Gloria Wang | 37fe158 | 2010-03-12 14:53:20 -0800 | [diff] [blame^] | 1 | /************************************************************************ |
| 2 | * Copyright (C) 2010, The Android Open Source Project |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions are |
| 7 | * met: |
| 8 | * |
| 9 | * * Redistributions of source code must retain the above copyright |
| 10 | * notice, this list of conditions and the following disclaimer. |
| 11 | * * Redistributions in binary form must reproduce the above |
| 12 | * copyright notice, this list of conditions and the following disclaimer |
| 13 | * in the documentation and/or other materials provided with the |
| 14 | * distribution. |
| 15 | * * Neither the name of the Android Open Source Project nor the |
| 16 | * names of its contributors may be used to endorse or promote products |
| 17 | * derived from this software without specific prior written permission. |
| 18 | * |
| 19 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 20 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 21 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 22 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
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| 25 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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| 29 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 30 | ************************************************************************ |
Gloria Wang | 7913073 | 2010-02-08 14:41:04 -0800 | [diff] [blame] | 31 | |
| 32 | function: stdio-based convenience library for opening/seeking/decoding |
| 33 | last mod: $Id: vorbisfile.c,v 1.6.2.5 2003/11/20 06:16:17 xiphmont Exp $ |
| 34 | |
Gloria Wang | 37fe158 | 2010-03-12 14:53:20 -0800 | [diff] [blame^] | 35 | ************************************************************************/ |
Gloria Wang | 7913073 | 2010-02-08 14:41:04 -0800 | [diff] [blame] | 36 | |
| 37 | #include <stdlib.h> |
| 38 | #include <stdio.h> |
Gloria Wang | d75baf2 | 2010-02-12 16:28:30 -0800 | [diff] [blame] | 39 | //#include <gerrno.h> |
Gloria Wang | 7913073 | 2010-02-08 14:41:04 -0800 | [diff] [blame] | 40 | #include <string.h> |
| 41 | #include <math.h> |
| 42 | |
| 43 | #include "codec_internal.h" |
| 44 | #include "ivorbisfile.h" |
| 45 | |
| 46 | #include "os.h" |
| 47 | #include "misc.h" |
| 48 | |
Gloria Wang | d75baf2 | 2010-02-12 16:28:30 -0800 | [diff] [blame] | 49 | int gerrno; |
Gloria Wang | 7913073 | 2010-02-08 14:41:04 -0800 | [diff] [blame] | 50 | |
| 51 | #define NOTOPEN 0 |
| 52 | #define PARTOPEN 1 |
| 53 | #define OPENED 2 |
| 54 | #define STREAMSET 3 /* serialno and link set, but not to current link */ |
| 55 | #define LINKSET 4 /* serialno and link set to current link */ |
| 56 | #define INITSET 5 |
| 57 | |
| 58 | /* A 'chained bitstream' is a Vorbis bitstream that contains more than |
| 59 | one logical bitstream arranged end to end (the only form of Ogg |
| 60 | multiplexing allowed in a Vorbis bitstream; grouping [parallel |
| 61 | multiplexing] is not allowed in Vorbis) */ |
| 62 | |
| 63 | /* A Vorbis file can be played beginning to end (streamed) without |
| 64 | worrying ahead of time about chaining (see decoder_example.c). If |
| 65 | we have the whole file, however, and want random access |
| 66 | (seeking/scrubbing) or desire to know the total length/time of a |
| 67 | file, we need to account for the possibility of chaining. */ |
| 68 | |
| 69 | /* We can handle things a number of ways; we can determine the entire |
| 70 | bitstream structure right off the bat, or find pieces on demand. |
| 71 | This example determines and caches structure for the entire |
| 72 | bitstream, but builds a virtual decoder on the fly when moving |
| 73 | between links in the chain. */ |
| 74 | |
| 75 | /* There are also different ways to implement seeking. Enough |
| 76 | information exists in an Ogg bitstream to seek to |
| 77 | sample-granularity positions in the output. Or, one can seek by |
| 78 | picking some portion of the stream roughly in the desired area if |
| 79 | we only want coarse navigation through the stream. */ |
| 80 | |
| 81 | /************************************************************************* |
| 82 | * Many, many internal helpers. The intention is not to be confusing; |
| 83 | * rampant duplication and monolithic function implementation would be |
| 84 | * harder to understand anyway. The high level functions are last. Begin |
| 85 | * grokking near the end of the file */ |
| 86 | |
| 87 | |
| 88 | /* read a little more data from the file/pipe into the ogg_sync framer */ |
| 89 | static long _get_data(OggVorbis_File *vf){ |
Gloria Wang | d75baf2 | 2010-02-12 16:28:30 -0800 | [diff] [blame] | 90 | gerrno=0; |
Gloria Wang | 7913073 | 2010-02-08 14:41:04 -0800 | [diff] [blame] | 91 | if(vf->datasource){ |
| 92 | unsigned char *buffer=ogg_sync_bufferin(vf->oy,CHUNKSIZE); |
| 93 | long bytes=(vf->callbacks.read_func)(buffer,1,CHUNKSIZE,vf->datasource); |
| 94 | if(bytes>0)ogg_sync_wrote(vf->oy,bytes); |
Gloria Wang | d75baf2 | 2010-02-12 16:28:30 -0800 | [diff] [blame] | 95 | if(bytes==0 && gerrno)return -1; |
Gloria Wang | 7913073 | 2010-02-08 14:41:04 -0800 | [diff] [blame] | 96 | return bytes; |
| 97 | }else |
| 98 | return 0; |
| 99 | } |
| 100 | |
| 101 | /* save a tiny smidge of verbosity to make the code more readable */ |
| 102 | static void _seek_helper(OggVorbis_File *vf,ogg_int64_t offset){ |
| 103 | if(vf->datasource){ |
| 104 | (vf->callbacks.seek_func)(vf->datasource, offset, SEEK_SET); |
| 105 | vf->offset=offset; |
| 106 | ogg_sync_reset(vf->oy); |
| 107 | }else{ |
| 108 | /* shouldn't happen unless someone writes a broken callback */ |
| 109 | return; |
| 110 | } |
| 111 | } |
| 112 | |
| 113 | /* The read/seek functions track absolute position within the stream */ |
| 114 | |
| 115 | /* from the head of the stream, get the next page. boundary specifies |
| 116 | if the function is allowed to fetch more data from the stream (and |
| 117 | how much) or only use internally buffered data. |
| 118 | |
| 119 | boundary: -1) unbounded search |
| 120 | 0) read no additional data; use cached only |
| 121 | n) search for a new page beginning for n bytes |
| 122 | |
| 123 | return: <0) did not find a page (OV_FALSE, OV_EOF, OV_EREAD) |
| 124 | n) found a page at absolute offset n |
| 125 | |
| 126 | produces a refcounted page */ |
| 127 | |
| 128 | static ogg_int64_t _get_next_page(OggVorbis_File *vf,ogg_page *og, |
| 129 | ogg_int64_t boundary){ |
| 130 | if(boundary>0)boundary+=vf->offset; |
| 131 | while(1){ |
| 132 | long more; |
| 133 | |
| 134 | if(boundary>0 && vf->offset>=boundary)return OV_FALSE; |
| 135 | more=ogg_sync_pageseek(vf->oy,og); |
| 136 | |
| 137 | if(more<0){ |
| 138 | /* skipped n bytes */ |
| 139 | vf->offset-=more; |
| 140 | }else{ |
| 141 | if(more==0){ |
| 142 | /* send more paramedics */ |
| 143 | if(!boundary)return OV_FALSE; |
| 144 | { |
| 145 | long ret=_get_data(vf); |
| 146 | if(ret==0)return OV_EOF; |
| 147 | if(ret<0)return OV_EREAD; |
| 148 | } |
| 149 | }else{ |
| 150 | /* got a page. Return the offset at the page beginning, |
| 151 | advance the internal offset past the page end */ |
| 152 | ogg_int64_t ret=vf->offset; |
| 153 | vf->offset+=more; |
| 154 | return ret; |
| 155 | |
| 156 | } |
| 157 | } |
| 158 | } |
| 159 | } |
| 160 | |
| 161 | /* find the latest page beginning before the current stream cursor |
| 162 | position. Much dirtier than the above as Ogg doesn't have any |
| 163 | backward search linkage. no 'readp' as it will certainly have to |
| 164 | read. */ |
| 165 | /* returns offset or OV_EREAD, OV_FAULT and produces a refcounted page */ |
| 166 | |
| 167 | static ogg_int64_t _get_prev_page(OggVorbis_File *vf,ogg_page *og){ |
| 168 | ogg_int64_t begin=vf->offset; |
| 169 | ogg_int64_t end=begin; |
| 170 | ogg_int64_t ret; |
| 171 | ogg_int64_t offset=-1; |
| 172 | |
| 173 | while(offset==-1){ |
| 174 | begin-=CHUNKSIZE; |
| 175 | if(begin<0) |
| 176 | begin=0; |
| 177 | _seek_helper(vf,begin); |
| 178 | while(vf->offset<end){ |
| 179 | ret=_get_next_page(vf,og,end-vf->offset); |
| 180 | if(ret==OV_EREAD)return OV_EREAD; |
| 181 | if(ret<0){ |
| 182 | break; |
| 183 | }else{ |
| 184 | offset=ret; |
| 185 | } |
| 186 | } |
| 187 | } |
| 188 | |
| 189 | /* we have the offset. Actually snork and hold the page now */ |
| 190 | _seek_helper(vf,offset); |
| 191 | ret=_get_next_page(vf,og,CHUNKSIZE); |
| 192 | if(ret<0) |
| 193 | /* this shouldn't be possible */ |
| 194 | return OV_EFAULT; |
| 195 | |
| 196 | return offset; |
| 197 | } |
| 198 | |
| 199 | /* finds each bitstream link one at a time using a bisection search |
| 200 | (has to begin by knowing the offset of the lb's initial page). |
| 201 | Recurses for each link so it can alloc the link storage after |
| 202 | finding them all, then unroll and fill the cache at the same time */ |
| 203 | static int _bisect_forward_serialno(OggVorbis_File *vf, |
| 204 | ogg_int64_t begin, |
| 205 | ogg_int64_t searched, |
| 206 | ogg_int64_t end, |
| 207 | ogg_uint32_t currentno, |
| 208 | long m){ |
| 209 | ogg_int64_t endsearched=end; |
| 210 | ogg_int64_t next=end; |
| 211 | ogg_page og={0,0,0,0}; |
| 212 | ogg_int64_t ret; |
| 213 | |
| 214 | /* the below guards against garbage seperating the last and |
| 215 | first pages of two links. */ |
| 216 | while(searched<endsearched){ |
| 217 | ogg_int64_t bisect; |
| 218 | |
| 219 | if(endsearched-searched<CHUNKSIZE){ |
| 220 | bisect=searched; |
| 221 | }else{ |
| 222 | bisect=(searched+endsearched)/2; |
| 223 | } |
| 224 | |
| 225 | _seek_helper(vf,bisect); |
| 226 | ret=_get_next_page(vf,&og,-1); |
| 227 | if(ret==OV_EREAD)return OV_EREAD; |
| 228 | if(ret<0 || ogg_page_serialno(&og)!=currentno){ |
| 229 | endsearched=bisect; |
| 230 | if(ret>=0)next=ret; |
| 231 | }else{ |
| 232 | searched=ret+og.header_len+og.body_len; |
| 233 | } |
| 234 | ogg_page_release(&og); |
| 235 | } |
| 236 | |
| 237 | _seek_helper(vf,next); |
| 238 | ret=_get_next_page(vf,&og,-1); |
| 239 | if(ret==OV_EREAD)return OV_EREAD; |
| 240 | |
| 241 | if(searched>=end || ret<0){ |
| 242 | ogg_page_release(&og); |
| 243 | vf->links=m+1; |
| 244 | vf->offsets=_ogg_malloc((vf->links+1)*sizeof(*vf->offsets)); |
| 245 | vf->serialnos=_ogg_malloc(vf->links*sizeof(*vf->serialnos)); |
| 246 | vf->offsets[m+1]=searched; |
| 247 | }else{ |
| 248 | ret=_bisect_forward_serialno(vf,next,vf->offset, |
| 249 | end,ogg_page_serialno(&og),m+1); |
| 250 | ogg_page_release(&og); |
| 251 | if(ret==OV_EREAD)return OV_EREAD; |
| 252 | } |
| 253 | |
| 254 | vf->offsets[m]=begin; |
| 255 | vf->serialnos[m]=currentno; |
| 256 | return 0; |
| 257 | } |
| 258 | |
| 259 | static int _decode_clear(OggVorbis_File *vf){ |
| 260 | if(vf->ready_state==INITSET){ |
| 261 | vorbis_dsp_destroy(vf->vd); |
| 262 | vf->vd=0; |
| 263 | vf->ready_state=STREAMSET; |
| 264 | } |
| 265 | |
| 266 | if(vf->ready_state>=STREAMSET){ |
| 267 | vorbis_info_clear(&vf->vi); |
| 268 | vorbis_comment_clear(&vf->vc); |
| 269 | vf->ready_state=OPENED; |
| 270 | } |
| 271 | return 0; |
| 272 | } |
| 273 | |
| 274 | /* uses the local ogg_stream storage in vf; this is important for |
| 275 | non-streaming input sources */ |
| 276 | /* consumes the page that's passed in (if any) */ |
| 277 | /* state is LINKSET upon successful return */ |
| 278 | |
| 279 | static int _fetch_headers(OggVorbis_File *vf, |
| 280 | vorbis_info *vi, |
| 281 | vorbis_comment *vc, |
| 282 | ogg_uint32_t *serialno, |
| 283 | ogg_page *og_ptr){ |
| 284 | ogg_page og={0,0,0,0}; |
| 285 | ogg_packet op={0,0,0,0,0,0}; |
| 286 | int i,ret; |
| 287 | |
| 288 | if(vf->ready_state>OPENED)_decode_clear(vf); |
| 289 | |
| 290 | if(!og_ptr){ |
| 291 | ogg_int64_t llret=_get_next_page(vf,&og,CHUNKSIZE); |
| 292 | if(llret==OV_EREAD)return OV_EREAD; |
| 293 | if(llret<0)return OV_ENOTVORBIS; |
| 294 | og_ptr=&og; |
| 295 | } |
| 296 | |
| 297 | ogg_stream_reset_serialno(vf->os,ogg_page_serialno(og_ptr)); |
| 298 | if(serialno)*serialno=vf->os->serialno; |
| 299 | |
| 300 | /* extract the initial header from the first page and verify that the |
| 301 | Ogg bitstream is in fact Vorbis data */ |
| 302 | |
| 303 | vorbis_info_init(vi); |
| 304 | vorbis_comment_init(vc); |
| 305 | |
| 306 | i=0; |
| 307 | while(i<3){ |
| 308 | ogg_stream_pagein(vf->os,og_ptr); |
| 309 | while(i<3){ |
| 310 | int result=ogg_stream_packetout(vf->os,&op); |
| 311 | if(result==0)break; |
| 312 | if(result==-1){ |
| 313 | ret=OV_EBADHEADER; |
| 314 | goto bail_header; |
| 315 | } |
| 316 | if((ret=vorbis_dsp_headerin(vi,vc,&op))){ |
| 317 | goto bail_header; |
| 318 | } |
| 319 | i++; |
| 320 | } |
| 321 | if(i<3) |
| 322 | if(_get_next_page(vf,og_ptr,CHUNKSIZE)<0){ |
| 323 | ret=OV_EBADHEADER; |
| 324 | goto bail_header; |
| 325 | } |
| 326 | } |
| 327 | |
| 328 | ogg_packet_release(&op); |
| 329 | ogg_page_release(&og); |
| 330 | vf->ready_state=LINKSET; |
| 331 | return 0; |
| 332 | |
| 333 | bail_header: |
| 334 | ogg_packet_release(&op); |
| 335 | ogg_page_release(&og); |
| 336 | vorbis_info_clear(vi); |
| 337 | vorbis_comment_clear(vc); |
| 338 | vf->ready_state=OPENED; |
| 339 | |
| 340 | return ret; |
| 341 | } |
| 342 | |
| 343 | /* we no longer preload all vorbis_info (and the associated |
| 344 | codec_setup) structs. Call this to seek and fetch the info from |
| 345 | the bitstream, if needed */ |
| 346 | static int _set_link_number(OggVorbis_File *vf,int link){ |
| 347 | if(link != vf->current_link) _decode_clear(vf); |
| 348 | if(vf->ready_state<STREAMSET){ |
| 349 | _seek_helper(vf,vf->offsets[link]); |
| 350 | ogg_stream_reset_serialno(vf->os,vf->serialnos[link]); |
| 351 | vf->current_serialno=vf->serialnos[link]; |
| 352 | vf->current_link=link; |
| 353 | return _fetch_headers(vf,&vf->vi,&vf->vc,&vf->current_serialno,NULL); |
| 354 | } |
| 355 | return 0; |
| 356 | } |
| 357 | |
| 358 | static int _set_link_number_preserve_pos(OggVorbis_File *vf,int link){ |
| 359 | ogg_int64_t pos=vf->offset; |
| 360 | int ret=_set_link_number(vf,link); |
| 361 | if(ret)return ret; |
| 362 | _seek_helper(vf,pos); |
| 363 | if(pos<vf->offsets[link] || pos>=vf->offsets[link+1]) |
| 364 | vf->ready_state=STREAMSET; |
| 365 | return 0; |
| 366 | } |
| 367 | |
| 368 | /* last step of the OggVorbis_File initialization; get all the offset |
| 369 | positions. Only called by the seekable initialization (local |
| 370 | stream storage is hacked slightly; pay attention to how that's |
| 371 | done) */ |
| 372 | |
| 373 | /* this is void and does not propogate errors up because we want to be |
| 374 | able to open and use damaged bitstreams as well as we can. Just |
| 375 | watch out for missing information for links in the OggVorbis_File |
| 376 | struct */ |
| 377 | static void _prefetch_all_offsets(OggVorbis_File *vf, ogg_int64_t dataoffset){ |
| 378 | ogg_page og={0,0,0,0}; |
| 379 | int i; |
| 380 | ogg_int64_t ret; |
| 381 | |
| 382 | vf->dataoffsets=_ogg_malloc(vf->links*sizeof(*vf->dataoffsets)); |
| 383 | vf->pcmlengths=_ogg_malloc(vf->links*2*sizeof(*vf->pcmlengths)); |
| 384 | |
| 385 | for(i=0;i<vf->links;i++){ |
| 386 | if(i==0){ |
| 387 | /* we already grabbed the initial header earlier. Just set the offset */ |
| 388 | vf->dataoffsets[i]=dataoffset; |
| 389 | _seek_helper(vf,dataoffset); |
| 390 | |
| 391 | }else{ |
| 392 | |
| 393 | /* seek to the location of the initial header */ |
| 394 | |
| 395 | _seek_helper(vf,vf->offsets[i]); |
| 396 | if(_fetch_headers(vf,&vf->vi,&vf->vc,NULL,NULL)<0){ |
| 397 | vf->dataoffsets[i]=-1; |
| 398 | }else{ |
| 399 | vf->dataoffsets[i]=vf->offset; |
| 400 | } |
| 401 | } |
| 402 | |
| 403 | /* fetch beginning PCM offset */ |
| 404 | |
| 405 | if(vf->dataoffsets[i]!=-1){ |
| 406 | ogg_int64_t accumulated=0,pos; |
| 407 | long lastblock=-1; |
| 408 | int result; |
| 409 | |
| 410 | ogg_stream_reset_serialno(vf->os,vf->serialnos[i]); |
| 411 | |
| 412 | while(1){ |
| 413 | ogg_packet op={0,0,0,0,0,0}; |
| 414 | |
| 415 | ret=_get_next_page(vf,&og,-1); |
| 416 | if(ret<0) |
| 417 | /* this should not be possible unless the file is |
| 418 | truncated/mangled */ |
| 419 | break; |
| 420 | |
| 421 | if(ogg_page_serialno(&og)!=vf->serialnos[i]) |
| 422 | break; |
| 423 | |
| 424 | pos=ogg_page_granulepos(&og); |
| 425 | |
| 426 | /* count blocksizes of all frames in the page */ |
| 427 | ogg_stream_pagein(vf->os,&og); |
| 428 | while((result=ogg_stream_packetout(vf->os,&op))){ |
| 429 | if(result>0){ /* ignore holes */ |
| 430 | long thisblock=vorbis_packet_blocksize(&vf->vi,&op); |
| 431 | if(lastblock!=-1) |
| 432 | accumulated+=(lastblock+thisblock)>>2; |
| 433 | lastblock=thisblock; |
| 434 | } |
| 435 | } |
| 436 | ogg_packet_release(&op); |
| 437 | |
| 438 | if(pos!=-1){ |
| 439 | /* pcm offset of last packet on the first audio page */ |
| 440 | accumulated= pos-accumulated; |
| 441 | break; |
| 442 | } |
| 443 | } |
| 444 | |
| 445 | /* less than zero? This is a stream with samples trimmed off |
| 446 | the beginning, a normal occurrence; set the offset to zero */ |
| 447 | if(accumulated<0)accumulated=0; |
| 448 | |
| 449 | vf->pcmlengths[i*2]=accumulated; |
| 450 | } |
| 451 | |
| 452 | /* get the PCM length of this link. To do this, |
| 453 | get the last page of the stream */ |
| 454 | { |
| 455 | ogg_int64_t end=vf->offsets[i+1]; |
| 456 | _seek_helper(vf,end); |
| 457 | |
| 458 | while(1){ |
| 459 | ret=_get_prev_page(vf,&og); |
| 460 | if(ret<0){ |
| 461 | /* this should not be possible */ |
| 462 | vorbis_info_clear(&vf->vi); |
| 463 | vorbis_comment_clear(&vf->vc); |
| 464 | break; |
| 465 | } |
| 466 | if(ogg_page_granulepos(&og)!=-1){ |
| 467 | vf->pcmlengths[i*2+1]=ogg_page_granulepos(&og)-vf->pcmlengths[i*2]; |
| 468 | break; |
| 469 | } |
| 470 | vf->offset=ret; |
| 471 | } |
| 472 | } |
| 473 | } |
| 474 | ogg_page_release(&og); |
| 475 | } |
| 476 | |
| 477 | static int _make_decode_ready(OggVorbis_File *vf){ |
| 478 | int i; |
| 479 | switch(vf->ready_state){ |
| 480 | case OPENED: |
| 481 | case STREAMSET: |
| 482 | for(i=0;i<vf->links;i++) |
| 483 | if(vf->offsets[i+1]>=vf->offset)break; |
| 484 | if(i==vf->links)return -1; |
| 485 | i=_set_link_number_preserve_pos(vf,i); |
| 486 | if(i)return i; |
| 487 | /* fall through */ |
| 488 | case LINKSET: |
| 489 | vf->vd=vorbis_dsp_create(&vf->vi); |
| 490 | vf->ready_state=INITSET; |
| 491 | vf->bittrack=0; |
| 492 | vf->samptrack=0; |
| 493 | case INITSET: |
| 494 | return 0; |
| 495 | default: |
| 496 | return -1; |
| 497 | } |
| 498 | |
| 499 | } |
| 500 | |
| 501 | static int _open_seekable2(OggVorbis_File *vf){ |
| 502 | ogg_uint32_t serialno=vf->current_serialno; |
| 503 | ogg_uint32_t tempserialno; |
| 504 | ogg_int64_t dataoffset=vf->offset, end; |
| 505 | ogg_page og={0,0,0,0}; |
| 506 | |
| 507 | /* we're partially open and have a first link header state in |
| 508 | storage in vf */ |
| 509 | /* we can seek, so set out learning all about this file */ |
| 510 | (vf->callbacks.seek_func)(vf->datasource,0,SEEK_END); |
| 511 | vf->offset=vf->end=(vf->callbacks.tell_func)(vf->datasource); |
| 512 | |
| 513 | /* We get the offset for the last page of the physical bitstream. |
| 514 | Most OggVorbis files will contain a single logical bitstream */ |
| 515 | end=_get_prev_page(vf,&og); |
| 516 | if(end<0)return (int)end; |
| 517 | |
| 518 | /* more than one logical bitstream? */ |
| 519 | tempserialno=ogg_page_serialno(&og); |
| 520 | ogg_page_release(&og); |
| 521 | |
| 522 | if(tempserialno!=serialno){ |
| 523 | |
| 524 | /* Chained bitstream. Bisect-search each logical bitstream |
| 525 | section. Do so based on serial number only */ |
| 526 | if(_bisect_forward_serialno(vf,0,0,end+1,serialno,0)<0)return OV_EREAD; |
| 527 | |
| 528 | }else{ |
| 529 | |
| 530 | /* Only one logical bitstream */ |
| 531 | if(_bisect_forward_serialno(vf,0,end,end+1,serialno,0))return OV_EREAD; |
| 532 | |
| 533 | } |
| 534 | |
| 535 | /* the initial header memory is referenced by vf after; don't free it */ |
| 536 | _prefetch_all_offsets(vf,dataoffset); |
| 537 | return ov_raw_seek(vf,0); |
| 538 | } |
| 539 | |
| 540 | /* fetch and process a packet. Handles the case where we're at a |
| 541 | bitstream boundary and dumps the decoding machine. If the decoding |
| 542 | machine is unloaded, it loads it. It also keeps pcm_offset up to |
| 543 | date (seek and read both use this. seek uses a special hack with |
| 544 | readp). |
| 545 | |
| 546 | return: <0) error, OV_HOLE (lost packet) or OV_EOF |
| 547 | 0) need more data (only if readp==0) |
| 548 | 1) got a packet |
| 549 | */ |
| 550 | |
| 551 | static int _fetch_and_process_packet(OggVorbis_File *vf, |
| 552 | int readp, |
| 553 | int spanp){ |
| 554 | ogg_page og={0,0,0,0}; |
| 555 | ogg_packet op={0,0,0,0,0,0}; |
| 556 | int ret=0; |
| 557 | |
| 558 | /* handle one packet. Try to fetch it from current stream state */ |
| 559 | /* extract packets from page */ |
| 560 | while(1){ |
| 561 | |
| 562 | /* process a packet if we can. If the machine isn't loaded, |
| 563 | neither is a page */ |
| 564 | if(vf->ready_state==INITSET){ |
| 565 | while(1) { |
| 566 | int result=ogg_stream_packetout(vf->os,&op); |
| 567 | ogg_int64_t granulepos; |
| 568 | |
| 569 | if(result<0){ |
| 570 | ret=OV_HOLE; /* hole in the data. */ |
| 571 | goto cleanup; |
| 572 | } |
| 573 | if(result>0){ |
| 574 | /* got a packet. process it */ |
| 575 | granulepos=op.granulepos; |
| 576 | if(!vorbis_dsp_synthesis(vf->vd,&op,1)){ /* lazy check for lazy |
| 577 | header handling. The |
| 578 | header packets aren't |
| 579 | audio, so if/when we |
| 580 | submit them, |
| 581 | vorbis_synthesis will |
| 582 | reject them */ |
| 583 | |
| 584 | vf->samptrack+=vorbis_dsp_pcmout(vf->vd,NULL,0); |
| 585 | vf->bittrack+=op.bytes*8; |
| 586 | |
| 587 | /* update the pcm offset. */ |
| 588 | if(granulepos!=-1 && !op.e_o_s){ |
| 589 | int link=(vf->seekable?vf->current_link:0); |
| 590 | int i,samples; |
| 591 | |
| 592 | /* this packet has a pcm_offset on it (the last packet |
| 593 | completed on a page carries the offset) After processing |
| 594 | (above), we know the pcm position of the *last* sample |
| 595 | ready to be returned. Find the offset of the *first* |
| 596 | |
| 597 | As an aside, this trick is inaccurate if we begin |
| 598 | reading anew right at the last page; the end-of-stream |
| 599 | granulepos declares the last frame in the stream, and the |
| 600 | last packet of the last page may be a partial frame. |
| 601 | So, we need a previous granulepos from an in-sequence page |
| 602 | to have a reference point. Thus the !op.e_o_s clause |
| 603 | above */ |
| 604 | |
| 605 | if(vf->seekable && link>0) |
| 606 | granulepos-=vf->pcmlengths[link*2]; |
| 607 | if(granulepos<0)granulepos=0; /* actually, this |
| 608 | shouldn't be possible |
| 609 | here unless the stream |
| 610 | is very broken */ |
| 611 | |
| 612 | samples=vorbis_dsp_pcmout(vf->vd,NULL,0); |
| 613 | |
| 614 | granulepos-=samples; |
| 615 | for(i=0;i<link;i++) |
| 616 | granulepos+=vf->pcmlengths[i*2+1]; |
| 617 | vf->pcm_offset=granulepos; |
| 618 | } |
| 619 | ret=1; |
| 620 | goto cleanup; |
| 621 | } |
| 622 | } |
| 623 | else |
| 624 | break; |
| 625 | } |
| 626 | } |
| 627 | |
| 628 | if(vf->ready_state>=OPENED){ |
| 629 | int ret; |
| 630 | if(!readp){ |
| 631 | ret=0; |
| 632 | goto cleanup; |
| 633 | } |
| 634 | ret=(int)_get_next_page(vf,&og,-1); |
| 635 | if(ret<0){ |
| 636 | ret=OV_EOF; /* eof. leave unitialized */ |
| 637 | goto cleanup; |
| 638 | } |
| 639 | |
| 640 | /* bitrate tracking; add the header's bytes here, the body bytes |
| 641 | are done by packet above */ |
| 642 | vf->bittrack+=og.header_len*8; |
| 643 | |
| 644 | /* has our decoding just traversed a bitstream boundary? */ |
| 645 | if(vf->ready_state==INITSET){ |
| 646 | if(vf->current_serialno!=ogg_page_serialno(&og)){ |
| 647 | if(!spanp){ |
| 648 | ret=OV_EOF; |
| 649 | goto cleanup; |
| 650 | } |
| 651 | |
| 652 | _decode_clear(vf); |
| 653 | } |
| 654 | } |
| 655 | } |
| 656 | |
| 657 | /* Do we need to load a new machine before submitting the page? */ |
| 658 | /* This is different in the seekable and non-seekable cases. |
| 659 | |
| 660 | In the seekable case, we already have all the header |
| 661 | information loaded and cached; we just initialize the machine |
| 662 | with it and continue on our merry way. |
| 663 | |
| 664 | In the non-seekable (streaming) case, we'll only be at a |
| 665 | boundary if we just left the previous logical bitstream and |
| 666 | we're now nominally at the header of the next bitstream |
| 667 | */ |
| 668 | |
| 669 | if(vf->ready_state!=INITSET){ |
| 670 | int link,ret; |
| 671 | |
| 672 | if(vf->ready_state<STREAMSET){ |
| 673 | if(vf->seekable){ |
| 674 | vf->current_serialno=ogg_page_serialno(&og); |
| 675 | |
| 676 | /* match the serialno to bitstream section. We use this rather than |
| 677 | offset positions to avoid problems near logical bitstream |
| 678 | boundaries */ |
| 679 | for(link=0;link<vf->links;link++) |
| 680 | if(vf->serialnos[link]==vf->current_serialno)break; |
| 681 | if(link==vf->links){ |
| 682 | ret=OV_EBADLINK; /* sign of a bogus stream. error out, |
| 683 | leave machine uninitialized */ |
| 684 | goto cleanup; |
| 685 | } |
| 686 | |
| 687 | vf->current_link=link; |
| 688 | ret=_fetch_headers(vf,&vf->vi,&vf->vc,&vf->current_serialno,&og); |
| 689 | if(ret) goto cleanup; |
| 690 | |
| 691 | }else{ |
| 692 | /* we're streaming */ |
| 693 | /* fetch the three header packets, build the info struct */ |
| 694 | |
| 695 | int ret=_fetch_headers(vf,&vf->vi,&vf->vc,&vf->current_serialno,&og); |
| 696 | if(ret) goto cleanup; |
| 697 | vf->current_link++; |
| 698 | } |
| 699 | } |
| 700 | |
| 701 | if(_make_decode_ready(vf)) return OV_EBADLINK; |
| 702 | } |
| 703 | ogg_stream_pagein(vf->os,&og); |
| 704 | } |
| 705 | cleanup: |
| 706 | ogg_packet_release(&op); |
| 707 | ogg_page_release(&og); |
| 708 | return ret; |
| 709 | } |
| 710 | |
| 711 | /* if, eg, 64 bit stdio is configured by default, this will build with |
| 712 | fseek64 */ |
| 713 | static int _fseek64_wrap(FILE *f,ogg_int64_t off,int whence){ |
| 714 | if(f==NULL)return -1; |
| 715 | return fseek(f,(long)off,whence); |
| 716 | } |
| 717 | |
| 718 | static int _ov_open1(void *f,OggVorbis_File *vf,char *initial, |
| 719 | long ibytes, ov_callbacks callbacks){ |
| 720 | int offsettest=(f?callbacks.seek_func(f,0,SEEK_CUR):-1); |
| 721 | int ret; |
| 722 | |
| 723 | memset(vf,0,sizeof(*vf)); |
| 724 | |
| 725 | /* Tremor assumes in multiple places that right shift of a signed |
| 726 | integer is an arithmetic shift */ |
| 727 | if( (-1>>1) != -1) return OV_EIMPL; |
| 728 | |
| 729 | vf->datasource=f; |
| 730 | vf->callbacks = callbacks; |
| 731 | |
| 732 | /* init the framing state */ |
| 733 | vf->oy=ogg_sync_create(); |
| 734 | |
| 735 | /* perhaps some data was previously read into a buffer for testing |
| 736 | against other stream types. Allow initialization from this |
| 737 | previously read data (as we may be reading from a non-seekable |
| 738 | stream) */ |
| 739 | if(initial){ |
| 740 | unsigned char *buffer=ogg_sync_bufferin(vf->oy,ibytes); |
| 741 | memcpy(buffer,initial,ibytes); |
| 742 | ogg_sync_wrote(vf->oy,ibytes); |
| 743 | } |
| 744 | |
| 745 | /* can we seek? Stevens suggests the seek test was portable */ |
| 746 | if(offsettest!=-1)vf->seekable=1; |
| 747 | |
| 748 | /* No seeking yet; Set up a 'single' (current) logical bitstream |
| 749 | entry for partial open */ |
| 750 | vf->links=1; |
| 751 | vf->os=ogg_stream_create(-1); /* fill in the serialno later */ |
| 752 | |
| 753 | /* Try to fetch the headers, maintaining all the storage */ |
| 754 | if((ret=_fetch_headers(vf,&vf->vi,&vf->vc,&vf->current_serialno,NULL))<0){ |
| 755 | vf->datasource=NULL; |
| 756 | ov_clear(vf); |
| 757 | }else if(vf->ready_state < PARTOPEN) |
| 758 | vf->ready_state=PARTOPEN; |
| 759 | return ret; |
| 760 | } |
| 761 | |
| 762 | static int _ov_open2(OggVorbis_File *vf){ |
| 763 | if(vf->ready_state < OPENED) |
| 764 | vf->ready_state=OPENED; |
| 765 | if(vf->seekable){ |
| 766 | int ret=_open_seekable2(vf); |
| 767 | if(ret){ |
| 768 | vf->datasource=NULL; |
| 769 | ov_clear(vf); |
| 770 | } |
| 771 | return ret; |
| 772 | } |
| 773 | return 0; |
| 774 | } |
| 775 | |
| 776 | |
| 777 | /* clear out the OggVorbis_File struct */ |
| 778 | int ov_clear(OggVorbis_File *vf){ |
| 779 | if(vf){ |
| 780 | vorbis_dsp_destroy(vf->vd); |
| 781 | vf->vd=0; |
| 782 | ogg_stream_destroy(vf->os); |
| 783 | vorbis_info_clear(&vf->vi); |
| 784 | vorbis_comment_clear(&vf->vc); |
| 785 | if(vf->dataoffsets)_ogg_free(vf->dataoffsets); |
| 786 | if(vf->pcmlengths)_ogg_free(vf->pcmlengths); |
| 787 | if(vf->serialnos)_ogg_free(vf->serialnos); |
| 788 | if(vf->offsets)_ogg_free(vf->offsets); |
| 789 | ogg_sync_destroy(vf->oy); |
| 790 | |
| 791 | if(vf->datasource)(vf->callbacks.close_func)(vf->datasource); |
| 792 | memset(vf,0,sizeof(*vf)); |
| 793 | } |
| 794 | #ifdef DEBUG_LEAKS |
| 795 | _VDBG_dump(); |
| 796 | #endif |
| 797 | return 0; |
| 798 | } |
| 799 | |
| 800 | /* inspects the OggVorbis file and finds/documents all the logical |
| 801 | bitstreams contained in it. Tries to be tolerant of logical |
| 802 | bitstream sections that are truncated/woogie. |
| 803 | |
| 804 | return: -1) error |
| 805 | 0) OK |
| 806 | */ |
| 807 | |
| 808 | int ov_open_callbacks(void *f,OggVorbis_File *vf,char *initial,long ibytes, |
| 809 | ov_callbacks callbacks){ |
| 810 | int ret=_ov_open1(f,vf,initial,ibytes,callbacks); |
| 811 | if(ret)return ret; |
| 812 | return _ov_open2(vf); |
| 813 | } |
| 814 | |
| 815 | int ov_open(FILE *f,OggVorbis_File *vf,char *initial,long ibytes){ |
| 816 | ov_callbacks callbacks = { |
| 817 | (size_t (*)(void *, size_t, size_t, void *)) fread, |
| 818 | (int (*)(void *, ogg_int64_t, int)) _fseek64_wrap, |
| 819 | (int (*)(void *)) fclose, |
| 820 | (long (*)(void *)) ftell |
| 821 | }; |
| 822 | |
| 823 | return ov_open_callbacks((void *)f, vf, initial, ibytes, callbacks); |
| 824 | } |
| 825 | |
| 826 | /* Only partially open the vorbis file; test for Vorbisness, and load |
| 827 | the headers for the first chain. Do not seek (although test for |
| 828 | seekability). Use ov_test_open to finish opening the file, else |
| 829 | ov_clear to close/free it. Same return codes as open. */ |
| 830 | |
| 831 | int ov_test_callbacks(void *f,OggVorbis_File *vf,char *initial,long ibytes, |
| 832 | ov_callbacks callbacks) |
| 833 | { |
| 834 | return _ov_open1(f,vf,initial,ibytes,callbacks); |
| 835 | } |
| 836 | |
| 837 | int ov_test(FILE *f,OggVorbis_File *vf,char *initial,long ibytes){ |
| 838 | ov_callbacks callbacks = { |
| 839 | (size_t (*)(void *, size_t, size_t, void *)) fread, |
| 840 | (int (*)(void *, ogg_int64_t, int)) _fseek64_wrap, |
| 841 | (int (*)(void *)) fclose, |
| 842 | (long (*)(void *)) ftell |
| 843 | }; |
| 844 | |
| 845 | return ov_test_callbacks((void *)f, vf, initial, ibytes, callbacks); |
| 846 | } |
| 847 | |
| 848 | int ov_test_open(OggVorbis_File *vf){ |
| 849 | if(vf->ready_state!=PARTOPEN)return OV_EINVAL; |
| 850 | return _ov_open2(vf); |
| 851 | } |
| 852 | |
| 853 | /* How many logical bitstreams in this physical bitstream? */ |
| 854 | long ov_streams(OggVorbis_File *vf){ |
| 855 | return vf->links; |
| 856 | } |
| 857 | |
| 858 | /* Is the FILE * associated with vf seekable? */ |
| 859 | long ov_seekable(OggVorbis_File *vf){ |
| 860 | return vf->seekable; |
| 861 | } |
| 862 | |
| 863 | /* returns the bitrate for a given logical bitstream or the entire |
| 864 | physical bitstream. If the file is open for random access, it will |
| 865 | find the *actual* average bitrate. If the file is streaming, it |
| 866 | returns the nominal bitrate (if set) else the average of the |
| 867 | upper/lower bounds (if set) else -1 (unset). |
| 868 | |
| 869 | If you want the actual bitrate field settings, get them from the |
| 870 | vorbis_info structs */ |
| 871 | |
| 872 | long ov_bitrate(OggVorbis_File *vf,int i){ |
| 873 | if(vf->ready_state<OPENED)return OV_EINVAL; |
| 874 | if(i>=vf->links)return OV_EINVAL; |
| 875 | if(!vf->seekable && i!=0)return ov_bitrate(vf,0); |
| 876 | if(i<0){ |
| 877 | ogg_int64_t bits=0; |
| 878 | int i; |
| 879 | for(i=0;i<vf->links;i++) |
| 880 | bits+=(vf->offsets[i+1]-vf->dataoffsets[i])*8; |
| 881 | /* This once read: return(rint(bits/ov_time_total(vf,-1))); |
| 882 | * gcc 3.x on x86 miscompiled this at optimisation level 2 and above, |
| 883 | * so this is slightly transformed to make it work. |
| 884 | */ |
| 885 | return (long)(bits*1000/ov_time_total(vf,-1)); |
| 886 | }else{ |
| 887 | if(vf->seekable){ |
| 888 | /* return the actual bitrate */ |
| 889 | return (long)((vf->offsets[i+1]-vf->dataoffsets[i])*8000/ov_time_total(vf,i)); |
| 890 | }else{ |
| 891 | /* return nominal if set */ |
| 892 | if(vf->vi.bitrate_nominal>0){ |
| 893 | return vf->vi.bitrate_nominal; |
| 894 | }else{ |
| 895 | if(vf->vi.bitrate_upper>0){ |
| 896 | if(vf->vi.bitrate_lower>0){ |
| 897 | return (vf->vi.bitrate_upper+vf->vi.bitrate_lower)/2; |
| 898 | }else{ |
| 899 | return vf->vi.bitrate_upper; |
| 900 | } |
| 901 | } |
| 902 | return OV_FALSE; |
| 903 | } |
| 904 | } |
| 905 | } |
| 906 | } |
| 907 | |
| 908 | /* returns the actual bitrate since last call. returns -1 if no |
| 909 | additional data to offer since last call (or at beginning of stream), |
| 910 | EINVAL if stream is only partially open |
| 911 | */ |
| 912 | long ov_bitrate_instant(OggVorbis_File *vf){ |
| 913 | long ret; |
| 914 | if(vf->ready_state<OPENED)return OV_EINVAL; |
| 915 | if(vf->samptrack==0)return OV_FALSE; |
| 916 | ret=(long)(vf->bittrack/vf->samptrack*vf->vi.rate); |
| 917 | vf->bittrack=0; |
| 918 | vf->samptrack=0; |
| 919 | return ret; |
| 920 | } |
| 921 | |
| 922 | /* Guess */ |
| 923 | long ov_serialnumber(OggVorbis_File *vf,int i){ |
| 924 | if(i>=vf->links)return ov_serialnumber(vf,vf->links-1); |
| 925 | if(!vf->seekable && i>=0)return ov_serialnumber(vf,-1); |
| 926 | if(i<0){ |
| 927 | return vf->current_serialno; |
| 928 | }else{ |
| 929 | return vf->serialnos[i]; |
| 930 | } |
| 931 | } |
| 932 | |
| 933 | /* returns: total raw (compressed) length of content if i==-1 |
| 934 | raw (compressed) length of that logical bitstream for i==0 to n |
| 935 | OV_EINVAL if the stream is not seekable (we can't know the length) |
| 936 | or if stream is only partially open |
| 937 | */ |
| 938 | ogg_int64_t ov_raw_total(OggVorbis_File *vf,int i){ |
| 939 | if(vf->ready_state<OPENED)return OV_EINVAL; |
| 940 | if(!vf->seekable || i>=vf->links)return OV_EINVAL; |
| 941 | if(i<0){ |
| 942 | ogg_int64_t acc=0; |
| 943 | int i; |
| 944 | for(i=0;i<vf->links;i++) |
| 945 | acc+=ov_raw_total(vf,i); |
| 946 | return acc; |
| 947 | }else{ |
| 948 | return vf->offsets[i+1]-vf->offsets[i]; |
| 949 | } |
| 950 | } |
| 951 | |
| 952 | /* returns: total PCM length (samples) of content if i==-1 PCM length |
| 953 | (samples) of that logical bitstream for i==0 to n |
| 954 | OV_EINVAL if the stream is not seekable (we can't know the |
| 955 | length) or only partially open |
| 956 | */ |
| 957 | ogg_int64_t ov_pcm_total(OggVorbis_File *vf,int i){ |
| 958 | if(vf->ready_state<OPENED)return OV_EINVAL; |
| 959 | if(!vf->seekable || i>=vf->links)return OV_EINVAL; |
| 960 | if(i<0){ |
| 961 | ogg_int64_t acc=0; |
| 962 | int i; |
| 963 | for(i=0;i<vf->links;i++) |
| 964 | acc+=ov_pcm_total(vf,i); |
| 965 | return acc; |
| 966 | }else{ |
| 967 | return vf->pcmlengths[i*2+1]; |
| 968 | } |
| 969 | } |
| 970 | |
| 971 | /* returns: total milliseconds of content if i==-1 |
| 972 | milliseconds in that logical bitstream for i==0 to n |
| 973 | OV_EINVAL if the stream is not seekable (we can't know the |
| 974 | length) or only partially open |
| 975 | */ |
| 976 | ogg_int64_t ov_time_total(OggVorbis_File *vf,int i){ |
| 977 | if(vf->ready_state<OPENED)return OV_EINVAL; |
| 978 | if(!vf->seekable || i>=vf->links)return OV_EINVAL; |
| 979 | if(i<0){ |
| 980 | ogg_int64_t acc=0; |
| 981 | int i; |
| 982 | for(i=0;i<vf->links;i++) |
| 983 | acc+=ov_time_total(vf,i); |
| 984 | return acc; |
| 985 | }else{ |
| 986 | return ((ogg_int64_t)vf->pcmlengths[i*2+1])*1000/vf->vi.rate; |
| 987 | } |
| 988 | } |
| 989 | |
| 990 | /* seek to an offset relative to the *compressed* data. This also |
| 991 | scans packets to update the PCM cursor. It will cross a logical |
| 992 | bitstream boundary, but only if it can't get any packets out of the |
| 993 | tail of the bitstream we seek to (so no surprises). |
| 994 | |
| 995 | returns zero on success, nonzero on failure */ |
| 996 | |
| 997 | int ov_raw_seek(OggVorbis_File *vf,ogg_int64_t pos){ |
| 998 | ogg_stream_state *work_os=NULL; |
| 999 | ogg_page og={0,0,0,0}; |
| 1000 | ogg_packet op={0,0,0,0,0,0}; |
| 1001 | |
| 1002 | if(vf->ready_state<OPENED)return OV_EINVAL; |
| 1003 | if(!vf->seekable) |
| 1004 | return OV_ENOSEEK; /* don't dump machine if we can't seek */ |
| 1005 | |
| 1006 | if(pos<0 || pos>vf->end)return OV_EINVAL; |
| 1007 | |
| 1008 | /* don't yet clear out decoding machine (if it's initialized), in |
| 1009 | the case we're in the same link. Restart the decode lapping, and |
| 1010 | let _fetch_and_process_packet deal with a potential bitstream |
| 1011 | boundary */ |
| 1012 | vf->pcm_offset=-1; |
| 1013 | ogg_stream_reset_serialno(vf->os, |
| 1014 | vf->current_serialno); /* must set serialno */ |
| 1015 | vorbis_dsp_restart(vf->vd); |
| 1016 | |
| 1017 | _seek_helper(vf,pos); |
| 1018 | |
| 1019 | /* we need to make sure the pcm_offset is set, but we don't want to |
| 1020 | advance the raw cursor past good packets just to get to the first |
| 1021 | with a granulepos. That's not equivalent behavior to beginning |
| 1022 | decoding as immediately after the seek position as possible. |
| 1023 | |
| 1024 | So, a hack. We use two stream states; a local scratch state and |
| 1025 | the shared vf->os stream state. We use the local state to |
| 1026 | scan, and the shared state as a buffer for later decode. |
| 1027 | |
| 1028 | Unfortuantely, on the last page we still advance to last packet |
| 1029 | because the granulepos on the last page is not necessarily on a |
| 1030 | packet boundary, and we need to make sure the granpos is |
| 1031 | correct. |
| 1032 | */ |
| 1033 | |
| 1034 | { |
| 1035 | int lastblock=0; |
| 1036 | int accblock=0; |
| 1037 | int thisblock; |
| 1038 | int eosflag; |
| 1039 | |
| 1040 | work_os=ogg_stream_create(vf->current_serialno); /* get the memory ready */ |
| 1041 | while(1){ |
| 1042 | if(vf->ready_state>=STREAMSET){ |
| 1043 | /* snarf/scan a packet if we can */ |
| 1044 | int result=ogg_stream_packetout(work_os,&op); |
| 1045 | |
| 1046 | if(result>0){ |
| 1047 | |
| 1048 | if(vf->vi.codec_setup){ |
| 1049 | thisblock=vorbis_packet_blocksize(&vf->vi,&op); |
| 1050 | if(thisblock<0){ |
| 1051 | ogg_stream_packetout(vf->os,NULL); |
| 1052 | thisblock=0; |
| 1053 | }else{ |
| 1054 | |
| 1055 | if(eosflag) |
| 1056 | ogg_stream_packetout(vf->os,NULL); |
| 1057 | else |
| 1058 | if(lastblock)accblock+=(lastblock+thisblock)>>2; |
| 1059 | } |
| 1060 | |
| 1061 | if(op.granulepos!=-1){ |
| 1062 | int i,link=vf->current_link; |
| 1063 | ogg_int64_t granulepos=op.granulepos-vf->pcmlengths[link*2]; |
| 1064 | if(granulepos<0)granulepos=0; |
| 1065 | |
| 1066 | for(i=0;i<link;i++) |
| 1067 | granulepos+=vf->pcmlengths[i*2+1]; |
| 1068 | vf->pcm_offset=granulepos-accblock; |
| 1069 | break; |
| 1070 | } |
| 1071 | lastblock=thisblock; |
| 1072 | continue; |
| 1073 | }else |
| 1074 | ogg_stream_packetout(vf->os,NULL); |
| 1075 | } |
| 1076 | } |
| 1077 | |
| 1078 | if(!lastblock){ |
| 1079 | if(_get_next_page(vf,&og,-1)<0){ |
| 1080 | vf->pcm_offset=ov_pcm_total(vf,-1); |
| 1081 | break; |
| 1082 | } |
| 1083 | }else{ |
| 1084 | /* huh? Bogus stream with packets but no granulepos */ |
| 1085 | vf->pcm_offset=-1; |
| 1086 | break; |
| 1087 | } |
| 1088 | |
| 1089 | /* did we just grab a page from other than current link? */ |
| 1090 | if(vf->ready_state>=STREAMSET) |
| 1091 | if(vf->current_serialno!=ogg_page_serialno(&og)){ |
| 1092 | _decode_clear(vf); /* clear out stream state */ |
| 1093 | ogg_stream_destroy(work_os); |
| 1094 | } |
| 1095 | |
| 1096 | if(vf->ready_state<STREAMSET){ |
| 1097 | int link; |
| 1098 | |
| 1099 | vf->current_serialno=ogg_page_serialno(&og); |
| 1100 | for(link=0;link<vf->links;link++) |
| 1101 | if(vf->serialnos[link]==vf->current_serialno)break; |
| 1102 | if(link==vf->links) |
| 1103 | goto seek_error; /* sign of a bogus stream. error out, |
| 1104 | leave machine uninitialized */ |
| 1105 | |
| 1106 | /* need to initialize machine to this link */ |
| 1107 | { |
| 1108 | int ret=_set_link_number_preserve_pos(vf,link); |
| 1109 | if(ret) goto seek_error; |
| 1110 | } |
| 1111 | ogg_stream_reset_serialno(vf->os,vf->current_serialno); |
| 1112 | ogg_stream_reset_serialno(work_os,vf->current_serialno); |
| 1113 | |
| 1114 | |
| 1115 | } |
| 1116 | |
| 1117 | { |
| 1118 | ogg_page dup; |
| 1119 | ogg_page_dup(&dup,&og); |
| 1120 | eosflag=ogg_page_eos(&og); |
| 1121 | ogg_stream_pagein(vf->os,&og); |
| 1122 | ogg_stream_pagein(work_os,&dup); |
| 1123 | } |
| 1124 | } |
| 1125 | } |
| 1126 | |
| 1127 | ogg_packet_release(&op); |
| 1128 | ogg_page_release(&og); |
| 1129 | ogg_stream_destroy(work_os); |
| 1130 | vf->bittrack=0; |
| 1131 | vf->samptrack=0; |
| 1132 | return 0; |
| 1133 | |
| 1134 | seek_error: |
| 1135 | ogg_packet_release(&op); |
| 1136 | ogg_page_release(&og); |
| 1137 | |
| 1138 | /* dump the machine so we're in a known state */ |
| 1139 | vf->pcm_offset=-1; |
| 1140 | ogg_stream_destroy(work_os); |
| 1141 | _decode_clear(vf); |
| 1142 | return OV_EBADLINK; |
| 1143 | } |
| 1144 | |
| 1145 | /* Page granularity seek (faster than sample granularity because we |
| 1146 | don't do the last bit of decode to find a specific sample). |
| 1147 | |
| 1148 | Seek to the last [granule marked] page preceeding the specified pos |
| 1149 | location, such that decoding past the returned point will quickly |
| 1150 | arrive at the requested position. */ |
| 1151 | int ov_pcm_seek_page(OggVorbis_File *vf,ogg_int64_t pos){ |
| 1152 | int link=-1; |
| 1153 | ogg_int64_t result=0; |
| 1154 | ogg_int64_t total=ov_pcm_total(vf,-1); |
| 1155 | ogg_page og={0,0,0,0}; |
| 1156 | ogg_packet op={0,0,0,0,0,0}; |
| 1157 | |
| 1158 | if(vf->ready_state<OPENED)return OV_EINVAL; |
| 1159 | if(!vf->seekable)return OV_ENOSEEK; |
| 1160 | if(pos<0 || pos>total)return OV_EINVAL; |
| 1161 | |
| 1162 | /* which bitstream section does this pcm offset occur in? */ |
| 1163 | for(link=vf->links-1;link>=0;link--){ |
| 1164 | total-=vf->pcmlengths[link*2+1]; |
| 1165 | if(pos>=total)break; |
| 1166 | } |
| 1167 | |
| 1168 | |
| 1169 | if(link!=vf->current_link){ |
| 1170 | int ret=_set_link_number(vf,link); |
| 1171 | if(ret) goto seek_error; |
| 1172 | }else{ |
| 1173 | vorbis_dsp_restart(vf->vd); |
| 1174 | } |
| 1175 | |
| 1176 | ogg_stream_reset_serialno(vf->os,vf->serialnos[link]); |
| 1177 | |
| 1178 | /* search within the logical bitstream for the page with the highest |
| 1179 | pcm_pos preceeding (or equal to) pos. There is a danger here; |
| 1180 | missing pages or incorrect frame number information in the |
| 1181 | bitstream could make our task impossible. Account for that (it |
| 1182 | would be an error condition) */ |
| 1183 | |
| 1184 | /* new search algorithm by HB (Nicholas Vinen) */ |
| 1185 | { |
| 1186 | ogg_int64_t end=vf->offsets[link+1]; |
| 1187 | ogg_int64_t begin=vf->offsets[link]; |
| 1188 | ogg_int64_t begintime = vf->pcmlengths[link*2]; |
| 1189 | ogg_int64_t endtime = vf->pcmlengths[link*2+1]+begintime; |
| 1190 | ogg_int64_t target=pos-total+begintime; |
| 1191 | ogg_int64_t best=begin; |
| 1192 | |
| 1193 | while(begin<end){ |
| 1194 | ogg_int64_t bisect; |
| 1195 | |
| 1196 | if(end-begin<CHUNKSIZE){ |
| 1197 | bisect=begin; |
| 1198 | }else{ |
| 1199 | /* take a (pretty decent) guess. */ |
| 1200 | bisect=begin + |
| 1201 | (target-begintime)*(end-begin)/(endtime-begintime) - CHUNKSIZE; |
| 1202 | if(bisect<=begin) |
| 1203 | bisect=begin+1; |
| 1204 | } |
| 1205 | |
| 1206 | _seek_helper(vf,bisect); |
| 1207 | |
| 1208 | while(begin<end){ |
| 1209 | result=_get_next_page(vf,&og,end-vf->offset); |
| 1210 | if(result==OV_EREAD) goto seek_error; |
| 1211 | if(result<0){ |
| 1212 | if(bisect<=begin+1) |
| 1213 | end=begin; /* found it */ |
| 1214 | else{ |
| 1215 | if(bisect==0) goto seek_error; |
| 1216 | bisect-=CHUNKSIZE; |
| 1217 | if(bisect<=begin)bisect=begin+1; |
| 1218 | _seek_helper(vf,bisect); |
| 1219 | } |
| 1220 | }else{ |
| 1221 | ogg_int64_t granulepos=ogg_page_granulepos(&og); |
| 1222 | if(granulepos==-1)continue; |
| 1223 | if(granulepos<target){ |
| 1224 | best=result; /* raw offset of packet with granulepos */ |
| 1225 | begin=vf->offset; /* raw offset of next page */ |
| 1226 | begintime=granulepos; |
| 1227 | |
| 1228 | if(target-begintime>44100)break; |
| 1229 | bisect=begin; /* *not* begin + 1 */ |
| 1230 | }else{ |
| 1231 | if(bisect<=begin+1) |
| 1232 | end=begin; /* found it */ |
| 1233 | else{ |
| 1234 | if(end==vf->offset){ /* we're pretty close - we'd be stuck in */ |
| 1235 | end=result; |
| 1236 | bisect-=CHUNKSIZE; /* an endless loop otherwise. */ |
| 1237 | if(bisect<=begin)bisect=begin+1; |
| 1238 | _seek_helper(vf,bisect); |
| 1239 | }else{ |
| 1240 | end=result; |
| 1241 | endtime=granulepos; |
| 1242 | break; |
| 1243 | } |
| 1244 | } |
| 1245 | } |
| 1246 | } |
| 1247 | } |
| 1248 | } |
| 1249 | |
| 1250 | /* found our page. seek to it, update pcm offset. Easier case than |
| 1251 | raw_seek, don't keep packets preceeding granulepos. */ |
| 1252 | { |
| 1253 | |
| 1254 | /* seek */ |
| 1255 | _seek_helper(vf,best); |
| 1256 | vf->pcm_offset=-1; |
| 1257 | |
| 1258 | if(_get_next_page(vf,&og,-1)<0){ |
| 1259 | ogg_page_release(&og); |
| 1260 | return OV_EOF; /* shouldn't happen */ |
| 1261 | } |
| 1262 | |
| 1263 | ogg_stream_pagein(vf->os,&og); |
| 1264 | |
| 1265 | /* pull out all but last packet; the one with granulepos */ |
| 1266 | while(1){ |
| 1267 | result=ogg_stream_packetpeek(vf->os,&op); |
| 1268 | if(result==0){ |
| 1269 | /* !!! the packet finishing this page originated on a |
| 1270 | preceeding page. Keep fetching previous pages until we |
| 1271 | get one with a granulepos or without the 'continued' flag |
| 1272 | set. Then just use raw_seek for simplicity. */ |
| 1273 | |
| 1274 | _seek_helper(vf,best); |
| 1275 | |
| 1276 | while(1){ |
| 1277 | result=_get_prev_page(vf,&og); |
| 1278 | if(result<0) goto seek_error; |
| 1279 | if(ogg_page_granulepos(&og)>-1 || |
| 1280 | !ogg_page_continued(&og)){ |
| 1281 | return ov_raw_seek(vf,result); |
| 1282 | } |
| 1283 | vf->offset=result; |
| 1284 | } |
| 1285 | } |
| 1286 | if(result<0){ |
| 1287 | result = OV_EBADPACKET; |
| 1288 | goto seek_error; |
| 1289 | } |
| 1290 | if(op.granulepos!=-1){ |
| 1291 | vf->pcm_offset=op.granulepos-vf->pcmlengths[vf->current_link*2]; |
| 1292 | if(vf->pcm_offset<0)vf->pcm_offset=0; |
| 1293 | vf->pcm_offset+=total; |
| 1294 | break; |
| 1295 | }else |
| 1296 | result=ogg_stream_packetout(vf->os,NULL); |
| 1297 | } |
| 1298 | } |
| 1299 | } |
| 1300 | |
| 1301 | /* verify result */ |
| 1302 | if(vf->pcm_offset>pos || pos>ov_pcm_total(vf,-1)){ |
| 1303 | result=OV_EFAULT; |
| 1304 | goto seek_error; |
| 1305 | } |
| 1306 | vf->bittrack=0; |
| 1307 | vf->samptrack=0; |
| 1308 | |
| 1309 | ogg_page_release(&og); |
| 1310 | ogg_packet_release(&op); |
| 1311 | return 0; |
| 1312 | |
| 1313 | seek_error: |
| 1314 | |
| 1315 | ogg_page_release(&og); |
| 1316 | ogg_packet_release(&op); |
| 1317 | |
| 1318 | /* dump machine so we're in a known state */ |
| 1319 | vf->pcm_offset=-1; |
| 1320 | _decode_clear(vf); |
| 1321 | return (int)result; |
| 1322 | } |
| 1323 | |
| 1324 | /* seek to a sample offset relative to the decompressed pcm stream |
| 1325 | returns zero on success, nonzero on failure */ |
| 1326 | |
| 1327 | int ov_pcm_seek(OggVorbis_File *vf,ogg_int64_t pos){ |
| 1328 | ogg_packet op={0,0,0,0,0,0}; |
| 1329 | ogg_page og={0,0,0,0}; |
| 1330 | int thisblock,lastblock=0; |
| 1331 | int ret=ov_pcm_seek_page(vf,pos); |
| 1332 | if(ret<0)return ret; |
| 1333 | if(_make_decode_ready(vf))return OV_EBADLINK; |
| 1334 | |
| 1335 | /* discard leading packets we don't need for the lapping of the |
| 1336 | position we want; don't decode them */ |
| 1337 | |
| 1338 | while(1){ |
| 1339 | |
| 1340 | int ret=ogg_stream_packetpeek(vf->os,&op); |
| 1341 | if(ret>0){ |
| 1342 | thisblock=vorbis_packet_blocksize(&vf->vi,&op); |
| 1343 | if(thisblock<0){ |
| 1344 | ogg_stream_packetout(vf->os,NULL); |
| 1345 | continue; /* non audio packet */ |
| 1346 | } |
| 1347 | if(lastblock)vf->pcm_offset+=(lastblock+thisblock)>>2; |
| 1348 | |
| 1349 | if(vf->pcm_offset+((thisblock+ |
| 1350 | vorbis_info_blocksize(&vf->vi,1))>>2)>=pos)break; |
| 1351 | |
| 1352 | /* remove the packet from packet queue and track its granulepos */ |
| 1353 | ogg_stream_packetout(vf->os,NULL); |
| 1354 | vorbis_dsp_synthesis(vf->vd,&op,0); /* set up a vb with |
| 1355 | only tracking, no |
| 1356 | pcm_decode */ |
| 1357 | |
| 1358 | /* end of logical stream case is hard, especially with exact |
| 1359 | length positioning. */ |
| 1360 | |
| 1361 | if(op.granulepos>-1){ |
| 1362 | int i; |
| 1363 | /* always believe the stream markers */ |
| 1364 | vf->pcm_offset=op.granulepos-vf->pcmlengths[vf->current_link*2]; |
| 1365 | if(vf->pcm_offset<0)vf->pcm_offset=0; |
| 1366 | for(i=0;i<vf->current_link;i++) |
| 1367 | vf->pcm_offset+=vf->pcmlengths[i*2+1]; |
| 1368 | } |
| 1369 | |
| 1370 | lastblock=thisblock; |
| 1371 | |
| 1372 | }else{ |
| 1373 | if(ret<0 && ret!=OV_HOLE)break; |
| 1374 | |
| 1375 | /* suck in a new page */ |
| 1376 | if(_get_next_page(vf,&og,-1)<0)break; |
| 1377 | if(vf->current_serialno!=ogg_page_serialno(&og))_decode_clear(vf); |
| 1378 | |
| 1379 | if(vf->ready_state<STREAMSET){ |
| 1380 | int link,ret; |
| 1381 | |
| 1382 | vf->current_serialno=ogg_page_serialno(&og); |
| 1383 | for(link=0;link<vf->links;link++) |
| 1384 | if(vf->serialnos[link]==vf->current_serialno)break; |
| 1385 | if(link==vf->links){ |
| 1386 | ogg_page_release(&og); |
| 1387 | ogg_packet_release(&op); |
| 1388 | return OV_EBADLINK; |
| 1389 | } |
| 1390 | |
| 1391 | |
| 1392 | vf->current_link=link; |
| 1393 | ret=_fetch_headers(vf,&vf->vi,&vf->vc,&vf->current_serialno,&og); |
| 1394 | if(ret) return ret; |
| 1395 | if(_make_decode_ready(vf))return OV_EBADLINK; |
| 1396 | lastblock=0; |
| 1397 | } |
| 1398 | |
| 1399 | ogg_stream_pagein(vf->os,&og); |
| 1400 | } |
| 1401 | } |
| 1402 | |
| 1403 | vf->bittrack=0; |
| 1404 | vf->samptrack=0; |
| 1405 | /* discard samples until we reach the desired position. Crossing a |
| 1406 | logical bitstream boundary with abandon is OK. */ |
| 1407 | while(vf->pcm_offset<pos){ |
| 1408 | ogg_int64_t target=pos-vf->pcm_offset; |
| 1409 | long samples=vorbis_dsp_pcmout(vf->vd,NULL,0); |
| 1410 | |
| 1411 | if(samples>target)samples=(long)target; |
| 1412 | vorbis_dsp_read(vf->vd,samples); |
| 1413 | vf->pcm_offset+=samples; |
| 1414 | |
| 1415 | if(samples<target) |
| 1416 | if(_fetch_and_process_packet(vf,1,1)<=0) |
| 1417 | vf->pcm_offset=ov_pcm_total(vf,-1); /* eof */ |
| 1418 | } |
| 1419 | |
| 1420 | ogg_page_release(&og); |
| 1421 | ogg_packet_release(&op); |
| 1422 | return 0; |
| 1423 | } |
| 1424 | |
| 1425 | /* seek to a playback time relative to the decompressed pcm stream |
| 1426 | returns zero on success, nonzero on failure */ |
| 1427 | int ov_time_seek(OggVorbis_File *vf,ogg_int64_t milliseconds){ |
| 1428 | /* translate time to PCM position and call ov_pcm_seek */ |
| 1429 | |
| 1430 | int link=-1; |
| 1431 | ogg_int64_t pcm_total=ov_pcm_total(vf,-1); |
| 1432 | ogg_int64_t time_total=ov_time_total(vf,-1); |
| 1433 | |
| 1434 | if(vf->ready_state<OPENED)return OV_EINVAL; |
| 1435 | if(!vf->seekable)return OV_ENOSEEK; |
| 1436 | if(milliseconds<0 || milliseconds>time_total)return OV_EINVAL; |
| 1437 | |
| 1438 | /* which bitstream section does this time offset occur in? */ |
| 1439 | for(link=vf->links-1;link>=0;link--){ |
| 1440 | pcm_total-=vf->pcmlengths[link*2+1]; |
| 1441 | time_total-=ov_time_total(vf,link); |
| 1442 | if(milliseconds>=time_total)break; |
| 1443 | } |
| 1444 | |
| 1445 | /* enough information to convert time offset to pcm offset */ |
| 1446 | { |
| 1447 | int ret=_set_link_number(vf,link); |
| 1448 | if(ret)return ret; |
| 1449 | return |
| 1450 | ov_pcm_seek(vf,pcm_total+(milliseconds-time_total)* |
| 1451 | vf->vi.rate/1000); |
| 1452 | } |
| 1453 | } |
| 1454 | |
| 1455 | /* page-granularity version of ov_time_seek |
| 1456 | returns zero on success, nonzero on failure */ |
| 1457 | int ov_time_seek_page(OggVorbis_File *vf,ogg_int64_t milliseconds){ |
| 1458 | /* translate time to PCM position and call ov_pcm_seek */ |
| 1459 | |
| 1460 | int link=-1; |
| 1461 | ogg_int64_t pcm_total=ov_pcm_total(vf,-1); |
| 1462 | ogg_int64_t time_total=ov_time_total(vf,-1); |
| 1463 | |
| 1464 | if(vf->ready_state<OPENED)return OV_EINVAL; |
| 1465 | if(!vf->seekable)return OV_ENOSEEK; |
| 1466 | if(milliseconds<0 || milliseconds>time_total)return OV_EINVAL; |
| 1467 | |
| 1468 | /* which bitstream section does this time offset occur in? */ |
| 1469 | for(link=vf->links-1;link>=0;link--){ |
| 1470 | pcm_total-=vf->pcmlengths[link*2+1]; |
| 1471 | time_total-=ov_time_total(vf,link); |
| 1472 | if(milliseconds>=time_total)break; |
| 1473 | } |
| 1474 | |
| 1475 | /* enough information to convert time offset to pcm offset */ |
| 1476 | { |
| 1477 | int ret=_set_link_number(vf,link); |
| 1478 | if(ret)return ret; |
| 1479 | return |
| 1480 | ov_pcm_seek_page(vf,pcm_total+(milliseconds-time_total)* |
| 1481 | vf->vi.rate/1000); |
| 1482 | } |
| 1483 | } |
| 1484 | |
| 1485 | /* tell the current stream offset cursor. Note that seek followed by |
| 1486 | tell will likely not give the set offset due to caching */ |
| 1487 | ogg_int64_t ov_raw_tell(OggVorbis_File *vf){ |
| 1488 | if(vf->ready_state<OPENED)return OV_EINVAL; |
| 1489 | return vf->offset; |
| 1490 | } |
| 1491 | |
| 1492 | /* return PCM offset (sample) of next PCM sample to be read */ |
| 1493 | ogg_int64_t ov_pcm_tell(OggVorbis_File *vf){ |
| 1494 | if(vf->ready_state<OPENED)return OV_EINVAL; |
| 1495 | return vf->pcm_offset; |
| 1496 | } |
| 1497 | |
| 1498 | /* return time offset (milliseconds) of next PCM sample to be read */ |
| 1499 | ogg_int64_t ov_time_tell(OggVorbis_File *vf){ |
| 1500 | int link=0; |
| 1501 | ogg_int64_t pcm_total=0; |
| 1502 | ogg_int64_t time_total=0; |
| 1503 | |
| 1504 | if(vf->ready_state<OPENED)return OV_EINVAL; |
| 1505 | if(vf->seekable){ |
| 1506 | pcm_total=ov_pcm_total(vf,-1); |
| 1507 | time_total=ov_time_total(vf,-1); |
| 1508 | |
| 1509 | /* which bitstream section does this time offset occur in? */ |
| 1510 | for(link=vf->links-1;link>=0;link--){ |
| 1511 | pcm_total-=vf->pcmlengths[link*2+1]; |
| 1512 | time_total-=ov_time_total(vf,link); |
| 1513 | if(vf->pcm_offset>=pcm_total)break; |
| 1514 | } |
| 1515 | } |
| 1516 | |
| 1517 | return time_total+(1000*vf->pcm_offset-pcm_total)/vf->vi.rate; |
| 1518 | } |
| 1519 | |
| 1520 | /* link: -1) return the vorbis_info struct for the bitstream section |
| 1521 | currently being decoded |
| 1522 | 0-n) to request information for a specific bitstream section |
| 1523 | |
| 1524 | In the case of a non-seekable bitstream, any call returns the |
| 1525 | current bitstream. NULL in the case that the machine is not |
| 1526 | initialized */ |
| 1527 | |
| 1528 | vorbis_info *ov_info(OggVorbis_File *vf,int link){ |
| 1529 | if(vf->seekable){ |
| 1530 | if(link>=vf->links)return NULL; |
| 1531 | if(link>=0){ |
| 1532 | int ret=_set_link_number_preserve_pos(vf,link); |
| 1533 | if(ret)return NULL; |
| 1534 | } |
| 1535 | } |
| 1536 | return &vf->vi; |
| 1537 | } |
| 1538 | |
| 1539 | /* grr, strong typing, grr, no templates/inheritence, grr */ |
| 1540 | vorbis_comment *ov_comment(OggVorbis_File *vf,int link){ |
| 1541 | if(vf->seekable){ |
| 1542 | if(link>=vf->links)return NULL; |
| 1543 | if(link>=0){ |
| 1544 | int ret=_set_link_number_preserve_pos(vf,link); |
| 1545 | if(ret)return NULL; |
| 1546 | } |
| 1547 | } |
| 1548 | return &vf->vc; |
| 1549 | } |
| 1550 | |
| 1551 | /* up to this point, everything could more or less hide the multiple |
| 1552 | logical bitstream nature of chaining from the toplevel application |
| 1553 | if the toplevel application didn't particularly care. However, at |
| 1554 | the point that we actually read audio back, the multiple-section |
| 1555 | nature must surface: Multiple bitstream sections do not necessarily |
| 1556 | have to have the same number of channels or sampling rate. |
| 1557 | |
| 1558 | ov_read returns the sequential logical bitstream number currently |
| 1559 | being decoded along with the PCM data in order that the toplevel |
| 1560 | application can take action on channel/sample rate changes. This |
| 1561 | number will be incremented even for streamed (non-seekable) streams |
| 1562 | (for seekable streams, it represents the actual logical bitstream |
| 1563 | index within the physical bitstream. Note that the accessor |
| 1564 | functions above are aware of this dichotomy). |
| 1565 | |
| 1566 | input values: buffer) a buffer to hold packed PCM data for return |
| 1567 | length) the byte length requested to be placed into buffer |
| 1568 | |
| 1569 | return values: <0) error/hole in data (OV_HOLE), partial open (OV_EINVAL) |
| 1570 | 0) EOF |
| 1571 | n) number of bytes of PCM actually returned. The |
| 1572 | below works on a packet-by-packet basis, so the |
| 1573 | return length is not related to the 'length' passed |
| 1574 | in, just guaranteed to fit. |
| 1575 | |
| 1576 | *section) set to the logical bitstream number */ |
| 1577 | |
| 1578 | long ov_read(OggVorbis_File *vf,void *buffer,int bytes_req,int *bitstream){ |
| 1579 | |
| 1580 | long samples; |
| 1581 | long channels; |
| 1582 | |
| 1583 | if(vf->ready_state<OPENED)return OV_EINVAL; |
| 1584 | |
| 1585 | while(1){ |
| 1586 | if(vf->ready_state==INITSET){ |
| 1587 | channels=vf->vi.channels; |
| 1588 | samples=vorbis_dsp_pcmout(vf->vd,buffer,(bytes_req>>1)/channels); |
| 1589 | if(samples){ |
| 1590 | if(samples>0){ |
| 1591 | vorbis_dsp_read(vf->vd,samples); |
| 1592 | vf->pcm_offset+=samples; |
| 1593 | if(bitstream)*bitstream=vf->current_link; |
| 1594 | return samples*2*channels; |
| 1595 | } |
| 1596 | return samples; |
| 1597 | } |
| 1598 | } |
| 1599 | |
| 1600 | /* suck in another packet */ |
| 1601 | { |
| 1602 | int ret=_fetch_and_process_packet(vf,1,1); |
| 1603 | if(ret==OV_EOF) |
| 1604 | return 0; |
| 1605 | if(ret<=0) |
| 1606 | return ret; |
| 1607 | } |
| 1608 | |
| 1609 | } |
| 1610 | } |