flacdec: cosmetics: indentation
[libav.git] / libavcodec / flacdec.c
CommitLineData
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1/*
2 * FLAC (Free Lossless Audio Codec) decoder
3 * Copyright (c) 2003 Alex Beregszaszi
4 *
b78e7197
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5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
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8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
b78e7197 10 * version 2.1 of the License, or (at your option) any later version.
4f52c312 11 *
b78e7197 12 * FFmpeg is distributed in the hope that it will be useful,
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13 * 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
b78e7197 18 * License along with FFmpeg; if not, write to the Free Software
5509bffa 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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20 */
21
22/**
8f51144b 23 * @file flacdec.c
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24 * FLAC (Free Lossless Audio Codec) decoder
25 * @author Alex Beregszaszi
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26 *
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.
4f52c312 34 */
115329f1 35
ac2570a8 36#include <limits.h>
115329f1 37
75c998a2 38#define ALT_BITSTREAM_READER
245976da 39#include "libavutil/crc.h"
4f52c312 40#include "avcodec.h"
caa336b4 41#include "bitstream.h"
4f52c312 42#include "golomb.h"
9d48410f 43#include "flac.h"
4f52c312 44
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45#undef NDEBUG
46#include <assert.h>
47
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48#define MAX_CHANNELS 8
49#define MAX_BLOCKSIZE 65535
9eda2f94 50#define FLAC_STREAMINFO_SIZE 34
4f52c312 51
9d656110 52enum decorrelation_type {
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53 INDEPENDENT,
54 LEFT_SIDE,
55 RIGHT_SIDE,
56 MID_SIDE,
57};
58
59typedef struct FLACContext {
9d48410f
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60 FLACSTREAMINFO
61
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62 AVCodecContext *avctx;
63 GetBitContext gb;
64
ac2570a8 65 int blocksize/*, last_blocksize*/;
9d48410f 66 int curr_bps;
9d656110 67 enum decorrelation_type decorrelation;
4f52c312 68
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69 int32_t *decoded[MAX_CHANNELS];
70 uint8_t *bitstream;
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71 unsigned int bitstream_size;
72 unsigned int bitstream_index;
f038fe8b 73 unsigned int allocated_bitstream_size;
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74} FLACContext;
75
76#define METADATA_TYPE_STREAMINFO 0
77
cf2baeb3 78static const int sample_rate_table[] =
959e0006
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79{ 0,
80 88200, 176400, 192000,
4f52c312 81 8000, 16000, 22050, 24000, 32000, 44100, 48000, 96000,
115329f1 82 0, 0, 0, 0 };
4f52c312 83
cf2baeb3 84static const int sample_size_table[] =
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85{ 0, 8, 12, 0, 16, 20, 24, 0 };
86
cf2baeb3 87static const int blocksize_table[] = {
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88 0, 192, 576<<0, 576<<1, 576<<2, 576<<3, 0, 0,
89256<<0, 256<<1, 256<<2, 256<<3, 256<<4, 256<<5, 256<<6, 256<<7
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90};
91
1bec121f
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92static int64_t get_utf8(GetBitContext *gb)
93{
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94 int64_t val;
95 GET_UTF8(val, get_bits(gb, 8), return -1;)
ac2570a8 96 return val;
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97}
98
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99static void allocate_buffers(FLACContext *s);
100static int metadata_parse(FLACContext *s);
9eda2f94 101
1bec121f 102static av_cold int flac_decode_init(AVCodecContext *avctx)
4f52c312 103{
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104 FLACContext *s = avctx->priv_data;
105 s->avctx = avctx;
106
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107 if (avctx->extradata_size > 4) {
108 /* initialize based on the demuxer-supplied streamdata header */
17c90b9d 109 if (avctx->extradata_size == FLAC_STREAMINFO_SIZE) {
9482171b 110 ff_flac_parse_streaminfo(avctx, (FLACStreaminfo *)s, avctx->extradata);
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111 allocate_buffers(s);
112 } else {
512b37bb 113 init_get_bits(&s->gb, avctx->extradata, avctx->extradata_size*8);
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114 metadata_parse(s);
115 }
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116 }
117
fd76c37f 118 avctx->sample_fmt = SAMPLE_FMT_S16;
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119 return 0;
120}
121
9482171b 122static void dump_headers(AVCodecContext *avctx, FLACStreaminfo *s)
4f52c312 123{
9482171b 124 av_log(avctx, AV_LOG_DEBUG, " Blocksize: %d .. %d\n", s->min_blocksize, s->max_blocksize);
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125 av_log(avctx, AV_LOG_DEBUG, " Max Framesize: %d\n", s->max_framesize);
126 av_log(avctx, AV_LOG_DEBUG, " Samplerate: %d\n", s->samplerate);
127 av_log(avctx, AV_LOG_DEBUG, " Channels: %d\n", s->channels);
128 av_log(avctx, AV_LOG_DEBUG, " Bits: %d\n", s->bps);
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129}
130
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131static void allocate_buffers(FLACContext *s)
132{
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133 int i;
134
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135 assert(s->max_blocksize);
136
1bec121f 137 if (s->max_framesize == 0 && s->max_blocksize) {
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138 s->max_framesize= (s->channels * s->bps * s->max_blocksize + 7)/ 8; //FIXME header overhead
139 }
140
1bec121f 141 for (i = 0; i < s->channels; i++) {
ac2570a8 142 s->decoded[i] = av_realloc(s->decoded[i], sizeof(int32_t)*s->max_blocksize);
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143 }
144
1bec121f 145 if (s->allocated_bitstream_size < s->max_framesize)
cfcd396b 146 s->bitstream= av_fast_realloc(s->bitstream, &s->allocated_bitstream_size, s->max_framesize);
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147}
148
9482171b
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149void ff_flac_parse_streaminfo(AVCodecContext *avctx, struct FLACStreaminfo *s,
150 const uint8_t *buffer)
ac2570a8 151{
a128cc91
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152 GetBitContext gb;
153 init_get_bits(&gb, buffer, FLAC_STREAMINFO_SIZE*8);
154
4f52c312 155 /* mandatory streaminfo */
a128cc91
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156 s->min_blocksize = get_bits(&gb, 16);
157 s->max_blocksize = get_bits(&gb, 16);
4f52c312 158
a128cc91
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159 skip_bits(&gb, 24); /* skip min frame size */
160 s->max_framesize = get_bits_long(&gb, 24);
115329f1 161
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162 s->samplerate = get_bits_long(&gb, 20);
163 s->channels = get_bits(&gb, 3) + 1;
164 s->bps = get_bits(&gb, 5) + 1;
115329f1 165
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166 avctx->channels = s->channels;
167 avctx->sample_rate = s->samplerate;
4f52c312 168
a128cc91 169 skip_bits(&gb, 36); /* total num of samples */
115329f1 170
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171 skip_bits(&gb, 64); /* md5 sum */
172 skip_bits(&gb, 64); /* md5 sum */
115329f1 173
4bc07e78 174 dump_headers(avctx, s);
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175}
176
177/**
178 * Parse a list of metadata blocks. This list of blocks must begin with
179 * the fLaC marker.
180 * @param s the flac decoding context containing the gb bit reader used to
181 * parse metadata
182 * @return 1 if some metadata was read, 0 if no fLaC marker was found
183 */
184static int metadata_parse(FLACContext *s)
185{
186 int i, metadata_last, metadata_type, metadata_size, streaminfo_updated=0;
e0168e3b 187 int initial_pos= get_bits_count(&s->gb);
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188
189 if (show_bits_long(&s->gb, 32) == MKBETAG('f','L','a','C')) {
190 skip_bits(&s->gb, 32);
191
17c90b9d 192 do {
5fc32c27 193 metadata_last = get_bits1(&s->gb);
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194 metadata_type = get_bits(&s->gb, 7);
195 metadata_size = get_bits_long(&s->gb, 24);
196
1bec121f 197 if (get_bits_count(&s->gb) + 8*metadata_size > s->gb.size_in_bits) {
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198 skip_bits_long(&s->gb, initial_pos - get_bits_count(&s->gb));
199 break;
200 }
201
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202 if (metadata_size) {
203 switch (metadata_type) {
204 case METADATA_TYPE_STREAMINFO:
9482171b 205 ff_flac_parse_streaminfo(s->avctx, (FLACStreaminfo *)s, s->gb.buffer+get_bits_count(&s->gb)/8);
17c90b9d 206 streaminfo_updated = 1;
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207
208 default:
1bec121f 209 for (i = 0; i < metadata_size; i++)
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210 skip_bits(&s->gb, 8);
211 }
212 }
213 } while (!metadata_last);
214
215 if (streaminfo_updated)
216 allocate_buffers(s);
217 return 1;
218 }
219 return 0;
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220}
221
222static int decode_residuals(FLACContext *s, int channel, int pred_order)
223{
224 int i, tmp, partition, method_type, rice_order;
225 int sample = 0, samples;
226
227 method_type = get_bits(&s->gb, 2);
1bec121f 228 if (method_type > 1) {
5305f40b 229 av_log(s->avctx, AV_LOG_ERROR, "illegal residual coding method %d\n", method_type);
4f52c312 230 return -1;
ac2570a8 231 }
115329f1 232
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233 rice_order = get_bits(&s->gb, 4);
234
ac2570a8 235 samples= s->blocksize >> rice_order;
5484dad7
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236 if (pred_order > samples) {
237 av_log(s->avctx, AV_LOG_ERROR, "invalid predictor order: %i > %i\n", pred_order, samples);
238 return -1;
239 }
4f52c312 240
115329f1 241 sample=
ac2570a8 242 i= pred_order;
1bec121f 243 for (partition = 0; partition < (1 << rice_order); partition++) {
e471443a 244 tmp = get_bits(&s->gb, method_type == 0 ? 4 : 5);
1bec121f 245 if (tmp == (method_type == 0 ? 15 : 31)) {
4f52c312 246 tmp = get_bits(&s->gb, 5);
4f52c312 247 for (; i < samples; i++, sample++)
4fd12598 248 s->decoded[channel][sample] = get_sbits(&s->gb, tmp);
1bec121f
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249 } else {
250 for (; i < samples; i++, sample++) {
4fd12598 251 s->decoded[channel][sample] = get_sr_golomb_flac(&s->gb, tmp, INT_MAX, 0);
ac2570a8 252 }
4f52c312 253 }
ac2570a8 254 i= 0;
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255 }
256
4f52c312 257 return 0;
115329f1 258}
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259
260static int decode_subframe_fixed(FLACContext *s, int channel, int pred_order)
261{
08965b22
LM
262 const int blocksize = s->blocksize;
263 int32_t *decoded = s->decoded[channel];
264 int a, b, c, d, i;
115329f1 265
4f52c312 266 /* warm up samples */
1bec121f 267 for (i = 0; i < pred_order; i++) {
08965b22 268 decoded[i] = get_sbits(&s->gb, s->curr_bps);
4f52c312 269 }
115329f1 270
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271 if (decode_residuals(s, channel, pred_order) < 0)
272 return -1;
273
1bec121f 274 if (pred_order > 0)
1f4fa6a4 275 a = decoded[pred_order-1];
1bec121f 276 if (pred_order > 1)
1f4fa6a4 277 b = a - decoded[pred_order-2];
1bec121f 278 if (pred_order > 2)
1f4fa6a4 279 c = b - decoded[pred_order-2] + decoded[pred_order-3];
1bec121f 280 if (pred_order > 3)
1f4fa6a4 281 d = c - decoded[pred_order-2] + 2*decoded[pred_order-3] - decoded[pred_order-4];
08965b22 282
1bec121f
JR
283 switch (pred_order) {
284 case 0:
285 break;
286 case 1:
287 for (i = pred_order; i < blocksize; i++)
288 decoded[i] = a += decoded[i];
289 break;
290 case 2:
291 for (i = pred_order; i < blocksize; i++)
292 decoded[i] = a += b += decoded[i];
293 break;
294 case 3:
295 for (i = pred_order; i < blocksize; i++)
296 decoded[i] = a += b += c += decoded[i];
297 break;
298 case 4:
299 for (i = pred_order; i < blocksize; i++)
300 decoded[i] = a += b += c += d += decoded[i];
301 break;
302 default:
303 av_log(s->avctx, AV_LOG_ERROR, "illegal pred order %d\n", pred_order);
304 return -1;
4f52c312 305 }
ac2570a8 306
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307 return 0;
308}
309
310static int decode_subframe_lpc(FLACContext *s, int channel, int pred_order)
311{
0187178e 312 int i, j;
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313 int coeff_prec, qlevel;
314 int coeffs[pred_order];
d1a5c421 315 int32_t *decoded = s->decoded[channel];
115329f1 316
4f52c312 317 /* warm up samples */
1bec121f 318 for (i = 0; i < pred_order; i++) {
d1a5c421 319 decoded[i] = get_sbits(&s->gb, s->curr_bps);
4f52c312 320 }
115329f1 321
4f52c312 322 coeff_prec = get_bits(&s->gb, 4) + 1;
1bec121f 323 if (coeff_prec == 16) {
5305f40b 324 av_log(s->avctx, AV_LOG_ERROR, "invalid coeff precision\n");
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325 return -1;
326 }
ac2570a8 327 qlevel = get_sbits(&s->gb, 5);
1bec121f 328 if (qlevel < 0) {
5305f40b 329 av_log(s->avctx, AV_LOG_ERROR, "qlevel %d not supported, maybe buggy stream\n", qlevel);
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330 return -1;
331 }
332
1bec121f 333 for (i = 0; i < pred_order; i++) {
ac2570a8 334 coeffs[i] = get_sbits(&s->gb, coeff_prec);
4f52c312 335 }
115329f1 336
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337 if (decode_residuals(s, channel, pred_order) < 0)
338 return -1;
339
0187178e
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340 if (s->bps > 16) {
341 int64_t sum;
1bec121f 342 for (i = pred_order; i < s->blocksize; i++) {
0187178e
LB
343 sum = 0;
344 for (j = 0; j < pred_order; j++)
d1a5c421
LM
345 sum += (int64_t)coeffs[j] * decoded[i-j-1];
346 decoded[i] += sum >> qlevel;
0187178e
LB
347 }
348 } else {
1bec121f 349 for (i = pred_order; i < s->blocksize-1; i += 2) {
d1a5c421
LM
350 int c;
351 int d = decoded[i-pred_order];
352 int s0 = 0, s1 = 0;
1bec121f 353 for (j = pred_order-1; j > 0; j--) {
d1a5c421 354 c = coeffs[j];
bd49d4fd 355 s0 += c*d;
d1a5c421
LM
356 d = decoded[i-j];
357 s1 += c*d;
bd49d4fd 358 }
d1a5c421
LM
359 c = coeffs[0];
360 s0 += c*d;
361 d = decoded[i] += s0 >> qlevel;
362 s1 += c*d;
363 decoded[i+1] += s1 >> qlevel;
bd49d4fd 364 }
1bec121f 365 if (i < s->blocksize) {
bd49d4fd 366 int sum = 0;
0187178e 367 for (j = 0; j < pred_order; j++)
d1a5c421
LM
368 sum += coeffs[j] * decoded[i-j-1];
369 decoded[i] += sum >> qlevel;
0187178e 370 }
4f52c312 371 }
115329f1 372
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373 return 0;
374}
375
376static inline int decode_subframe(FLACContext *s, int channel)
377{
378 int type, wasted = 0;
379 int i, tmp;
115329f1 380
4f52c312 381 s->curr_bps = s->bps;
1bec121f
JR
382 if (channel == 0) {
383 if (s->decorrelation == RIGHT_SIDE)
ac2570a8 384 s->curr_bps++;
1bec121f
JR
385 } else {
386 if (s->decorrelation == LEFT_SIDE || s->decorrelation == MID_SIDE)
ac2570a8
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387 s->curr_bps++;
388 }
389
1bec121f 390 if (get_bits1(&s->gb)) {
1cef211d 391 av_log(s->avctx, AV_LOG_ERROR, "invalid subframe padding\n");
4f52c312
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392 return -1;
393 }
394 type = get_bits(&s->gb, 6);
c5706efd 395
1bec121f 396 if (get_bits1(&s->gb)) {
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397 wasted = 1;
398 while (!get_bits1(&s->gb))
399 wasted++;
400 s->curr_bps -= wasted;
401 }
c5706efd 402
ac2570a8 403//FIXME use av_log2 for types
1bec121f 404 if (type == 0) {
ac2570a8 405 tmp = get_sbits(&s->gb, s->curr_bps);
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MN
406 for (i = 0; i < s->blocksize; i++)
407 s->decoded[channel][i] = tmp;
1bec121f 408 } else if (type == 1) {
4f52c312 409 for (i = 0; i < s->blocksize; i++)
ac2570a8 410 s->decoded[channel][i] = get_sbits(&s->gb, s->curr_bps);
1bec121f 411 } else if ((type >= 8) && (type <= 12)) {
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412 if (decode_subframe_fixed(s, channel, type & ~0x8) < 0)
413 return -1;
1bec121f 414 } else if (type >= 32) {
4f52c312
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415 if (decode_subframe_lpc(s, channel, (type & ~0x20)+1) < 0)
416 return -1;
1bec121f 417 } else {
1cef211d 418 av_log(s->avctx, AV_LOG_ERROR, "invalid coding type\n");
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MN
419 return -1;
420 }
115329f1 421
1bec121f 422 if (wasted) {
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423 int i;
424 for (i = 0; i < s->blocksize; i++)
425 s->decoded[channel][i] <<= wasted;
426 }
427
428 return 0;
429}
430
ac66834c 431static int decode_frame(FLACContext *s, int alloc_data_size)
4f52c312 432{
9d656110 433 int blocksize_code, sample_rate_code, sample_size_code, assignment, i, crc8;
0496a034 434 int decorrelation, bps, blocksize, samplerate;
115329f1 435
4f52c312 436 blocksize_code = get_bits(&s->gb, 4);
4f52c312
MN
437
438 sample_rate_code = get_bits(&s->gb, 4);
115329f1 439
4f52c312 440 assignment = get_bits(&s->gb, 4); /* channel assignment */
0496a034
MN
441 if (assignment < 8 && s->channels == assignment+1)
442 decorrelation = INDEPENDENT;
443 else if (assignment >=8 && assignment < 11 && s->channels == 2)
444 decorrelation = LEFT_SIDE + assignment - 8;
1bec121f 445 else {
1cef211d 446 av_log(s->avctx, AV_LOG_ERROR, "unsupported channel assignment %d (channels=%d)\n", assignment, s->channels);
4f52c312
MN
447 return -1;
448 }
115329f1 449
4f52c312 450 sample_size_code = get_bits(&s->gb, 3);
1bec121f 451 if (sample_size_code == 0)
0496a034 452 bps= s->bps;
1bec121f 453 else if ((sample_size_code != 3) && (sample_size_code != 7))
0496a034 454 bps = sample_size_table[sample_size_code];
1bec121f 455 else {
1cef211d 456 av_log(s->avctx, AV_LOG_ERROR, "invalid sample size code (%d)\n", sample_size_code);
4f52c312
MN
457 return -1;
458 }
459
1bec121f 460 if (get_bits1(&s->gb)) {
1cef211d 461 av_log(s->avctx, AV_LOG_ERROR, "broken stream, invalid padding\n");
0496a034 462 return -1;
4f52c312 463 }
115329f1 464
1bec121f 465 if (get_utf8(&s->gb) < 0) {
0496a034
MN
466 av_log(s->avctx, AV_LOG_ERROR, "utf8 fscked\n");
467 return -1;
468 }
115329f1 469
ac2570a8 470 if (blocksize_code == 0)
0496a034 471 blocksize = s->min_blocksize;
ac2570a8 472 else if (blocksize_code == 6)
0496a034 473 blocksize = get_bits(&s->gb, 8)+1;
ac2570a8 474 else if (blocksize_code == 7)
0496a034 475 blocksize = get_bits(&s->gb, 16)+1;
115329f1 476 else
0496a034 477 blocksize = blocksize_table[blocksize_code];
4f52c312 478
1bec121f 479 if (blocksize > s->max_blocksize) {
0496a034 480 av_log(s->avctx, AV_LOG_ERROR, "blocksize %d > %d\n", blocksize, s->max_blocksize);
ac2570a8
MN
481 return -1;
482 }
483
1bec121f 484 if (blocksize * s->channels * sizeof(int16_t) > alloc_data_size)
ac66834c
MN
485 return -1;
486
1bec121f 487 if (sample_rate_code == 0)
0496a034 488 samplerate= s->samplerate;
1bec121f 489 else if (sample_rate_code < 12)
0496a034 490 samplerate = sample_rate_table[sample_rate_code];
ac2570a8 491 else if (sample_rate_code == 12)
0496a034 492 samplerate = get_bits(&s->gb, 8) * 1000;
ac2570a8 493 else if (sample_rate_code == 13)
0496a034 494 samplerate = get_bits(&s->gb, 16);
ac2570a8 495 else if (sample_rate_code == 14)
0496a034 496 samplerate = get_bits(&s->gb, 16) * 10;
1bec121f 497 else {
ac2570a8
MN
498 av_log(s->avctx, AV_LOG_ERROR, "illegal sample rate code %d\n", sample_rate_code);
499 return -1;
4f52c312
MN
500 }
501
9d656110 502 skip_bits(&s->gb, 8);
3abe5fbd
AJ
503 crc8 = av_crc(av_crc_get_table(AV_CRC_8_ATM), 0,
504 s->gb.buffer, get_bits_count(&s->gb)/8);
1bec121f 505 if (crc8) {
160d679c 506 av_log(s->avctx, AV_LOG_ERROR, "header crc mismatch crc=%2X\n", crc8);
9d656110
MN
507 return -1;
508 }
115329f1 509
0496a034
MN
510 s->blocksize = blocksize;
511 s->samplerate = samplerate;
512 s->bps = bps;
513 s->decorrelation= decorrelation;
4f52c312 514
9482171b 515// dump_headers(s->avctx, (FLACStreaminfo *)s);
4f52c312
MN
516
517 /* subframes */
1bec121f 518 for (i = 0; i < s->channels; i++) {
4f52c312
MN
519 if (decode_subframe(s, i) < 0)
520 return -1;
521 }
115329f1 522
4f52c312
MN
523 align_get_bits(&s->gb);
524
525 /* frame footer */
526 skip_bits(&s->gb, 16); /* data crc */
527
528 return 0;
529}
530
531static int flac_decode_frame(AVCodecContext *avctx,
532 void *data, int *data_size,
1545c5e5 533 const uint8_t *buf, int buf_size)
4f52c312
MN
534{
535 FLACContext *s = avctx->priv_data;
3f1899a8
MM
536 int tmp = 0, i, j = 0, input_buf_size = 0;
537 int16_t *samples = data;
ac66834c
MN
538 int alloc_data_size= *data_size;
539
540 *data_size=0;
4f52c312 541
1bec121f 542 if (s->max_framesize == 0) {
d3ce0792 543 s->max_framesize= FFMAX(4, buf_size); // should hopefully be enough for the first header
ac2570a8
MN
544 s->bitstream= av_fast_realloc(s->bitstream, &s->allocated_bitstream_size, s->max_framesize);
545 }
546
1bec121f 547 if (1 && s->max_framesize) { //FIXME truncated
1df0390e
JR
548 if (s->bitstream_size < 4 || AV_RL32(s->bitstream) != MKTAG('f','L','a','C'))
549 buf_size= FFMIN(buf_size, s->max_framesize - FFMIN(s->bitstream_size, s->max_framesize));
550 input_buf_size= buf_size;
ac2570a8 551
1df0390e
JR
552 if (s->bitstream_size + buf_size < buf_size || s->bitstream_index + s->bitstream_size + buf_size < s->bitstream_index)
553 return -1;
e0168e3b 554
1df0390e
JR
555 if (s->allocated_bitstream_size < s->bitstream_size + buf_size)
556 s->bitstream= av_fast_realloc(s->bitstream, &s->allocated_bitstream_size, s->bitstream_size + buf_size);
e0168e3b 557
1df0390e
JR
558 if (s->bitstream_index + s->bitstream_size + buf_size > s->allocated_bitstream_size) {
559 memmove(s->bitstream, &s->bitstream[s->bitstream_index], s->bitstream_size);
560 s->bitstream_index=0;
561 }
562 memcpy(&s->bitstream[s->bitstream_index + s->bitstream_size], buf, buf_size);
563 buf= &s->bitstream[s->bitstream_index];
564 buf_size += s->bitstream_size;
565 s->bitstream_size= buf_size;
115329f1 566
1df0390e
JR
567 if (buf_size < s->max_framesize && input_buf_size) {
568 return input_buf_size;
569 }
ac2570a8 570 }
4f52c312
MN
571
572 init_get_bits(&s->gb, buf, buf_size*8);
115329f1 573
1bec121f 574 if (metadata_parse(s))
2b4b8c82
MN
575 goto end;
576
13de8a08 577 tmp = show_bits(&s->gb, 16);
1bec121f 578 if ((tmp & 0xFFFE) != 0xFFF8) {
13de8a08 579 av_log(s->avctx, AV_LOG_ERROR, "FRAME HEADER not here\n");
1bec121f 580 while (get_bits_count(&s->gb)/8+2 < buf_size && (show_bits(&s->gb, 16) & 0xFFFE) != 0xFFF8)
13de8a08
JR
581 skip_bits(&s->gb, 8);
582 goto end; // we may not have enough bits left to decode a frame, so try next time
583 }
584 skip_bits(&s->gb, 16);
1bec121f 585 if (decode_frame(s, alloc_data_size) < 0) {
13de8a08
JR
586 av_log(s->avctx, AV_LOG_ERROR, "decode_frame() failed\n");
587 s->bitstream_size=0;
588 s->bitstream_index=0;
589 return -1;
590 }
ac2570a8 591
c448303d
MN
592#define DECORRELATE(left, right)\
593 assert(s->channels == 2);\
1bec121f 594 for (i = 0; i < s->blocksize; i++) {\
c448303d
MN
595 int a= s->decoded[0][i];\
596 int b= s->decoded[1][i];\
71fd1225
BF
597 *samples++ = ((left) << (24 - s->bps)) >> 8;\
598 *samples++ = ((right) << (24 - s->bps)) >> 8;\
c448303d
MN
599 }\
600 break;
601
1bec121f
JR
602 switch (s->decorrelation) {
603 case INDEPENDENT:
604 for (j = 0; j < s->blocksize; j++) {
605 for (i = 0; i < s->channels; i++)
606 *samples++ = (s->decoded[i][j] << (24 - s->bps)) >> 8;
607 }
608 break;
609 case LEFT_SIDE:
610 DECORRELATE(a,a-b)
611 case RIGHT_SIDE:
612 DECORRELATE(a+b,b)
613 case MID_SIDE:
614 DECORRELATE( (a-=b>>1) + b, a)
4f52c312 615 }
4f52c312 616
ac2570a8 617 *data_size = (int8_t *)samples - (int8_t *)data;
4f52c312 618
ac2570a8 619end:
cea96420 620 i= (get_bits_count(&s->gb)+7)/8;
1bec121f 621 if (i > buf_size) {
ac2570a8 622 av_log(s->avctx, AV_LOG_ERROR, "overread: %d\n", i - buf_size);
9d656110
MN
623 s->bitstream_size=0;
624 s->bitstream_index=0;
ac2570a8
MN
625 return -1;
626 }
4f52c312 627
1bec121f 628 if (s->bitstream_size) {
ac2570a8
MN
629 s->bitstream_index += i;
630 s->bitstream_size -= i;
631 return input_buf_size;
1bec121f 632 } else
ac2570a8 633 return i;
4f52c312
MN
634}
635
98a6fff9 636static av_cold int flac_decode_close(AVCodecContext *avctx)
4f52c312
MN
637{
638 FLACContext *s = avctx->priv_data;
639 int i;
115329f1 640
1bec121f 641 for (i = 0; i < s->channels; i++) {
ac2570a8 642 av_freep(&s->decoded[i]);
4f52c312 643 }
ac2570a8 644 av_freep(&s->bitstream);
115329f1 645
4f52c312
MN
646 return 0;
647}
648
1bec121f
JR
649static void flac_flush(AVCodecContext *avctx)
650{
1e31d32c
MN
651 FLACContext *s = avctx->priv_data;
652
653 s->bitstream_size=
654 s->bitstream_index= 0;
655}
656
4f52c312
MN
657AVCodec flac_decoder = {
658 "flac",
659 CODEC_TYPE_AUDIO,
660 CODEC_ID_FLAC,
661 sizeof(FLACContext),
662 flac_decode_init,
663 NULL,
664 flac_decode_close,
665 flac_decode_frame,
4c453ddb 666 CODEC_CAP_DELAY,
115329f1 667 .flush= flac_flush,
fe4bf374 668 .long_name= NULL_IF_CONFIG_SMALL("FLAC (Free Lossless Audio Codec)"),
4f52c312 669};