2
* FLAC (Free Lossless Audio Codec) decoder
3
* Copyright (c) 2003 Alex Beregszaszi
5
* This library is free software; you can redistribute it and/or
6
* modify it under the terms of the GNU Lesser General Public
7
* License as published by the Free Software Foundation; either
8
* version 2 of the License, or (at your option) any later version.
10
* This library is distributed in the hope that it will be useful,
11
* but WITHOUT ANY WARRANTY; without even the implied warranty of
12
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13
* Lesser General Public License for more details.
15
* You should have received a copy of the GNU Lesser General Public
16
* License along with this library; if not, write to the Free Software
17
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22
* FLAC (Free Lossless Audio Codec) decoder
23
* @author Alex Beregszaszi
25
* For more information on the FLAC format, visit:
26
* http://flac.sourceforge.net/
28
* This decoder can be used in 1 of 2 ways: Either raw FLAC data can be fed
29
* through, starting from the initial 'fLaC' signature; or by passing the
30
* 34-byte streaminfo structure through avctx->extradata[_size] followed
31
* by data starting with the 0xFFF8 marker.
37
#include "bitstream.h"
44
#define MAX_CHANNELS 8
45
#define MAX_BLOCKSIZE 65535
46
#define FLAC_STREAMINFO_SIZE 34
48
enum decorrelation_type {
55
typedef struct FLACContext {
56
AVCodecContext *avctx;
59
int min_blocksize, max_blocksize;
60
int min_framesize, max_framesize;
61
int samplerate, channels;
62
int blocksize/*, last_blocksize*/;
64
enum decorrelation_type decorrelation;
66
int32_t *decoded[MAX_CHANNELS];
70
unsigned int allocated_bitstream_size;
73
#define METADATA_TYPE_STREAMINFO 0
75
static int sample_rate_table[] =
77
8000, 16000, 22050, 24000, 32000, 44100, 48000, 96000,
80
static int sample_size_table[] =
81
{ 0, 8, 12, 0, 16, 20, 24, 0 };
83
static int blocksize_table[] = {
84
0, 192, 576<<0, 576<<1, 576<<2, 576<<3, 0, 0,
85
256<<0, 256<<1, 256<<2, 256<<3, 256<<4, 256<<5, 256<<6, 256<<7
88
static int64_t get_utf8(GetBitContext *gb){
90
GET_UTF8(val, get_bits(gb, 8), return -1;)
94
static void metadata_streaminfo(FLACContext *s);
95
static void dump_headers(FLACContext *s);
97
static int flac_decode_init(AVCodecContext * avctx)
99
FLACContext *s = avctx->priv_data;
102
/* initialize based on the demuxer-supplied streamdata header */
103
if (avctx->extradata_size == FLAC_STREAMINFO_SIZE) {
104
init_get_bits(&s->gb, avctx->extradata, avctx->extradata_size*8);
105
metadata_streaminfo(s);
112
static void dump_headers(FLACContext *s)
114
av_log(s->avctx, AV_LOG_DEBUG, " Blocksize: %d .. %d (%d)\n", s->min_blocksize, s->max_blocksize, s->blocksize);
115
av_log(s->avctx, AV_LOG_DEBUG, " Framesize: %d .. %d\n", s->min_framesize, s->max_framesize);
116
av_log(s->avctx, AV_LOG_DEBUG, " Samplerate: %d\n", s->samplerate);
117
av_log(s->avctx, AV_LOG_DEBUG, " Channels: %d\n", s->channels);
118
av_log(s->avctx, AV_LOG_DEBUG, " Bits: %d\n", s->bps);
121
static void allocate_buffers(FLACContext *s){
124
assert(s->max_blocksize);
126
if(s->max_framesize == 0 && s->max_blocksize){
127
s->max_framesize= (s->channels * s->bps * s->max_blocksize + 7)/ 8; //FIXME header overhead
130
for (i = 0; i < s->channels; i++)
132
s->decoded[i] = av_realloc(s->decoded[i], sizeof(int32_t)*s->max_blocksize);
135
s->bitstream= av_fast_realloc(s->bitstream, &s->allocated_bitstream_size, s->max_framesize);
138
static void metadata_streaminfo(FLACContext *s)
140
/* mandatory streaminfo */
141
s->min_blocksize = get_bits(&s->gb, 16);
142
s->max_blocksize = get_bits(&s->gb, 16);
144
s->min_framesize = get_bits_long(&s->gb, 24);
145
s->max_framesize = get_bits_long(&s->gb, 24);
147
s->samplerate = get_bits_long(&s->gb, 20);
148
s->channels = get_bits(&s->gb, 3) + 1;
149
s->bps = get_bits(&s->gb, 5) + 1;
151
s->avctx->channels = s->channels;
152
s->avctx->sample_rate = s->samplerate;
154
skip_bits(&s->gb, 36); /* total num of samples */
156
skip_bits(&s->gb, 64); /* md5 sum */
157
skip_bits(&s->gb, 64); /* md5 sum */
162
static int decode_residuals(FLACContext *s, int channel, int pred_order)
164
int i, tmp, partition, method_type, rice_order;
165
int sample = 0, samples;
167
method_type = get_bits(&s->gb, 2);
168
if (method_type != 0){
169
av_log(s->avctx, AV_LOG_DEBUG, "illegal residual coding method %d\n", method_type);
173
rice_order = get_bits(&s->gb, 4);
175
samples= s->blocksize >> rice_order;
179
for (partition = 0; partition < (1 << rice_order); partition++)
181
tmp = get_bits(&s->gb, 4);
184
av_log(s->avctx, AV_LOG_DEBUG, "fixed len partition\n");
185
tmp = get_bits(&s->gb, 5);
186
for (; i < samples; i++, sample++)
187
s->decoded[channel][sample] = get_sbits(&s->gb, tmp);
191
// av_log(s->avctx, AV_LOG_DEBUG, "rice coded partition k=%d\n", tmp);
192
for (; i < samples; i++, sample++){
193
s->decoded[channel][sample] = get_sr_golomb_flac(&s->gb, tmp, INT_MAX, 0);
199
// av_log(s->avctx, AV_LOG_DEBUG, "partitions: %d, samples: %d\n", 1 << rice_order, sample);
204
static int decode_subframe_fixed(FLACContext *s, int channel, int pred_order)
208
// av_log(s->avctx, AV_LOG_DEBUG, " SUBFRAME FIXED\n");
210
/* warm up samples */
211
// av_log(s->avctx, AV_LOG_DEBUG, " warm up samples: %d\n", pred_order);
213
for (i = 0; i < pred_order; i++)
215
s->decoded[channel][i] = get_sbits(&s->gb, s->curr_bps);
216
// av_log(s->avctx, AV_LOG_DEBUG, " %d: %d\n", i, s->decoded[channel][i]);
219
if (decode_residuals(s, channel, pred_order) < 0)
227
for (i = pred_order; i < s->blocksize; i++)
228
s->decoded[channel][i] += s->decoded[channel][i-1];
231
for (i = pred_order; i < s->blocksize; i++)
232
s->decoded[channel][i] += 2*s->decoded[channel][i-1]
233
- s->decoded[channel][i-2];
236
for (i = pred_order; i < s->blocksize; i++)
237
s->decoded[channel][i] += 3*s->decoded[channel][i-1]
238
- 3*s->decoded[channel][i-2]
239
+ s->decoded[channel][i-3];
242
for (i = pred_order; i < s->blocksize; i++)
243
s->decoded[channel][i] += 4*s->decoded[channel][i-1]
244
- 6*s->decoded[channel][i-2]
245
+ 4*s->decoded[channel][i-3]
246
- s->decoded[channel][i-4];
249
av_log(s->avctx, AV_LOG_ERROR, "illegal pred order %d\n", pred_order);
256
static int decode_subframe_lpc(FLACContext *s, int channel, int pred_order)
259
int coeff_prec, qlevel;
260
int coeffs[pred_order];
262
// av_log(s->avctx, AV_LOG_DEBUG, " SUBFRAME LPC\n");
264
/* warm up samples */
265
// av_log(s->avctx, AV_LOG_DEBUG, " warm up samples: %d\n", pred_order);
267
for (i = 0; i < pred_order; i++)
269
s->decoded[channel][i] = get_sbits(&s->gb, s->curr_bps);
270
// av_log(s->avctx, AV_LOG_DEBUG, " %d: %d\n", i, s->decoded[channel][i]);
273
coeff_prec = get_bits(&s->gb, 4) + 1;
274
if (coeff_prec == 16)
276
av_log(s->avctx, AV_LOG_DEBUG, "invalid coeff precision\n");
279
// av_log(s->avctx, AV_LOG_DEBUG, " qlp coeff prec: %d\n", coeff_prec);
280
qlevel = get_sbits(&s->gb, 5);
281
// av_log(s->avctx, AV_LOG_DEBUG, " quant level: %d\n", qlevel);
283
av_log(s->avctx, AV_LOG_DEBUG, "qlevel %d not supported, maybe buggy stream\n", qlevel);
287
for (i = 0; i < pred_order; i++)
289
coeffs[i] = get_sbits(&s->gb, coeff_prec);
290
// av_log(s->avctx, AV_LOG_DEBUG, " %d: %d\n", i, coeffs[i]);
293
if (decode_residuals(s, channel, pred_order) < 0)
298
for (i = pred_order; i < s->blocksize; i++)
301
for (j = 0; j < pred_order; j++)
302
sum += (int64_t)coeffs[j] * s->decoded[channel][i-j-1];
303
s->decoded[channel][i] += sum >> qlevel;
307
for (i = pred_order; i < s->blocksize; i++)
310
for (j = 0; j < pred_order; j++)
311
sum += coeffs[j] * s->decoded[channel][i-j-1];
312
s->decoded[channel][i] += sum >> qlevel;
319
static inline int decode_subframe(FLACContext *s, int channel)
321
int type, wasted = 0;
324
s->curr_bps = s->bps;
326
if(s->decorrelation == RIGHT_SIDE)
329
if(s->decorrelation == LEFT_SIDE || s->decorrelation == MID_SIDE)
333
if (get_bits1(&s->gb))
335
av_log(s->avctx, AV_LOG_ERROR, "invalid subframe padding\n");
338
type = get_bits(&s->gb, 6);
339
// wasted = get_bits1(&s->gb);
343
// while (!get_bits1(&s->gb))
347
// s->curr_bps -= wasted;
350
wasted= 16 - av_log2(show_bits(&s->gb, 17));
351
skip_bits(&s->gb, wasted+1);
352
s->curr_bps -= wasted;
354
if (get_bits1(&s->gb))
357
while (!get_bits1(&s->gb))
359
s->curr_bps -= wasted;
360
av_log(s->avctx, AV_LOG_DEBUG, "%d wasted bits\n", wasted);
363
//FIXME use av_log2 for types
366
av_log(s->avctx, AV_LOG_DEBUG, "coding type: constant\n");
367
tmp = get_sbits(&s->gb, s->curr_bps);
368
for (i = 0; i < s->blocksize; i++)
369
s->decoded[channel][i] = tmp;
373
av_log(s->avctx, AV_LOG_DEBUG, "coding type: verbatim\n");
374
for (i = 0; i < s->blocksize; i++)
375
s->decoded[channel][i] = get_sbits(&s->gb, s->curr_bps);
377
else if ((type >= 8) && (type <= 12))
379
// av_log(s->avctx, AV_LOG_DEBUG, "coding type: fixed\n");
380
if (decode_subframe_fixed(s, channel, type & ~0x8) < 0)
385
// av_log(s->avctx, AV_LOG_DEBUG, "coding type: lpc\n");
386
if (decode_subframe_lpc(s, channel, (type & ~0x20)+1) < 0)
391
av_log(s->avctx, AV_LOG_ERROR, "invalid coding type\n");
398
for (i = 0; i < s->blocksize; i++)
399
s->decoded[channel][i] <<= wasted;
405
static int decode_frame(FLACContext *s)
407
int blocksize_code, sample_rate_code, sample_size_code, assignment, i, crc8;
408
int decorrelation, bps, blocksize, samplerate;
410
blocksize_code = get_bits(&s->gb, 4);
412
sample_rate_code = get_bits(&s->gb, 4);
414
assignment = get_bits(&s->gb, 4); /* channel assignment */
415
if (assignment < 8 && s->channels == assignment+1)
416
decorrelation = INDEPENDENT;
417
else if (assignment >=8 && assignment < 11 && s->channels == 2)
418
decorrelation = LEFT_SIDE + assignment - 8;
421
av_log(s->avctx, AV_LOG_ERROR, "unsupported channel assignment %d (channels=%d)\n", assignment, s->channels);
425
sample_size_code = get_bits(&s->gb, 3);
426
if(sample_size_code == 0)
428
else if((sample_size_code != 3) && (sample_size_code != 7))
429
bps = sample_size_table[sample_size_code];
432
av_log(s->avctx, AV_LOG_ERROR, "invalid sample size code (%d)\n", sample_size_code);
436
if (get_bits1(&s->gb))
438
av_log(s->avctx, AV_LOG_ERROR, "broken stream, invalid padding\n");
442
if(get_utf8(&s->gb) < 0){
443
av_log(s->avctx, AV_LOG_ERROR, "utf8 fscked\n");
447
if (/*((blocksize_code == 6) || (blocksize_code == 7)) &&*/
448
(s->min_blocksize != s->max_blocksize)){
453
if (blocksize_code == 0)
454
blocksize = s->min_blocksize;
455
else if (blocksize_code == 6)
456
blocksize = get_bits(&s->gb, 8)+1;
457
else if (blocksize_code == 7)
458
blocksize = get_bits(&s->gb, 16)+1;
460
blocksize = blocksize_table[blocksize_code];
462
if(blocksize > s->max_blocksize){
463
av_log(s->avctx, AV_LOG_ERROR, "blocksize %d > %d\n", blocksize, s->max_blocksize);
467
if (sample_rate_code == 0){
468
samplerate= s->samplerate;
469
}else if ((sample_rate_code > 3) && (sample_rate_code < 12))
470
samplerate = sample_rate_table[sample_rate_code];
471
else if (sample_rate_code == 12)
472
samplerate = get_bits(&s->gb, 8) * 1000;
473
else if (sample_rate_code == 13)
474
samplerate = get_bits(&s->gb, 16);
475
else if (sample_rate_code == 14)
476
samplerate = get_bits(&s->gb, 16) * 10;
478
av_log(s->avctx, AV_LOG_ERROR, "illegal sample rate code %d\n", sample_rate_code);
482
skip_bits(&s->gb, 8);
483
crc8= av_crc(av_crc07, 0, s->gb.buffer, get_bits_count(&s->gb)/8);
485
av_log(s->avctx, AV_LOG_ERROR, "header crc mismatch crc=%2X\n", crc8);
489
s->blocksize = blocksize;
490
s->samplerate = samplerate;
492
s->decorrelation= decorrelation;
497
for (i = 0; i < s->channels; i++)
499
// av_log(s->avctx, AV_LOG_DEBUG, "decoded: %x residual: %x\n", s->decoded[i], s->residual[i]);
500
if (decode_subframe(s, i) < 0)
504
align_get_bits(&s->gb);
507
skip_bits(&s->gb, 16); /* data crc */
512
static inline int16_t shift_to_16_bits(int32_t data, int bps)
516
} else if (bps == 20) {
523
static int flac_decode_frame(AVCodecContext *avctx,
524
void *data, int *data_size,
525
uint8_t *buf, int buf_size)
527
FLACContext *s = avctx->priv_data;
528
int metadata_last, metadata_type, metadata_size;
529
int tmp = 0, i, j = 0, input_buf_size = 0;
530
int16_t *samples = data;
532
if(s->max_framesize == 0){
533
s->max_framesize= 65536; // should hopefully be enough for the first header
534
s->bitstream= av_fast_realloc(s->bitstream, &s->allocated_bitstream_size, s->max_framesize);
537
if(1 && s->max_framesize){//FIXME truncated
538
buf_size= FFMAX(FFMIN(buf_size, s->max_framesize - s->bitstream_size), 0);
539
input_buf_size= buf_size;
541
if(s->bitstream_index + s->bitstream_size + buf_size > s->allocated_bitstream_size){
542
// printf("memmove\n");
543
memmove(s->bitstream, &s->bitstream[s->bitstream_index], s->bitstream_size);
544
s->bitstream_index=0;
546
memcpy(&s->bitstream[s->bitstream_index + s->bitstream_size], buf, buf_size);
547
buf= &s->bitstream[s->bitstream_index];
548
buf_size += s->bitstream_size;
549
s->bitstream_size= buf_size;
551
if(buf_size < s->max_framesize){
552
// printf("wanna more data ...\n");
553
return input_buf_size;
557
init_get_bits(&s->gb, buf, buf_size*8);
559
/* fLaC signature (be) */
560
if (show_bits_long(&s->gb, 32) == bswap_32(ff_get_fourcc("fLaC")))
562
skip_bits(&s->gb, 32);
564
av_log(s->avctx, AV_LOG_DEBUG, "STREAM HEADER\n");
566
metadata_last = get_bits(&s->gb, 1);
567
metadata_type = get_bits(&s->gb, 7);
568
metadata_size = get_bits_long(&s->gb, 24);
570
av_log(s->avctx, AV_LOG_DEBUG, " metadata block: flag = %d, type = %d, size = %d\n",
571
metadata_last, metadata_type,
574
switch(metadata_type)
576
case METADATA_TYPE_STREAMINFO:{
577
metadata_streaminfo(s);
579
/* Buffer might have been reallocated, reinit bitreader */
580
if(buf != &s->bitstream[s->bitstream_index])
582
int bits_count = get_bits_count(&s->gb);
583
buf= &s->bitstream[s->bitstream_index];
584
init_get_bits(&s->gb, buf, buf_size*8);
585
skip_bits(&s->gb, bits_count);
591
for(i=0; i<metadata_size; i++)
592
skip_bits(&s->gb, 8);
595
} while(!metadata_last);
600
tmp = show_bits(&s->gb, 16);
602
av_log(s->avctx, AV_LOG_ERROR, "FRAME HEADER not here\n");
603
while(get_bits_count(&s->gb)/8+2 < buf_size && show_bits(&s->gb, 16) != 0xFFF8)
604
skip_bits(&s->gb, 8);
605
goto end; // we may not have enough bits left to decode a frame, so try next time
607
skip_bits(&s->gb, 16);
608
if (decode_frame(s) < 0){
609
av_log(s->avctx, AV_LOG_ERROR, "decode_frame() failed\n");
611
s->bitstream_index=0;
618
/* fix the channel order here */
619
if (s->order == MID_SIDE)
621
short *left = samples;
622
short *right = samples + s->blocksize;
623
for (i = 0; i < s->blocksize; i += 2)
625
uint32_t x = s->decoded[0][i];
626
uint32_t y = s->decoded[0][i+1];
628
right[i] = x - (y / 2);
629
left[i] = right[i] + y;
631
*data_size = 2 * s->blocksize;
635
for (i = 0; i < s->channels; i++)
640
for (j = 0; j < s->blocksize; j++)
641
samples[(s->blocksize*i)+j] = s->decoded[i][j];
646
for (j = 0; j < s->blocksize; j++)
647
samples[(s->blocksize*i)+j] = s->decoded[0][j];
649
for (j = 0; j < s->blocksize; j++)
650
samples[(s->blocksize*i)+j] = s->decoded[0][j] - s->decoded[i][j];
653
// av_log(s->avctx, AV_LOG_DEBUG, "mid-side unsupported\n");
655
*data_size += s->blocksize;
659
#define DECORRELATE(left, right)\
660
assert(s->channels == 2);\
661
for (i = 0; i < s->blocksize; i++)\
663
int a= s->decoded[0][i];\
664
int b= s->decoded[1][i];\
665
*(samples++) = (left ) >> (16 - s->bps);\
666
*(samples++) = (right) >> (16 - s->bps);\
670
switch(s->decorrelation)
673
for (j = 0; j < s->blocksize; j++)
675
for (i = 0; i < s->channels; i++)
676
*(samples++) = shift_to_16_bits(s->decoded[i][j], s->bps);
684
DECORRELATE( (a-=b>>1) + b, a)
688
*data_size = (int8_t *)samples - (int8_t *)data;
689
// av_log(s->avctx, AV_LOG_DEBUG, "data size: %d\n", *data_size);
691
// s->last_blocksize = s->blocksize;
693
i= (get_bits_count(&s->gb)+7)/8;;
695
av_log(s->avctx, AV_LOG_ERROR, "overread: %d\n", i - buf_size);
697
s->bitstream_index=0;
701
if(s->bitstream_size){
702
s->bitstream_index += i;
703
s->bitstream_size -= i;
704
return input_buf_size;
709
static int flac_decode_close(AVCodecContext *avctx)
711
FLACContext *s = avctx->priv_data;
714
for (i = 0; i < s->channels; i++)
716
av_freep(&s->decoded[i]);
718
av_freep(&s->bitstream);
723
static void flac_flush(AVCodecContext *avctx){
724
FLACContext *s = avctx->priv_data;
727
s->bitstream_index= 0;
730
AVCodec flac_decoder = {
added
removed
avidemux/ADM_lavcodec/flac.c
