FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavformat/mpc8.c
Date: 2026-04-20 20:24:43
Exec Total Coverage
Lines: 146 204 71.6%
Functions: 8 9 88.9%
Branches: 64 122 52.5%
Line Branch Exec Source
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 "libavutil/mem.h"
23 #include "libavcodec/get_bits.h"
24 #include "libavcodec/unary.h"
25 #include "apetag.h"
26 #include "avformat.h"
27 #include "demux.h"
28 #include "internal.h"
29 #include "avio_internal.h"
30
31 /// Two-byte MPC tag
32 #define MKMPCTAG(a, b) ((a) | ((b) << 8))
33
34 #define TAG_MPCK MKTAG('M','P','C','K')
35
36 /// Reserved MPC tags
37 enum MPCPacketTags{
38 TAG_STREAMHDR = MKMPCTAG('S','H'),
39 TAG_STREAMEND = MKMPCTAG('S','E'),
40
41 TAG_AUDIOPACKET = MKMPCTAG('A','P'),
42
43 TAG_SEEKTBLOFF = MKMPCTAG('S','O'),
44 TAG_SEEKTABLE = MKMPCTAG('S','T'),
45
46 TAG_REPLAYGAIN = MKMPCTAG('R','G'),
47 TAG_ENCINFO = MKMPCTAG('E','I'),
48 };
49
50 static const int mpc8_rate[8] = { 44100, 48000, 37800, 32000, -1, -1, -1, -1 };
51
52 typedef struct MPCContext {
53 int ver;
54 int64_t header_pos;
55 int64_t samples;
56
57 int64_t apetag_start;
58 } MPCContext;
59
60 2 static inline int64_t bs_get_v(const uint8_t **bs)
61 {
62 2 uint64_t v = 0;
63 2 int br = 0;
64 int c;
65
66 do {
67 2 c = **bs; (*bs)++;
68 2 v <<= 7;
69 2 v |= c & 0x7F;
70 2 br++;
71
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 2 if (br > 10)
72 ✗ return -1;
73
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 2 } while (c & 0x80);
74
75 2 return v - br;
76 }
77
78 7467 static int mpc8_probe(const AVProbeData *p)
79 {
80 7467 const uint8_t *bs = p->buf + 4;
81 7467 const uint8_t *bs_end = bs + p->buf_size;
82 int64_t size;
83
84
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 7467 if (p->buf_size < 16)
85 ✗ return 0;
86
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 7467 if (AV_RL32(p->buf) != TAG_MPCK)
87 7465 return 0;
88
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 2 while (bs < bs_end + 3) {
89
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 2 int header_found = (bs[0] == 'S' && bs[1] == 'H');
90
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 2 if (bs[0] < 'A' || bs[0] > 'Z' || bs[1] < 'A' || bs[1] > 'Z')
91 ✗ return 0;
92 2 bs += 2;
93 2 size = bs_get_v(&bs);
94
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 2 if (size < 2)
95 ✗ return 0;
96
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 2 if (size >= bs_end - bs + 2)
97 ✗ return AVPROBE_SCORE_EXTENSION - 1; // seems to be valid MPC but no header yet
98
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 2 if (header_found) {
99
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 2 if (size < 11 || size > 28)
100 ✗ return 0;
101
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 2 if (!AV_RL32(bs)) //zero CRC is invalid
102 ✗ return 0;
103 2 return AVPROBE_SCORE_MAX;
104 } else {
105 ✗ bs += size - 2;
106 }
107 }
108 ✗ return 0;
109 }
110
111 6 static inline int64_t gb_get_v(GetBitContext *gb)
112 {
113 6 uint64_t v = 0;
114 6 int bits = 0;
115
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 10 while(get_bits1(gb) && bits < 64-7){
116 4 v <<= 7;
117 4 v |= get_bits(gb, 7);
118 4 bits += 7;
119 }
120 6 v <<= 7;
121 6 v |= get_bits(gb, 7);
122
123 6 return v;
124 }
125
126 30 static void mpc8_get_chunk_header(AVIOContext *pb, int *tag, int64_t *size)
127 {
128 int64_t pos;
129 30 pos = avio_tell(pb);
130 30 *tag = avio_rl16(pb);
131 30 *size = ffio_read_varlen(pb);
132 30 pos -= avio_tell(pb);
133
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 30 if (av_sat_add64(*size, pos) != (uint64_t)*size + pos) {
134 ✗ *size = -1;
135 } else
136 30 *size += pos;
137 30 }
138
139 2 static int mpc8_parse_seektable(AVFormatContext *s, int64_t off)
140 {
141 2 MPCContext *c = s->priv_data;
142 int tag;
143 int64_t size, pos, ppos[2];
144 uint8_t *buf;
145 int i, t, seekd, ret;
146 int64_t ret64;
147 GetBitContext gb;
148
149
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 2 if (s->nb_streams == 0) {
150 ✗ av_log(s, AV_LOG_ERROR, "No stream added before parsing seek table\n");
151 ✗ return AVERROR_INVALIDDATA;
152 }
153
154 2 ret64 = avio_seek(s->pb, off, SEEK_SET);
155
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 2 if (ret64 < 0)
156 ✗ return AVERROR_INVALIDDATA;
157 2 mpc8_get_chunk_header(s->pb, &tag, &size);
158
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 2 if(tag != TAG_SEEKTABLE || avio_feof(s->pb)){
159 ✗ av_log(s, AV_LOG_ERROR, "No seek table at given position\n");
160 ✗ return AVERROR_INVALIDDATA;
161 }
162
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 2 if (size > INT_MAX/10 || size<=0) {
163 ✗ av_log(s, AV_LOG_ERROR, "Bad seek table size\n");
164 ✗ return AVERROR_INVALIDDATA;
165 }
166
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 2 if(!(buf = av_malloc(size + AV_INPUT_BUFFER_PADDING_SIZE)))
167 ✗ return AVERROR(ENOMEM);
168 2 ret = avio_read(s->pb, buf, size);
169
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 2 if (ret != size) {
170 ✗ av_log(s, AV_LOG_ERROR, "seek table truncated\n");
171 ✗ av_free(buf);
172 ✗ return AVERROR_INVALIDDATA;
173 }
174 2 memset(buf+size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
175
176 2 init_get_bits(&gb, buf, size * 8);
177 2 size = gb_get_v(&gb);
178
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 2 if(size > UINT_MAX/4 || size > c->samples/1152){
179 ✗ av_log(s, AV_LOG_ERROR, "Seek table is too big\n");
180 ✗ av_free(buf);
181 ✗ return AVERROR_INVALIDDATA;
182 }
183 2 seekd = get_bits(&gb, 4);
184
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 6 for(i = 0; i < 2; i++){
185 4 pos = gb_get_v(&gb);
186
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 4 if (av_sat_add64(pos, c->header_pos) != pos + (uint64_t)c->header_pos) {
187 ✗ av_free(buf);
188 ✗ return AVERROR_INVALIDDATA;
189 }
190
191 4 pos += c->header_pos;
192 4 ppos[1 - i] = pos;
193 4 av_add_index_entry(s->streams[0], pos, i, 0, 0, AVINDEX_KEYFRAME);
194 }
195
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 6 for(; i < size; i++){
196
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 4 if (get_bits_left(&gb) < 13) {
197 ✗ av_free(buf);
198 ✗ return AVERROR_INVALIDDATA;
199 }
200 4 t = get_unary(&gb, 1, 33) << 12;
201 4 t += get_bits(&gb, 12);
202
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 4 if(t & 1)
203 ✗ t = -(t & ~1);
204 4 pos = (t >> 1) + (uint64_t)ppos[0]*2 - ppos[1];
205 4 av_add_index_entry(s->streams[0], pos, (int64_t)i << seekd, 0, 0, AVINDEX_KEYFRAME);
206 4 ppos[1] = ppos[0];
207 4 ppos[0] = pos;
208 }
209 2 av_free(buf);
210 2 return 0;
211 }
212
213 8 static int mpc8_handle_chunk(AVFormatContext *s, int tag, int64_t chunk_pos, int64_t size)
214 {
215 8 AVIOContext *pb = s->pb;
216 int64_t pos, off;
217 int ret;
218
219
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 8 switch(tag){
220 2 case TAG_SEEKTBLOFF:
221 2 pos = avio_tell(pb);
222 2 off = ffio_read_varlen(pb);
223
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 2 if (pos > INT64_MAX - size || off < 0 || off > INT64_MAX - chunk_pos)
224 ✗ return AVERROR_INVALIDDATA;
225 2 pos += size;
226 2 ret = mpc8_parse_seektable(s, chunk_pos + off);
227
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 2 if (ret < 0)
228 ✗ return AVERROR_INVALIDDATA;
229 2 avio_seek(pb, pos, SEEK_SET);
230 2 break;
231 6 default:
232 6 avio_skip(pb, size);
233 }
234 8 return 0;
235 }
236
237 2 static int mpc8_read_header(AVFormatContext *s)
238 {
239 2 MPCContext *c = s->priv_data;
240 2 AVIOContext *pb = s->pb;
241 AVStream *st;
242 2 int tag = 0, ret;
243 int channels;
244 int64_t size, pos;
245
246 2 c->header_pos = avio_tell(pb);
247
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 2 if(avio_rl32(pb) != TAG_MPCK){
248 ✗ av_log(s, AV_LOG_ERROR, "Not a Musepack8 file\n");
249 ✗ return AVERROR_INVALIDDATA;
250 }
251
252
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 2 while(!avio_feof(pb)){
253 2 pos = avio_tell(pb);
254 2 mpc8_get_chunk_header(pb, &tag, &size);
255
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 2 if (size < 0) {
256 ✗ av_log(s, AV_LOG_ERROR, "Invalid chunk length\n");
257 ✗ return AVERROR_INVALIDDATA;
258 }
259
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 2 if(tag == TAG_STREAMHDR)
260 2 break;
261 ✗ ret = mpc8_handle_chunk(s, tag, pos, size);
262 ✗ if (ret < 0)
263 ✗ return ret;
264 }
265
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 2 if(tag != TAG_STREAMHDR){
266 ✗ av_log(s, AV_LOG_ERROR, "Stream header not found\n");
267 ✗ return AVERROR_INVALIDDATA;
268 }
269 2 pos = avio_tell(pb);
270 2 avio_skip(pb, 4); //CRC
271 2 c->ver = avio_r8(pb);
272
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 2 if(c->ver != 8){
273 ✗ avpriv_report_missing_feature(s, "Stream version %d", c->ver);
274 ✗ return AVERROR_PATCHWELCOME;
275 }
276 2 c->samples = ffio_read_varlen(pb);
277 2 ffio_read_varlen(pb); //silence samples at the beginning
278
279 2 st = avformat_new_stream(s, NULL);
280
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 2 if (!st)
281 ✗ return AVERROR(ENOMEM);
282 2 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
283 2 st->codecpar->codec_id = AV_CODEC_ID_MUSEPACK8;
284 2 st->codecpar->bits_per_coded_sample = 16;
285
286
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 2 if ((ret = ff_get_extradata(s, st->codecpar, pb, 2)) < 0)
287 ✗ return ret;
288
289 2 channels = (st->codecpar->extradata[1] >> 4) + 1;
290 2 st->codecpar->ch_layout.nb_channels = channels;
291 2 st->codecpar->sample_rate = mpc8_rate[st->codecpar->extradata[0] >> 5];
292 2 avpriv_set_pts_info(st, 64, 1152 << (st->codecpar->extradata[1]&3)*2, st->codecpar->sample_rate);
293 2 st->start_time = 0;
294 2 st->duration = c->samples / (1152 << (st->codecpar->extradata[1]&3)*2);
295 2 size -= avio_tell(pb) - pos;
296
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 2 if (size > 0)
297 ✗ avio_skip(pb, size);
298
299
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 2 if (pb->seekable & AVIO_SEEKABLE_NORMAL) {
300 2 pos = avio_tell(s->pb);
301 2 c->apetag_start = ff_ape_parse_tag(s);
302 2 avio_seek(s->pb, pos, SEEK_SET);
303 }
304
305 2 return 0;
306 }
307
308 18 static int mpc8_read_packet(AVFormatContext *s, AVPacket *pkt)
309 {
310 18 MPCContext *c = s->priv_data;
311 int tag, ret;
312 int64_t pos, size;
313
314
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 26 while(!avio_feof(s->pb)){
315 26 pos = avio_tell(s->pb);
316
317 /* don't return bogus packets with the ape tag data */
318
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 26 if (c->apetag_start && pos >= c->apetag_start)
319 ✗ return AVERROR_EOF;
320
321 26 mpc8_get_chunk_header(s->pb, &tag, &size);
322
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 26 if (size < 0 || size > INT_MAX)
323 ✗ return -1;
324
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 26 if(tag == TAG_AUDIOPACKET){
325
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 16 if ((ret = av_get_packet(s->pb, pkt, size)) < 0)
326 ✗ return ret;
327 16 pkt->stream_index = 0;
328 16 pkt->duration = 1;
329 16 return 0;
330 }
331
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 10 if(tag == TAG_STREAMEND)
332 2 return AVERROR_EOF;
333 8 mpc8_handle_chunk(s, tag, pos, size);
334 }
335 ✗ return AVERROR_EOF;
336 }
337
338 ✗ static int mpc8_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
339 {
340 ✗ AVStream *st = s->streams[stream_index];
341 ✗ FFStream *const sti = ffstream(st);
342 ✗ int index = av_index_search_timestamp(st, timestamp, flags);
343
344 ✗ if(index < 0) return -1;
345 ✗ if (avio_seek(s->pb, sti->index_entries[index].pos, SEEK_SET) < 0)
346 ✗ return -1;
347 ✗ avpriv_update_cur_dts(s, st, sti->index_entries[index].timestamp);
348 ✗ return 0;
349 }
350
351
352 const FFInputFormat ff_mpc8_demuxer = {
353 .p.name = "mpc8",
354 .p.long_name = NULL_IF_CONFIG_SMALL("Musepack SV8"),
355 .priv_data_size = sizeof(MPCContext),
356 .read_probe = mpc8_probe,
357 .read_header = mpc8_read_header,
358 .read_packet = mpc8_read_packet,
359 .read_seek = mpc8_read_seek,
360 };
361