Work at SourceForge, help us to make it a better place! We have an immediate need for a Support Technician in our San Francisco or Denver office.

Close

[6c7e9c]: lib / vorbisfile.c Maximize Restore History

Download this file

vorbisfile.c    1991 lines (1679 with data), 57.7 kB

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
/********************************************************************
* *
* THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE. *
* USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
* GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
* IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
* *
* THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2002 *
* by the XIPHOPHORUS Company http://www.xiph.org/ *
* *
********************************************************************
function: stdio-based convenience library for opening/seeking/decoding
last mod: $Id$
********************************************************************/
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <math.h>
#include "vorbis/codec.h"
#include "vorbis/vorbisfile.h"
#include "os.h"
#include "misc.h"
/* A 'chained bitstream' is a Vorbis bitstream that contains more than
one logical bitstream arranged end to end (the only form of Ogg
multiplexing allowed in a Vorbis bitstream; grouping [parallel
multiplexing] is not allowed in Vorbis) */
/* A Vorbis file can be played beginning to end (streamed) without
worrying ahead of time about chaining (see decoder_example.c). If
we have the whole file, however, and want random access
(seeking/scrubbing) or desire to know the total length/time of a
file, we need to account for the possibility of chaining. */
/* We can handle things a number of ways; we can determine the entire
bitstream structure right off the bat, or find pieces on demand.
This example determines and caches structure for the entire
bitstream, but builds a virtual decoder on the fly when moving
between links in the chain. */
/* There are also different ways to implement seeking. Enough
information exists in an Ogg bitstream to seek to
sample-granularity positions in the output. Or, one can seek by
picking some portion of the stream roughly in the desired area if
we only want coarse navigation through the stream. */
/*************************************************************************
* Many, many internal helpers. The intention is not to be confusing;
* rampant duplication and monolithic function implementation would be
* harder to understand anyway. The high level functions are last. Begin
* grokking near the end of the file */
/* read a little more data from the file/pipe into the ogg_sync framer
*/
#define CHUNKSIZE 8500 /* a shade over 8k; anyone using pages well
over 8k gets what they deserve */
static long _get_data(OggVorbis_File *vf){
errno=0;
if(vf->datasource){
char *buffer=ogg_sync_buffer(&vf->oy,CHUNKSIZE);
long bytes=(vf->callbacks.read_func)(buffer,1,CHUNKSIZE,vf->datasource);
if(bytes>0)ogg_sync_wrote(&vf->oy,bytes);
if(bytes==0 && errno)return(-1);
return(bytes);
}else
return(0);
}
/* save a tiny smidge of verbosity to make the code more readable */
static void _seek_helper(OggVorbis_File *vf,ogg_int64_t offset){
if(vf->datasource){
(vf->callbacks.seek_func)(vf->datasource, offset, SEEK_SET);
vf->offset=offset;
ogg_sync_reset(&vf->oy);
}else{
/* shouldn't happen unless someone writes a broken callback */
return;
}
}
/* The read/seek functions track absolute position within the stream */
/* from the head of the stream, get the next page. boundary specifies
if the function is allowed to fetch more data from the stream (and
how much) or only use internally buffered data.
boundary: -1) unbounded search
0) read no additional data; use cached only
n) search for a new page beginning for n bytes
return: <0) did not find a page (OV_FALSE, OV_EOF, OV_EREAD)
n) found a page at absolute offset n */
static ogg_int64_t _get_next_page(OggVorbis_File *vf,ogg_page *og,
ogg_int64_t boundary){
if(boundary>0)boundary+=vf->offset;
while(1){
long more;
if(boundary>0 && vf->offset>=boundary)return(OV_FALSE);
more=ogg_sync_pageseek(&vf->oy,og);
if(more<0){
/* skipped n bytes */
vf->offset-=more;
}else{
if(more==0){
/* send more paramedics */
if(!boundary)return(OV_FALSE);
{
long ret=_get_data(vf);
if(ret==0)return(OV_EOF);
if(ret<0)return(OV_EREAD);
}
}else{
/* got a page. Return the offset at the page beginning,
advance the internal offset past the page end */
ogg_int64_t ret=vf->offset;
vf->offset+=more;
return(ret);
}
}
}
}
/* find the latest page beginning before the current stream cursor
position. Much dirtier than the above as Ogg doesn't have any
backward search linkage. no 'readp' as it will certainly have to
read. */
/* returns offset or OV_EREAD, OV_FAULT */
static ogg_int64_t _get_prev_page(OggVorbis_File *vf,ogg_page *og){
ogg_int64_t begin=vf->offset;
ogg_int64_t end=begin;
ogg_int64_t ret;
ogg_int64_t offset=-1;
while(offset==-1){
begin-=CHUNKSIZE;
if(begin<0)
begin=0;
_seek_helper(vf,begin);
while(vf->offset<end){
ret=_get_next_page(vf,og,end-vf->offset);
if(ret==OV_EREAD)return(OV_EREAD);
if(ret<0){
break;
}else{
offset=ret;
}
}
}
/* we have the offset. Actually snork and hold the page now */
_seek_helper(vf,offset);
ret=_get_next_page(vf,og,CHUNKSIZE);
if(ret<0)
/* this shouldn't be possible */
return(OV_EFAULT);
return(offset);
}
/* finds each bitstream link one at a time using a bisection search
(has to begin by knowing the offset of the lb's initial page).
Recurses for each link so it can alloc the link storage after
finding them all, then unroll and fill the cache at the same time */
static int _bisect_forward_serialno(OggVorbis_File *vf,
ogg_int64_t begin,
ogg_int64_t searched,
ogg_int64_t end,
long currentno,
long m){
ogg_int64_t endsearched=end;
ogg_int64_t next=end;
ogg_page og;
ogg_int64_t ret;
/* the below guards against garbage seperating the last and
first pages of two links. */
while(searched<endsearched){
ogg_int64_t bisect;
if(endsearched-searched<CHUNKSIZE){
bisect=searched;
}else{
bisect=(searched+endsearched)/2;
}
_seek_helper(vf,bisect);
ret=_get_next_page(vf,&og,-1);
if(ret==OV_EREAD)return(OV_EREAD);
if(ret<0 || ogg_page_serialno(&og)!=currentno){
endsearched=bisect;
if(ret>=0)next=ret;
}else{
searched=ret+og.header_len+og.body_len;
}
}
_seek_helper(vf,next);
ret=_get_next_page(vf,&og,-1);
if(ret==OV_EREAD)return(OV_EREAD);
if(searched>=end || ret<0){
vf->links=m+1;
vf->offsets=_ogg_malloc((vf->links+1)*sizeof(*vf->offsets));
vf->serialnos=_ogg_malloc(vf->links*sizeof(*vf->serialnos));
vf->offsets[m+1]=searched;
}else{
ret=_bisect_forward_serialno(vf,next,vf->offset,
end,ogg_page_serialno(&og),m+1);
if(ret==OV_EREAD)return(OV_EREAD);
}
vf->offsets[m]=begin;
vf->serialnos[m]=currentno;
return(0);
}
/* uses the local ogg_stream storage in vf; this is important for
non-streaming input sources */
static int _fetch_headers(OggVorbis_File *vf,vorbis_info *vi,vorbis_comment *vc,
long *serialno,ogg_page *og_ptr){
ogg_page og;
ogg_packet op;
int i,ret;
if(!og_ptr){
ogg_int64_t llret=_get_next_page(vf,&og,CHUNKSIZE);
if(llret==OV_EREAD)return(OV_EREAD);
if(llret<0)return OV_ENOTVORBIS;
og_ptr=&og;
}
ogg_stream_reset_serialno(&vf->os,ogg_page_serialno(og_ptr));
if(serialno)*serialno=vf->os.serialno;
vf->ready_state=STREAMSET;
/* extract the initial header from the first page and verify that the
Ogg bitstream is in fact Vorbis data */
vorbis_info_init(vi);
vorbis_comment_init(vc);
i=0;
while(i<3){
ogg_stream_pagein(&vf->os,og_ptr);
while(i<3){
int result=ogg_stream_packetout(&vf->os,&op);
if(result==0)break;
if(result==-1){
ret=OV_EBADHEADER;
goto bail_header;
}
if((ret=vorbis_synthesis_headerin(vi,vc,&op))){
goto bail_header;
}
i++;
}
if(i<3)
if(_get_next_page(vf,og_ptr,CHUNKSIZE)<0){
ret=OV_EBADHEADER;
goto bail_header;
}
}
return 0;
bail_header:
vorbis_info_clear(vi);
vorbis_comment_clear(vc);
vf->ready_state=OPENED;
return ret;
}
/* last step of the OggVorbis_File initialization; get all the
vorbis_info structs and PCM positions. Only called by the seekable
initialization (local stream storage is hacked slightly; pay
attention to how that's done) */
/* this is void and does not propogate errors up because we want to be
able to open and use damaged bitstreams as well as we can. Just
watch out for missing information for links in the OggVorbis_File
struct */
static void _prefetch_all_headers(OggVorbis_File *vf, ogg_int64_t dataoffset){
ogg_page og;
int i;
ogg_int64_t ret;
vf->vi=_ogg_realloc(vf->vi,vf->links*sizeof(*vf->vi));
vf->vc=_ogg_realloc(vf->vc,vf->links*sizeof(*vf->vc));
vf->dataoffsets=_ogg_malloc(vf->links*sizeof(*vf->dataoffsets));
vf->pcmlengths=_ogg_malloc(vf->links*2*sizeof(*vf->pcmlengths));
for(i=0;i<vf->links;i++){
if(i==0){
/* we already grabbed the initial header earlier. Just set the offset */
vf->dataoffsets[i]=dataoffset;
_seek_helper(vf,dataoffset);
}else{
/* seek to the location of the initial header */
_seek_helper(vf,vf->offsets[i]);
if(_fetch_headers(vf,vf->vi+i,vf->vc+i,NULL,NULL)<0){
vf->dataoffsets[i]=-1;
}else{
vf->dataoffsets[i]=vf->offset;
}
}
/* fetch beginning PCM offset */
if(vf->dataoffsets[i]!=-1){
ogg_int64_t accumulated=0;
long lastblock=-1;
int result;
ogg_stream_reset_serialno(&vf->os,vf->serialnos[i]);
while(1){
ogg_packet op;
ret=_get_next_page(vf,&og,-1);
if(ret<0)
/* this should not be possible unless the file is
truncated/mangled */
break;
if(ogg_page_serialno(&og)!=vf->serialnos[i])
break;
/* count blocksizes of all frames in the page */
ogg_stream_pagein(&vf->os,&og);
while((result=ogg_stream_packetout(&vf->os,&op))){
if(result>0){ /* ignore holes */
long thisblock=vorbis_packet_blocksize(vf->vi+i,&op);
if(lastblock!=-1)
accumulated+=(lastblock+thisblock)>>2;
lastblock=thisblock;
}
}
if(ogg_page_granulepos(&og)!=-1){
/* pcm offset of last packet on the first audio page */
accumulated= ogg_page_granulepos(&og)-accumulated;
break;
}
}
/* less than zero? This is a stream with samples trimmed off
the beginning, a normal occurrence; set the offset to zero */
if(accumulated<0)accumulated=0;
vf->pcmlengths[i*2]=accumulated;
}
/* get the PCM length of this link. To do this,
get the last page of the stream */
{
ogg_int64_t end=vf->offsets[i+1];
_seek_helper(vf,end);
while(1){
ret=_get_prev_page(vf,&og);
if(ret<0){
/* this should not be possible */
vorbis_info_clear(vf->vi+i);
vorbis_comment_clear(vf->vc+i);
break;
}
if(ogg_page_granulepos(&og)!=-1){
vf->pcmlengths[i*2+1]=ogg_page_granulepos(&og)-vf->pcmlengths[i*2];
break;
}
vf->offset=ret;
}
}
}
}
static int _make_decode_ready(OggVorbis_File *vf){
if(vf->ready_state>STREAMSET)return 0;
if(vf->ready_state<STREAMSET)return OV_EFAULT;
if(vf->seekable){
if(vorbis_synthesis_init(&vf->vd,vf->vi+vf->current_link))
return OV_EBADLINK;
}else{
if(vorbis_synthesis_init(&vf->vd,vf->vi))
return OV_EBADLINK;
}
vorbis_block_init(&vf->vd,&vf->vb);
vf->ready_state=INITSET;
vf->bittrack=0.f;
vf->samptrack=0.f;
return 0;
}
static int _open_seekable2(OggVorbis_File *vf){
long serialno=vf->current_serialno;
ogg_int64_t dataoffset=vf->offset, end;
ogg_page og;
/* we're partially open and have a first link header state in
storage in vf */
/* we can seek, so set out learning all about this file */
(vf->callbacks.seek_func)(vf->datasource,0,SEEK_END);
vf->offset=vf->end=(vf->callbacks.tell_func)(vf->datasource);
/* If seek_func is implemented, tell_func must also be implemented */
if(vf->end==-1) return(OV_EINVAL);
/* We get the offset for the last page of the physical bitstream.
Most OggVorbis files will contain a single logical bitstream */
end=_get_prev_page(vf,&og);
if(end<0)return(end);
/* more than one logical bitstream? */
if(ogg_page_serialno(&og)!=serialno){
/* Chained bitstream. Bisect-search each logical bitstream
section. Do so based on serial number only */
if(_bisect_forward_serialno(vf,0,0,end+1,serialno,0)<0)return(OV_EREAD);
}else{
/* Only one logical bitstream */
if(_bisect_forward_serialno(vf,0,end,end+1,serialno,0))return(OV_EREAD);
}
/* the initial header memory is referenced by vf after; don't free it */
_prefetch_all_headers(vf,dataoffset);
return(ov_raw_seek(vf,0));
}
/* clear out the current logical bitstream decoder */
static void _decode_clear(OggVorbis_File *vf){
vorbis_dsp_clear(&vf->vd);
vorbis_block_clear(&vf->vb);
vf->ready_state=OPENED;
}
/* fetch and process a packet. Handles the case where we're at a
bitstream boundary and dumps the decoding machine. If the decoding
machine is unloaded, it loads it. It also keeps pcm_offset up to
date (seek and read both use this. seek uses a special hack with
readp).
return: <0) error, OV_HOLE (lost packet) or OV_EOF
0) need more data (only if readp==0)
1) got a packet
*/
static int _fetch_and_process_packet(OggVorbis_File *vf,
ogg_packet *op_in,
int readp,
int spanp){
ogg_page og;
/* handle one packet. Try to fetch it from current stream state */
/* extract packets from page */
while(1){
/* process a packet if we can. If the machine isn't loaded,
neither is a page */
if(vf->ready_state==INITSET){
while(1) {
ogg_packet op;
ogg_packet *op_ptr=(op_in?op_in:&op);
int result=ogg_stream_packetout(&vf->os,op_ptr);
ogg_int64_t granulepos;
op_in=NULL;
if(result==-1)return(OV_HOLE); /* hole in the data. */
if(result>0){
/* got a packet. process it */
granulepos=op_ptr->granulepos;
if(!vorbis_synthesis(&vf->vb,op_ptr)){ /* lazy check for lazy
header handling. The
header packets aren't
audio, so if/when we
submit them,
vorbis_synthesis will
reject them */
/* suck in the synthesis data and track bitrate */
{
int oldsamples=vorbis_synthesis_pcmout(&vf->vd,NULL);
/* for proper use of libvorbis within libvorbisfile,
oldsamples will always be zero. */
if(oldsamples)return(OV_EFAULT);
vorbis_synthesis_blockin(&vf->vd,&vf->vb);
vf->samptrack+=vorbis_synthesis_pcmout(&vf->vd,NULL)-oldsamples;
vf->bittrack+=op_ptr->bytes*8;
}
/* update the pcm offset. */
if(granulepos!=-1 && !op_ptr->e_o_s){
int link=(vf->seekable?vf->current_link:0);
int i,samples;
/* this packet has a pcm_offset on it (the last packet
completed on a page carries the offset) After processing
(above), we know the pcm position of the *last* sample
ready to be returned. Find the offset of the *first*
As an aside, this trick is inaccurate if we begin
reading anew right at the last page; the end-of-stream
granulepos declares the last frame in the stream, and the
last packet of the last page may be a partial frame.
So, we need a previous granulepos from an in-sequence page
to have a reference point. Thus the !op_ptr->e_o_s clause
above */
if(vf->seekable && link>0)
granulepos-=vf->pcmlengths[link*2];
if(granulepos<0)granulepos=0; /* actually, this
shouldn't be possible
here unless the stream
is very broken */
samples=vorbis_synthesis_pcmout(&vf->vd,NULL);
granulepos-=samples;
for(i=0;i<link;i++)
granulepos+=vf->pcmlengths[i*2+1];
vf->pcm_offset=granulepos;
}
return(1);
}
}
else
break;
}
}
if(vf->ready_state>=OPENED){
ogg_int64_t ret;
if(!readp)return(0);
if((ret=_get_next_page(vf,&og,-1))<0){
return(OV_EOF); /* eof.
leave unitialized */
}
/* bitrate tracking; add the header's bytes here, the body bytes
are done by packet above */
vf->bittrack+=og.header_len*8;
/* has our decoding just traversed a bitstream boundary? */
if(vf->ready_state==INITSET){
if(vf->current_serialno!=ogg_page_serialno(&og)){
if(!spanp)
return(OV_EOF);
_decode_clear(vf);
if(!vf->seekable){
vorbis_info_clear(vf->vi);
vorbis_comment_clear(vf->vc);
}
}
}
}
/* Do we need to load a new machine before submitting the page? */
/* This is different in the seekable and non-seekable cases.
In the seekable case, we already have all the header
information loaded and cached; we just initialize the machine
with it and continue on our merry way.
In the non-seekable (streaming) case, we'll only be at a
boundary if we just left the previous logical bitstream and
we're now nominally at the header of the next bitstream
*/
if(vf->ready_state!=INITSET){
int link;
if(vf->ready_state<STREAMSET){
if(vf->seekable){
vf->current_serialno=ogg_page_serialno(&og);
/* match the serialno to bitstream section. We use this rather than
offset positions to avoid problems near logical bitstream
boundaries */
for(link=0;link<vf->links;link++)
if(vf->serialnos[link]==vf->current_serialno)break;
if(link==vf->links)return(OV_EBADLINK); /* sign of a bogus
stream. error out,
leave machine
uninitialized */
vf->current_link=link;
ogg_stream_reset_serialno(&vf->os,vf->current_serialno);
vf->ready_state=STREAMSET;
}else{
/* we're streaming */
/* fetch the three header packets, build the info struct */
int ret=_fetch_headers(vf,vf->vi,vf->vc,&vf->current_serialno,&og);
if(ret)return(ret);
vf->current_link++;
link=0;
}
}
{
int ret=_make_decode_ready(vf);
if(ret<0)return ret;
}
}
ogg_stream_pagein(&vf->os,&og);
}
}
/* if, eg, 64 bit stdio is configured by default, this will build with
fseek64 */
static int _fseek64_wrap(FILE *f,ogg_int64_t off,int whence){
if(f==NULL)return(-1);
return fseek(f,off,whence);
}
static int _ov_open1(void *f,OggVorbis_File *vf,char *initial,
long ibytes, ov_callbacks callbacks){
int offsettest=(f?callbacks.seek_func(f,0,SEEK_CUR):-1);
int ret;
memset(vf,0,sizeof(*vf));
vf->datasource=f;
vf->callbacks = callbacks;
/* init the framing state */
ogg_sync_init(&vf->oy);
/* perhaps some data was previously read into a buffer for testing
against other stream types. Allow initialization from this
previously read data (as we may be reading from a non-seekable
stream) */
if(initial){
char *buffer=ogg_sync_buffer(&vf->oy,ibytes);
memcpy(buffer,initial,ibytes);
ogg_sync_wrote(&vf->oy,ibytes);
}
/* can we seek? Stevens suggests the seek test was portable */
if(offsettest!=-1)vf->seekable=1;
/* No seeking yet; Set up a 'single' (current) logical bitstream
entry for partial open */
vf->links=1;
vf->vi=_ogg_calloc(vf->links,sizeof(*vf->vi));
vf->vc=_ogg_calloc(vf->links,sizeof(*vf->vc));
ogg_stream_init(&vf->os,-1); /* fill in the serialno later */
/* Try to fetch the headers, maintaining all the storage */
if((ret=_fetch_headers(vf,vf->vi,vf->vc,&vf->current_serialno,NULL))<0){
vf->datasource=NULL;
ov_clear(vf);
}else
vf->ready_state=PARTOPEN;
return(ret);
}
static int _ov_open2(OggVorbis_File *vf){
if(vf->ready_state != PARTOPEN) return OV_EINVAL;
vf->ready_state=OPENED;
if(vf->seekable){
int ret=_open_seekable2(vf);
if(ret){
vf->datasource=NULL;
ov_clear(vf);
}
return(ret);
}else
vf->ready_state=STREAMSET;
return 0;
}
/* clear out the OggVorbis_File struct */
int ov_clear(OggVorbis_File *vf){
if(vf){
vorbis_block_clear(&vf->vb);
vorbis_dsp_clear(&vf->vd);
ogg_stream_clear(&vf->os);
if(vf->vi && vf->links){
int i;
for(i=0;i<vf->links;i++){
vorbis_info_clear(vf->vi+i);
vorbis_comment_clear(vf->vc+i);
}
_ogg_free(vf->vi);
_ogg_free(vf->vc);
}
if(vf->dataoffsets)_ogg_free(vf->dataoffsets);
if(vf->pcmlengths)_ogg_free(vf->pcmlengths);
if(vf->serialnos)_ogg_free(vf->serialnos);
if(vf->offsets)_ogg_free(vf->offsets);
ogg_sync_clear(&vf->oy);
if(vf->datasource)(vf->callbacks.close_func)(vf->datasource);
memset(vf,0,sizeof(*vf));
}
#ifdef DEBUG_LEAKS
_VDBG_dump();
#endif
return(0);
}
/* inspects the OggVorbis file and finds/documents all the logical
bitstreams contained in it. Tries to be tolerant of logical
bitstream sections that are truncated/woogie.
return: -1) error
0) OK
*/
int ov_open_callbacks(void *f,OggVorbis_File *vf,char *initial,long ibytes,
ov_callbacks callbacks){
int ret=_ov_open1(f,vf,initial,ibytes,callbacks);
if(ret)return ret;
return _ov_open2(vf);
}
int ov_open(FILE *f,OggVorbis_File *vf,char *initial,long ibytes){
ov_callbacks callbacks = {
(size_t (*)(void *, size_t, size_t, void *)) fread,
(int (*)(void *, ogg_int64_t, int)) _fseek64_wrap,
(int (*)(void *)) fclose,
(long (*)(void *)) ftell
};
return ov_open_callbacks((void *)f, vf, initial, ibytes, callbacks);
}
/* cheap hack for game usage where downsampling is desirable; there's
no need for SRC as we can just do it cheaply in libvorbis. */
int ov_halfrate(OggVorbis_File *vf,int flag){
int i;
if(vf->vi==NULL)return OV_EINVAL;
if(!vf->seekable)return OV_EINVAL;
if(vf->ready_state>=STREAMSET)
_decode_clear(vf); /* clear out stream state; later on libvorbis
will be able to swap this on the fly, but
for now dumping the decode machine is needed
to reinit the MDCT lookups. 1.1 libvorbis
is planned to be able to switch on the fly */
for(i=0;i<vf->links;i++){
if(vorbis_synthesis_halfrate(vf->vi+i,flag)){
ov_halfrate(vf,0);
return OV_EINVAL;
}
}
return 0;
}
int ov_halfrate_p(OggVorbis_File *vf){
if(vf->vi==NULL)return OV_EINVAL;
return vorbis_synthesis_halfrate_p(vf->vi);
}
/* Only partially open the vorbis file; test for Vorbisness, and load
the headers for the first chain. Do not seek (although test for
seekability). Use ov_test_open to finish opening the file, else
ov_clear to close/free it. Same return codes as open. */
int ov_test_callbacks(void *f,OggVorbis_File *vf,char *initial,long ibytes,
ov_callbacks callbacks)
{
return _ov_open1(f,vf,initial,ibytes,callbacks);
}
int ov_test(FILE *f,OggVorbis_File *vf,char *initial,long ibytes){
ov_callbacks callbacks = {
(size_t (*)(void *, size_t, size_t, void *)) fread,
(int (*)(void *, ogg_int64_t, int)) _fseek64_wrap,
(int (*)(void *)) fclose,
(long (*)(void *)) ftell
};
return ov_test_callbacks((void *)f, vf, initial, ibytes, callbacks);
}
int ov_test_open(OggVorbis_File *vf){
if(vf->ready_state!=PARTOPEN)return(OV_EINVAL);
return _ov_open2(vf);
}
/* How many logical bitstreams in this physical bitstream? */
long ov_streams(OggVorbis_File *vf){
return vf->links;
}
/* Is the FILE * associated with vf seekable? */
long ov_seekable(OggVorbis_File *vf){
return vf->seekable;
}
/* returns the bitrate for a given logical bitstream or the entire
physical bitstream. If the file is open for random access, it will
find the *actual* average bitrate. If the file is streaming, it
returns the nominal bitrate (if set) else the average of the
upper/lower bounds (if set) else -1 (unset).
If you want the actual bitrate field settings, get them from the
vorbis_info structs */
long ov_bitrate(OggVorbis_File *vf,int i){
if(vf->ready_state<OPENED)return(OV_EINVAL);
if(i>=vf->links)return(OV_EINVAL);
if(!vf->seekable && i!=0)return(ov_bitrate(vf,0));
if(i<0){
ogg_int64_t bits=0;
int i;
float br;
for(i=0;i<vf->links;i++)
bits+=(vf->offsets[i+1]-vf->dataoffsets[i])*8;
/* This once read: return(rint(bits/ov_time_total(vf,-1)));
* gcc 3.x on x86 miscompiled this at optimisation level 2 and above,
* so this is slightly transformed to make it work.
*/
br = bits/ov_time_total(vf,-1);
return(rint(br));
}else{
if(vf->seekable){
/* return the actual bitrate */
return(rint((vf->offsets[i+1]-vf->dataoffsets[i])*8/ov_time_total(vf,i)));
}else{
/* return nominal if set */
if(vf->vi[i].bitrate_nominal>0){
return vf->vi[i].bitrate_nominal;
}else{
if(vf->vi[i].bitrate_upper>0){
if(vf->vi[i].bitrate_lower>0){
return (vf->vi[i].bitrate_upper+vf->vi[i].bitrate_lower)/2;
}else{
return vf->vi[i].bitrate_upper;
}
}
return(OV_FALSE);
}
}
}
}
/* returns the actual bitrate since last call. returns -1 if no
additional data to offer since last call (or at beginning of stream),
EINVAL if stream is only partially open
*/
long ov_bitrate_instant(OggVorbis_File *vf){
int link=(vf->seekable?vf->current_link:0);
long ret;
if(vf->ready_state<OPENED)return(OV_EINVAL);
if(vf->samptrack==0)return(OV_FALSE);
ret=vf->bittrack/vf->samptrack*vf->vi[link].rate+.5;
vf->bittrack=0.f;
vf->samptrack=0.f;
return(ret);
}
/* Guess */
long ov_serialnumber(OggVorbis_File *vf,int i){
if(i>=vf->links)return(ov_serialnumber(vf,vf->links-1));
if(!vf->seekable && i>=0)return(ov_serialnumber(vf,-1));
if(i<0){
return(vf->current_serialno);
}else{
return(vf->serialnos[i]);
}
}
/* returns: total raw (compressed) length of content if i==-1
raw (compressed) length of that logical bitstream for i==0 to n
OV_EINVAL if the stream is not seekable (we can't know the length)
or if stream is only partially open
*/
ogg_int64_t ov_raw_total(OggVorbis_File *vf,int i){
if(vf->ready_state<OPENED)return(OV_EINVAL);
if(!vf->seekable || i>=vf->links)return(OV_EINVAL);
if(i<0){
ogg_int64_t acc=0;
int i;
for(i=0;i<vf->links;i++)
acc+=ov_raw_total(vf,i);
return(acc);
}else{
return(vf->offsets[i+1]-vf->offsets[i]);
}
}
/* returns: total PCM length (samples) of content if i==-1 PCM length
(samples) of that logical bitstream for i==0 to n
OV_EINVAL if the stream is not seekable (we can't know the
length) or only partially open
*/
ogg_int64_t ov_pcm_total(OggVorbis_File *vf,int i){
if(vf->ready_state<OPENED)return(OV_EINVAL);
if(!vf->seekable || i>=vf->links)return(OV_EINVAL);
if(i<0){
ogg_int64_t acc=0;
int i;
for(i=0;i<vf->links;i++)
acc+=ov_pcm_total(vf,i);
return(acc);
}else{
return(vf->pcmlengths[i*2+1]);
}
}
/* returns: total seconds of content if i==-1
seconds in that logical bitstream for i==0 to n
OV_EINVAL if the stream is not seekable (we can't know the
length) or only partially open
*/
double ov_time_total(OggVorbis_File *vf,int i){
if(vf->ready_state<OPENED)return(OV_EINVAL);
if(!vf->seekable || i>=vf->links)return(OV_EINVAL);
if(i<0){
double acc=0;
int i;
for(i=0;i<vf->links;i++)
acc+=ov_time_total(vf,i);
return(acc);
}else{
return((double)(vf->pcmlengths[i*2+1])/vf->vi[i].rate);
}
}
/* seek to an offset relative to the *compressed* data. This also
scans packets to update the PCM cursor. It will cross a logical
bitstream boundary, but only if it can't get any packets out of the
tail of the bitstream we seek to (so no surprises).
returns zero on success, nonzero on failure */
int ov_raw_seek(OggVorbis_File *vf,ogg_int64_t pos){
ogg_stream_state work_os;
if(vf->ready_state<OPENED)return(OV_EINVAL);
if(!vf->seekable)
return(OV_ENOSEEK); /* don't dump machine if we can't seek */
if(pos<0 || pos>vf->end)return(OV_EINVAL);
/* don't yet clear out decoding machine (if it's initialized), in
the case we're in the same link. Restart the decode lapping, and
let _fetch_and_process_packet deal with a potential bitstream
boundary */
vf->pcm_offset=-1;
ogg_stream_reset_serialno(&vf->os,
vf->current_serialno); /* must set serialno */
vorbis_synthesis_restart(&vf->vd);
_seek_helper(vf,pos);
/* we need to make sure the pcm_offset is set, but we don't want to
advance the raw cursor past good packets just to get to the first
with a granulepos. That's not equivalent behavior to beginning
decoding as immediately after the seek position as possible.
So, a hack. We use two stream states; a local scratch state and
the shared vf->os stream state. We use the local state to
scan, and the shared state as a buffer for later decode.
Unfortuantely, on the last page we still advance to last packet
because the granulepos on the last page is not necessarily on a
packet boundary, and we need to make sure the granpos is
correct.
*/
{
ogg_page og;
ogg_packet op;
int lastblock=0;
int accblock=0;
int thisblock=0;
int eosflag=0;
ogg_stream_init(&work_os,vf->current_serialno); /* get the memory ready */
ogg_stream_reset(&work_os); /* eliminate the spurious OV_HOLE
return from not necessarily
starting from the beginning */
while(1){
if(vf->ready_state>=STREAMSET){
/* snarf/scan a packet if we can */
int result=ogg_stream_packetout(&work_os,&op);
if(result>0){
if(vf->vi[vf->current_link].codec_setup){
thisblock=vorbis_packet_blocksize(vf->vi+vf->current_link,&op);
if(thisblock<0){
ogg_stream_packetout(&vf->os,NULL);
thisblock=0;
}else{
if(eosflag)
ogg_stream_packetout(&vf->os,NULL);
else
if(lastblock)accblock+=(lastblock+thisblock)>>2;
}
if(op.granulepos!=-1){
int i,link=vf->current_link;
ogg_int64_t granulepos=op.granulepos-vf->pcmlengths[link*2];
if(granulepos<0)granulepos=0;
for(i=0;i<link;i++)
granulepos+=vf->pcmlengths[i*2+1];
vf->pcm_offset=granulepos-accblock;
break;
}
lastblock=thisblock;
continue;
}else
ogg_stream_packetout(&vf->os,NULL);
}
}
if(!lastblock){
if(_get_next_page(vf,&og,-1)<0){
vf->pcm_offset=ov_pcm_total(vf,-1);
break;
}
}else{
/* huh? Bogus stream with packets but no granulepos */
vf->pcm_offset=-1;
break;
}
/* has our decoding just traversed a bitstream boundary? */
if(vf->ready_state>=STREAMSET)
if(vf->current_serialno!=ogg_page_serialno(&og)){
_decode_clear(vf); /* clear out stream state */
ogg_stream_clear(&work_os);
}
if(vf->ready_state<STREAMSET){
int link;
vf->current_serialno=ogg_page_serialno(&og);
for(link=0;link<vf->links;link++)
if(vf->serialnos[link]==vf->current_serialno)break;
if(link==vf->links)goto seek_error; /* sign of a bogus stream.
error out, leave
machine uninitialized */
vf->current_link=link;
ogg_stream_reset_serialno(&vf->os,vf->current_serialno);
ogg_stream_reset_serialno(&work_os,vf->current_serialno);
vf->ready_state=STREAMSET;
}
ogg_stream_pagein(&vf->os,&og);
ogg_stream_pagein(&work_os,&og);
eosflag=ogg_page_eos(&og);
}
}
ogg_stream_clear(&work_os);
vf->bittrack=0.f;
vf->samptrack=0.f;
return(0);
seek_error:
/* dump the machine so we're in a known state */
vf->pcm_offset=-1;
ogg_stream_clear(&work_os);
_decode_clear(vf);
return OV_EBADLINK;
}
/* Page granularity seek (faster than sample granularity because we
don't do the last bit of decode to find a specific sample).
Seek to the last [granule marked] page preceeding the specified pos
location, such that decoding past the returned point will quickly
arrive at the requested position. */
int ov_pcm_seek_page(OggVorbis_File *vf,ogg_int64_t pos){
int link=-1;
ogg_int64_t result=0;
ogg_int64_t total=ov_pcm_total(vf,-1);
if(vf->ready_state<OPENED)return(OV_EINVAL);
if(!vf->seekable)return(OV_ENOSEEK);
if(pos<0 || pos>total)return(OV_EINVAL);
/* which bitstream section does this pcm offset occur in? */
for(link=vf->links-1;link>=0;link--){
total-=vf->pcmlengths[link*2+1];
if(pos>=total)break;
}
/* search within the logical bitstream for the page with the highest
pcm_pos preceeding (or equal to) pos. There is a danger here;
missing pages or incorrect frame number information in the
bitstream could make our task impossible. Account for that (it
would be an error condition) */
/* new search algorithm by HB (Nicholas Vinen) */
{
ogg_int64_t end=vf->offsets[link+1];
ogg_int64_t begin=vf->offsets[link];
ogg_int64_t begintime = vf->pcmlengths[link*2];
ogg_int64_t endtime = vf->pcmlengths[link*2+1]+begintime;
ogg_int64_t target=pos-total+begintime;
ogg_int64_t best=begin;
ogg_page og;
while(begin<end){
ogg_int64_t bisect;
if(end-begin<CHUNKSIZE){
bisect=begin;
}else{
/* take a (pretty decent) guess. */
bisect=begin +
(target-begintime)*(end-begin)/(endtime-begintime) - CHUNKSIZE;
if(bisect<=begin)
bisect=begin+1;
}
_seek_helper(vf,bisect);
while(begin<end){
result=_get_next_page(vf,&og,end-vf->offset);
if(result==OV_EREAD) goto seek_error;
if(result<0){
if(bisect<=begin+1)
end=begin; /* found it */
else{
if(bisect==0) goto seek_error;
bisect-=CHUNKSIZE;
if(bisect<=begin)bisect=begin+1;
_seek_helper(vf,bisect);
}
}else{
ogg_int64_t granulepos=ogg_page_granulepos(&og);
if(granulepos==-1)continue;
if(granulepos<target){
best=result; /* raw offset of packet with granulepos */
begin=vf->offset; /* raw offset of next page */
begintime=granulepos;
if(target-begintime>44100)break;
bisect=begin; /* *not* begin + 1 */
}else{
if(bisect<=begin+1)
end=begin; /* found it */
else{
if(end==vf->offset){ /* we're pretty close - we'd be stuck in */
end=result;
bisect-=CHUNKSIZE; /* an endless loop otherwise. */
if(bisect<=begin)bisect=begin+1;
_seek_helper(vf,bisect);
}else{
end=result;
endtime=granulepos;
break;
}
}
}
}
}
}
/* found our page. seek to it, update pcm offset. Easier case than
raw_seek, don't keep packets preceeding granulepos. */
{
ogg_page og;
ogg_packet op;
/* seek */
_seek_helper(vf,best);
vf->pcm_offset=-1;
if(_get_next_page(vf,&og,-1)<0)return(OV_EOF); /* shouldn't happen */
if(link!=vf->current_link){
/* Different link; dump entire decode machine */
_decode_clear(vf);
vf->current_link=link;
vf->current_serialno=ogg_page_serialno(&og);
vf->ready_state=STREAMSET;
}else{
vorbis_synthesis_restart(&vf->vd);
}
ogg_stream_reset_serialno(&vf->os,vf->current_serialno);
ogg_stream_pagein(&vf->os,&og);
/* pull out all but last packet; the one with granulepos */
while(1){
result=ogg_stream_packetpeek(&vf->os,&op);
if(result==0){
/* !!! the packet finishing this page originated on a
preceeding page. Keep fetching previous pages until we
get one with a granulepos or without the 'continued' flag
set. Then just use raw_seek for simplicity. */
_seek_helper(vf,best);
while(1){
result=_get_prev_page(vf,&og);
if(result<0) goto seek_error;
if(ogg_page_granulepos(&og)>-1 ||
!ogg_page_continued(&og)){
return ov_raw_seek(vf,result);
}
vf->offset=result;
}
}
if(result<0){
result = OV_EBADPACKET;
goto seek_error;
}
if(op.granulepos!=-1){
vf->pcm_offset=op.granulepos-vf->pcmlengths[vf->current_link*2];
if(vf->pcm_offset<0)vf->pcm_offset=0;
vf->pcm_offset+=total;
break;
}else
result=ogg_stream_packetout(&vf->os,NULL);
}
}
}
/* verify result */
if(vf->pcm_offset>pos || pos>ov_pcm_total(vf,-1)){
result=OV_EFAULT;
goto seek_error;
}
vf->bittrack=0.f;
vf->samptrack=0.f;
return(0);
seek_error:
/* dump machine so we're in a known state */
vf->pcm_offset=-1;
_decode_clear(vf);
return (int)result;
}
/* seek to a sample offset relative to the decompressed pcm stream
returns zero on success, nonzero on failure */
int ov_pcm_seek(OggVorbis_File *vf,ogg_int64_t pos){
int thisblock,lastblock=0;
int ret=ov_pcm_seek_page(vf,pos);
if(ret<0)return(ret);
if((ret=_make_decode_ready(vf)))return ret;
/* discard leading packets we don't need for the lapping of the
position we want; don't decode them */
while(1){
ogg_packet op;
ogg_page og;
int ret=ogg_stream_packetpeek(&vf->os,&op);
if(ret>0){
thisblock=vorbis_packet_blocksize(vf->vi+vf->current_link,&op);
if(thisblock<0){
ogg_stream_packetout(&vf->os,NULL);
continue; /* non audio packet */
}
if(lastblock)vf->pcm_offset+=(lastblock+thisblock)>>2;
if(vf->pcm_offset+((thisblock+
vorbis_info_blocksize(vf->vi,1))>>2)>=pos)break;
/* remove the packet from packet queue and track its granulepos */
ogg_stream_packetout(&vf->os,NULL);
vorbis_synthesis_trackonly(&vf->vb,&op); /* set up a vb with
only tracking, no
pcm_decode */
vorbis_synthesis_blockin(&vf->vd,&vf->vb);
/* end of logical stream case is hard, especially with exact
length positioning. */
if(op.granulepos>-1){
int i;
/* always believe the stream markers */
vf->pcm_offset=op.granulepos-vf->pcmlengths[vf->current_link*2];
if(vf->pcm_offset<0)vf->pcm_offset=0;
for(i=0;i<vf->current_link;i++)
vf->pcm_offset+=vf->pcmlengths[i*2+1];
}
lastblock=thisblock;
}else{
if(ret<0 && ret!=OV_HOLE)break;
/* suck in a new page */
if(_get_next_page(vf,&og,-1)<0)break;
if(vf->current_serialno!=ogg_page_serialno(&og))_decode_clear(vf);
if(vf->ready_state<STREAMSET){
int link;
vf->current_serialno=ogg_page_serialno(&og);
for(link=0;link<vf->links;link++)
if(vf->serialnos[link]==vf->current_serialno)break;
if(link==vf->links)return(OV_EBADLINK);
vf->current_link=link;
ogg_stream_reset_serialno(&vf->os,vf->current_serialno);
vf->ready_state=STREAMSET;
ret=_make_decode_ready(vf);
if(ret)return ret;
lastblock=0;
}
ogg_stream_pagein(&vf->os,&og);
}
}
vf->bittrack=0.f;
vf->samptrack=0.f;
/* discard samples until we reach the desired position. Crossing a
logical bitstream boundary with abandon is OK. */
while(vf->pcm_offset<pos){
ogg_int64_t target=pos-vf->pcm_offset;
long samples=vorbis_synthesis_pcmout(&vf->vd,NULL);
if(samples>target)samples=target;
vorbis_synthesis_read(&vf->vd,samples);
vf->pcm_offset+=samples;
if(samples<target)
if(_fetch_and_process_packet(vf,NULL,1,1)<=0)
vf->pcm_offset=ov_pcm_total(vf,-1); /* eof */
}
return 0;
}
/* seek to a playback time relative to the decompressed pcm stream
returns zero on success, nonzero on failure */
int ov_time_seek(OggVorbis_File *vf,double seconds){
/* translate time to PCM position and call ov_pcm_seek */
int link=-1;
ogg_int64_t pcm_total=0;
double time_total=0.;
if(vf->ready_state<OPENED)return(OV_EINVAL);
if(!vf->seekable)return(OV_ENOSEEK);
if(seconds<0)return(OV_EINVAL);
/* which bitstream section does this time offset occur in? */
for(link=0;link<vf->links;link++){
double addsec = ov_time_total(vf,link);
if(seconds<time_total+addsec)break;
time_total+=addsec;
pcm_total+=vf->pcmlengths[link*2+1];
}
if(link==vf->links)return(OV_EINVAL);
/* enough information to convert time offset to pcm offset */
{
ogg_int64_t target=pcm_total+(seconds-time_total)*vf->vi[link].rate;
return(ov_pcm_seek(vf,target));
}
}
/* page-granularity version of ov_time_seek
returns zero on success, nonzero on failure */
int ov_time_seek_page(OggVorbis_File *vf,double seconds){
/* translate time to PCM position and call ov_pcm_seek */
int link=-1;
ogg_int64_t pcm_total=0;
double time_total=0.;
if(vf->ready_state<OPENED)return(OV_EINVAL);
if(!vf->seekable)return(OV_ENOSEEK);
if(seconds<0)return(OV_EINVAL);
/* which bitstream section does this time offset occur in? */
for(link=0;link<vf->links;link++){
double addsec = ov_time_total(vf,link);
if(seconds<time_total+addsec)break;
time_total+=addsec;
pcm_total+=vf->pcmlengths[link*2+1];
}
if(link==vf->links)return(OV_EINVAL);
/* enough information to convert time offset to pcm offset */
{
ogg_int64_t target=pcm_total+(seconds-time_total)*vf->vi[link].rate;
return(ov_pcm_seek_page(vf,target));
}
}
/* tell the current stream offset cursor. Note that seek followed by
tell will likely not give the set offset due to caching */
ogg_int64_t ov_raw_tell(OggVorbis_File *vf){
if(vf->ready_state<OPENED)return(OV_EINVAL);
return(vf->offset);
}
/* return PCM offset (sample) of next PCM sample to be read */
ogg_int64_t ov_pcm_tell(OggVorbis_File *vf){
if(vf->ready_state<OPENED)return(OV_EINVAL);
return(vf->pcm_offset);
}
/* return time offset (seconds) of next PCM sample to be read */
double ov_time_tell(OggVorbis_File *vf){
int link=0;
ogg_int64_t pcm_total=0;
double time_total=0.f;
if(vf->ready_state<OPENED)return(OV_EINVAL);
if(vf->seekable){
pcm_total=ov_pcm_total(vf,-1);
time_total=ov_time_total(vf,-1);
/* which bitstream section does this time offset occur in? */
for(link=vf->links-1;link>=0;link--){
pcm_total-=vf->pcmlengths[link*2+1];
time_total-=ov_time_total(vf,link);
if(vf->pcm_offset>=pcm_total)break;
}
}
return((double)time_total+(double)(vf->pcm_offset-pcm_total)/vf->vi[link].rate);
}
/* link: -1) return the vorbis_info struct for the bitstream section
currently being decoded
0-n) to request information for a specific bitstream section
In the case of a non-seekable bitstream, any call returns the
current bitstream. NULL in the case that the machine is not
initialized */
vorbis_info *ov_info(OggVorbis_File *vf,int link){
if(vf->seekable){
if(link<0)
if(vf->ready_state>=STREAMSET)
return vf->vi+vf->current_link;
else
return vf->vi;
else
if(link>=vf->links)
return NULL;
else
return vf->vi+link;
}else{
return vf->vi;
}
}
/* grr, strong typing, grr, no templates/inheritence, grr */
vorbis_comment *ov_comment(OggVorbis_File *vf,int link){
if(vf->seekable){
if(link<0)
if(vf->ready_state>=STREAMSET)
return vf->vc+vf->current_link;
else
return vf->vc;
else
if(link>=vf->links)
return NULL;
else
return vf->vc+link;
}else{
return vf->vc;
}
}
static int host_is_big_endian() {
ogg_int32_t pattern = 0xfeedface; /* deadbeef */
unsigned char *bytewise = (unsigned char *)&pattern;
if (bytewise[0] == 0xfe) return 1;
return 0;
}
/* up to this point, everything could more or less hide the multiple
logical bitstream nature of chaining from the toplevel application
if the toplevel application didn't particularly care. However, at
the point that we actually read audio back, the multiple-section
nature must surface: Multiple bitstream sections do not necessarily
have to have the same number of channels or sampling rate.
ov_read returns the sequential logical bitstream number currently
being decoded along with the PCM data in order that the toplevel
application can take action on channel/sample rate changes. This
number will be incremented even for streamed (non-seekable) streams
(for seekable streams, it represents the actual logical bitstream
index within the physical bitstream. Note that the accessor
functions above are aware of this dichotomy).
input values: buffer) a buffer to hold packed PCM data for return
length) the byte length requested to be placed into buffer
bigendianp) should the data be packed LSB first (0) or
MSB first (1)
word) word size for output. currently 1 (byte) or
2 (16 bit short)
return values: <0) error/hole in data (OV_HOLE), partial open (OV_EINVAL)
0) EOF
n) number of bytes of PCM actually returned. The
below works on a packet-by-packet basis, so the
return length is not related to the 'length' passed
in, just guaranteed to fit.
*section) set to the logical bitstream number */
long ov_read(OggVorbis_File *vf,char *buffer,int length,
int bigendianp,int word,int sgned,int *bitstream){
int i,j;
int host_endian = host_is_big_endian();
float **pcm;
long samples;
if(vf->ready_state<OPENED)return(OV_EINVAL);
while(1){
if(vf->ready_state==INITSET){
samples=vorbis_synthesis_pcmout(&vf->vd,&pcm);
if(samples)break;
}
/* suck in another packet */
{
int ret=_fetch_and_process_packet(vf,NULL,1,1);
if(ret==OV_EOF)
return(0);
if(ret<=0)
return(ret);
}
}
if(samples>0){
/* yay! proceed to pack data into the byte buffer */
long channels=ov_info(vf,-1)->channels;
long bytespersample=word * channels;
vorbis_fpu_control fpu;
if(samples>length/bytespersample)samples=length/bytespersample;
if(samples <= 0)
return OV_EINVAL;
/* a tight loop to pack each size */
{
int val;
if(word==1){
int off=(sgned?0:128);
vorbis_fpu_setround(&fpu);
for(j=0;j<samples;j++)
for(i=0;i<channels;i++){
val=vorbis_ftoi(pcm[i][j]*128.f);
if(val>127)val=127;
else if(val<-128)val=-128;
*buffer++=val+off;
}
vorbis_fpu_restore(fpu);
}else{
int off=(sgned?0:32768);
if(host_endian==bigendianp){
if(sgned){
vorbis_fpu_setround(&fpu);
for(i=0;i<channels;i++) { /* It's faster in this order */
float *src=pcm[i];
short *dest=((short *)buffer)+i;
for(j=0;j<samples;j++) {
val=vorbis_ftoi(src[j]*32768.f);
if(val>32767)val=32767;
else if(val<-32768)val=-32768;
*dest=val;
dest+=channels;
}
}
vorbis_fpu_restore(fpu);
}else{
vorbis_fpu_setround(&fpu);
for(i=0;i<channels;i++) {
float *src=pcm[i];
short *dest=((short *)buffer)+i;
for(j=0;j<samples;j++) {
val=vorbis_ftoi(src[j]*32768.f);
if(val>32767)val=32767;
else if(val<-32768)val=-32768;
*dest=val+off;
dest+=channels;
}
}
vorbis_fpu_restore(fpu);
}
}else if(bigendianp){
vorbis_fpu_setround(&fpu);
for(j=0;j<samples;j++)
for(i=0;i<channels;i++){
val=vorbis_ftoi(pcm[i][j]*32768.f);
if(val>32767)val=32767;
else if(val<-32768)val=-32768;
val+=off;
*buffer++=(val>>8);
*buffer++=(val&0xff);
}
vorbis_fpu_restore(fpu);
}else{
int val;
vorbis_fpu_setround(&fpu);
for(j=0;j<samples;j++)
for(i=0;i<channels;i++){
val=vorbis_ftoi(pcm[i][j]*32768.f);
if(val>32767)val=32767;
else if(val<-32768)val=-32768;
val+=off;
*buffer++=(val&0xff);
*buffer++=(val>>8);
}
vorbis_fpu_restore(fpu);
}
}
}
vorbis_synthesis_read(&vf->vd,samples);
vf->pcm_offset+=samples;
if(bitstream)*bitstream=vf->current_link;
return(samples*bytespersample);
}else{
return(samples);
}
}
/* input values: pcm_channels) a float vector per channel of output
length) the sample length being read by the app
return values: <0) error/hole in data (OV_HOLE), partial open (OV_EINVAL)
0) EOF
n) number of samples of PCM actually returned. The
below works on a packet-by-packet basis, so the
return length is not related to the 'length' passed
in, just guaranteed to fit.
*section) set to the logical bitstream number */
long ov_read_float(OggVorbis_File *vf,float ***pcm_channels,int length,
int *bitstream){
if(vf->ready_state<OPENED)return(OV_EINVAL);
while(1){
if(vf->ready_state==INITSET){
float **pcm;
long samples=vorbis_synthesis_pcmout(&vf->vd,&pcm);
if(samples){
if(pcm_channels)*pcm_channels=pcm;
if(samples>length)samples=length;
vorbis_synthesis_read(&vf->vd,samples);
vf->pcm_offset+=samples;
if(bitstream)*bitstream=vf->current_link;
return samples;
}
}
/* suck in another packet */
{
int ret=_fetch_and_process_packet(vf,NULL,1,1);
if(ret==OV_EOF)return(0);
if(ret<=0)return(ret);
}
}
}
extern float *vorbis_window(vorbis_dsp_state *v,int W);
extern void _analysis_output_always(char *base,int i,float *v,int n,int bark,int dB,
ogg_int64_t off);
static void _ov_splice(float **pcm,float **lappcm,
int n1, int n2,
int ch1, int ch2,
float *w1, float *w2){
int i,j;
float *w=w1;
int n=n1;
if(n1>n2){
n=n2;
w=w2;
}
/* splice */
for(j=0;j<ch1 && j<ch2;j++){
float *s=lappcm[j];
float *d=pcm[j];
for(i=0;i<n;i++){
float wd=w[i]*w[i];
float ws=1.-wd;
d[i]=d[i]*wd + s[i]*ws;
}
}
/* window from zero */
for(;j<ch2;j++){
float *d=pcm[j];
for(i=0;i<n;i++){
float wd=w[i]*w[i];
d[i]=d[i]*wd;
}
}
}
/* make sure vf is INITSET */
static int _ov_initset(OggVorbis_File *vf){
while(1){
if(vf->ready_state==INITSET)break;
/* suck in another packet */
{
int ret=_fetch_and_process_packet(vf,NULL,1,0);
if(ret<0 && ret!=OV_HOLE)return(ret);
}
}
return 0;
}
/* make sure vf is INITSET and that we have a primed buffer; if
we're crosslapping at a stream section boundary, this also makes
sure we're sanity checking against the right stream information */
static int _ov_initprime(OggVorbis_File *vf){
vorbis_dsp_state *vd=&vf->vd;
while(1){
if(vf->ready_state==INITSET)
if(vorbis_synthesis_pcmout(vd,NULL))break;
/* suck in another packet */
{
int ret=_fetch_and_process_packet(vf,NULL,1,0);
if(ret<0 && ret!=OV_HOLE)return(ret);
}
}
return 0;
}
/* grab enough data for lapping from vf; this may be in the form of
unreturned, already-decoded pcm, remaining PCM we will need to
decode, or synthetic postextrapolation from last packets. */
static void _ov_getlap(OggVorbis_File *vf,vorbis_info *vi,vorbis_dsp_state *vd,
float **lappcm,int lapsize){
int lapcount=0,i;
float **pcm;
/* try first to decode the lapping data */
while(lapcount<lapsize){
int samples=vorbis_synthesis_pcmout(vd,&pcm);
if(samples){
if(samples>lapsize-lapcount)samples=lapsize-lapcount;
for(i=0;i<vi->channels;i++)
memcpy(lappcm[i]+lapcount,pcm[i],sizeof(**pcm)*samples);
lapcount+=samples;
vorbis_synthesis_read(vd,samples);
}else{
/* suck in another packet */
int ret=_fetch_and_process_packet(vf,NULL,1,0); /* do *not* span */
if(ret==OV_EOF)break;
}
}
if(lapcount<lapsize){
/* failed to get lapping data from normal decode; pry it from the
postextrapolation buffering, or the second half of the MDCT
from the last packet */
int samples=vorbis_synthesis_lapout(&vf->vd,&pcm);
if(samples==0){
for(i=0;i<vi->channels;i++)
memset(lappcm[i]+lapcount,0,sizeof(**pcm)*lapsize-lapcount);
lapcount=lapsize;
}else{
if(samples>lapsize-lapcount)samples=lapsize-lapcount;
for(i=0;i<vi->channels;i++)
memcpy(lappcm[i]+lapcount,pcm[i],sizeof(**pcm)*samples);
lapcount+=samples;
}
}
}
/* this sets up crosslapping of a sample by using trailing data from
sample 1 and lapping it into the windowing buffer of sample 2 */
int ov_crosslap(OggVorbis_File *vf1, OggVorbis_File *vf2){
vorbis_info *vi1,*vi2;
float **lappcm;
float **pcm;
float *w1,*w2;
int n1,n2,i,ret,hs1,hs2;
if(vf1==vf2)return(0); /* degenerate case */
if(vf1->ready_state<OPENED)return(OV_EINVAL);
if(vf2->ready_state<OPENED)return(OV_EINVAL);
/* the relevant overlap buffers must be pre-checked and pre-primed
before looking at settings in the event that priming would cross
a bitstream boundary. So, do it now */
ret=_ov_initset(vf1);
if(ret)return(ret);
ret=_ov_initprime(vf2);
if(ret)return(ret);
vi1=ov_info(vf1,-1);
vi2=ov_info(vf2,-1);
hs1=ov_halfrate_p(vf1);
hs2=ov_halfrate_p(vf2);
lappcm=alloca(sizeof(*lappcm)*vi1->channels);
n1=vorbis_info_blocksize(vi1,0)>>(1+hs1);
n2=vorbis_info_blocksize(vi2,0)>>(1+hs2);
w1=vorbis_window(&vf1->vd,0);
w2=vorbis_window(&vf2->vd,0);
for(i=0;i<vi1->channels;i++)
lappcm[i]=alloca(sizeof(**lappcm)*n1);
_ov_getlap(vf1,vi1,&vf1->vd,lappcm,n1);
/* have a lapping buffer from vf1; now to splice it into the lapping
buffer of vf2 */
/* consolidate and expose the buffer. */
vorbis_synthesis_lapout(&vf2->vd,&pcm);
_analysis_output_always("pcmL",0,pcm[0],n1*2,0,0,0);
_analysis_output_always("pcmR",0,pcm[1],n1*2,0,0,0);
/* splice */
_ov_splice(pcm,lappcm,n1,n2,vi1->channels,vi2->channels,w1,w2);
/* done */
return(0);
}
static int _ov_64_seek_lap(OggVorbis_File *vf,ogg_int64_t pos,
int (*localseek)(OggVorbis_File *,ogg_int64_t)){
vorbis_info *vi;
float **lappcm;
float **pcm;
float *w1,*w2;
int n1,n2,ch1,ch2,hs;
int i,ret;
if(vf->ready_state<OPENED)return(OV_EINVAL);
ret=_ov_initset(vf);
if(ret)return(ret);
vi=ov_info(vf,-1);
hs=ov_halfrate_p(vf);
ch1=vi->channels;
n1=vorbis_info_blocksize(vi,0)>>(1+hs);
w1=vorbis_window(&vf->vd,0); /* window arrays from libvorbis are
persistent; even if the decode state
from this link gets dumped, this
window array continues to exist */
lappcm=alloca(sizeof(*lappcm)*ch1);
for(i=0;i<ch1;i++)
lappcm[i]=alloca(sizeof(**lappcm)*n1);
_ov_getlap(vf,vi,&vf->vd,lappcm,n1);
/* have lapping data; seek and prime the buffer */
ret=localseek(vf,pos);
if(ret)return ret;
ret=_ov_initprime(vf);
if(ret)return(ret);
/* Guard against cross-link changes; they're perfectly legal */
vi=ov_info(vf,-1);
ch2=vi->channels;
n2=vorbis_info_blocksize(vi,0)>>(1+hs);
w2=vorbis_window(&vf->vd,0);
/* consolidate and expose the buffer. */
vorbis_synthesis_lapout(&vf->vd,&pcm);
/* splice */
_ov_splice(pcm,lappcm,n1,n2,ch1,ch2,w1,w2);
/* done */
return(0);
}
int ov_raw_seek_lap(OggVorbis_File *vf,ogg_int64_t pos){
return _ov_64_seek_lap(vf,pos,ov_raw_seek);
}
int ov_pcm_seek_lap(OggVorbis_File *vf,ogg_int64_t pos){
return _ov_64_seek_lap(vf,pos,ov_pcm_seek);
}
int ov_pcm_seek_page_lap(OggVorbis_File *vf,ogg_int64_t pos){
return _ov_64_seek_lap(vf,pos,ov_pcm_seek_page);
}
static int _ov_d_seek_lap(OggVorbis_File *vf,double pos,
int (*localseek)(OggVorbis_File *,double)){
vorbis_info *vi;
float **lappcm;
float **pcm;
float *w1,*w2;
int n1,n2,ch1,ch2,hs;
int i,ret;
if(vf->ready_state<OPENED)return(OV_EINVAL);
ret=_ov_initset(vf);
if(ret)return(ret);
vi=ov_info(vf,-1);
hs=ov_halfrate_p(vf);
ch1=vi->channels;
n1=vorbis_info_blocksize(vi,0)>>(1+hs);
w1=vorbis_window(&vf->vd,0); /* window arrays from libvorbis are
persistent; even if the decode state
from this link gets dumped, this
window array continues to exist */
lappcm=alloca(sizeof(*lappcm)*ch1);
for(i=0;i<ch1;i++)
lappcm[i]=alloca(sizeof(**lappcm)*n1);
_ov_getlap(vf,vi,&vf->vd,lappcm,n1);
/* have lapping data; seek and prime the buffer */
ret=localseek(vf,pos);
if(ret)return ret;
ret=_ov_initprime(vf);
if(ret)return(ret);
/* Guard against cross-link changes; they're perfectly legal */
vi=ov_info(vf,-1);
ch2=vi->channels;
n2=vorbis_info_blocksize(vi,0)>>(1+hs);
w2=vorbis_window(&vf->vd,0);
/* consolidate and expose the buffer. */
vorbis_synthesis_lapout(&vf->vd,&pcm);
/* splice */
_ov_splice(pcm,lappcm,n1,n2,ch1,ch2,w1,w2);
/* done */
return(0);
}
int ov_time_seek_lap(OggVorbis_File *vf,double pos){
return _ov_d_seek_lap(vf,pos,ov_time_seek);
}
int ov_time_seek_page_lap(OggVorbis_File *vf,double pos){
return _ov_d_seek_lap(vf,pos,ov_time_seek_page);
}