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
35 enum MPCPacketTags{
36 TAG_STREAMHDR = MKMPCTAG('S','H'),
37 TAG_STREAMEND = MKMPCTAG('S','E'),
38
39 TAG_AUDIOPACKET = MKMPCTAG('A','P'),
40
41 TAG_SEEKTBLOFF = MKMPCTAG('S','O'),
42 TAG_SEEKTABLE = MKMPCTAG('S','T'),
43
44 TAG_REPLAYGAIN = MKMPCTAG('R','G'),
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
bs_get_v(const uint8_t ** bs)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
mpc8_probe(const AVProbeData * p)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
gb_get_v(GetBitContext * gb)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
mpc8_get_chunk_header(AVIOContext * pb,int * tag,int64_t * size)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 pos -= avio_tell(pb);
131 if (av_sat_add64(*size, pos) != (uint64_t)*size + pos) {
132 *size = -1;
133 } else
134 *size += pos;
135 }
136
mpc8_parse_seektable(AVFormatContext * s,int64_t off)137 static void mpc8_parse_seektable(AVFormatContext *s, int64_t off)
138 {
139 MPCContext *c = s->priv_data;
140 int tag;
141 int64_t size, pos, ppos[2];
142 uint8_t *buf;
143 int i, t, seekd, ret;
144 GetBitContext gb;
145
146 if (s->nb_streams == 0) {
147 av_log(s, AV_LOG_ERROR, "No stream added before parsing seek table\n");
148 return;
149 }
150
151 avio_seek(s->pb, off, SEEK_SET);
152 mpc8_get_chunk_header(s->pb, &tag, &size);
153 if(tag != TAG_SEEKTABLE){
154 av_log(s, AV_LOG_ERROR, "No seek table at given position\n");
155 return;
156 }
157 if (size > INT_MAX/10 || size<=0) {
158 av_log(s, AV_LOG_ERROR, "Bad seek table size\n");
159 return;
160 }
161 if(!(buf = av_malloc(size + AV_INPUT_BUFFER_PADDING_SIZE)))
162 return;
163 ret = avio_read(s->pb, buf, size);
164 if (ret != size) {
165 av_log(s, AV_LOG_ERROR, "seek table truncated\n");
166 av_free(buf);
167 return;
168 }
169 memset(buf+size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
170
171 init_get_bits(&gb, buf, size * 8);
172 size = gb_get_v(&gb);
173 if(size > UINT_MAX/4 || size > c->samples/1152){
174 av_log(s, AV_LOG_ERROR, "Seek table is too big\n");
175 av_free(buf);
176 return;
177 }
178 seekd = get_bits(&gb, 4);
179 for(i = 0; i < 2; i++){
180 pos = gb_get_v(&gb);
181 if (av_sat_add64(pos, c->header_pos) != pos + (uint64_t)c->header_pos) {
182 av_free(buf);
183 return;
184 }
185
186 pos += c->header_pos;
187 ppos[1 - i] = pos;
188 av_add_index_entry(s->streams[0], pos, i, 0, 0, AVINDEX_KEYFRAME);
189 }
190 for(; i < size; i++){
191 if (get_bits_left(&gb) < 13) {
192 av_free(buf);
193 return;
194 }
195 t = get_unary(&gb, 1, 33) << 12;
196 t += get_bits(&gb, 12);
197 if(t & 1)
198 t = -(t & ~1);
199 pos = (t >> 1) + (uint64_t)ppos[0]*2 - ppos[1];
200 av_add_index_entry(s->streams[0], pos, (int64_t)i << seekd, 0, 0, AVINDEX_KEYFRAME);
201 ppos[1] = ppos[0];
202 ppos[0] = pos;
203 }
204 av_free(buf);
205 }
206
mpc8_handle_chunk(AVFormatContext * s,int tag,int64_t chunk_pos,int64_t size)207 static void mpc8_handle_chunk(AVFormatContext *s, int tag, int64_t chunk_pos, int64_t size)
208 {
209 AVIOContext *pb = s->pb;
210 int64_t pos, off;
211
212 switch(tag){
213 case TAG_SEEKTBLOFF:
214 pos = avio_tell(pb);
215 off = ffio_read_varlen(pb);
216 if (pos > INT64_MAX - size || off < 0 || off > INT64_MAX - chunk_pos)
217 return;
218 pos += size;
219 mpc8_parse_seektable(s, chunk_pos + off);
220 avio_seek(pb, pos, SEEK_SET);
221 break;
222 default:
223 avio_skip(pb, size);
224 }
225 }
226
mpc8_read_header(AVFormatContext * s)227 static int mpc8_read_header(AVFormatContext *s)
228 {
229 MPCContext *c = s->priv_data;
230 AVIOContext *pb = s->pb;
231 AVStream *st;
232 int tag = 0, ret;
233 int64_t size, pos;
234
235 c->header_pos = avio_tell(pb);
236 if(avio_rl32(pb) != TAG_MPCK){
237 av_log(s, AV_LOG_ERROR, "Not a Musepack8 file\n");
238 return AVERROR_INVALIDDATA;
239 }
240
241 while(!avio_feof(pb)){
242 pos = avio_tell(pb);
243 mpc8_get_chunk_header(pb, &tag, &size);
244 if (size < 0) {
245 av_log(s, AV_LOG_ERROR, "Invalid chunk length\n");
246 return AVERROR_INVALIDDATA;
247 }
248 if(tag == TAG_STREAMHDR)
249 break;
250 mpc8_handle_chunk(s, tag, pos, size);
251 }
252 if(tag != TAG_STREAMHDR){
253 av_log(s, AV_LOG_ERROR, "Stream header not found\n");
254 return AVERROR_INVALIDDATA;
255 }
256 pos = avio_tell(pb);
257 avio_skip(pb, 4); //CRC
258 c->ver = avio_r8(pb);
259 if(c->ver != 8){
260 avpriv_report_missing_feature(s, "Stream version %d", c->ver);
261 return AVERROR_PATCHWELCOME;
262 }
263 c->samples = ffio_read_varlen(pb);
264 ffio_read_varlen(pb); //silence samples at the beginning
265
266 st = avformat_new_stream(s, NULL);
267 if (!st)
268 return AVERROR(ENOMEM);
269 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
270 st->codecpar->codec_id = AV_CODEC_ID_MUSEPACK8;
271 st->codecpar->bits_per_coded_sample = 16;
272
273 if ((ret = ff_get_extradata(s, st->codecpar, pb, 2)) < 0)
274 return ret;
275
276 st->codecpar->channels = (st->codecpar->extradata[1] >> 4) + 1;
277 st->codecpar->sample_rate = mpc8_rate[st->codecpar->extradata[0] >> 5];
278 avpriv_set_pts_info(st, 64, 1152 << (st->codecpar->extradata[1]&3)*2, st->codecpar->sample_rate);
279 st->start_time = 0;
280 st->duration = c->samples / (1152 << (st->codecpar->extradata[1]&3)*2);
281 size -= avio_tell(pb) - pos;
282 if (size > 0)
283 avio_skip(pb, size);
284
285 if (pb->seekable & AVIO_SEEKABLE_NORMAL) {
286 int64_t pos = avio_tell(s->pb);
287 c->apetag_start = ff_ape_parse_tag(s);
288 avio_seek(s->pb, pos, SEEK_SET);
289 }
290
291 return 0;
292 }
293
mpc8_read_packet(AVFormatContext * s,AVPacket * pkt)294 static int mpc8_read_packet(AVFormatContext *s, AVPacket *pkt)
295 {
296 MPCContext *c = s->priv_data;
297 int tag, ret;
298 int64_t pos, size;
299
300 while(!avio_feof(s->pb)){
301 pos = avio_tell(s->pb);
302
303 /* don't return bogus packets with the ape tag data */
304 if (c->apetag_start && pos >= c->apetag_start)
305 return AVERROR_EOF;
306
307 mpc8_get_chunk_header(s->pb, &tag, &size);
308 if (size < 0 || size > INT_MAX)
309 return -1;
310 if(tag == TAG_AUDIOPACKET){
311 if ((ret = av_get_packet(s->pb, pkt, size)) < 0)
312 return ret;
313 pkt->stream_index = 0;
314 pkt->duration = 1;
315 return 0;
316 }
317 if(tag == TAG_STREAMEND)
318 return AVERROR_EOF;
319 mpc8_handle_chunk(s, tag, pos, size);
320 }
321 return AVERROR_EOF;
322 }
323
mpc8_read_seek(AVFormatContext * s,int stream_index,int64_t timestamp,int flags)324 static int mpc8_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
325 {
326 AVStream *st = s->streams[stream_index];
327 int index = av_index_search_timestamp(st, timestamp, flags);
328
329 if(index < 0) return -1;
330 if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
331 return -1;
332 ff_update_cur_dts(s, st, st->index_entries[index].timestamp);
333 return 0;
334 }
335
336
337 AVInputFormat ff_mpc8_demuxer = {
338 .name = "mpc8",
339 .long_name = NULL_IF_CONFIG_SMALL("Musepack SV8"),
340 .priv_data_size = sizeof(MPCContext),
341 .read_probe = mpc8_probe,
342 .read_header = mpc8_read_header,
343 .read_packet = mpc8_read_packet,
344 .read_seek = mpc8_read_seek,
345 };
346