Statistics
| Branch: | Revision:

ffmpeg / libavcodec / flac.c @ 7a886063

History | View | Annotate | Download (21.5 KB)

1 4f52c312 Michael Niedermayer
/*
2
 * FLAC (Free Lossless Audio Codec) decoder
3
 * Copyright (c) 2003 Alex Beregszaszi
4
 *
5 b78e7197 Diego Biurrun
 * This file is part of FFmpeg.
6
 *
7
 * FFmpeg is free software; you can redistribute it and/or
8 4f52c312 Michael Niedermayer
 * modify it under the terms of the GNU Lesser General Public
9
 * License as published by the Free Software Foundation; either
10 b78e7197 Diego Biurrun
 * version 2.1 of the License, or (at your option) any later version.
11 4f52c312 Michael Niedermayer
 *
12 b78e7197 Diego Biurrun
 * FFmpeg is distributed in the hope that it will be useful,
13 4f52c312 Michael Niedermayer
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15
 * Lesser General Public License for more details.
16
 *
17
 * You should have received a copy of the GNU Lesser General Public
18 b78e7197 Diego Biurrun
 * License along with FFmpeg; if not, write to the Free Software
19 5509bffa Diego Biurrun
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 4f52c312 Michael Niedermayer
 */
21
22
/**
23
 * @file flac.c
24
 * FLAC (Free Lossless Audio Codec) decoder
25
 * @author Alex Beregszaszi
26 9eda2f94 Mike Melanson
 *
27
 * For more information on the FLAC format, visit:
28
 *  http://flac.sourceforge.net/
29
 *
30
 * This decoder can be used in 1 of 2 ways: Either raw FLAC data can be fed
31
 * through, starting from the initial 'fLaC' signature; or by passing the
32
 * 34-byte streaminfo structure through avctx->extradata[_size] followed
33
 * by data starting with the 0xFFF8 marker.
34 4f52c312 Michael Niedermayer
 */
35 115329f1 Diego Biurrun
36 ac2570a8 Michael Niedermayer
#include <limits.h>
37 115329f1 Diego Biurrun
38 75c998a2 Aurelien Jacobs
#define ALT_BITSTREAM_READER
39 4f52c312 Michael Niedermayer
#include "avcodec.h"
40 caa336b4 Michael Niedermayer
#include "bitstream.h"
41 4f52c312 Michael Niedermayer
#include "golomb.h"
42 b865838e Michael Niedermayer
#include "crc.h"
43 4f52c312 Michael Niedermayer
44 ac2570a8 Michael Niedermayer
#undef NDEBUG
45
#include <assert.h>
46
47 4f52c312 Michael Niedermayer
#define MAX_CHANNELS 8
48
#define MAX_BLOCKSIZE 65535
49 9eda2f94 Mike Melanson
#define FLAC_STREAMINFO_SIZE 34
50 4f52c312 Michael Niedermayer
51 9d656110 Michael Niedermayer
enum decorrelation_type {
52 4f52c312 Michael Niedermayer
    INDEPENDENT,
53
    LEFT_SIDE,
54
    RIGHT_SIDE,
55
    MID_SIDE,
56
};
57
58
typedef struct FLACContext {
59
    AVCodecContext *avctx;
60
    GetBitContext gb;
61
62
    int min_blocksize, max_blocksize;
63
    int min_framesize, max_framesize;
64
    int samplerate, channels;
65 ac2570a8 Michael Niedermayer
    int blocksize/*, last_blocksize*/;
66 4f52c312 Michael Niedermayer
    int bps, curr_bps;
67 9d656110 Michael Niedermayer
    enum decorrelation_type decorrelation;
68 4f52c312 Michael Niedermayer
69 ac2570a8 Michael Niedermayer
    int32_t *decoded[MAX_CHANNELS];
70
    uint8_t *bitstream;
71
    int bitstream_size;
72
    int bitstream_index;
73 f038fe8b Diego Biurrun
    unsigned int allocated_bitstream_size;
74 4f52c312 Michael Niedermayer
} FLACContext;
75
76
#define METADATA_TYPE_STREAMINFO 0
77
78
static int sample_rate_table[] =
79
{ 0, 0, 0, 0,
80
  8000, 16000, 22050, 24000, 32000, 44100, 48000, 96000,
81 115329f1 Diego Biurrun
  0, 0, 0, 0 };
82 4f52c312 Michael Niedermayer
83 115329f1 Diego Biurrun
static int sample_size_table[] =
84 4f52c312 Michael Niedermayer
{ 0, 8, 12, 0, 16, 20, 24, 0 };
85
86 0496a034 Michael Niedermayer
static int blocksize_table[] = {
87 115329f1 Diego Biurrun
     0,    192, 576<<0, 576<<1, 576<<2, 576<<3,      0,      0,
88
256<<0, 256<<1, 256<<2, 256<<3, 256<<4, 256<<5, 256<<6, 256<<7
89 0496a034 Michael Niedermayer
};
90
91 9d82b0dd Michael Niedermayer
static int64_t get_utf8(GetBitContext *gb){
92
    int64_t val;
93
    GET_UTF8(val, get_bits(gb, 8), return -1;)
94 ac2570a8 Michael Niedermayer
    return val;
95 4f52c312 Michael Niedermayer
}
96
97 9eda2f94 Mike Melanson
static void metadata_streaminfo(FLACContext *s);
98 17c90b9d Aurelien Jacobs
static void allocate_buffers(FLACContext *s);
99
static int metadata_parse(FLACContext *s);
100 9eda2f94 Mike Melanson
101 4f52c312 Michael Niedermayer
static int flac_decode_init(AVCodecContext * avctx)
102
{
103 9eda2f94 Mike Melanson
    FLACContext *s = avctx->priv_data;
104
    s->avctx = avctx;
105
106 17c90b9d Aurelien Jacobs
    if (avctx->extradata_size > 4) {
107
        /* initialize based on the demuxer-supplied streamdata header */
108 9eda2f94 Mike Melanson
        init_get_bits(&s->gb, avctx->extradata, avctx->extradata_size*8);
109 17c90b9d Aurelien Jacobs
        if (avctx->extradata_size == FLAC_STREAMINFO_SIZE) {
110
            metadata_streaminfo(s);
111
            allocate_buffers(s);
112
        } else {
113
            metadata_parse(s);
114
        }
115 9eda2f94 Mike Melanson
    }
116
117 4f52c312 Michael Niedermayer
    return 0;
118
}
119
120
static void dump_headers(FLACContext *s)
121
{
122 ac2570a8 Michael Niedermayer
    av_log(s->avctx, AV_LOG_DEBUG, "  Blocksize: %d .. %d (%d)\n", s->min_blocksize, s->max_blocksize, s->blocksize);
123
    av_log(s->avctx, AV_LOG_DEBUG, "  Framesize: %d .. %d\n", s->min_framesize, s->max_framesize);
124
    av_log(s->avctx, AV_LOG_DEBUG, "  Samplerate: %d\n", s->samplerate);
125
    av_log(s->avctx, AV_LOG_DEBUG, "  Channels: %d\n", s->channels);
126
    av_log(s->avctx, AV_LOG_DEBUG, "  Bits: %d\n", s->bps);
127 4f52c312 Michael Niedermayer
}
128
129 ac2570a8 Michael Niedermayer
static void allocate_buffers(FLACContext *s){
130 4f52c312 Michael Niedermayer
    int i;
131
132 ac2570a8 Michael Niedermayer
    assert(s->max_blocksize);
133
134
    if(s->max_framesize == 0 && s->max_blocksize){
135
        s->max_framesize= (s->channels * s->bps * s->max_blocksize + 7)/ 8; //FIXME header overhead
136
    }
137
138
    for (i = 0; i < s->channels; i++)
139
    {
140
        s->decoded[i] = av_realloc(s->decoded[i], sizeof(int32_t)*s->max_blocksize);
141
    }
142
143
    s->bitstream= av_fast_realloc(s->bitstream, &s->allocated_bitstream_size, s->max_framesize);
144
}
145
146
static void metadata_streaminfo(FLACContext *s)
147
{
148 4f52c312 Michael Niedermayer
    /* mandatory streaminfo */
149
    s->min_blocksize = get_bits(&s->gb, 16);
150
    s->max_blocksize = get_bits(&s->gb, 16);
151
152
    s->min_framesize = get_bits_long(&s->gb, 24);
153
    s->max_framesize = get_bits_long(&s->gb, 24);
154 115329f1 Diego Biurrun
155 4f52c312 Michael Niedermayer
    s->samplerate = get_bits_long(&s->gb, 20);
156
    s->channels = get_bits(&s->gb, 3) + 1;
157
    s->bps = get_bits(&s->gb, 5) + 1;
158 115329f1 Diego Biurrun
159 4f52c312 Michael Niedermayer
    s->avctx->channels = s->channels;
160
    s->avctx->sample_rate = s->samplerate;
161
162
    skip_bits(&s->gb, 36); /* total num of samples */
163 115329f1 Diego Biurrun
164 4f52c312 Michael Niedermayer
    skip_bits(&s->gb, 64); /* md5 sum */
165
    skip_bits(&s->gb, 64); /* md5 sum */
166 115329f1 Diego Biurrun
167 17c90b9d Aurelien Jacobs
    dump_headers(s);
168
}
169
170
/**
171
 * Parse a list of metadata blocks. This list of blocks must begin with
172
 * the fLaC marker.
173
 * @param s the flac decoding context containing the gb bit reader used to
174
 *          parse metadata
175
 * @return 1 if some metadata was read, 0 if no fLaC marker was found
176
 */
177
static int metadata_parse(FLACContext *s)
178
{
179
    int i, metadata_last, metadata_type, metadata_size, streaminfo_updated=0;
180
181
    if (show_bits_long(&s->gb, 32) == MKBETAG('f','L','a','C')) {
182
        skip_bits(&s->gb, 32);
183
184
        av_log(s->avctx, AV_LOG_DEBUG, "STREAM HEADER\n");
185
        do {
186
            metadata_last = get_bits(&s->gb, 1);
187
            metadata_type = get_bits(&s->gb, 7);
188
            metadata_size = get_bits_long(&s->gb, 24);
189
190
            av_log(s->avctx, AV_LOG_DEBUG,
191
                   " metadata block: flag = %d, type = %d, size = %d\n",
192
                   metadata_last, metadata_type, metadata_size);
193
            if (metadata_size) {
194
                switch (metadata_type) {
195
                case METADATA_TYPE_STREAMINFO:
196
                    metadata_streaminfo(s);
197
                    streaminfo_updated = 1;
198
                    break;
199
200
                default:
201
                    for (i=0; i<metadata_size; i++)
202
                        skip_bits(&s->gb, 8);
203
                }
204
            }
205
        } while (!metadata_last);
206
207
        if (streaminfo_updated)
208
            allocate_buffers(s);
209
        return 1;
210
    }
211
    return 0;
212 4f52c312 Michael Niedermayer
}
213
214
static int decode_residuals(FLACContext *s, int channel, int pred_order)
215
{
216
    int i, tmp, partition, method_type, rice_order;
217
    int sample = 0, samples;
218
219
    method_type = get_bits(&s->gb, 2);
220 ac2570a8 Michael Niedermayer
    if (method_type != 0){
221
        av_log(s->avctx, AV_LOG_DEBUG, "illegal residual coding method %d\n", method_type);
222 4f52c312 Michael Niedermayer
        return -1;
223 ac2570a8 Michael Niedermayer
    }
224 115329f1 Diego Biurrun
225 4f52c312 Michael Niedermayer
    rice_order = get_bits(&s->gb, 4);
226
227 ac2570a8 Michael Niedermayer
    samples= s->blocksize >> rice_order;
228 4f52c312 Michael Niedermayer
229 115329f1 Diego Biurrun
    sample=
230 ac2570a8 Michael Niedermayer
    i= pred_order;
231 4f52c312 Michael Niedermayer
    for (partition = 0; partition < (1 << rice_order); partition++)
232
    {
233
        tmp = get_bits(&s->gb, 4);
234 ac2570a8 Michael Niedermayer
        if (tmp == 15)
235 4f52c312 Michael Niedermayer
        {
236 ac2570a8 Michael Niedermayer
            av_log(s->avctx, AV_LOG_DEBUG, "fixed len partition\n");
237 4f52c312 Michael Niedermayer
            tmp = get_bits(&s->gb, 5);
238
            for (; i < samples; i++, sample++)
239 4fd12598 Michael Niedermayer
                s->decoded[channel][sample] = get_sbits(&s->gb, tmp);
240 4f52c312 Michael Niedermayer
        }
241
        else
242
        {
243 ac2570a8 Michael Niedermayer
//            av_log(s->avctx, AV_LOG_DEBUG, "rice coded partition k=%d\n", tmp);
244
            for (; i < samples; i++, sample++){
245 4fd12598 Michael Niedermayer
                s->decoded[channel][sample] = get_sr_golomb_flac(&s->gb, tmp, INT_MAX, 0);
246 ac2570a8 Michael Niedermayer
            }
247 4f52c312 Michael Niedermayer
        }
248 ac2570a8 Michael Niedermayer
        i= 0;
249 4f52c312 Michael Niedermayer
    }
250
251 ac2570a8 Michael Niedermayer
//    av_log(s->avctx, AV_LOG_DEBUG, "partitions: %d, samples: %d\n", 1 << rice_order, sample);
252 4f52c312 Michael Niedermayer
253
    return 0;
254 115329f1 Diego Biurrun
}
255 4f52c312 Michael Niedermayer
256
static int decode_subframe_fixed(FLACContext *s, int channel, int pred_order)
257
{
258
    int i;
259 115329f1 Diego Biurrun
260 9d656110 Michael Niedermayer
//    av_log(s->avctx, AV_LOG_DEBUG, "  SUBFRAME FIXED\n");
261 115329f1 Diego Biurrun
262 4f52c312 Michael Niedermayer
    /* warm up samples */
263 9d656110 Michael Niedermayer
//    av_log(s->avctx, AV_LOG_DEBUG, "   warm up samples: %d\n", pred_order);
264 115329f1 Diego Biurrun
265 4f52c312 Michael Niedermayer
    for (i = 0; i < pred_order; i++)
266
    {
267 ac2570a8 Michael Niedermayer
        s->decoded[channel][i] = get_sbits(&s->gb, s->curr_bps);
268
//        av_log(s->avctx, AV_LOG_DEBUG, "    %d: %d\n", i, s->decoded[channel][i]);
269 4f52c312 Michael Niedermayer
    }
270 115329f1 Diego Biurrun
271 4f52c312 Michael Niedermayer
    if (decode_residuals(s, channel, pred_order) < 0)
272
        return -1;
273
274
    switch(pred_order)
275
    {
276
        case 0:
277
            break;
278
        case 1:
279
            for (i = pred_order; i < s->blocksize; i++)
280 4fd12598 Michael Niedermayer
                s->decoded[channel][i] +=   s->decoded[channel][i-1];
281 4f52c312 Michael Niedermayer
            break;
282
        case 2:
283
            for (i = pred_order; i < s->blocksize; i++)
284 4fd12598 Michael Niedermayer
                s->decoded[channel][i] += 2*s->decoded[channel][i-1]
285
                                          - s->decoded[channel][i-2];
286 4f52c312 Michael Niedermayer
            break;
287
        case 3:
288
            for (i = pred_order; i < s->blocksize; i++)
289 115329f1 Diego Biurrun
                s->decoded[channel][i] += 3*s->decoded[channel][i-1]
290 4fd12598 Michael Niedermayer
                                        - 3*s->decoded[channel][i-2]
291
                                        +   s->decoded[channel][i-3];
292 4f52c312 Michael Niedermayer
            break;
293
        case 4:
294
            for (i = pred_order; i < s->blocksize; i++)
295 115329f1 Diego Biurrun
                s->decoded[channel][i] += 4*s->decoded[channel][i-1]
296 4fd12598 Michael Niedermayer
                                        - 6*s->decoded[channel][i-2]
297
                                        + 4*s->decoded[channel][i-3]
298
                                        -   s->decoded[channel][i-4];
299 4f52c312 Michael Niedermayer
            break;
300 ac2570a8 Michael Niedermayer
        default:
301
            av_log(s->avctx, AV_LOG_ERROR, "illegal pred order %d\n", pred_order);
302
            return -1;
303 4f52c312 Michael Niedermayer
    }
304 ac2570a8 Michael Niedermayer
305 4f52c312 Michael Niedermayer
    return 0;
306
}
307
308
static int decode_subframe_lpc(FLACContext *s, int channel, int pred_order)
309
{
310 0187178e Luca Barbato
    int i, j;
311 4f52c312 Michael Niedermayer
    int coeff_prec, qlevel;
312
    int coeffs[pred_order];
313 115329f1 Diego Biurrun
314 ac2570a8 Michael Niedermayer
//    av_log(s->avctx, AV_LOG_DEBUG, "  SUBFRAME LPC\n");
315 115329f1 Diego Biurrun
316 4f52c312 Michael Niedermayer
    /* warm up samples */
317 ac2570a8 Michael Niedermayer
//    av_log(s->avctx, AV_LOG_DEBUG, "   warm up samples: %d\n", pred_order);
318 115329f1 Diego Biurrun
319 4f52c312 Michael Niedermayer
    for (i = 0; i < pred_order; i++)
320
    {
321 ac2570a8 Michael Niedermayer
        s->decoded[channel][i] = get_sbits(&s->gb, s->curr_bps);
322
//        av_log(s->avctx, AV_LOG_DEBUG, "    %d: %d\n", i, s->decoded[channel][i]);
323 4f52c312 Michael Niedermayer
    }
324 115329f1 Diego Biurrun
325 4f52c312 Michael Niedermayer
    coeff_prec = get_bits(&s->gb, 4) + 1;
326
    if (coeff_prec == 16)
327
    {
328 ac2570a8 Michael Niedermayer
        av_log(s->avctx, AV_LOG_DEBUG, "invalid coeff precision\n");
329 4f52c312 Michael Niedermayer
        return -1;
330
    }
331 9d656110 Michael Niedermayer
//    av_log(s->avctx, AV_LOG_DEBUG, "   qlp coeff prec: %d\n", coeff_prec);
332 ac2570a8 Michael Niedermayer
    qlevel = get_sbits(&s->gb, 5);
333 9d656110 Michael Niedermayer
//    av_log(s->avctx, AV_LOG_DEBUG, "   quant level: %d\n", qlevel);
334
    if(qlevel < 0){
335
        av_log(s->avctx, AV_LOG_DEBUG, "qlevel %d not supported, maybe buggy stream\n", qlevel);
336
        return -1;
337
    }
338
339 4f52c312 Michael Niedermayer
    for (i = 0; i < pred_order; i++)
340
    {
341 ac2570a8 Michael Niedermayer
        coeffs[i] = get_sbits(&s->gb, coeff_prec);
342
//        av_log(s->avctx, AV_LOG_DEBUG, "    %d: %d\n", i, coeffs[i]);
343 4f52c312 Michael Niedermayer
    }
344 115329f1 Diego Biurrun
345 4f52c312 Michael Niedermayer
    if (decode_residuals(s, channel, pred_order) < 0)
346
        return -1;
347
348 0187178e Luca Barbato
    if (s->bps > 16) {
349
        int64_t sum;
350
        for (i = pred_order; i < s->blocksize; i++)
351
        {
352
            sum = 0;
353
            for (j = 0; j < pred_order; j++)
354
                sum += (int64_t)coeffs[j] * s->decoded[channel][i-j-1];
355
            s->decoded[channel][i] += sum >> qlevel;
356
        }
357
    } else {
358
        int sum;
359
        for (i = pred_order; i < s->blocksize; i++)
360
        {
361
            sum = 0;
362
            for (j = 0; j < pred_order; j++)
363
                sum += coeffs[j] * s->decoded[channel][i-j-1];
364
            s->decoded[channel][i] += sum >> qlevel;
365
        }
366 4f52c312 Michael Niedermayer
    }
367 115329f1 Diego Biurrun
368 4f52c312 Michael Niedermayer
    return 0;
369
}
370
371
static inline int decode_subframe(FLACContext *s, int channel)
372
{
373
    int type, wasted = 0;
374
    int i, tmp;
375 115329f1 Diego Biurrun
376 4f52c312 Michael Niedermayer
    s->curr_bps = s->bps;
377 ac2570a8 Michael Niedermayer
    if(channel == 0){
378 9d656110 Michael Niedermayer
        if(s->decorrelation == RIGHT_SIDE)
379 ac2570a8 Michael Niedermayer
            s->curr_bps++;
380
    }else{
381 9d656110 Michael Niedermayer
        if(s->decorrelation == LEFT_SIDE || s->decorrelation == MID_SIDE)
382 ac2570a8 Michael Niedermayer
            s->curr_bps++;
383
    }
384
385 4f52c312 Michael Niedermayer
    if (get_bits1(&s->gb))
386
    {
387 1cef211d Michael Niedermayer
        av_log(s->avctx, AV_LOG_ERROR, "invalid subframe padding\n");
388 4f52c312 Michael Niedermayer
        return -1;
389
    }
390
    type = get_bits(&s->gb, 6);
391
//    wasted = get_bits1(&s->gb);
392 115329f1 Diego Biurrun
393 4f52c312 Michael Niedermayer
//    if (wasted)
394
//    {
395
//        while (!get_bits1(&s->gb))
396
//            wasted++;
397
//        if (wasted)
398
//            wasted++;
399
//        s->curr_bps -= wasted;
400
//    }
401 ac2570a8 Michael Niedermayer
#if 0
402
    wasted= 16 - av_log2(show_bits(&s->gb, 17));
403
    skip_bits(&s->gb, wasted+1);
404
    s->curr_bps -= wasted;
405
#else
406 4f52c312 Michael Niedermayer
    if (get_bits1(&s->gb))
407
    {
408
        wasted = 1;
409
        while (!get_bits1(&s->gb))
410
            wasted++;
411
        s->curr_bps -= wasted;
412 ac2570a8 Michael Niedermayer
        av_log(s->avctx, AV_LOG_DEBUG, "%d wasted bits\n", wasted);
413 4f52c312 Michael Niedermayer
    }
414 ac2570a8 Michael Niedermayer
#endif
415
//FIXME use av_log2 for types
416 4f52c312 Michael Niedermayer
    if (type == 0)
417
    {
418 ac2570a8 Michael Niedermayer
        av_log(s->avctx, AV_LOG_DEBUG, "coding type: constant\n");
419
        tmp = get_sbits(&s->gb, s->curr_bps);
420 4f52c312 Michael Niedermayer
        for (i = 0; i < s->blocksize; i++)
421
            s->decoded[channel][i] = tmp;
422
    }
423
    else if (type == 1)
424
    {
425 ac2570a8 Michael Niedermayer
        av_log(s->avctx, AV_LOG_DEBUG, "coding type: verbatim\n");
426 4f52c312 Michael Niedermayer
        for (i = 0; i < s->blocksize; i++)
427 ac2570a8 Michael Niedermayer
            s->decoded[channel][i] = get_sbits(&s->gb, s->curr_bps);
428 4f52c312 Michael Niedermayer
    }
429
    else if ((type >= 8) && (type <= 12))
430
    {
431 9d656110 Michael Niedermayer
//        av_log(s->avctx, AV_LOG_DEBUG, "coding type: fixed\n");
432 4f52c312 Michael Niedermayer
        if (decode_subframe_fixed(s, channel, type & ~0x8) < 0)
433
            return -1;
434
    }
435
    else if (type >= 32)
436
    {
437 ac2570a8 Michael Niedermayer
//        av_log(s->avctx, AV_LOG_DEBUG, "coding type: lpc\n");
438 4f52c312 Michael Niedermayer
        if (decode_subframe_lpc(s, channel, (type & ~0x20)+1) < 0)
439
            return -1;
440
    }
441
    else
442
    {
443 1cef211d Michael Niedermayer
        av_log(s->avctx, AV_LOG_ERROR, "invalid coding type\n");
444 4f52c312 Michael Niedermayer
        return -1;
445
    }
446 115329f1 Diego Biurrun
447 4f52c312 Michael Niedermayer
    if (wasted)
448
    {
449
        int i;
450
        for (i = 0; i < s->blocksize; i++)
451
            s->decoded[channel][i] <<= wasted;
452
    }
453
454
    return 0;
455
}
456
457
static int decode_frame(FLACContext *s)
458
{
459 9d656110 Michael Niedermayer
    int blocksize_code, sample_rate_code, sample_size_code, assignment, i, crc8;
460 0496a034 Michael Niedermayer
    int decorrelation, bps, blocksize, samplerate;
461 115329f1 Diego Biurrun
462 4f52c312 Michael Niedermayer
    blocksize_code = get_bits(&s->gb, 4);
463
464
    sample_rate_code = get_bits(&s->gb, 4);
465 115329f1 Diego Biurrun
466 4f52c312 Michael Niedermayer
    assignment = get_bits(&s->gb, 4); /* channel assignment */
467 0496a034 Michael Niedermayer
    if (assignment < 8 && s->channels == assignment+1)
468
        decorrelation = INDEPENDENT;
469
    else if (assignment >=8 && assignment < 11 && s->channels == 2)
470
        decorrelation = LEFT_SIDE + assignment - 8;
471 4f52c312 Michael Niedermayer
    else
472
    {
473 1cef211d Michael Niedermayer
        av_log(s->avctx, AV_LOG_ERROR, "unsupported channel assignment %d (channels=%d)\n", assignment, s->channels);
474 4f52c312 Michael Niedermayer
        return -1;
475
    }
476 115329f1 Diego Biurrun
477 4f52c312 Michael Niedermayer
    sample_size_code = get_bits(&s->gb, 3);
478 0496a034 Michael Niedermayer
    if(sample_size_code == 0)
479
        bps= s->bps;
480
    else if((sample_size_code != 3) && (sample_size_code != 7))
481
        bps = sample_size_table[sample_size_code];
482 115329f1 Diego Biurrun
    else
483 4f52c312 Michael Niedermayer
    {
484 1cef211d Michael Niedermayer
        av_log(s->avctx, AV_LOG_ERROR, "invalid sample size code (%d)\n", sample_size_code);
485 4f52c312 Michael Niedermayer
        return -1;
486
    }
487
488
    if (get_bits1(&s->gb))
489
    {
490 1cef211d Michael Niedermayer
        av_log(s->avctx, AV_LOG_ERROR, "broken stream, invalid padding\n");
491 0496a034 Michael Niedermayer
        return -1;
492 4f52c312 Michael Niedermayer
    }
493 115329f1 Diego Biurrun
494 0496a034 Michael Niedermayer
    if(get_utf8(&s->gb) < 0){
495
        av_log(s->avctx, AV_LOG_ERROR, "utf8 fscked\n");
496
        return -1;
497
    }
498 115329f1 Diego Biurrun
#if 0
499 ac2570a8 Michael Niedermayer
    if (/*((blocksize_code == 6) || (blocksize_code == 7)) &&*/
500
        (s->min_blocksize != s->max_blocksize)){
501
    }else{
502 4f52c312 Michael Niedermayer
    }
503 0496a034 Michael Niedermayer
#endif
504 115329f1 Diego Biurrun
505 ac2570a8 Michael Niedermayer
    if (blocksize_code == 0)
506 0496a034 Michael Niedermayer
        blocksize = s->min_blocksize;
507 ac2570a8 Michael Niedermayer
    else if (blocksize_code == 6)
508 0496a034 Michael Niedermayer
        blocksize = get_bits(&s->gb, 8)+1;
509 ac2570a8 Michael Niedermayer
    else if (blocksize_code == 7)
510 0496a034 Michael Niedermayer
        blocksize = get_bits(&s->gb, 16)+1;
511 115329f1 Diego Biurrun
    else
512 0496a034 Michael Niedermayer
        blocksize = blocksize_table[blocksize_code];
513 4f52c312 Michael Niedermayer
514 0496a034 Michael Niedermayer
    if(blocksize > s->max_blocksize){
515
        av_log(s->avctx, AV_LOG_ERROR, "blocksize %d > %d\n", blocksize, s->max_blocksize);
516 ac2570a8 Michael Niedermayer
        return -1;
517
    }
518
519
    if (sample_rate_code == 0){
520 0496a034 Michael Niedermayer
        samplerate= s->samplerate;
521 ac2570a8 Michael Niedermayer
    }else if ((sample_rate_code > 3) && (sample_rate_code < 12))
522 0496a034 Michael Niedermayer
        samplerate = sample_rate_table[sample_rate_code];
523 ac2570a8 Michael Niedermayer
    else if (sample_rate_code == 12)
524 0496a034 Michael Niedermayer
        samplerate = get_bits(&s->gb, 8) * 1000;
525 ac2570a8 Michael Niedermayer
    else if (sample_rate_code == 13)
526 0496a034 Michael Niedermayer
        samplerate = get_bits(&s->gb, 16);
527 ac2570a8 Michael Niedermayer
    else if (sample_rate_code == 14)
528 0496a034 Michael Niedermayer
        samplerate = get_bits(&s->gb, 16) * 10;
529 ac2570a8 Michael Niedermayer
    else{
530
        av_log(s->avctx, AV_LOG_ERROR, "illegal sample rate code %d\n", sample_rate_code);
531
        return -1;
532 4f52c312 Michael Niedermayer
    }
533
534 9d656110 Michael Niedermayer
    skip_bits(&s->gb, 8);
535 b865838e Michael Niedermayer
    crc8= av_crc(av_crc07, 0, s->gb.buffer, get_bits_count(&s->gb)/8);
536 9d656110 Michael Niedermayer
    if(crc8){
537 160d679c Mike Melanson
        av_log(s->avctx, AV_LOG_ERROR, "header crc mismatch crc=%2X\n", crc8);
538 9d656110 Michael Niedermayer
        return -1;
539
    }
540 115329f1 Diego Biurrun
541 0496a034 Michael Niedermayer
    s->blocksize    = blocksize;
542
    s->samplerate   = samplerate;
543
    s->bps          = bps;
544
    s->decorrelation= decorrelation;
545 4f52c312 Michael Niedermayer
546 ac2570a8 Michael Niedermayer
//    dump_headers(s);
547 4f52c312 Michael Niedermayer
548
    /* subframes */
549
    for (i = 0; i < s->channels; i++)
550
    {
551 ac2570a8 Michael Niedermayer
//        av_log(s->avctx, AV_LOG_DEBUG, "decoded: %x residual: %x\n", s->decoded[i], s->residual[i]);
552 4f52c312 Michael Niedermayer
        if (decode_subframe(s, i) < 0)
553
            return -1;
554
    }
555 115329f1 Diego Biurrun
556 4f52c312 Michael Niedermayer
    align_get_bits(&s->gb);
557
558
    /* frame footer */
559
    skip_bits(&s->gb, 16); /* data crc */
560
561
    return 0;
562
}
563
564 0187178e Luca Barbato
static inline int16_t shift_to_16_bits(int32_t data, int bps)
565
{
566
    if (bps == 24) {
567
        return (data >> 8);
568
    } else if (bps == 20) {
569
        return (data >> 4);
570
    } else {
571
        return data;
572
    }
573
}
574
575 4f52c312 Michael Niedermayer
static int flac_decode_frame(AVCodecContext *avctx,
576
                            void *data, int *data_size,
577
                            uint8_t *buf, int buf_size)
578
{
579
    FLACContext *s = avctx->priv_data;
580 3f1899a8 Mike Melanson
    int tmp = 0, i, j = 0, input_buf_size = 0;
581
    int16_t *samples = data;
582 4f52c312 Michael Niedermayer
583 ac2570a8 Michael Niedermayer
    if(s->max_framesize == 0){
584 09f20d37 Loren Merritt
        s->max_framesize= 65536; // should hopefully be enough for the first header
585 ac2570a8 Michael Niedermayer
        s->bitstream= av_fast_realloc(s->bitstream, &s->allocated_bitstream_size, s->max_framesize);
586
    }
587
588
    if(1 && s->max_framesize){//FIXME truncated
589 09f20d37 Loren Merritt
            buf_size= FFMAX(FFMIN(buf_size, s->max_framesize - s->bitstream_size), 0);
590 ac2570a8 Michael Niedermayer
            input_buf_size= buf_size;
591
592
            if(s->bitstream_index + s->bitstream_size + buf_size > s->allocated_bitstream_size){
593
//                printf("memmove\n");
594
                memmove(s->bitstream, &s->bitstream[s->bitstream_index], s->bitstream_size);
595
                s->bitstream_index=0;
596
            }
597
            memcpy(&s->bitstream[s->bitstream_index + s->bitstream_size], buf, buf_size);
598
            buf= &s->bitstream[s->bitstream_index];
599
            buf_size += s->bitstream_size;
600
            s->bitstream_size= buf_size;
601 115329f1 Diego Biurrun
602 ac2570a8 Michael Niedermayer
            if(buf_size < s->max_framesize){
603
//                printf("wanna more data ...\n");
604
                return input_buf_size;
605
            }
606
    }
607 4f52c312 Michael Niedermayer
608
    init_get_bits(&s->gb, buf, buf_size*8);
609 115329f1 Diego Biurrun
610 17c90b9d Aurelien Jacobs
    if (!metadata_parse(s))
611 4f52c312 Michael Niedermayer
    {
612 9d656110 Michael Niedermayer
        tmp = show_bits(&s->gb, 16);
613 ac2570a8 Michael Niedermayer
        if(tmp != 0xFFF8){
614
            av_log(s->avctx, AV_LOG_ERROR, "FRAME HEADER not here\n");
615
            while(get_bits_count(&s->gb)/8+2 < buf_size && show_bits(&s->gb, 16) != 0xFFF8)
616
                skip_bits(&s->gb, 8);
617
            goto end; // we may not have enough bits left to decode a frame, so try next time
618
        }
619
        skip_bits(&s->gb, 16);
620 9d656110 Michael Niedermayer
        if (decode_frame(s) < 0){
621
            av_log(s->avctx, AV_LOG_ERROR, "decode_frame() failed\n");
622
            s->bitstream_size=0;
623
            s->bitstream_index=0;
624 4f52c312 Michael Niedermayer
            return -1;
625 9d656110 Michael Niedermayer
        }
626 4f52c312 Michael Niedermayer
    }
627 ac2570a8 Michael Niedermayer
628 115329f1 Diego Biurrun
629 4f52c312 Michael Niedermayer
#if 0
630
    /* fix the channel order here */
631
    if (s->order == MID_SIDE)
632
    {
633
        short *left = samples;
634
        short *right = samples + s->blocksize;
635
        for (i = 0; i < s->blocksize; i += 2)
636
        {
637
            uint32_t x = s->decoded[0][i];
638
            uint32_t y = s->decoded[0][i+1];
639

640
            right[i] = x - (y / 2);
641
            left[i] = right[i] + y;
642
        }
643
        *data_size = 2 * s->blocksize;
644
    }
645
    else
646
    {
647
    for (i = 0; i < s->channels; i++)
648
    {
649
        switch(s->order)
650
        {
651
            case INDEPENDENT:
652
                for (j = 0; j < s->blocksize; j++)
653
                    samples[(s->blocksize*i)+j] = s->decoded[i][j];
654
                break;
655
            case LEFT_SIDE:
656
            case RIGHT_SIDE:
657
                if (i == 0)
658
                    for (j = 0; j < s->blocksize; j++)
659
                        samples[(s->blocksize*i)+j] = s->decoded[0][j];
660
                else
661
                    for (j = 0; j < s->blocksize; j++)
662
                        samples[(s->blocksize*i)+j] = s->decoded[0][j] - s->decoded[i][j];
663
                break;
664
//            case MID_SIDE:
665 ac2570a8 Michael Niedermayer
//                av_log(s->avctx, AV_LOG_DEBUG, "mid-side unsupported\n");
666 4f52c312 Michael Niedermayer
        }
667
        *data_size += s->blocksize;
668
    }
669
    }
670
#else
671 c448303d Michael Niedermayer
#define DECORRELATE(left, right)\
672
            assert(s->channels == 2);\
673
            for (i = 0; i < s->blocksize; i++)\
674
            {\
675
                int a= s->decoded[0][i];\
676
                int b= s->decoded[1][i];\
677
                *(samples++) = (left ) >> (16 - s->bps);\
678
                *(samples++) = (right) >> (16 - s->bps);\
679
            }\
680
            break;
681
682 9d656110 Michael Niedermayer
    switch(s->decorrelation)
683 4f52c312 Michael Niedermayer
    {
684
        case INDEPENDENT:
685 ac2570a8 Michael Niedermayer
            for (j = 0; j < s->blocksize; j++)
686 4f52c312 Michael Niedermayer
            {
687 ac2570a8 Michael Niedermayer
                for (i = 0; i < s->channels; i++)
688 0187178e Luca Barbato
                    *(samples++) = shift_to_16_bits(s->decoded[i][j], s->bps);
689 4f52c312 Michael Niedermayer
            }
690
            break;
691
        case LEFT_SIDE:
692 c448303d Michael Niedermayer
            DECORRELATE(a,a-b)
693 4f52c312 Michael Niedermayer
        case RIGHT_SIDE:
694 c448303d Michael Niedermayer
            DECORRELATE(a+b,b)
695 4f52c312 Michael Niedermayer
        case MID_SIDE:
696 c448303d Michael Niedermayer
            DECORRELATE( (a-=b>>1) + b, a)
697 4f52c312 Michael Niedermayer
    }
698
#endif
699
700 ac2570a8 Michael Niedermayer
    *data_size = (int8_t *)samples - (int8_t *)data;
701 9d656110 Michael Niedermayer
//    av_log(s->avctx, AV_LOG_DEBUG, "data size: %d\n", *data_size);
702 4f52c312 Michael Niedermayer
703 ac2570a8 Michael Niedermayer
//    s->last_blocksize = s->blocksize;
704
end:
705
    i= (get_bits_count(&s->gb)+7)/8;;
706
    if(i > buf_size){
707
        av_log(s->avctx, AV_LOG_ERROR, "overread: %d\n", i - buf_size);
708 9d656110 Michael Niedermayer
        s->bitstream_size=0;
709
        s->bitstream_index=0;
710 ac2570a8 Michael Niedermayer
        return -1;
711
    }
712 4f52c312 Michael Niedermayer
713 ac2570a8 Michael Niedermayer
    if(s->bitstream_size){
714
        s->bitstream_index += i;
715
        s->bitstream_size  -= i;
716
        return input_buf_size;
717 115329f1 Diego Biurrun
    }else
718 ac2570a8 Michael Niedermayer
        return i;
719 4f52c312 Michael Niedermayer
}
720
721
static int flac_decode_close(AVCodecContext *avctx)
722
{
723
    FLACContext *s = avctx->priv_data;
724
    int i;
725 115329f1 Diego Biurrun
726 4f52c312 Michael Niedermayer
    for (i = 0; i < s->channels; i++)
727
    {
728 ac2570a8 Michael Niedermayer
        av_freep(&s->decoded[i]);
729 4f52c312 Michael Niedermayer
    }
730 ac2570a8 Michael Niedermayer
    av_freep(&s->bitstream);
731 115329f1 Diego Biurrun
732 4f52c312 Michael Niedermayer
    return 0;
733
}
734
735 1e31d32c Michael Niedermayer
static void flac_flush(AVCodecContext *avctx){
736
    FLACContext *s = avctx->priv_data;
737
738
    s->bitstream_size=
739
    s->bitstream_index= 0;
740
}
741
742 4f52c312 Michael Niedermayer
AVCodec flac_decoder = {
743
    "flac",
744
    CODEC_TYPE_AUDIO,
745
    CODEC_ID_FLAC,
746
    sizeof(FLACContext),
747
    flac_decode_init,
748
    NULL,
749
    flac_decode_close,
750
    flac_decode_frame,
751 115329f1 Diego Biurrun
    .flush= flac_flush,
752 4f52c312 Michael Niedermayer
};