
224  c->header_pos = avio_tell(pb);
225  if(avio_rl32(pb) != TAG_MPCK){
226  av_log(s, AV_LOG_ERROR, "Not a Musepack8 file\n");
227  return AVERROR_INVALIDDATA;
228  }
229 
230  while(!avio_feof(pb)){
231  pos = avio_tell(pb);
233  if (size < 0) {
234  av_log(s, AV_LOG_ERROR, "Invalid chunk length\n");
235  return AVERROR_INVALIDDATA;
236  }
237  if(tag == TAG_STREAMHDR)
238  break;
239  mpc8_handle_chunk(s, tag, pos, size);
240  }
241  if(tag != TAG_STREAMHDR){
242  av_log(s, AV_LOG_ERROR, "Stream header not found\n");
243  return AVERROR_INVALIDDATA;
244  }
245  pos = avio_tell(pb);
246  avio_skip(pb, 4); //CRC
247  c->ver = avio_r8(pb);
248  if(c->ver != 8){
249  avpriv_report_missing_feature(s, "Stream version %d", c->ver);
250  return AVERROR_PATCHWELCOME;
251  }
252  c->samples = ffio_read_varlen(pb);
253  ffio_read_varlen(pb); //silence samples at the beginning
254 
255  st = avformat_new_stream(s, NULL);
256  if (!st)
257  return AVERROR(ENOMEM);
261 
262  if (ff_get_extradata(s, st->codecpar, pb, 2) < 0)
263  return AVERROR(ENOMEM);
264 
265  st->codecpar->channels = (st->codecpar->extradata[1] >> 4) + 1;
266  st->codecpar->sample_rate = mpc8_rate[st->codecpar->extradata[0] >> 5];
267  avpriv_set_pts_info(st, 64, 1152 << (st->codecpar->extradata[1]&3)*2, st->codecpar->sample_rate);
268  st->start_time = 0;
269  st->duration = c->samples / (1152 << (st->codecpar->extradata[1]&3)*2);
270  size -= avio_tell(pb) - pos;
271  if (size > 0)
272  avio_skip(pb, size);
273 
274  if (pb->seekable & AVIO_SEEKABLE_NORMAL) {
275  int64_t pos = avio_tell(s->pb);
276  c->apetag_start = ff_ape_parse_tag(s);
277  avio_seek(s->pb, pos, SEEK_SET);
278  }
279 
280  return 0;
281 }
282 
284 {
285  MPCContext *c = s->priv_data;
286  int tag;
287  int64_t pos, size;
288 
289  while(!avio_feof(s->pb)){
290  pos = avio_tell(s->pb);
291 
292  /* don't return bogus packets with the ape tag data */
293  if (c->apetag_start && pos >= c->apetag_start)
294  return AVERROR_EOF;
295 
296  mpc8_get_chunk_header(s->pb, &tag, &size);
297  if (size < 0 || size > INT_MAX)
298  return -1;
299  if(tag == TAG_AUDIOPACKET){
300  if(av_get_packet(s->pb, pkt, size) < 0)
301  return AVERROR(ENOMEM);
302  pkt->stream_index = 0;
303  pkt->duration = 1;
304  return 0;
305  }
306  if(tag == TAG_STREAMEND)
307  return AVERROR_EOF;
308  mpc8_handle_chunk(s, tag, pos, size);
309  }
310  return AVERROR_EOF;
311 }
312 
313 static int mpc8_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
314 {
315  AVStream *st = s->streams[stream_index];
316  int index = av_index_search_timestamp(st, timestamp, flags);
317 
318  if(index < 0) return -1;
319  if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
320  return -1;
322  return 0;
323 }
324 
325 
327  .name = "mpc8",
328  .long_name = NULL_IF_CONFIG_SMALL("Musepack SV8"),
329  .priv_data_size = sizeof(MPCContext),
334 };
AVStream::index_entries
AVIndexEntry * index_entries
Only used if the format does not support seeking natively.
Definition: avformat.h:1099
AVCodecParameters::extradata
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: avcodec.h:3971
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:4480
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3953
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:3327
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:313
apetag.h
mpc8_get_chunk_header
static void mpc8_get_chunk_header(AVIOContext *pb, int *tag, int64_t *size)
Definition: mpc8.c:124
MPCContext
Definition: mpc.h:52
mpc8_read_packet
static int mpc8_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: mpc8.c:283
AVPacket::duration
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: avcodec.h:1495
AVProbeData::buf_size
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:449
mpc8_parse_seektable
static void mpc8_parse_seektable(AVFormatContext *s, int64_t off)
Definition: mpc8.c:133
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:118
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:31
AVINDEX_KEYFRAME
#define AVINDEX_KEYFRAME
Definition: avformat.h:808
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
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: avcodec.h:4063
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:2056
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:919
avio_rl16
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:753
ff_mpc8_demuxer
AVInputFormat ff_mpc8_demuxer
Definition: mpc8.c:326
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
buf
void * buf
Definition: avisynth_c.h:766
AVInputFormat
Definition: avformat.h:640
mpc8_read_header
static int mpc8_read_header(AVFormatContext *s)
Definition: mpc8.c:216
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:448
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
bits
uint8_t bits
Definition: vp3data.h:202
AVIndexEntry::timestamp
int64_t timestamp
Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are...
Definition: avformat.h:802
get_bits.h
AVFormatContext
Format I/O context.
Definition: avformat.h:1342
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:1970
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1017
read_header
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:530
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:446
MPCContext::samples
int64_t samples
Definition: mpc8.c:53
TAG_MPCK
#define TAG_MPCK
Definition: mpc8.c:32
index
int index
Definition: gxfenc.c:89
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:456
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: avcodec.h:4067
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:769
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:188
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:4910
size
int size
Definition: twinvq_data.h:11134
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:638
ffio_read_varlen
uint64_t ffio_read_varlen(AVIOContext *bc)
Definition: aviobuf.c:929
unary.h
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
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:313
tag
uint32_t tag
Definition: movenc.c:1496
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:870
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:246
avformat.h
AV_INPUT_BUFFER_PADDING_SIZE
#define AV_INPUT_BUFFER_PADDING_SIZE
Definition: avcodec.h:790
AV_CODEC_ID_MUSEPACK8
@ AV_CODEC_ID_MUSEPACK8
Definition: avcodec.h:598
AV_RL32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:88
MKMPCTAG
#define MKMPCTAG(a, b)
Two-byte MPC tag.
Definition: mpc8.c:30
pkt
static AVPacket pkt
Definition: demuxing_decoding.c:54
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:647
AVIndexEntry::pos
int64_t pos
Definition: avformat.h:801
AVPacket::stream_index
int stream_index
Definition: avcodec.h:1479
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:331
mpc8_handle_chunk
static void mpc8_handle_chunk(AVFormatContext *s, int tag, int64_t chunk_pos, int64_t size)
Definition: mpc8.c:196
AVCodecParameters::bits_per_coded_sample
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: avcodec.h:3999
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: avcodec.h:3957
AVPacket
This structure stores compressed data.
Definition: avcodec.h:1454
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:565
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:909
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:2167
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:358