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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(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  }
157  if(!(buf = av_malloc(size + AV_INPUT_BUFFER_PADDING_SIZE)))
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  }
165  memset(buf+size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
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  t = get_unary(&gb, 1, 33) << 12;
181  t += get_bits(&gb, 12);
182  if(t & 1)
183  t = -(t & ~1);
184  pos = (t >> 1) + ppos[0]*2 - ppos[1];
185  av_add_index_entry(s->streams[0], pos, i << seekd, 0, 0, AVINDEX_KEYFRAME);
186  ppos[1] = ppos[0];
187  ppos[0] = pos;
188  }
189  av_free(buf);
190 }
191 
192 static void mpc8_handle_chunk(AVFormatContext *s, int tag, int64_t chunk_pos, int64_t size)
193 {
194  AVIOContext *pb = s->pb;
195  int64_t pos, off;
196 
197  switch(tag){
198  case TAG_SEEKTBLOFF:
199  pos = avio_tell(pb) + size;
200  off = ffio_read_varlen(pb);
201  mpc8_parse_seektable(s, chunk_pos + off);
202  avio_seek(pb, pos, SEEK_SET);
203  break;
204  default:
205  avio_skip(pb, size);
206  }
207 }
208 
210 {
211  MPCContext *c = s->priv_data;
212  AVIOContext *pb = s->pb;
213  AVStream *st;
214  int tag = 0;
215  int64_t size, pos;
216 
217  c->header_pos = avio_tell(pb);
218  if(avio_rl32(pb) != TAG_MPCK){
219  av_log(s, AV_LOG_ERROR, "Not a Musepack8 file\n");
220  return AVERROR_INVALIDDATA;
221  }
222 
223  while(!avio_feof(pb)){
224  pos = avio_tell(pb);
225  mpc8_get_chunk_header(pb, &tag, &size);
226  if (size < 0) {
227  av_log(s, AV_LOG_ERROR, "Invalid chunk length\n");
228  return AVERROR_INVALIDDATA;
229  }
230  if(tag == TAG_STREAMHDR)
231  break;
232  mpc8_handle_chunk(s, tag, pos, size);
233  }
234  if(tag != TAG_STREAMHDR){
235  av_log(s, AV_LOG_ERROR, "Stream header not found\n");
236  return AVERROR_INVALIDDATA;
237  }
238  pos = avio_tell(pb);
239  avio_skip(pb, 4); //CRC
240  c->ver = avio_r8(pb);
241  if(c->ver != 8){
242  av_log(s, AV_LOG_ERROR, "Unknown stream version %d\n", c->ver);
243  return AVERROR_PATCHWELCOME;
244  }
245  c->samples = ffio_read_varlen(pb);
246  ffio_read_varlen(pb); //silence samples at the beginning
247 
248  st = avformat_new_stream(s, NULL);
249  if (!st)
250  return AVERROR(ENOMEM);
254 
255  if (ff_get_extradata(s, st->codecpar, pb, 2) < 0)
256  return AVERROR(ENOMEM);
257 
258  st->codecpar->channels = (st->codecpar->extradata[1] >> 4) + 1;
259  st->codecpar->sample_rate = mpc8_rate[st->codecpar->extradata[0] >> 5];
260  avpriv_set_pts_info(st, 32, 1152 << (st->codecpar->extradata[1]&3)*2, st->codecpar->sample_rate);
261  st->start_time = 0;
262  st->duration = c->samples / (1152 << (st->codecpar->extradata[1]&3)*2);
263  size -= avio_tell(pb) - pos;
264  if (size > 0)
265  avio_skip(pb, size);
266 
267  if (pb->seekable) {
268  int64_t pos = avio_tell(s->pb);
270  avio_seek(s->pb, pos, SEEK_SET);
271  }
272 
273  return 0;
274 }
275 
277 {
278  MPCContext *c = s->priv_data;
279  int tag;
280  int64_t pos, size;
281 
282  while(!avio_feof(s->pb)){
283  pos = avio_tell(s->pb);
284 
285  /* don't return bogus packets with the ape tag data */
286  if (c->apetag_start && pos >= c->apetag_start)
287  return AVERROR_EOF;
288 
289  mpc8_get_chunk_header(s->pb, &tag, &size);
290  if (size < 0)
291  return -1;
292  if(tag == TAG_AUDIOPACKET){
293  if(av_get_packet(s->pb, pkt, size) < 0)
294  return AVERROR(ENOMEM);
295  pkt->stream_index = 0;
296  pkt->duration = 1;
297  return 0;
298  }
299  if(tag == TAG_STREAMEND)
300  return AVERROR(EIO);
301  mpc8_handle_chunk(s, tag, pos, size);
302  }
303  return AVERROR_EOF;
304 }
305 
306 static int mpc8_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
307 {
308  AVStream *st = s->streams[stream_index];
309  int index = av_index_search_timestamp(st, timestamp, flags);
310 
311  if(index < 0) return -1;
312  if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
313  return -1;
314  ff_update_cur_dts(s, st, st->index_entries[index].timestamp);
315  return 0;
316 }
317 
318 
320  .name = "mpc8",
321  .long_name = NULL_IF_CONFIG_SMALL("Musepack SV8"),
322  .priv_data_size = sizeof(MPCContext),
327 };
#define NULL
Definition: coverity.c:32
uint64_t ffio_read_varlen(AVIOContext *bc)
Definition: aviobuf.c:832
const char * s
Definition: avisynth_c.h:768
Bytestream IO Context.
Definition: avio.h:147
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
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:1957
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:247
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:4581
int64_t pos
Definition: avformat.h:820
#define MKMPCTAG(a, b)
Two-byte MPC tag.
Definition: mpc8.c:30
static int read_seek(AVFormatContext *ctx, int stream_index, int64_t timestamp, int flags)
Definition: libcdio.c:153
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3981
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:230
AVIndexEntry * index_entries
Only used if the format does not support seeking natively.
Definition: avformat.h:1087
static int64_t bs_get_v(const uint8_t **bs)
Definition: mpc8.c:58
static void mpc8_get_chunk_header(AVIOContext *pb, int *tag, int64_t *size)
Definition: mpc8.c:124
static const int mpc8_rate[8]
Definition: mpc8.c:48
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:304
static AVPacket pkt
Format I/O context.
Definition: avformat.h:1338
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:1871
static void mpc8_handle_chunk(AVFormatContext *s, int tag, int64_t chunk_pos, int64_t size)
Definition: mpc8.c:192
uint8_t bits
Definition: crc.c:296
uint8_t
#define av_malloc(s)
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: avcodec.h:1619
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4214
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1406
static int flags
Definition: log.c:57
uint32_t tag
Definition: movenc.c:1412
#define AVERROR_EOF
End of file.
Definition: error.h:55
bitstream reader API header.
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:289
ptrdiff_t size
Definition: opengl_enc.c:101
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:511
#define av_log(a,...)
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:604
#define AVINDEX_KEYFRAME
Definition: avformat.h:827
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags)
Get the index for a specific timestamp.
Definition: utils.c:2066
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:726
#define AVERROR(e)
Definition: error.h:43
int64_t timestamp
Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are...
Definition: avformat.h:821
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
int64_t samples
Definition: mpc8.c:53
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3977
int64_t ff_ape_parse_tag(AVFormatContext *s)
Read and parse an APE tag.
Definition: apetag.c:118
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:595
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:464
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:463
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1394
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:243
static int read_probe(AVProbeData *pd)
Definition: jvdec.c:55
MPCPacketTags
Reserved MPC tags.
Definition: mpc8.c:35
static int64_t gb_get_v(GetBitContext *gb)
Definition: mpc8.c:109
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:514
static int mpc8_probe(AVProbeData *p)
Definition: mpc8.c:76
Stream structure.
Definition: avformat.h:889
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
AVIOContext * pb
I/O context.
Definition: avformat.h:1380
void * buf
Definition: avisynth_c.h:690
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:299
int index
Definition: gxfenc.c:89
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:410
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:471
This structure contains the data a format has to probe a file.
Definition: avformat.h:461
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:943
int sample_rate
Audio only.
Definition: avcodec.h:4091
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:473
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:710
Main libavformat public API header.
static int mpc8_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Definition: mpc8.c:306
#define TAG_MPCK
Definition: mpc8.c:32
static int get_unary(GetBitContext *gb, int stop, int len)
Get unary code of limited length.
Definition: unary.h:33
int64_t start_time
Decoding: pts of the first frame of the stream in presentation order, in stream time base...
Definition: avformat.h:936
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:3211
int64_t header_pos
Definition: mpc8.c:52
#define AV_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:734
#define av_free(p)
void * priv_data
Format private data.
Definition: avformat.h:1366
int64_t apetag_start
Definition: mpc8.c:55
static AVCodec * c
static int mpc8_read_header(AVFormatContext *s)
Definition: mpc8.c:209
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: avcodec.h:4023
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: avcodec.h:3995
int channels
Audio only.
Definition: avcodec.h:4087
static void mpc8_parse_seektable(AVFormatContext *s, int64_t off)
Definition: mpc8.c:133
static int mpc8_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: mpc8.c:276
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:664
AVCodecParameters * codecpar
Definition: avformat.h:1241
int avio_feof(AVIOContext *s)
feof() equivalent for AVIOContext.
Definition: aviobuf.c:328
int stream_index
Definition: avcodec.h:1603
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:87
This structure stores compressed data.
Definition: avcodec.h:1578
AVInputFormat ff_mpc8_demuxer
Definition: mpc8.c:319
Definition: mpc.h:52
int ver
Definition: mpc.c:40