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path: root/apps/codecs/libffmpegFLAC/decoder.c
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Diffstat (limited to 'apps/codecs/libffmpegFLAC/decoder.c')
-rw-r--r--apps/codecs/libffmpegFLAC/decoder.c80
1 files changed, 18 insertions, 62 deletions
diff --git a/apps/codecs/libffmpegFLAC/decoder.c b/apps/codecs/libffmpegFLAC/decoder.c
index 1fafec17fb..2dbedf3110 100644
--- a/apps/codecs/libffmpegFLAC/decoder.c
+++ b/apps/codecs/libffmpegFLAC/decoder.c
@@ -381,17 +381,13 @@ static inline int decode_subframe(FLACContext *s, int channel, int32_t* decoded)
381} 381}
382 382
383static int decode_frame(FLACContext *s, 383static int decode_frame(FLACContext *s,
384 int32_t* decoded0,
385 int32_t* decoded1,
386 void (*yield)(void)) ICODE_ATTR_FLAC; 384 void (*yield)(void)) ICODE_ATTR_FLAC;
387static int decode_frame(FLACContext *s, 385static int decode_frame(FLACContext *s,
388 int32_t* decoded0,
389 int32_t* decoded1,
390 void (*yield)(void)) 386 void (*yield)(void))
391{ 387{
392 int blocksize_code, sample_rate_code, sample_size_code, assignment, crc8; 388 int blocksize_code, sample_rate_code, sample_size_code, assignment, crc8;
393 int decorrelation, bps, blocksize, samplerate; 389 int decorrelation, bps, blocksize, samplerate;
394 int res; 390 int res, ch;
395 391
396 blocksize_code = get_bits(&s->gb, 4); 392 blocksize_code = get_bits(&s->gb, 4);
397 393
@@ -477,16 +473,10 @@ static int decode_frame(FLACContext *s,
477 s->bps = bps; 473 s->bps = bps;
478 s->decorrelation= decorrelation; 474 s->decorrelation= decorrelation;
479 475
480 yield(); 476 for (ch=0; ch<s->channels; ++ch) {
481 /* subframes */ 477 yield();
482 if ((res=decode_subframe(s, 0, decoded0)) < 0) 478 if ((res=decode_subframe(s, ch, s->decoded[ch])) < 0)
483 return res-100; 479 return res-100;
484
485 yield();
486
487 if (s->channels==2) {
488 if ((res=decode_subframe(s, 1, decoded1)) < 0)
489 return res-200;
490 } 480 }
491 481
492 yield(); 482 yield();
@@ -499,8 +489,6 @@ static int decode_frame(FLACContext *s,
499} 489}
500 490
501int flac_decode_frame(FLACContext *s, 491int flac_decode_frame(FLACContext *s,
502 int32_t* decoded0,
503 int32_t* decoded1,
504 uint8_t *buf, int buf_size, 492 uint8_t *buf, int buf_size,
505 void (*yield)(void)) 493 void (*yield)(void))
506{ 494{
@@ -516,68 +504,36 @@ int flac_decode_frame(FLACContext *s,
516 return -41; 504 return -41;
517 } 505 }
518 506
519 if ((framesize=decode_frame(s,decoded0,decoded1,yield)) < 0){ 507 if ((framesize=decode_frame(s,yield)) < 0){
520 s->bitstream_size=0; 508 s->bitstream_size=0;
521 s->bitstream_index=0; 509 s->bitstream_index=0;
522 return framesize; 510 return framesize;
523 } 511 }
524 512
525 yield(); 513 yield();
514
515#define DECORRELATE(left, right)\
516 for (i = 0; i < s->blocksize; i++) {\
517 int a = s->decoded[0][i];\
518 int b = s->decoded[1][i];\
519 s->decoded[0][i] = (left) << scale;\
520 s->decoded[1][i] = (right) << scale;\
521 }\
526 522
527 scale=FLAC_OUTPUT_DEPTH-s->bps; 523 scale=FLAC_OUTPUT_DEPTH-s->bps;
528 switch(s->decorrelation) 524 switch(s->decorrelation)
529 { 525 {
530 case INDEPENDENT: 526 case INDEPENDENT:
531 if (s->channels==1) {; 527 DECORRELATE(a, b) /* Always decorrelate exactly the two supported channels. */
532 for (i = 0; i < s->blocksize; i++)
533 {
534 decoded0[i] = decoded0[i] << scale;
535 }
536 } else {
537 for (i = 0; i < s->blocksize; i++)
538 {
539 decoded0[i] = decoded0[i] << scale;
540 decoded1[i] = decoded1[i] << scale;
541 }
542 }
543 break; 528 break;
544 case LEFT_SIDE: 529 case LEFT_SIDE:
545 //assert(s->channels == 2); 530 DECORRELATE(a, a-b)
546 for (i = 0; i < s->blocksize; i++)
547 {
548 decoded1[i] = (decoded0[i] - decoded1[i]) << scale;
549 decoded0[i] = decoded0[i] << scale;
550 }
551 break; 531 break;
552 case RIGHT_SIDE: 532 case RIGHT_SIDE:
553 //assert(s->channels == 2); 533 DECORRELATE(a+b, a)
554 for (i = 0; i < s->blocksize; i++)
555 {
556 decoded0[i] = (decoded0[i] + decoded1[i]) << scale;
557 decoded1[i] = decoded1[i] << scale;
558 }
559 break; 534 break;
560 case MID_SIDE: 535 case MID_SIDE:
561 //assert(s->channels == 2); 536 DECORRELATE( (a-=b>>1) + b, a)
562 for (i = 0; i < s->blocksize; i++)
563 {
564 int mid, side;
565 mid = decoded0[i];
566 side = decoded1[i];
567
568#if 1 //needs to be checked but IMHO it should be binary identical
569 mid -= side>>1;
570 decoded0[i] = (mid + side) << scale;
571 decoded1[i] = mid << scale;
572#else
573
574 mid <<= 1;
575 if (side & 1)
576 mid++;
577 decoded0[i] = ((mid + side) >> 1) << scale;
578 decoded1[i] = ((mid - side) >> 1) << scale;
579#endif
580 }
581 break; 537 break;
582 } 538 }
583 539