3 * Copyright (c) 2007 Konstantin Shishkov
5 * This file is part of Libav.
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.
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.
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
22 #include "libavcodec/get_bits.h"
23 #include "libavcodec/unary.h"
27 #include "avio_internal.h"
30 #define MKMPCTAG(a, b) (a | (b << 8))
32 #define TAG_MPCK MKTAG('M','P','C','K')
36 TAG_STREAMHDR = MKMPCTAG('S','H'),
37 TAG_STREAMEND = MKMPCTAG('S','E'),
39 TAG_AUDIOPACKET = MKMPCTAG('A','P'),
41 TAG_SEEKTBLOFF = MKMPCTAG('S','O'),
42 TAG_SEEKTABLE = MKMPCTAG('S','T'),
44 TAG_REPLAYGAIN = MKMPCTAG('R','G'),
45 TAG_ENCINFO = MKMPCTAG('E','I'),
48 static const int mpc8_rate[8] = { 44100, 48000, 37800, 32000, -1, -1, -1, -1 };
59 static inline int64_t bs_get_v(uint8_t **bs)
77 static int mpc8_probe(AVProbeData *p)
79 uint8_t *bs = p->buf + 4;
80 uint8_t *bs_end = bs + p->buf_size;
85 if (AV_RL32(p->buf) != TAG_MPCK)
87 while (bs < bs_end + 3) {
88 int header_found = (bs[0] == 'S' && bs[1] == 'H');
89 if (bs[0] < 'A' || bs[0] > 'Z' || bs[1] < 'A' || bs[1] > 'Z')
95 if (bs + size - 2 >= bs_end)
96 return AVPROBE_SCORE_MAX / 4 - 1; //seems to be valid MPC but no header yet
98 if (size < 11 || size > 28)
100 if (!AV_RL32(bs)) //zero CRC is invalid
102 return AVPROBE_SCORE_MAX;
110 static inline int64_t gb_get_v(GetBitContext *gb)
114 while(get_bits1(gb) && bits < 64-7){
116 v |= get_bits(gb, 7);
120 v |= get_bits(gb, 7);
125 static void mpc8_get_chunk_header(AVIOContext *pb, int *tag, int64_t *size)
129 *tag = avio_rl16(pb);
130 *size = ffio_read_varlen(pb);
131 *size -= avio_tell(pb) - pos;
134 static void mpc8_parse_seektable(AVFormatContext *s, int64_t off)
136 MPCContext *c = s->priv_data;
138 int64_t size, pos, ppos[2];
143 avio_seek(s->pb, off, SEEK_SET);
144 mpc8_get_chunk_header(s->pb, &tag, &size);
145 if(tag != TAG_SEEKTABLE){
146 av_log(s, AV_LOG_ERROR, "No seek table at given position\n");
149 if(!(buf = av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE)))
151 avio_read(s->pb, buf, size);
152 init_get_bits(&gb, buf, size * 8);
153 size = gb_get_v(&gb);
154 if(size > UINT_MAX/4 || size > c->samples/1152){
155 av_log(s, AV_LOG_ERROR, "Seek table is too big\n");
158 seekd = get_bits(&gb, 4);
159 for(i = 0; i < 2; i++){
160 pos = gb_get_v(&gb) + c->header_pos;
162 av_add_index_entry(s->streams[0], pos, i, 0, 0, AVINDEX_KEYFRAME);
164 for(; i < size; i++){
165 t = get_unary(&gb, 1, 33) << 12;
166 t += get_bits(&gb, 12);
169 pos = (t >> 1) + ppos[0]*2 - ppos[1];
170 av_add_index_entry(s->streams[0], pos, i << seekd, 0, 0, AVINDEX_KEYFRAME);
177 static void mpc8_handle_chunk(AVFormatContext *s, int tag, int64_t chunk_pos, int64_t size)
179 AVIOContext *pb = s->pb;
184 pos = avio_tell(pb) + size;
185 off = ffio_read_varlen(pb);
186 mpc8_parse_seektable(s, chunk_pos + off);
187 avio_seek(pb, pos, SEEK_SET);
194 static int mpc8_read_header(AVFormatContext *s)
196 MPCContext *c = s->priv_data;
197 AVIOContext *pb = s->pb;
202 c->header_pos = avio_tell(pb);
203 if(avio_rl32(pb) != TAG_MPCK){
204 av_log(s, AV_LOG_ERROR, "Not a Musepack8 file\n");
205 return AVERROR_INVALIDDATA;
208 while(!pb->eof_reached){
210 mpc8_get_chunk_header(pb, &tag, &size);
211 if(tag == TAG_STREAMHDR)
213 mpc8_handle_chunk(s, tag, pos, size);
215 if(tag != TAG_STREAMHDR){
216 av_log(s, AV_LOG_ERROR, "Stream header not found\n");
217 return AVERROR_INVALIDDATA;
220 avio_skip(pb, 4); //CRC
221 c->ver = avio_r8(pb);
223 av_log(s, AV_LOG_ERROR, "Unknown stream version %d\n", c->ver);
224 return AVERROR_PATCHWELCOME;
226 c->samples = ffio_read_varlen(pb);
227 ffio_read_varlen(pb); //silence samples at the beginning
229 st = avformat_new_stream(s, NULL);
231 return AVERROR(ENOMEM);
232 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
233 st->codec->codec_id = CODEC_ID_MUSEPACK8;
234 st->codec->bits_per_coded_sample = 16;
236 st->codec->extradata_size = 2;
237 st->codec->extradata = av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
238 avio_read(pb, st->codec->extradata, st->codec->extradata_size);
240 st->codec->channels = (st->codec->extradata[1] >> 4) + 1;
241 st->codec->sample_rate = mpc8_rate[st->codec->extradata[0] >> 5];
242 avpriv_set_pts_info(st, 32, 1152 << (st->codec->extradata[1]&3)*2, st->codec->sample_rate);
243 st->duration = c->samples / (1152 << (st->codec->extradata[1]&3)*2);
244 size -= avio_tell(pb) - pos;
247 int64_t pos = avio_tell(s->pb);
248 c->apetag_start = ff_ape_parse_tag(s);
249 avio_seek(s->pb, pos, SEEK_SET);
255 static int mpc8_read_packet(AVFormatContext *s, AVPacket *pkt)
257 MPCContext *c = s->priv_data;
261 while(!s->pb->eof_reached){
262 pos = avio_tell(s->pb);
264 /* don't return bogus packets with the ape tag data */
265 if (c->apetag_start && pos >= c->apetag_start)
268 mpc8_get_chunk_header(s->pb, &tag, &size);
271 if(tag == TAG_AUDIOPACKET){
272 if(av_get_packet(s->pb, pkt, size) < 0)
273 return AVERROR(ENOMEM);
274 pkt->stream_index = 0;
278 if(tag == TAG_STREAMEND)
280 mpc8_handle_chunk(s, tag, pos, size);
285 static int mpc8_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
287 AVStream *st = s->streams[stream_index];
288 MPCContext *c = s->priv_data;
289 int index = av_index_search_timestamp(st, timestamp, flags);
291 if(index < 0) return -1;
292 if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
294 c->frame = st->index_entries[index].timestamp;
299 AVInputFormat ff_mpc8_demuxer = {
301 .long_name = NULL_IF_CONFIG_SMALL("Musepack SV8"),
302 .priv_data_size = sizeof(MPCContext),
303 .read_probe = mpc8_probe,
304 .read_header = mpc8_read_header,
305 .read_packet = mpc8_read_packet,
306 .read_seek = mpc8_read_seek,