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1
/*
2
 * FLAC (Free Lossless Audio Codec) decoder
3
 * Copyright (c) 2003 Alex Beregszaszi
4
 *
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 * This library is free software; you can redistribute it and/or
6
 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2 of the License, or (at your option) any later version.
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 *
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 * This library is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13
 * Lesser General Public License for more details.
14
 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with this library; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
19

    
20
/**
21
 * @file flac.c
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 * FLAC (Free Lossless Audio Codec) decoder
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 * @author Alex Beregszaszi
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 *
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 * For more information on the FLAC format, visit:
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 *  http://flac.sourceforge.net/
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 *
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 * This decoder can be used in 1 of 2 ways: Either raw FLAC data can be fed
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 * through, starting from the initial 'fLaC' signature; or by passing the
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 * 34-byte streaminfo structure through avctx->extradata[_size] followed
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 * by data starting with the 0xFFF8 marker.
32
 */
33

    
34
#include <limits.h>
35

    
36
#include "avcodec.h"
37
#include "bitstream.h"
38
#include "golomb.h"
39
#include "crc.h"
40

    
41
#undef NDEBUG
42
#include <assert.h>
43

    
44
#define MAX_CHANNELS 8
45
#define MAX_BLOCKSIZE 65535
46
#define FLAC_STREAMINFO_SIZE 34
47

    
48
enum decorrelation_type {
49
    INDEPENDENT,
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    LEFT_SIDE,
51
    RIGHT_SIDE,
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    MID_SIDE,
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};
54

    
55
typedef struct FLACContext {
56
    AVCodecContext *avctx;
57
    GetBitContext gb;
58

    
59
    int min_blocksize, max_blocksize;
60
    int min_framesize, max_framesize;
61
    int samplerate, channels;
62
    int blocksize/*, last_blocksize*/;
63
    int bps, curr_bps;
64
    enum decorrelation_type decorrelation;
65

    
66
    int32_t *decoded[MAX_CHANNELS];
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    uint8_t *bitstream;
68
    int bitstream_size;
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    int bitstream_index;
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    unsigned int allocated_bitstream_size;
71
} FLACContext;
72

    
73
#define METADATA_TYPE_STREAMINFO 0
74

    
75
static int sample_rate_table[] =
76
{ 0, 0, 0, 0,
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  8000, 16000, 22050, 24000, 32000, 44100, 48000, 96000,
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  0, 0, 0, 0 };
79

    
80
static int sample_size_table[] =
81
{ 0, 8, 12, 0, 16, 20, 24, 0 };
82

    
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
86
};
87

    
88
static int64_t get_utf8(GetBitContext *gb){
89
    int64_t val;
90
    GET_UTF8(val, get_bits(gb, 8), return -1;)
91
    return val;
92
}
93

    
94
static void metadata_streaminfo(FLACContext *s);
95
static void dump_headers(FLACContext *s);
96

    
97
static int flac_decode_init(AVCodecContext * avctx)
98
{
99
    FLACContext *s = avctx->priv_data;
100
    s->avctx = avctx;
101

    
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);
106
        dump_headers(s);
107
    }
108

    
109
    return 0;
110
}
111

    
112
static void dump_headers(FLACContext *s)
113
{
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);
119
}
120

    
121
static void allocate_buffers(FLACContext *s){
122
    int i;
123

    
124
    assert(s->max_blocksize);
125

    
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
128
    }
129

    
130
    for (i = 0; i < s->channels; i++)
131
    {
132
        s->decoded[i] = av_realloc(s->decoded[i], sizeof(int32_t)*s->max_blocksize);
133
    }
134

    
135
    s->bitstream= av_fast_realloc(s->bitstream, &s->allocated_bitstream_size, s->max_framesize);
136
}
137

    
138
static void metadata_streaminfo(FLACContext *s)
139
{
140
    /* mandatory streaminfo */
141
    s->min_blocksize = get_bits(&s->gb, 16);
142
    s->max_blocksize = get_bits(&s->gb, 16);
143

    
144
    s->min_framesize = get_bits_long(&s->gb, 24);
145
    s->max_framesize = get_bits_long(&s->gb, 24);
146

    
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;
150

    
151
    s->avctx->channels = s->channels;
152
    s->avctx->sample_rate = s->samplerate;
153

    
154
    skip_bits(&s->gb, 36); /* total num of samples */
155

    
156
    skip_bits(&s->gb, 64); /* md5 sum */
157
    skip_bits(&s->gb, 64); /* md5 sum */
158

    
159
    allocate_buffers(s);
160
}
161

    
162
static int decode_residuals(FLACContext *s, int channel, int pred_order)
163
{
164
    int i, tmp, partition, method_type, rice_order;
165
    int sample = 0, samples;
166

    
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);
170
        return -1;
171
    }
172

    
173
    rice_order = get_bits(&s->gb, 4);
174

    
175
    samples= s->blocksize >> rice_order;
176

    
177
    sample=
178
    i= pred_order;
179
    for (partition = 0; partition < (1 << rice_order); partition++)
180
    {
181
        tmp = get_bits(&s->gb, 4);
182
        if (tmp == 15)
183
        {
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);
188
        }
189
        else
190
        {
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);
194
            }
195
        }
196
        i= 0;
197
    }
198

    
199
//    av_log(s->avctx, AV_LOG_DEBUG, "partitions: %d, samples: %d\n", 1 << rice_order, sample);
200

    
201
    return 0;
202
}
203

    
204
static int decode_subframe_fixed(FLACContext *s, int channel, int pred_order)
205
{
206
    int i;
207

    
208
//    av_log(s->avctx, AV_LOG_DEBUG, "  SUBFRAME FIXED\n");
209

    
210
    /* warm up samples */
211
//    av_log(s->avctx, AV_LOG_DEBUG, "   warm up samples: %d\n", pred_order);
212

    
213
    for (i = 0; i < pred_order; i++)
214
    {
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]);
217
    }
218

    
219
    if (decode_residuals(s, channel, pred_order) < 0)
220
        return -1;
221

    
222
    switch(pred_order)
223
    {
224
        case 0:
225
            break;
226
        case 1:
227
            for (i = pred_order; i < s->blocksize; i++)
228
                s->decoded[channel][i] +=   s->decoded[channel][i-1];
229
            break;
230
        case 2:
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];
234
            break;
235
        case 3:
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];
240
            break;
241
        case 4:
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];
247
            break;
248
        default:
249
            av_log(s->avctx, AV_LOG_ERROR, "illegal pred order %d\n", pred_order);
250
            return -1;
251
    }
252

    
253
    return 0;
254
}
255

    
256
static int decode_subframe_lpc(FLACContext *s, int channel, int pred_order)
257
{
258
    int i, j;
259
    int coeff_prec, qlevel;
260
    int coeffs[pred_order];
261

    
262
//    av_log(s->avctx, AV_LOG_DEBUG, "  SUBFRAME LPC\n");
263

    
264
    /* warm up samples */
265
//    av_log(s->avctx, AV_LOG_DEBUG, "   warm up samples: %d\n", pred_order);
266

    
267
    for (i = 0; i < pred_order; i++)
268
    {
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]);
271
    }
272

    
273
    coeff_prec = get_bits(&s->gb, 4) + 1;
274
    if (coeff_prec == 16)
275
    {
276
        av_log(s->avctx, AV_LOG_DEBUG, "invalid coeff precision\n");
277
        return -1;
278
    }
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);
282
    if(qlevel < 0){
283
        av_log(s->avctx, AV_LOG_DEBUG, "qlevel %d not supported, maybe buggy stream\n", qlevel);
284
        return -1;
285
    }
286

    
287
    for (i = 0; i < pred_order; i++)
288
    {
289
        coeffs[i] = get_sbits(&s->gb, coeff_prec);
290
//        av_log(s->avctx, AV_LOG_DEBUG, "    %d: %d\n", i, coeffs[i]);
291
    }
292

    
293
    if (decode_residuals(s, channel, pred_order) < 0)
294
        return -1;
295

    
296
    if (s->bps > 16) {
297
        int64_t sum;
298
        for (i = pred_order; i < s->blocksize; i++)
299
        {
300
            sum = 0;
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;
304
        }
305
    } else {
306
        int sum;
307
        for (i = pred_order; i < s->blocksize; i++)
308
        {
309
            sum = 0;
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;
313
        }
314
    }
315

    
316
    return 0;
317
}
318

    
319
static inline int decode_subframe(FLACContext *s, int channel)
320
{
321
    int type, wasted = 0;
322
    int i, tmp;
323

    
324
    s->curr_bps = s->bps;
325
    if(channel == 0){
326
        if(s->decorrelation == RIGHT_SIDE)
327
            s->curr_bps++;
328
    }else{
329
        if(s->decorrelation == LEFT_SIDE || s->decorrelation == MID_SIDE)
330
            s->curr_bps++;
331
    }
332

    
333
    if (get_bits1(&s->gb))
334
    {
335
        av_log(s->avctx, AV_LOG_ERROR, "invalid subframe padding\n");
336
        return -1;
337
    }
338
    type = get_bits(&s->gb, 6);
339
//    wasted = get_bits1(&s->gb);
340

    
341
//    if (wasted)
342
//    {
343
//        while (!get_bits1(&s->gb))
344
//            wasted++;
345
//        if (wasted)
346
//            wasted++;
347
//        s->curr_bps -= wasted;
348
//    }
349
#if 0
350
    wasted= 16 - av_log2(show_bits(&s->gb, 17));
351
    skip_bits(&s->gb, wasted+1);
352
    s->curr_bps -= wasted;
353
#else
354
    if (get_bits1(&s->gb))
355
    {
356
        wasted = 1;
357
        while (!get_bits1(&s->gb))
358
            wasted++;
359
        s->curr_bps -= wasted;
360
        av_log(s->avctx, AV_LOG_DEBUG, "%d wasted bits\n", wasted);
361
    }
362
#endif
363
//FIXME use av_log2 for types
364
    if (type == 0)
365
    {
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;
370
    }
371
    else if (type == 1)
372
    {
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);
376
    }
377
    else if ((type >= 8) && (type <= 12))
378
    {
379
//        av_log(s->avctx, AV_LOG_DEBUG, "coding type: fixed\n");
380
        if (decode_subframe_fixed(s, channel, type & ~0x8) < 0)
381
            return -1;
382
    }
383
    else if (type >= 32)
384
    {
385
//        av_log(s->avctx, AV_LOG_DEBUG, "coding type: lpc\n");
386
        if (decode_subframe_lpc(s, channel, (type & ~0x20)+1) < 0)
387
            return -1;
388
    }
389
    else
390
    {
391
        av_log(s->avctx, AV_LOG_ERROR, "invalid coding type\n");
392
        return -1;
393
    }
394

    
395
    if (wasted)
396
    {
397
        int i;
398
        for (i = 0; i < s->blocksize; i++)
399
            s->decoded[channel][i] <<= wasted;
400
    }
401

    
402
    return 0;
403
}
404

    
405
static int decode_frame(FLACContext *s)
406
{
407
    int blocksize_code, sample_rate_code, sample_size_code, assignment, i, crc8;
408
    int decorrelation, bps, blocksize, samplerate;
409

    
410
    blocksize_code = get_bits(&s->gb, 4);
411

    
412
    sample_rate_code = get_bits(&s->gb, 4);
413

    
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;
419
    else
420
    {
421
        av_log(s->avctx, AV_LOG_ERROR, "unsupported channel assignment %d (channels=%d)\n", assignment, s->channels);
422
        return -1;
423
    }
424

    
425
    sample_size_code = get_bits(&s->gb, 3);
426
    if(sample_size_code == 0)
427
        bps= s->bps;
428
    else if((sample_size_code != 3) && (sample_size_code != 7))
429
        bps = sample_size_table[sample_size_code];
430
    else
431
    {
432
        av_log(s->avctx, AV_LOG_ERROR, "invalid sample size code (%d)\n", sample_size_code);
433
        return -1;
434
    }
435

    
436
    if (get_bits1(&s->gb))
437
    {
438
        av_log(s->avctx, AV_LOG_ERROR, "broken stream, invalid padding\n");
439
        return -1;
440
    }
441

    
442
    if(get_utf8(&s->gb) < 0){
443
        av_log(s->avctx, AV_LOG_ERROR, "utf8 fscked\n");
444
        return -1;
445
    }
446
#if 0
447
    if (/*((blocksize_code == 6) || (blocksize_code == 7)) &&*/
448
        (s->min_blocksize != s->max_blocksize)){
449
    }else{
450
    }
451
#endif
452

    
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;
459
    else
460
        blocksize = blocksize_table[blocksize_code];
461

    
462
    if(blocksize > s->max_blocksize){
463
        av_log(s->avctx, AV_LOG_ERROR, "blocksize %d > %d\n", blocksize, s->max_blocksize);
464
        return -1;
465
    }
466

    
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;
477
    else{
478
        av_log(s->avctx, AV_LOG_ERROR, "illegal sample rate code %d\n", sample_rate_code);
479
        return -1;
480
    }
481

    
482
    skip_bits(&s->gb, 8);
483
    crc8= av_crc(av_crc07, 0, s->gb.buffer, get_bits_count(&s->gb)/8);
484
    if(crc8){
485
        av_log(s->avctx, AV_LOG_ERROR, "header crc mismatch crc=%2X\n", crc8);
486
        return -1;
487
    }
488

    
489
    s->blocksize    = blocksize;
490
    s->samplerate   = samplerate;
491
    s->bps          = bps;
492
    s->decorrelation= decorrelation;
493

    
494
//    dump_headers(s);
495

    
496
    /* subframes */
497
    for (i = 0; i < s->channels; i++)
498
    {
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)
501
            return -1;
502
    }
503

    
504
    align_get_bits(&s->gb);
505

    
506
    /* frame footer */
507
    skip_bits(&s->gb, 16); /* data crc */
508

    
509
    return 0;
510
}
511

    
512
static inline int16_t shift_to_16_bits(int32_t data, int bps)
513
{
514
    if (bps == 24) {
515
        return (data >> 8);
516
    } else if (bps == 20) {
517
        return (data >> 4);
518
    } else {
519
        return data;
520
    }
521
}
522

    
523
static int flac_decode_frame(AVCodecContext *avctx,
524
                            void *data, int *data_size,
525
                            uint8_t *buf, int buf_size)
526
{
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;
531

    
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);
535
    }
536

    
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;
540

    
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;
545
            }
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;
550

    
551
            if(buf_size < s->max_framesize){
552
//                printf("wanna more data ...\n");
553
                return input_buf_size;
554
            }
555
    }
556

    
557
    init_get_bits(&s->gb, buf, buf_size*8);
558

    
559
    /* fLaC signature (be) */
560
    if (show_bits_long(&s->gb, 32) == bswap_32(ff_get_fourcc("fLaC")))
561
    {
562
        skip_bits(&s->gb, 32);
563

    
564
        av_log(s->avctx, AV_LOG_DEBUG, "STREAM HEADER\n");
565
        do {
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);
569

    
570
            av_log(s->avctx, AV_LOG_DEBUG, " metadata block: flag = %d, type = %d, size = %d\n",
571
                metadata_last, metadata_type,
572
                metadata_size);
573
            if(metadata_size){
574
                switch(metadata_type)
575
                {
576
                case METADATA_TYPE_STREAMINFO:{
577
                    metadata_streaminfo(s);
578

    
579
                    /* Buffer might have been reallocated, reinit bitreader */
580
                    if(buf != &s->bitstream[s->bitstream_index])
581
                    {
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);
586
                    }
587

    
588
                    dump_headers(s);
589
                    break;}
590
                default:
591
                    for(i=0; i<metadata_size; i++)
592
                        skip_bits(&s->gb, 8);
593
                }
594
            }
595
        } while(!metadata_last);
596
    }
597
    else
598
    {
599

    
600
        tmp = show_bits(&s->gb, 16);
601
        if(tmp != 0xFFF8){
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
606
        }
607
        skip_bits(&s->gb, 16);
608
        if (decode_frame(s) < 0){
609
            av_log(s->avctx, AV_LOG_ERROR, "decode_frame() failed\n");
610
            s->bitstream_size=0;
611
            s->bitstream_index=0;
612
            return -1;
613
        }
614
    }
615

    
616

    
617
#if 0
618
    /* fix the channel order here */
619
    if (s->order == MID_SIDE)
620
    {
621
        short *left = samples;
622
        short *right = samples + s->blocksize;
623
        for (i = 0; i < s->blocksize; i += 2)
624
        {
625
            uint32_t x = s->decoded[0][i];
626
            uint32_t y = s->decoded[0][i+1];
627

628
            right[i] = x - (y / 2);
629
            left[i] = right[i] + y;
630
        }
631
        *data_size = 2 * s->blocksize;
632
    }
633
    else
634
    {
635
    for (i = 0; i < s->channels; i++)
636
    {
637
        switch(s->order)
638
        {
639
            case INDEPENDENT:
640
                for (j = 0; j < s->blocksize; j++)
641
                    samples[(s->blocksize*i)+j] = s->decoded[i][j];
642
                break;
643
            case LEFT_SIDE:
644
            case RIGHT_SIDE:
645
                if (i == 0)
646
                    for (j = 0; j < s->blocksize; j++)
647
                        samples[(s->blocksize*i)+j] = s->decoded[0][j];
648
                else
649
                    for (j = 0; j < s->blocksize; j++)
650
                        samples[(s->blocksize*i)+j] = s->decoded[0][j] - s->decoded[i][j];
651
                break;
652
//            case MID_SIDE:
653
//                av_log(s->avctx, AV_LOG_DEBUG, "mid-side unsupported\n");
654
        }
655
        *data_size += s->blocksize;
656
    }
657
    }
658
#else
659
#define DECORRELATE(left, right)\
660
            assert(s->channels == 2);\
661
            for (i = 0; i < s->blocksize; i++)\
662
            {\
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);\
667
            }\
668
            break;
669

    
670
    switch(s->decorrelation)
671
    {
672
        case INDEPENDENT:
673
            for (j = 0; j < s->blocksize; j++)
674
            {
675
                for (i = 0; i < s->channels; i++)
676
                    *(samples++) = shift_to_16_bits(s->decoded[i][j], s->bps);
677
            }
678
            break;
679
        case LEFT_SIDE:
680
            DECORRELATE(a,a-b)
681
        case RIGHT_SIDE:
682
            DECORRELATE(a+b,b)
683
        case MID_SIDE:
684
            DECORRELATE( (a-=b>>1) + b, a)
685
    }
686
#endif
687

    
688
    *data_size = (int8_t *)samples - (int8_t *)data;
689
//    av_log(s->avctx, AV_LOG_DEBUG, "data size: %d\n", *data_size);
690

    
691
//    s->last_blocksize = s->blocksize;
692
end:
693
    i= (get_bits_count(&s->gb)+7)/8;;
694
    if(i > buf_size){
695
        av_log(s->avctx, AV_LOG_ERROR, "overread: %d\n", i - buf_size);
696
        s->bitstream_size=0;
697
        s->bitstream_index=0;
698
        return -1;
699
    }
700

    
701
    if(s->bitstream_size){
702
        s->bitstream_index += i;
703
        s->bitstream_size  -= i;
704
        return input_buf_size;
705
    }else
706
        return i;
707
}
708

    
709
static int flac_decode_close(AVCodecContext *avctx)
710
{
711
    FLACContext *s = avctx->priv_data;
712
    int i;
713

    
714
    for (i = 0; i < s->channels; i++)
715
    {
716
        av_freep(&s->decoded[i]);
717
    }
718
    av_freep(&s->bitstream);
719

    
720
    return 0;
721
}
722

    
723
static void flac_flush(AVCodecContext *avctx){
724
    FLACContext *s = avctx->priv_data;
725

    
726
    s->bitstream_size=
727
    s->bitstream_index= 0;
728
}
729

    
730
AVCodec flac_decoder = {
731
    "flac",
732
    CODEC_TYPE_AUDIO,
733
    CODEC_ID_FLAC,
734
    sizeof(FLACContext),
735
    flac_decode_init,
736
    NULL,
737
    flac_decode_close,
738
    flac_decode_frame,
739
    .flush= flac_flush,
740
};