| 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 { |
| 51 | int ver; |
| 52 | int64_t header_pos; |
| 53 | int64_t samples; |
| 54 | |
| 55 | int64_t apetag_start; |
| 56 | } MPCContext; |
| 57 | |
| 58 | static inline int64_t bs_get_v(const uint8_t **bs) |
| 59 | { |
| 60 | int64_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 | |
| 76 | static int mpc8_probe(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 (bs + size - 2 >= bs_end) |
| 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 | |
| 109 | static inline int64_t gb_get_v(GetBitContext *gb) |
| 110 | { |
| 111 | int64_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 | |
| 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 | *size -= avio_tell(pb) - pos; |
| 131 | } |
| 132 | |
| 133 | static void mpc8_parse_seektable(AVFormatContext *s, int64_t off) |
| 134 | { |
| 135 | MPCContext *c = s->priv_data; |
| 136 | int tag; |
| 137 | int64_t size, pos, ppos[2]; |
| 138 | uint8_t *buf; |
| 139 | int i, t, seekd, ret; |
| 140 | GetBitContext gb; |
| 141 | |
| 142 | if (s->nb_streams == 0) { |
| 143 | av_log(s, AV_LOG_ERROR, "No stream added before parsing seek table\n"); |
| 144 | return; |
| 145 | } |
| 146 | |
| 147 | avio_seek(s->pb, off, SEEK_SET); |
| 148 | mpc8_get_chunk_header(s->pb, &tag, &size); |
| 149 | if(tag != TAG_SEEKTABLE){ |
| 150 | av_log(s, AV_LOG_ERROR, "No seek table at given position\n"); |
| 151 | return; |
| 152 | } |
| 153 | if (size > INT_MAX/10 || size<=0) { |
| 154 | av_log(s, AV_LOG_ERROR, "Bad seek table size\n"); |
| 155 | return; |
| 156 | } |
| 157 | if(!(buf = av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE))) |
| 158 | return; |
| 159 | ret = avio_read(s->pb, buf, size); |
| 160 | if (ret != size) { |
| 161 | av_log(s, AV_LOG_ERROR, "seek table truncated\n"); |
| 162 | av_free(buf); |
| 163 | return; |
| 164 | } |
| 165 | memset(buf+size, 0, FF_INPUT_BUFFER_PADDING_SIZE); |
| 166 | |
| 167 | init_get_bits(&gb, buf, size * 8); |
| 168 | size = gb_get_v(&gb); |
| 169 | if(size > UINT_MAX/4 || size > c->samples/1152){ |
| 170 | av_log(s, AV_LOG_ERROR, "Seek table is too big\n"); |
| 171 | return; |
| 172 | } |
| 173 | seekd = get_bits(&gb, 4); |
| 174 | for(i = 0; i < 2; i++){ |
| 175 | pos = gb_get_v(&gb) + c->header_pos; |
| 176 | ppos[1 - i] = pos; |
| 177 | av_add_index_entry(s->streams[0], pos, i, 0, 0, AVINDEX_KEYFRAME); |
| 178 | } |
| 179 | for(; i < size; i++){ |
| 180 | t = get_unary(&gb, 1, 33) << 12; |
| 181 | t += get_bits(&gb, 12); |
| 182 | if(t & 1) |
| 183 | t = -(t & ~1); |
| 184 | pos = (t >> 1) + ppos[0]*2 - ppos[1]; |
| 185 | av_add_index_entry(s->streams[0], pos, i << seekd, 0, 0, AVINDEX_KEYFRAME); |
| 186 | ppos[1] = ppos[0]; |
| 187 | ppos[0] = pos; |
| 188 | } |
| 189 | av_free(buf); |
| 190 | } |
| 191 | |
| 192 | static void mpc8_handle_chunk(AVFormatContext *s, int tag, int64_t chunk_pos, int64_t size) |
| 193 | { |
| 194 | AVIOContext *pb = s->pb; |
| 195 | int64_t pos, off; |
| 196 | |
| 197 | switch(tag){ |
| 198 | case TAG_SEEKTBLOFF: |
| 199 | pos = avio_tell(pb) + size; |
| 200 | off = ffio_read_varlen(pb); |
| 201 | mpc8_parse_seektable(s, chunk_pos + off); |
| 202 | avio_seek(pb, pos, SEEK_SET); |
| 203 | break; |
| 204 | default: |
| 205 | avio_skip(pb, size); |
| 206 | } |
| 207 | } |
| 208 | |
| 209 | static int mpc8_read_header(AVFormatContext *s) |
| 210 | { |
| 211 | MPCContext *c = s->priv_data; |
| 212 | AVIOContext *pb = s->pb; |
| 213 | AVStream *st; |
| 214 | int tag = 0; |
| 215 | int64_t size, pos; |
| 216 | |
| 217 | c->header_pos = avio_tell(pb); |
| 218 | if(avio_rl32(pb) != TAG_MPCK){ |
| 219 | av_log(s, AV_LOG_ERROR, "Not a Musepack8 file\n"); |
| 220 | return AVERROR_INVALIDDATA; |
| 221 | } |
| 222 | |
| 223 | while(!avio_feof(pb)){ |
| 224 | pos = avio_tell(pb); |
| 225 | mpc8_get_chunk_header(pb, &tag, &size); |
| 226 | if(tag == TAG_STREAMHDR) |
| 227 | break; |
| 228 | mpc8_handle_chunk(s, tag, pos, size); |
| 229 | } |
| 230 | if(tag != TAG_STREAMHDR){ |
| 231 | av_log(s, AV_LOG_ERROR, "Stream header not found\n"); |
| 232 | return AVERROR_INVALIDDATA; |
| 233 | } |
| 234 | pos = avio_tell(pb); |
| 235 | avio_skip(pb, 4); //CRC |
| 236 | c->ver = avio_r8(pb); |
| 237 | if(c->ver != 8){ |
| 238 | av_log(s, AV_LOG_ERROR, "Unknown stream version %d\n", c->ver); |
| 239 | return AVERROR_PATCHWELCOME; |
| 240 | } |
| 241 | c->samples = ffio_read_varlen(pb); |
| 242 | ffio_read_varlen(pb); //silence samples at the beginning |
| 243 | |
| 244 | st = avformat_new_stream(s, NULL); |
| 245 | if (!st) |
| 246 | return AVERROR(ENOMEM); |
| 247 | st->codec->codec_type = AVMEDIA_TYPE_AUDIO; |
| 248 | st->codec->codec_id = AV_CODEC_ID_MUSEPACK8; |
| 249 | st->codec->bits_per_coded_sample = 16; |
| 250 | |
| 251 | if (ff_get_extradata(st->codec, pb, 2) < 0) |
| 252 | return AVERROR(ENOMEM); |
| 253 | |
| 254 | st->codec->channels = (st->codec->extradata[1] >> 4) + 1; |
| 255 | st->codec->sample_rate = mpc8_rate[st->codec->extradata[0] >> 5]; |
| 256 | avpriv_set_pts_info(st, 32, 1152 << (st->codec->extradata[1]&3)*2, st->codec->sample_rate); |
| 257 | st->start_time = 0; |
| 258 | st->duration = c->samples / (1152 << (st->codec->extradata[1]&3)*2); |
| 259 | size -= avio_tell(pb) - pos; |
| 260 | if (size > 0) |
| 261 | avio_skip(pb, size); |
| 262 | |
| 263 | if (pb->seekable) { |
| 264 | int64_t pos = avio_tell(s->pb); |
| 265 | c->apetag_start = ff_ape_parse_tag(s); |
| 266 | avio_seek(s->pb, pos, SEEK_SET); |
| 267 | } |
| 268 | |
| 269 | return 0; |
| 270 | } |
| 271 | |
| 272 | static int mpc8_read_packet(AVFormatContext *s, AVPacket *pkt) |
| 273 | { |
| 274 | MPCContext *c = s->priv_data; |
| 275 | int tag; |
| 276 | int64_t pos, size; |
| 277 | |
| 278 | while(!avio_feof(s->pb)){ |
| 279 | pos = avio_tell(s->pb); |
| 280 | |
| 281 | /* don't return bogus packets with the ape tag data */ |
| 282 | if (c->apetag_start && pos >= c->apetag_start) |
| 283 | return AVERROR_EOF; |
| 284 | |
| 285 | mpc8_get_chunk_header(s->pb, &tag, &size); |
| 286 | if (size < 0) |
| 287 | return -1; |
| 288 | if(tag == TAG_AUDIOPACKET){ |
| 289 | if(av_get_packet(s->pb, pkt, size) < 0) |
| 290 | return AVERROR(ENOMEM); |
| 291 | pkt->stream_index = 0; |
| 292 | pkt->duration = 1; |
| 293 | return 0; |
| 294 | } |
| 295 | if(tag == TAG_STREAMEND) |
| 296 | return AVERROR(EIO); |
| 297 | mpc8_handle_chunk(s, tag, pos, size); |
| 298 | } |
| 299 | return AVERROR_EOF; |
| 300 | } |
| 301 | |
| 302 | static int mpc8_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) |
| 303 | { |
| 304 | AVStream *st = s->streams[stream_index]; |
| 305 | int index = av_index_search_timestamp(st, timestamp, flags); |
| 306 | |
| 307 | if(index < 0) return -1; |
| 308 | if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0) |
| 309 | return -1; |
| 310 | ff_update_cur_dts(s, st, st->index_entries[index].timestamp); |
| 311 | return 0; |
| 312 | } |
| 313 | |
| 314 | |
| 315 | AVInputFormat ff_mpc8_demuxer = { |
| 316 | .name = "mpc8", |
| 317 | .long_name = NULL_IF_CONFIG_SMALL("Musepack SV8"), |
| 318 | .priv_data_size = sizeof(MPCContext), |
| 319 | .read_probe = mpc8_probe, |
| 320 | .read_header = mpc8_read_header, |
| 321 | .read_packet = mpc8_read_packet, |
| 322 | .read_seek = mpc8_read_seek, |
| 323 | }; |