mpc.c
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1 /*
2  * Musepack demuxer
3  * Copyright (c) 2006 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 "avformat.h"
24 #include "internal.h"
25 #include "apetag.h"
26 #include "id3v1.h"
27 #include "libavutil/dict.h"
28 
29 #define MPC_FRAMESIZE 1152
30 #define DELAY_FRAMES 32
31 
32 static const int mpc_rate[4] = { 44100, 48000, 37800, 32000 };
33 typedef struct {
34  int64_t pos;
35  int size, skip;
36 }MPCFrame;
37 
38 typedef struct {
39  int ver;
40  uint32_t curframe, lastframe;
41  uint32_t fcount;
43  int curbits;
45 } MPCContext;
46 
47 static int mpc_probe(AVProbeData *p)
48 {
49  const uint8_t *d = p->buf;
50  if (d[0] == 'M' && d[1] == 'P' && d[2] == '+' && (d[3] == 0x17 || d[3] == 0x7))
51  return AVPROBE_SCORE_MAX;
52  return 0;
53 }
54 
56 {
57  MPCContext *c = s->priv_data;
58  AVStream *st;
59 
60  if(avio_rl24(s->pb) != MKTAG('M', 'P', '+', 0)){
61  av_log(s, AV_LOG_ERROR, "Not a Musepack file\n");
62  return -1;
63  }
64  c->ver = avio_r8(s->pb);
65  if(c->ver != 0x07 && c->ver != 0x17){
66  av_log(s, AV_LOG_ERROR, "Can demux Musepack SV7, got version %02X\n", c->ver);
67  return -1;
68  }
69  c->fcount = avio_rl32(s->pb);
70  if((int64_t)c->fcount * sizeof(MPCFrame) >= UINT_MAX){
71  av_log(s, AV_LOG_ERROR, "Too many frames, seeking is not possible\n");
72  return -1;
73  }
74  if(c->fcount){
75  c->frames = av_malloc(c->fcount * sizeof(MPCFrame));
76  if(!c->frames){
77  av_log(s, AV_LOG_ERROR, "Cannot allocate seektable\n");
78  return AVERROR(ENOMEM);
79  }
80  }else{
81  av_log(s, AV_LOG_WARNING, "Container reports no frames\n");
82  }
83  c->curframe = 0;
84  c->lastframe = -1;
85  c->curbits = 8;
86  c->frames_noted = 0;
87 
88  st = avformat_new_stream(s, NULL);
89  if (!st)
90  return AVERROR(ENOMEM);
93  st->codec->channels = 2;
94  st->codec->bits_per_coded_sample = 16;
95 
96  st->codec->extradata_size = 16;
98  avio_read(s->pb, st->codec->extradata, 16);
99  st->codec->sample_rate = mpc_rate[st->codec->extradata[2] & 3];
101  /* scan for seekpoints */
102  st->start_time = 0;
103  st->duration = c->fcount;
104 
105  /* try to read APE tags */
106  if (s->pb->seekable) {
107  int64_t pos = avio_tell(s->pb);
108  ff_ape_parse_tag(s);
110  ff_id3v1_read(s);
111  avio_seek(s->pb, pos, SEEK_SET);
112  }
113 
114  return 0;
115 }
116 
118 {
119  MPCContext *c = s->priv_data;
120  int ret, size, size2, curbits, cur = c->curframe;
121  unsigned tmp;
122  int64_t pos;
123 
124  if (c->curframe >= c->fcount && c->fcount)
125  return -1;
126 
127  if(c->curframe != c->lastframe + 1){
128  avio_seek(s->pb, c->frames[c->curframe].pos, SEEK_SET);
129  c->curbits = c->frames[c->curframe].skip;
130  }
131  c->lastframe = c->curframe;
132  c->curframe++;
133  curbits = c->curbits;
134  pos = avio_tell(s->pb);
135  tmp = avio_rl32(s->pb);
136  if(curbits <= 12){
137  size2 = (tmp >> (12 - curbits)) & 0xFFFFF;
138  }else{
139  size2 = (tmp << (curbits - 12) | avio_rl32(s->pb) >> (44 - curbits)) & 0xFFFFF;
140  }
141  curbits += 20;
142  avio_seek(s->pb, pos, SEEK_SET);
143 
144  size = ((size2 + curbits + 31) & ~31) >> 3;
145  if(cur == c->frames_noted && c->fcount){
146  c->frames[cur].pos = pos;
147  c->frames[cur].size = size;
148  c->frames[cur].skip = curbits - 20;
149  av_add_index_entry(s->streams[0], cur, cur, size, 0, AVINDEX_KEYFRAME);
150  c->frames_noted++;
151  }
152  c->curbits = (curbits + size2) & 0x1F;
153 
154  if (av_new_packet(pkt, size) < 0)
155  return AVERROR(EIO);
156 
157  pkt->data[0] = curbits;
158  pkt->data[1] = (c->curframe > c->fcount) && c->fcount;
159  pkt->data[2] = 0;
160  pkt->data[3] = 0;
161 
162  pkt->stream_index = 0;
163  pkt->pts = cur;
164  ret = avio_read(s->pb, pkt->data + 4, size);
165  if(c->curbits)
166  avio_seek(s->pb, -4, SEEK_CUR);
167  if(ret < size){
168  av_free_packet(pkt);
169  return AVERROR(EIO);
170  }
171  pkt->size = ret + 4;
172 
173  return 0;
174 }
175 
177 {
178  MPCContext *c = s->priv_data;
179 
180  av_freep(&c->frames);
181  return 0;
182 }
183 
191 static int mpc_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
192 {
193  AVStream *st = s->streams[stream_index];
194  MPCContext *c = s->priv_data;
195  AVPacket pkt1, *pkt = &pkt1;
196  int ret;
197  int index = av_index_search_timestamp(st, timestamp - DELAY_FRAMES, flags);
198  uint32_t lastframe;
199 
200  /* if found, seek there */
201  if (index >= 0){
202  c->curframe = st->index_entries[index].pos;
203  return 0;
204  }
205  /* if timestamp is out of bounds, return error */
206  if(timestamp < 0 || timestamp >= c->fcount)
207  return -1;
208  timestamp -= DELAY_FRAMES;
209  /* seek to the furthest known position and read packets until
210  we reach desired position */
211  lastframe = c->curframe;
212  if(c->frames_noted) c->curframe = c->frames_noted - 1;
213  while(c->curframe < timestamp){
214  ret = av_read_frame(s, pkt);
215  if (ret < 0){
216  c->curframe = lastframe;
217  return -1;
218  }
219  av_free_packet(pkt);
220  }
221  return 0;
222 }
223 
224 
226  .name = "mpc",
227  .long_name = NULL_IF_CONFIG_SMALL("Musepack"),
228  .priv_data_size = sizeof(MPCContext),
234  .extensions = "mpc",
235 };
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:154
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:1474
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the pts for a given stream.
Definition: utils.c:3828
int64_t pos
Definition: avformat.h:588
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:60
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:117
uint32_t fcount
Definition: mpc.c:41
static int read_seek(AVFormatContext *ctx, int stream_index, int64_t timestamp, int flags)
Definition: libcdio.c:148
void ff_id3v1_read(AVFormatContext *s)
Read an ID3v1 tag.
Definition: id3v1.c:227
int size
Definition: avcodec.h:909
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:211
AVIndexEntry * index_entries
Only used if the format does not support seeking natively.
Definition: avformat.h:818
AVDictionaryEntry * av_dict_get(AVDictionary *m, const char *key, const AVDictionaryEntry *prev, int flags)
Get a dictionary entry with matching key.
Definition: dict.c:27
void av_freep(void *arg)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc() and set the pointer ...
Definition: mem.c:147
Format I/O context.
Definition: avformat.h:863
Public dictionary API.
static int mpc_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: mpc.c:117
static int mpc_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Seek to the given position If position is unknown but is within the limits of file then packets are s...
Definition: mpc.c:191
static int mpc_read_close(AVFormatContext *s)
Definition: mpc.c:176
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1387
AVStream ** streams
Definition: avformat.h:908
static int read_header(FFV1Context *f)
Definition: ffv1.c:1513
uint8_t * data
Definition: avcodec.h:908
static int flags
Definition: log.c:34
void av_free_packet(AVPacket *pkt)
Free a packet.
Definition: avpacket.c:151
bitstream reader API header.
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:140
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:492
int bits_per_coded_sample
bits per sample/pixel from the demuxer (needed for huffyuv).
Definition: avcodec.h:1974
uint32_t lastframe
Definition: mpc.c:40
static const int mpc_rate[4]
Definition: mpc.c:32
MPCFrame * frames
Definition: mpc.c:42
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:652
#define AVINDEX_KEYFRAME
Definition: avformat.h:590
AVDictionary * metadata
Definition: avformat.h:1085
int frames_noted
Definition: mpc.c:44
int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags)
Get the index for a specific timestamp.
Definition: utils.c:1516
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:738
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:191
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:140
AVStream * avformat_new_stream(AVFormatContext *s, AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:2776
#define DELAY_FRAMES
Definition: mpc.c:30
static int mpc_read_header(AVFormatContext *s, AVFormatParameters *ap)
Definition: mpc.c:55
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:632
AVCodecContext * codec
codec context
Definition: avformat.h:623
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:341
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:122
uint32_t curframe
Definition: mpc.c:40
void ff_ape_parse_tag(AVFormatContext *s)
Read and parse an APE tag.
Definition: apetag.c:67
static int read_probe(AVProbeData *p)
Definition: img2.c:185
int skip
Definition: mpc.c:35
AVInputFormat ff_mpc_demuxer
Definition: mpc.c:225
#define MPC_FRAMESIZE
Definition: mpc.c:29
Stream structure.
Definition: avformat.h:620
NULL
Definition: eval.c:50
int64_t pos
Definition: mpc.c:34
enum AVMediaType codec_type
Definition: avcodec.h:1574
int sample_rate
samples per second
Definition: avcodec.h:1456
AVIOContext * pb
Definition: avformat.h:896
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:111
int extradata_size
Definition: avcodec.h:1388
static int read_packet(AVFormatContext *ctx, AVPacket *pkt)
Definition: libcdio.c:109
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:64
int index
Definition: gxfenc.c:73
#define FF_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:497
Definition: mpc.c:33
This structure contains the data a format has to probe a file.
Definition: avformat.h:339
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
Definition: utils.c:1264
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:684
#define AVPROBE_SCORE_MAX
maximum score, half of that is used for file-extension-based detection
Definition: avformat.h:345
Main libavformat public API header.
int curbits
Definition: mpc.c:43
static int mpc_probe(AVProbeData *p)
Definition: mpc.c:47
int64_t start_time
Decoding: pts of the first frame of the stream, in stream time base.
Definition: avformat.h:677
int channels
number of audio channels
Definition: avcodec.h:1457
int frames
Definition: mpc.h:64
void * priv_data
Format private data.
Definition: avformat.h:883
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:460
#define AV_DICT_IGNORE_SUFFIX
Definition: dict.h:62
unsigned int avio_rl24(AVIOContext *s)
Definition: aviobuf.c:730
int stream_index
Definition: avcodec.h:910
#define MKTAG(a, b, c, d)
Definition: common.h:231
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:901
Definition: mpc.h:52
int ver
Definition: mpc.c:39
enum CodecID codec_id
Definition: avcodec.h:1575