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"
25 #include "avio_internal.h"
28 #define MKMPCTAG(a, b) (a | (b << 8))
30 #define TAG_MPCK MKTAG('M','P','C','K')
34 TAG_STREAMHDR = MKMPCTAG('S','H'),
35 TAG_STREAMEND = MKMPCTAG('S','E'),
37 TAG_AUDIOPACKET = MKMPCTAG('A','P'),
39 TAG_SEEKTBLOFF = MKMPCTAG('S','O'),
40 TAG_SEEKTABLE = MKMPCTAG('S','T'),
42 TAG_REPLAYGAIN = MKMPCTAG('R','G'),
43 TAG_ENCINFO = MKMPCTAG('E','I'),
46 static const int mpc8_rate[8] = { 44100, 48000, 37800, 32000, -1, -1, -1, -1 };
55 static inline int64_t bs_get_v(uint8_t **bs)
73 static int mpc8_probe(AVProbeData *p)
75 uint8_t *bs = p->buf + 4;
76 uint8_t *bs_end = bs + p->buf_size;
81 if (AV_RL32(p->buf) != TAG_MPCK)
83 while (bs < bs_end + 3) {
84 int header_found = (bs[0] == 'S' && bs[1] == 'H');
85 if (bs[0] < 'A' || bs[0] > 'Z' || bs[1] < 'A' || bs[1] > 'Z')
91 if (bs + size - 2 >= bs_end)
92 return AVPROBE_SCORE_MAX / 4 - 1; //seems to be valid MPC but no header yet
94 if (size < 11 || size > 28)
96 if (!AV_RL32(bs)) //zero CRC is invalid
98 return AVPROBE_SCORE_MAX;
106 static inline int64_t gb_get_v(GetBitContext *gb)
110 while(get_bits1(gb) && bits < 64-7){
112 v |= get_bits(gb, 7);
116 v |= get_bits(gb, 7);
121 static void mpc8_get_chunk_header(AVIOContext *pb, int *tag, int64_t *size)
125 *tag = avio_rl16(pb);
126 *size = ffio_read_varlen(pb);
127 *size -= avio_tell(pb) - pos;
130 static void mpc8_parse_seektable(AVFormatContext *s, int64_t off)
132 MPCContext *c = s->priv_data;
134 int64_t size, pos, ppos[2];
139 avio_seek(s->pb, off, SEEK_SET);
140 mpc8_get_chunk_header(s->pb, &tag, &size);
141 if(tag != TAG_SEEKTABLE){
142 av_log(s, AV_LOG_ERROR, "No seek table at given position\n");
145 if(!(buf = av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE)))
147 avio_read(s->pb, buf, size);
148 init_get_bits(&gb, buf, size * 8);
149 size = gb_get_v(&gb);
150 if(size > UINT_MAX/4 || size > c->samples/1152){
151 av_log(s, AV_LOG_ERROR, "Seek table is too big\n");
154 seekd = get_bits(&gb, 4);
155 for(i = 0; i < 2; i++){
156 pos = gb_get_v(&gb) + c->header_pos;
158 av_add_index_entry(s->streams[0], pos, i, 0, 0, AVINDEX_KEYFRAME);
160 for(; i < size; i++){
161 t = get_unary(&gb, 1, 33) << 12;
162 t += get_bits(&gb, 12);
165 pos = (t >> 1) + ppos[0]*2 - ppos[1];
166 av_add_index_entry(s->streams[0], pos, i << seekd, 0, 0, AVINDEX_KEYFRAME);
173 static void mpc8_handle_chunk(AVFormatContext *s, int tag, int64_t chunk_pos, int64_t size)
175 AVIOContext *pb = s->pb;
180 pos = avio_tell(pb) + size;
181 off = ffio_read_varlen(pb);
182 mpc8_parse_seektable(s, chunk_pos + off);
183 avio_seek(pb, pos, SEEK_SET);
190 static int mpc8_read_header(AVFormatContext *s, AVFormatParameters *ap)
192 MPCContext *c = s->priv_data;
193 AVIOContext *pb = s->pb;
198 c->header_pos = avio_tell(pb);
199 if(avio_rl32(pb) != TAG_MPCK){
200 av_log(s, AV_LOG_ERROR, "Not a Musepack8 file\n");
204 while(!pb->eof_reached){
206 mpc8_get_chunk_header(pb, &tag, &size);
207 if(tag == TAG_STREAMHDR)
209 mpc8_handle_chunk(s, tag, pos, size);
211 if(tag != TAG_STREAMHDR){
212 av_log(s, AV_LOG_ERROR, "Stream header not found\n");
216 avio_skip(pb, 4); //CRC
217 c->ver = avio_r8(pb);
219 av_log(s, AV_LOG_ERROR, "Unknown stream version %d\n", c->ver);
222 c->samples = ffio_read_varlen(pb);
223 ffio_read_varlen(pb); //silence samples at the beginning
225 st = av_new_stream(s, 0);
227 return AVERROR(ENOMEM);
228 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
229 st->codec->codec_id = CODEC_ID_MUSEPACK8;
230 st->codec->bits_per_coded_sample = 16;
232 st->codec->extradata_size = 2;
233 st->codec->extradata = av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
234 avio_read(pb, st->codec->extradata, st->codec->extradata_size);
236 st->codec->channels = (st->codec->extradata[1] >> 4) + 1;
237 st->codec->sample_rate = mpc8_rate[st->codec->extradata[0] >> 5];
238 av_set_pts_info(st, 32, 1152 << (st->codec->extradata[1]&3)*2, st->codec->sample_rate);
239 st->duration = c->samples / (1152 << (st->codec->extradata[1]&3)*2);
240 size -= avio_tell(pb) - pos;
245 static int mpc8_read_packet(AVFormatContext *s, AVPacket *pkt)
247 MPCContext *c = s->priv_data;
251 while(!s->pb->eof_reached){
252 pos = avio_tell(s->pb);
253 mpc8_get_chunk_header(s->pb, &tag, &size);
256 if(tag == TAG_AUDIOPACKET){
257 if(av_get_packet(s->pb, pkt, size) < 0)
258 return AVERROR(ENOMEM);
259 pkt->stream_index = 0;
263 if(tag == TAG_STREAMEND)
265 mpc8_handle_chunk(s, tag, pos, size);
270 static int mpc8_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
272 AVStream *st = s->streams[stream_index];
273 MPCContext *c = s->priv_data;
274 int index = av_index_search_timestamp(st, timestamp, flags);
276 if(index < 0) return -1;
277 avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET);
278 c->frame = st->index_entries[index].timestamp;
283 AVInputFormat ff_mpc8_demuxer = {
285 NULL_IF_CONFIG_SMALL("Musepack SV8"),