Libav
alac.c
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1 /*
2  * ALAC (Apple Lossless Audio Codec) decoder
3  * Copyright (c) 2005 David Hammerton
4  *
5  * This file is part of Libav.
6  *
7  * Libav is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * Libav is distributed in the hope that it will be useful,
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
18  * License along with Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
48 #include <inttypes.h>
49 
50 #include "libavutil/channel_layout.h"
51 #include "avcodec.h"
52 #include "get_bits.h"
53 #include "bytestream.h"
54 #include "internal.h"
55 #include "unary.h"
56 #include "mathops.h"
57 #include "alac_data.h"
58 
59 #define ALAC_EXTRADATA_SIZE 36
60 
61 typedef struct {
64  int channels;
65 
66  int32_t *predict_error_buffer[2];
67  int32_t *output_samples_buffer[2];
68  int32_t *extra_bits_buffer[2];
69 
75 
76  int extra_bits;
77  int nb_samples;
78 } ALACContext;
79 
80 static inline unsigned int decode_scalar(GetBitContext *gb, int k, int bps)
81 {
82  unsigned int x = get_unary_0_9(gb);
83 
84  if (x > 8) { /* RICE THRESHOLD */
85  /* use alternative encoding */
86  x = get_bits_long(gb, bps);
87  } else if (k != 1) {
88  int extrabits = show_bits(gb, k);
89 
90  /* multiply x by 2^k - 1, as part of their strange algorithm */
91  x = (x << k) - x;
92 
93  if (extrabits > 1) {
94  x += extrabits - 1;
95  skip_bits(gb, k);
96  } else
97  skip_bits(gb, k - 1);
98  }
99  return x;
100 }
101 
103  int nb_samples, int bps, int rice_history_mult)
104 {
105  int i;
106  unsigned int history = alac->rice_initial_history;
107  int sign_modifier = 0;
108 
109  for (i = 0; i < nb_samples; i++) {
110  int k;
111  unsigned int x;
112 
113  /* calculate rice param and decode next value */
114  k = av_log2((history >> 9) + 3);
115  k = FFMIN(k, alac->rice_limit);
116  x = decode_scalar(&alac->gb, k, bps);
117  x += sign_modifier;
118  sign_modifier = 0;
119  output_buffer[i] = (x >> 1) ^ -(x & 1);
120 
121  /* update the history */
122  if (x > 0xffff)
123  history = 0xffff;
124  else
125  history += x * rice_history_mult -
126  ((history * rice_history_mult) >> 9);
127 
128  /* special case: there may be compressed blocks of 0 */
129  if ((history < 128) && (i + 1 < nb_samples)) {
130  int block_size;
131 
132  /* calculate rice param and decode block size */
133  k = 7 - av_log2(history) + ((history + 16) >> 6);
134  k = FFMIN(k, alac->rice_limit);
135  block_size = decode_scalar(&alac->gb, k, 16);
136 
137  if (block_size > 0) {
138  if (block_size >= nb_samples - i) {
139  av_log(alac->avctx, AV_LOG_ERROR,
140  "invalid zero block size of %d %d %d\n", block_size,
141  nb_samples, i);
142  block_size = nb_samples - i - 1;
143  }
144  memset(&output_buffer[i + 1], 0,
145  block_size * sizeof(*output_buffer));
146  i += block_size;
147  }
148  if (block_size <= 0xffff)
149  sign_modifier = 1;
150  history = 0;
151  }
152  }
153 }
154 
155 static inline int sign_only(int v)
156 {
157  return v ? FFSIGN(v) : 0;
158 }
159 
160 static void lpc_prediction(int32_t *error_buffer, int32_t *buffer_out,
161  int nb_samples, int bps, int16_t *lpc_coefs,
162  int lpc_order, int lpc_quant)
163 {
164  int i;
165  int32_t *pred = buffer_out;
166 
167  /* first sample always copies */
168  *buffer_out = *error_buffer;
169 
170  if (nb_samples <= 1)
171  return;
172 
173  if (!lpc_order) {
174  memcpy(&buffer_out[1], &error_buffer[1],
175  (nb_samples - 1) * sizeof(*buffer_out));
176  return;
177  }
178 
179  if (lpc_order == 31) {
180  /* simple 1st-order prediction */
181  for (i = 1; i < nb_samples; i++) {
182  buffer_out[i] = sign_extend(buffer_out[i - 1] + error_buffer[i],
183  bps);
184  }
185  return;
186  }
187 
188  /* read warm-up samples */
189  for (i = 1; i <= lpc_order; i++)
190  buffer_out[i] = sign_extend(buffer_out[i - 1] + error_buffer[i], bps);
191 
192  /* NOTE: 4 and 8 are very common cases that could be optimized. */
193 
194  for (; i < nb_samples; i++) {
195  int j;
196  int val = 0;
197  int error_val = error_buffer[i];
198  int error_sign;
199  int d = *pred++;
200 
201  /* LPC prediction */
202  for (j = 0; j < lpc_order; j++)
203  val += (pred[j] - d) * lpc_coefs[j];
204  val = (val + (1 << (lpc_quant - 1))) >> lpc_quant;
205  val += d + error_val;
206  buffer_out[i] = sign_extend(val, bps);
207 
208  /* adapt LPC coefficients */
209  error_sign = sign_only(error_val);
210  if (error_sign) {
211  for (j = 0; j < lpc_order && error_val * error_sign > 0; j++) {
212  int sign;
213  val = d - pred[j];
214  sign = sign_only(val) * error_sign;
215  lpc_coefs[j] -= sign;
216  val *= sign;
217  error_val -= (val >> lpc_quant) * (j + 1);
218  }
219  }
220  }
221 }
222 
223 static void decorrelate_stereo(int32_t *buffer[2], int nb_samples,
224  int decorr_shift, int decorr_left_weight)
225 {
226  int i;
227 
228  for (i = 0; i < nb_samples; i++) {
229  int32_t a, b;
230 
231  a = buffer[0][i];
232  b = buffer[1][i];
233 
234  a -= (b * decorr_left_weight) >> decorr_shift;
235  b += a;
236 
237  buffer[0][i] = b;
238  buffer[1][i] = a;
239  }
240 }
241 
242 static void append_extra_bits(int32_t *buffer[2], int32_t *extra_bits_buffer[2],
243  int extra_bits, int channels, int nb_samples)
244 {
245  int i, ch;
246 
247  for (ch = 0; ch < channels; ch++)
248  for (i = 0; i < nb_samples; i++)
249  buffer[ch][i] = (buffer[ch][i] << extra_bits) | extra_bits_buffer[ch][i];
250 }
251 
252 static int decode_element(AVCodecContext *avctx, AVFrame *frame, int ch_index,
253  int channels)
254 {
255  ALACContext *alac = avctx->priv_data;
256  int has_size, bps, is_compressed, decorr_shift, decorr_left_weight, ret;
257  uint32_t output_samples;
258  int i, ch;
259 
260  skip_bits(&alac->gb, 4); /* element instance tag */
261  skip_bits(&alac->gb, 12); /* unused header bits */
262 
263  /* the number of output samples is stored in the frame */
264  has_size = get_bits1(&alac->gb);
265 
266  alac->extra_bits = get_bits(&alac->gb, 2) << 3;
267  bps = alac->sample_size - alac->extra_bits + channels - 1;
268  if (bps > 32) {
269  av_log(avctx, AV_LOG_ERROR, "bps is unsupported: %d\n", bps);
270  return AVERROR_PATCHWELCOME;
271  }
272 
273  /* whether the frame is compressed */
274  is_compressed = !get_bits1(&alac->gb);
275 
276  if (has_size)
277  output_samples = get_bits_long(&alac->gb, 32);
278  else
279  output_samples = alac->max_samples_per_frame;
280  if (!output_samples || output_samples > alac->max_samples_per_frame) {
281  av_log(avctx, AV_LOG_ERROR, "invalid samples per frame: %"PRIu32"\n",
282  output_samples);
283  return AVERROR_INVALIDDATA;
284  }
285  if (!alac->nb_samples) {
286  /* get output buffer */
287  frame->nb_samples = output_samples;
288  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
289  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
290  return ret;
291  }
292  } else if (output_samples != alac->nb_samples) {
293  av_log(avctx, AV_LOG_ERROR, "sample count mismatch: %"PRIu32" != %d\n",
294  output_samples, alac->nb_samples);
295  return AVERROR_INVALIDDATA;
296  }
297  alac->nb_samples = output_samples;
298  if (alac->sample_size > 16) {
299  for (ch = 0; ch < channels; ch++)
300  alac->output_samples_buffer[ch] = (int32_t *)frame->extended_data[ch_index + ch];
301  }
302 
303  if (is_compressed) {
304  int16_t lpc_coefs[2][32];
305  int lpc_order[2];
306  int prediction_type[2];
307  int lpc_quant[2];
308  int rice_history_mult[2];
309 
310  decorr_shift = get_bits(&alac->gb, 8);
311  decorr_left_weight = get_bits(&alac->gb, 8);
312 
313  for (ch = 0; ch < channels; ch++) {
314  prediction_type[ch] = get_bits(&alac->gb, 4);
315  lpc_quant[ch] = get_bits(&alac->gb, 4);
316  rice_history_mult[ch] = get_bits(&alac->gb, 3);
317  lpc_order[ch] = get_bits(&alac->gb, 5);
318 
319  if (lpc_order[ch] >= alac->max_samples_per_frame)
320  return AVERROR_INVALIDDATA;
321 
322  /* read the predictor table */
323  for (i = lpc_order[ch] - 1; i >= 0; i--)
324  lpc_coefs[ch][i] = get_sbits(&alac->gb, 16);
325  }
326 
327  if (alac->extra_bits) {
328  for (i = 0; i < alac->nb_samples; i++) {
329  for (ch = 0; ch < channels; ch++)
330  alac->extra_bits_buffer[ch][i] = get_bits(&alac->gb, alac->extra_bits);
331  }
332  }
333  for (ch = 0; ch < channels; ch++) {
334  rice_decompress(alac, alac->predict_error_buffer[ch],
335  alac->nb_samples, bps,
336  rice_history_mult[ch] * alac->rice_history_mult / 4);
337 
338  /* adaptive FIR filter */
339  if (prediction_type[ch] == 15) {
340  /* Prediction type 15 runs the adaptive FIR twice.
341  * The first pass uses the special-case coef_num = 31, while
342  * the second pass uses the coefs from the bitstream.
343  *
344  * However, this prediction type is not currently used by the
345  * reference encoder.
346  */
348  alac->predict_error_buffer[ch],
349  alac->nb_samples, bps, NULL, 31, 0);
350  } else if (prediction_type[ch] > 0) {
351  av_log(avctx, AV_LOG_WARNING, "unknown prediction type: %i\n",
352  prediction_type[ch]);
353  }
355  alac->output_samples_buffer[ch], alac->nb_samples,
356  bps, lpc_coefs[ch], lpc_order[ch], lpc_quant[ch]);
357  }
358  } else {
359  /* not compressed, easy case */
360  for (i = 0; i < alac->nb_samples; i++) {
361  for (ch = 0; ch < channels; ch++) {
362  alac->output_samples_buffer[ch][i] =
363  get_sbits_long(&alac->gb, alac->sample_size);
364  }
365  }
366  alac->extra_bits = 0;
367  decorr_shift = 0;
368  decorr_left_weight = 0;
369  }
370 
371  if (channels == 2 && decorr_left_weight) {
373  decorr_shift, decorr_left_weight);
374  }
375 
376  if (alac->extra_bits) {
378  alac->extra_bits, channels, alac->nb_samples);
379  }
380 
381  switch(alac->sample_size) {
382  case 16: {
383  for (ch = 0; ch < channels; ch++) {
384  int16_t *outbuffer = (int16_t *)frame->extended_data[ch_index + ch];
385  for (i = 0; i < alac->nb_samples; i++)
386  *outbuffer++ = alac->output_samples_buffer[ch][i];
387  }}
388  break;
389  case 24: {
390  for (ch = 0; ch < channels; ch++) {
391  for (i = 0; i < alac->nb_samples; i++)
392  alac->output_samples_buffer[ch][i] <<= 8;
393  }}
394  break;
395  }
396 
397  return 0;
398 }
399 
400 static int alac_decode_frame(AVCodecContext *avctx, void *data,
401  int *got_frame_ptr, AVPacket *avpkt)
402 {
403  ALACContext *alac = avctx->priv_data;
404  AVFrame *frame = data;
405  enum AlacRawDataBlockType element;
406  int channels;
407  int ch, ret, got_end;
408 
409  init_get_bits(&alac->gb, avpkt->data, avpkt->size * 8);
410 
411  got_end = 0;
412  alac->nb_samples = 0;
413  ch = 0;
414  while (get_bits_left(&alac->gb) >= 3) {
415  element = get_bits(&alac->gb, 3);
416  if (element == TYPE_END) {
417  got_end = 1;
418  break;
419  }
420  if (element > TYPE_CPE && element != TYPE_LFE) {
421  av_log(avctx, AV_LOG_ERROR, "syntax element unsupported: %d", element);
422  return AVERROR_PATCHWELCOME;
423  }
424 
425  channels = (element == TYPE_CPE) ? 2 : 1;
426  if (ch + channels > alac->channels ||
427  ff_alac_channel_layout_offsets[alac->channels - 1][ch] + channels > alac->channels) {
428  av_log(avctx, AV_LOG_ERROR, "invalid element channel count\n");
429  return AVERROR_INVALIDDATA;
430  }
431 
432  ret = decode_element(avctx, frame,
434  channels);
435  if (ret < 0 && get_bits_left(&alac->gb))
436  return ret;
437 
438  ch += channels;
439  }
440  if (!got_end) {
441  av_log(avctx, AV_LOG_ERROR, "no end tag found. incomplete packet.\n");
442  return AVERROR_INVALIDDATA;
443  }
444 
445  if (avpkt->size * 8 - get_bits_count(&alac->gb) > 8) {
446  av_log(avctx, AV_LOG_ERROR, "Error : %d bits left\n",
447  avpkt->size * 8 - get_bits_count(&alac->gb));
448  }
449 
450  *got_frame_ptr = 1;
451 
452  return avpkt->size;
453 }
454 
456 {
457  ALACContext *alac = avctx->priv_data;
458 
459  int ch;
460  for (ch = 0; ch < FFMIN(alac->channels, 2); ch++) {
461  av_freep(&alac->predict_error_buffer[ch]);
462  if (alac->sample_size == 16)
463  av_freep(&alac->output_samples_buffer[ch]);
464  av_freep(&alac->extra_bits_buffer[ch]);
465  }
466 
467  return 0;
468 }
469 
470 static int allocate_buffers(ALACContext *alac)
471 {
472  int ch;
473  int buf_size = alac->max_samples_per_frame * sizeof(int32_t);
474 
475  for (ch = 0; ch < FFMIN(alac->channels, 2); ch++) {
477  buf_size, buf_alloc_fail);
478 
479  if (alac->sample_size == 16) {
481  buf_size, buf_alloc_fail);
482  }
483 
484  FF_ALLOC_OR_GOTO(alac->avctx, alac->extra_bits_buffer[ch],
485  buf_size, buf_alloc_fail);
486  }
487  return 0;
488 buf_alloc_fail:
489  alac_decode_close(alac->avctx);
490  return AVERROR(ENOMEM);
491 }
492 
493 static int alac_set_info(ALACContext *alac)
494 {
495  GetByteContext gb;
496 
497  bytestream2_init(&gb, alac->avctx->extradata,
498  alac->avctx->extradata_size);
499 
500  bytestream2_skipu(&gb, 12); // size:4, alac:4, version:4
501 
502  alac->max_samples_per_frame = bytestream2_get_be32u(&gb);
503  if (!alac->max_samples_per_frame ||
504  alac->max_samples_per_frame > INT_MAX / sizeof(int32_t)) {
505  av_log(alac->avctx, AV_LOG_ERROR,
506  "max samples per frame invalid: %"PRIu32"\n",
507  alac->max_samples_per_frame);
508  return AVERROR_INVALIDDATA;
509  }
510  bytestream2_skipu(&gb, 1); // compatible version
511  alac->sample_size = bytestream2_get_byteu(&gb);
512  alac->rice_history_mult = bytestream2_get_byteu(&gb);
513  alac->rice_initial_history = bytestream2_get_byteu(&gb);
514  alac->rice_limit = bytestream2_get_byteu(&gb);
515  alac->channels = bytestream2_get_byteu(&gb);
516  bytestream2_get_be16u(&gb); // maxRun
517  bytestream2_get_be32u(&gb); // max coded frame size
518  bytestream2_get_be32u(&gb); // average bitrate
519  bytestream2_get_be32u(&gb); // samplerate
520 
521  return 0;
522 }
523 
525 {
526  int ret;
527  ALACContext *alac = avctx->priv_data;
528  alac->avctx = avctx;
529 
530  /* initialize from the extradata */
532  av_log(avctx, AV_LOG_ERROR, "alac: extradata is too small\n");
533  return AVERROR_INVALIDDATA;
534  }
535  if (alac_set_info(alac)) {
536  av_log(avctx, AV_LOG_ERROR, "alac: set_info failed\n");
537  return -1;
538  }
539 
540  switch (alac->sample_size) {
541  case 16: avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
542  break;
543  case 24:
544  case 32: avctx->sample_fmt = AV_SAMPLE_FMT_S32P;
545  break;
546  default: avpriv_request_sample(avctx, "Sample depth %d", alac->sample_size);
547  return AVERROR_PATCHWELCOME;
548  }
549  avctx->bits_per_raw_sample = alac->sample_size;
550 
551  if (alac->channels < 1) {
552  av_log(avctx, AV_LOG_WARNING, "Invalid channel count\n");
553  alac->channels = avctx->channels;
554  } else {
555  if (alac->channels > ALAC_MAX_CHANNELS)
556  alac->channels = avctx->channels;
557  else
558  avctx->channels = alac->channels;
559  }
560  if (avctx->channels > ALAC_MAX_CHANNELS) {
561  av_log(avctx, AV_LOG_ERROR, "Unsupported channel count: %d\n",
562  avctx->channels);
563  return AVERROR_PATCHWELCOME;
564  }
565  avctx->channel_layout = ff_alac_channel_layouts[alac->channels - 1];
566 
567  if ((ret = allocate_buffers(alac)) < 0) {
568  av_log(avctx, AV_LOG_ERROR, "Error allocating buffers\n");
569  return ret;
570  }
571 
572  return 0;
573 }
574 
576  .name = "alac",
577  .long_name = NULL_IF_CONFIG_SMALL("ALAC (Apple Lossless Audio Codec)"),
578  .type = AVMEDIA_TYPE_AUDIO,
579  .id = AV_CODEC_ID_ALAC,
580  .priv_data_size = sizeof(ALACContext),
584  .capabilities = CODEC_CAP_DR1,
585 };
#define extra_bits(eb)
Definition: intrax8.c:153
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:54
int nb_samples
number of samples in the current frame
Definition: alac.c:77
This structure describes decoded (raw) audio or video data.
Definition: frame.h:135
#define ALAC_EXTRADATA_SIZE
Definition: alac.c:59
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:240
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:129
static int decode_element(AVCodecContext *avctx, AVFrame *frame, int ch_index, int channels)
Definition: alac.c:252
Definition: aac.h:56
Definition: aac.h:50
int size
Definition: avcodec.h:974
uint8_t ** extended_data
pointers to the data planes/channels.
Definition: frame.h:169
void av_log(void *avcl, int level, const char *fmt,...) av_printf_format(3
Send the specified message to the log if the level is less than or equal to the current av_log_level...
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:130
int bits_per_raw_sample
Bits per sample/pixel of internal libavcodec pixel/sample format.
Definition: avcodec.h:2514
int32_t * extra_bits_buffer[2]
Definition: alac.c:68
AVCodec.
Definition: avcodec.h:2796
static int get_sbits(GetBitContext *s, int n)
Definition: get_bits.h:226
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1164
static int get_sbits_long(GetBitContext *s, int n)
Read 0-32 bits as a signed integer.
Definition: get_bits.h:340
void av_freep(void *ptr)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc() and set the pointer ...
Definition: mem.c:198
int32_t * predict_error_buffer[2]
Definition: alac.c:66
static int get_unary_0_9(GetBitContext *gb)
Definition: unary.h:51
static int decode(MimicContext *ctx, int quality, int num_coeffs, int is_iframe)
Definition: mimic.c:275
void void avpriv_request_sample(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:1799
uint8_t
uint8_t rice_initial_history
Definition: alac.c:73
Definition: aac.h:52
static av_cold int alac_decode_close(AVCodecContext *avctx)
Definition: alac.c:455
#define b
Definition: input.c:52
const char * name
Name of the codec implementation.
Definition: avcodec.h:2803
#define CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:684
const char data[16]
Definition: mxf.c:70
static int get_bits_count(const GetBitContext *s)
Definition: get_bits.h:194
static av_always_inline void bytestream2_skipu(GetByteContext *g, unsigned int size)
Definition: bytestream.h:165
bitstream reader API header.
int32_t * output_samples_buffer[2]
Definition: alac.c:67
static int alac_decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
Definition: alac.c:400
int extra_bits
number of extra bits beyond 16-bit
Definition: alac.c:76
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:555
static void append_extra_bits(int32_t *buffer[2], int32_t *extra_bits_buffer[2], int extra_bits, int channels, int nb_samples)
Definition: alac.c:242
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:123
static void lpc_prediction(int32_t *error_buffer, int32_t *buffer_out, int nb_samples, int bps, int16_t *lpc_coefs, int lpc_order, int lpc_quant)
Definition: alac.c:160
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:150
static int sign_only(int v)
Definition: alac.c:155
AlacRawDataBlockType
Definition: alac_data.h:26
Libavcodec external API header.
uint64_t channel_layout
Audio channel layout.
Definition: avcodec.h:1852
#define ALAC_MAX_CHANNELS
Definition: alac_data.h:38
uint32_t max_samples_per_frame
Definition: alac.c:70
static void output_buffer(int16_t **samples, int nchan, int blocksize, int32_t **buffer)
Definition: shorten.c:257
#define FFSIGN(a)
Definition: common.h:53
static void decorrelate_stereo(int32_t *buffer[2], int nb_samples, int decorr_shift, int decorr_left_weight)
Definition: alac.c:223
signed 32 bits, planar
Definition: samplefmt.h:71
GetBitContext gb
Definition: alac.c:63
int32_t
static unsigned int show_bits(GetBitContext *s, int n)
Show 1-25 bits.
Definition: get_bits.h:254
static int alac_set_info(ALACContext *alac)
Definition: alac.c:493
static char buffer[20]
Definition: seek-test.c:31
uint8_t rice_history_mult
Definition: alac.c:72
const uint64_t ff_alac_channel_layouts[ALAC_MAX_CHANNELS+1]
Definition: alac_data.c:35
static const float pred[4]
Definition: siprdata.h:259
#define AVERROR_PATCHWELCOME
Not yet implemented in Libav, patches welcome.
Definition: error.h:57
NULL
Definition: eval.c:55
#define av_cold
Definition: attributes.h:66
main external API structure.
Definition: avcodec.h:1050
static void close(AVCodecParserContext *s)
Definition: h264_parser.c:490
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: utils.c:612
int extradata_size
Definition: avcodec.h:1165
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:271
static void skip_bits(GetBitContext *s, int n)
Definition: get_bits.h:263
static void rice_decompress(ALACContext *alac, int32_t *output_buffer, int nb_samples, int bps, int rice_history_mult)
Definition: alac.c:102
uint8_t * data
Definition: avcodec.h:973
static unsigned int decode_scalar(GetBitContext *gb, int k, int bps)
Definition: alac.c:80
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:375
static unsigned int get_bits_long(GetBitContext *s, int n)
Read 0-32 bits.
Definition: get_bits.h:304
const uint8_t ff_alac_channel_layout_offsets[ALAC_MAX_CHANNELS][ALAC_MAX_CHANNELS]
Definition: alac_data.c:24
static av_const int sign_extend(int val, unsigned bits)
Definition: mathops.h:127
void * priv_data
Definition: avcodec.h:1092
uint8_t sample_size
Definition: alac.c:71
int channels
Definition: alac.c:64
AVCodec ff_alac_decoder
Definition: alac.c:575
common internal api header.
static av_cold int alac_decode_init(AVCodecContext *avctx)
Definition: alac.c:524
#define FF_ALLOC_OR_GOTO(ctx, p, size, label)
Definition: internal.h:117
uint8_t rice_limit
Definition: alac.c:74
unsigned bps
Definition: movenc.c:845
static av_cold int init(AVCodecParserContext *s)
Definition: h264_parser.c:499
static int allocate_buffers(ALACContext *alac)
Definition: alac.c:470
int channels
number of audio channels
Definition: avcodec.h:1792
#define av_log2
Definition: intmath.h:85
AVCodecContext * avctx
Definition: alac.c:62
signed 16 bits, planar
Definition: samplefmt.h:70
This structure stores compressed data.
Definition: avcodec.h:950
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:179
#define FFMIN(a, b)
Definition: common.h:57
for(j=16;j >0;--j)