Libav
mpc8.c
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1 /*
2  * Musepack SV8 demuxer
3  * Copyright (c) 2007 Konstantin Shishkov
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; 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 
30 #define MKMPCTAG(a, b) (a | (b << 8))
31 
32 #define TAG_MPCK MKTAG('M','P','C','K')
33 
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 {
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(uint8_t **bs)
59 {
60  int64_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  uint8_t *bs = p->buf + 4;
79  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  int64_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;
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 < 0 || size >= INT_MAX / 2) {
154  av_log(s, AV_LOG_ERROR, "Bad seek table size\n");
155  return;
156  }
157  if(!(buf = av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE)))
158  return;
159  avio_read(s->pb, buf, size);
160  init_get_bits(&gb, buf, size * 8);
161  size = gb_get_v(&gb);
162  if(size > UINT_MAX/4 || size > c->samples/1152){
163  av_log(s, AV_LOG_ERROR, "Seek table is too big\n");
164  return;
165  }
166  seekd = get_bits(&gb, 4);
167  for(i = 0; i < 2; i++){
168  pos = gb_get_v(&gb) + c->header_pos;
169  ppos[1 - i] = pos;
170  av_add_index_entry(s->streams[0], pos, i, 0, 0, AVINDEX_KEYFRAME);
171  }
172  for(; i < size; i++){
173  t = get_unary(&gb, 1, 33) << 12;
174  t += get_bits(&gb, 12);
175  if(t & 1)
176  t = -(t & ~1);
177  pos = (t >> 1) + ppos[0]*2 - ppos[1];
178  av_add_index_entry(s->streams[0], pos, i << seekd, 0, 0, AVINDEX_KEYFRAME);
179  ppos[1] = ppos[0];
180  ppos[0] = pos;
181  }
182  av_free(buf);
183 }
184 
185 static void mpc8_handle_chunk(AVFormatContext *s, int tag, int64_t chunk_pos, int64_t size)
186 {
187  AVIOContext *pb = s->pb;
188  int64_t pos, off;
189 
190  switch(tag){
191  case TAG_SEEKTBLOFF:
192  pos = avio_tell(pb) + size;
193  off = ffio_read_varlen(pb);
194  mpc8_parse_seektable(s, chunk_pos + off);
195  avio_seek(pb, pos, SEEK_SET);
196  break;
197  default:
198  avio_skip(pb, size);
199  }
200 }
201 
203 {
204  MPCContext *c = s->priv_data;
205  AVIOContext *pb = s->pb;
206  AVStream *st;
207  int tag = 0;
208  int64_t size, pos;
209 
210  c->header_pos = avio_tell(pb);
211  if(avio_rl32(pb) != TAG_MPCK){
212  av_log(s, AV_LOG_ERROR, "Not a Musepack8 file\n");
213  return AVERROR_INVALIDDATA;
214  }
215 
216  while(!pb->eof_reached){
217  pos = avio_tell(pb);
218  mpc8_get_chunk_header(pb, &tag, &size);
219  if (size < 0) {
220  av_log(s, AV_LOG_ERROR, "Invalid chunk length\n");
221  return AVERROR_INVALIDDATA;
222  }
223  if(tag == TAG_STREAMHDR)
224  break;
225  mpc8_handle_chunk(s, tag, pos, size);
226  }
227  if(tag != TAG_STREAMHDR){
228  av_log(s, AV_LOG_ERROR, "Stream header not found\n");
229  return AVERROR_INVALIDDATA;
230  }
231  pos = avio_tell(pb);
232  avio_skip(pb, 4); //CRC
233  c->ver = avio_r8(pb);
234  if(c->ver != 8){
235  av_log(s, AV_LOG_ERROR, "Unknown stream version %d\n", c->ver);
236  return AVERROR_PATCHWELCOME;
237  }
238  c->samples = ffio_read_varlen(pb);
239  ffio_read_varlen(pb); //silence samples at the beginning
240 
241  st = avformat_new_stream(s, NULL);
242  if (!st)
243  return AVERROR(ENOMEM);
246  st->codec->bits_per_coded_sample = 16;
247 
248  st->codec->extradata_size = 2;
250  avio_read(pb, st->codec->extradata, st->codec->extradata_size);
251 
252  st->codec->channels = (st->codec->extradata[1] >> 4) + 1;
253  st->codec->sample_rate = mpc8_rate[st->codec->extradata[0] >> 5];
254  avpriv_set_pts_info(st, 32, 1152 << (st->codec->extradata[1]&3)*2, st->codec->sample_rate);
255  st->start_time = 0;
256  st->duration = c->samples / (1152 << (st->codec->extradata[1]&3)*2);
257  size -= avio_tell(pb) - pos;
258 
259  if (pb->seekable) {
260  int64_t pos = avio_tell(s->pb);
262  avio_seek(s->pb, pos, SEEK_SET);
263  }
264 
265  return 0;
266 }
267 
269 {
270  MPCContext *c = s->priv_data;
271  int tag;
272  int64_t pos, size;
273 
274  while(!s->pb->eof_reached){
275  pos = avio_tell(s->pb);
276 
277  /* don't return bogus packets with the ape tag data */
278  if (c->apetag_start && pos >= c->apetag_start)
279  return AVERROR_EOF;
280 
281  mpc8_get_chunk_header(s->pb, &tag, &size);
282  if (size < 0)
283  return -1;
284  if(tag == TAG_AUDIOPACKET){
285  if(av_get_packet(s->pb, pkt, size) < 0)
286  return AVERROR(ENOMEM);
287  pkt->stream_index = 0;
288  pkt->duration = 1;
289  return 0;
290  }
291  if(tag == TAG_STREAMEND)
292  return AVERROR(EIO);
293  mpc8_handle_chunk(s, tag, pos, size);
294  }
295  return AVERROR_EOF;
296 }
297 
298 static int mpc8_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
299 {
300  AVStream *st = s->streams[stream_index];
301  int index = av_index_search_timestamp(st, timestamp, flags);
302 
303  if(index < 0) return -1;
304  if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
305  return -1;
306  ff_update_cur_dts(s, st, st->index_entries[index].timestamp);
307  return 0;
308 }
309 
310 
312  .name = "mpc8",
313  .long_name = NULL_IF_CONFIG_SMALL("Musepack SV8"),
314  .priv_data_size = sizeof(MPCContext),
319 };
uint64_t ffio_read_varlen(AVIOContext *bc)
Definition: aviobuf.c:679
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:62
Bytestream IO Context.
Definition: avio.h:68
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:54
int size
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:1181
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:240
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:2829
int64_t pos
Definition: avformat.h:660
#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
static int64_t bs_get_v(uint8_t **bs)
Definition: mpc8.c:58
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:186
AVIndexEntry * index_entries
Only used if the format does not support seeking natively.
Definition: avformat.h:878
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
Format I/O context.
Definition: avformat.h:922
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:1104
static void mpc8_handle_chunk(AVFormatContext *s, int tag, int64_t chunk_pos, int64_t size)
Definition: mpc8.c:185
uint8_t bits
Definition: crc.c:251
uint8_t
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1164
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:2521
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:990
static int flags
Definition: log.c:44
uint32_t tag
Definition: movenc.c:844
#define AVERROR_EOF
End of file.
Definition: error.h:51
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:117
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:219
int bits_per_coded_sample
bits per sample/pixel from the demuxer (needed for huffyuv).
Definition: avcodec.h:2523
int duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: avcodec.h:991
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:463
#define AVINDEX_KEYFRAME
Definition: avformat.h:662
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:123
void av_free(void *ptr)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc(). ...
Definition: mem.c:186
int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags)
Get the index for a specific timestamp.
Definition: utils.c:1222
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:575
#define AVERROR(e)
Definition: error.h:43
int64_t timestamp
Definition: avformat.h:661
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:145
int64_t samples
Definition: mpc8.c:53
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:169
int64_t ff_ape_parse_tag(AVFormatContext *s)
Read and parse an APE tag.
Definition: apetag.c:122
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:454
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:718
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:398
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:397
#define FF_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:531
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:978
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:117
static int read_probe(AVProbeData *pd)
Definition: jvdec.c:55
static av_always_inline int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: avio.h:210
MPCPacketTags
Reserved MPC tags.
Definition: mpc8.c:35
static int64_t gb_get_v(GetBitContext *gb)
Definition: mpc8.c:109
#define AV_RL32
Definition: intreadwrite.h:146
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:544
static int mpc8_probe(AVProbeData *p)
Definition: mpc8.c:76
Stream structure.
Definition: avformat.h:699
#define AVERROR_PATCHWELCOME
Not yet implemented in Libav, patches welcome.
Definition: error.h:57
NULL
Definition: eval.c:55
enum AVMediaType codec_type
Definition: avcodec.h:1058
enum AVCodecID codec_id
Definition: avcodec.h:1067
int sample_rate
samples per second
Definition: avcodec.h:1807
AVIOContext * pb
I/O context.
Definition: avformat.h:964
int extradata_size
Definition: avcodec.h:1165
static int read_packet(AVFormatContext *ctx, AVPacket *pkt)
Definition: libcdio.c:114
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:271
int index
Definition: gxfenc.c:72
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:375
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:402
This structure contains the data a format has to probe a file.
Definition: avformat.h:395
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:756
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:404
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:559
Main libavformat public API header.
static int mpc8_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Definition: mpc8.c:298
#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 stream time base.
Definition: avformat.h:749
int64_t header_pos
Definition: mpc8.c:52
int eof_reached
true if eof reached
Definition: avio.h:96
int channels
number of audio channels
Definition: avcodec.h:1808
void * priv_data
Format private data.
Definition: avformat.h:950
int64_t apetag_start
Definition: mpc8.c:55
static int mpc8_read_header(AVFormatContext *s)
Definition: mpc8.c:202
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:268
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:525
int stream_index
Definition: avcodec.h:975
This structure stores compressed data.
Definition: avcodec.h:950
void * av_mallocz(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:205
AVInputFormat ff_mpc8_demuxer
Definition: mpc8.c:311
Definition: mpc.h:52
int ver
Definition: mpc.c:40