FFmpeg
 All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
flacenc.c
Go to the documentation of this file.
1 /*
2  * FLAC audio encoder
3  * Copyright (c) 2006 Justin Ruggles <justin.ruggles@gmail.com>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "libavutil/avassert.h"
23 #include "libavutil/crc.h"
24 #include "libavutil/intmath.h"
25 #include "libavutil/md5.h"
26 #include "libavutil/opt.h"
27 #include "avcodec.h"
28 #include "dsputil.h"
29 #include "put_bits.h"
30 #include "golomb.h"
31 #include "internal.h"
32 #include "lpc.h"
33 #include "flac.h"
34 #include "flacdata.h"
35 #include "flacdsp.h"
36 
37 #define FLAC_SUBFRAME_CONSTANT 0
38 #define FLAC_SUBFRAME_VERBATIM 1
39 #define FLAC_SUBFRAME_FIXED 8
40 #define FLAC_SUBFRAME_LPC 32
41 
42 #define MAX_FIXED_ORDER 4
43 #define MAX_PARTITION_ORDER 8
44 #define MAX_PARTITIONS (1 << MAX_PARTITION_ORDER)
45 #define MAX_LPC_PRECISION 15
46 #define MAX_LPC_SHIFT 15
47 
48 enum CodingMode {
49  CODING_MODE_RICE = 4,
50  CODING_MODE_RICE2 = 5,
51 };
52 
53 typedef struct CompressionOptions {
54  int compression_level;
55  int block_time_ms;
56  enum FFLPCType lpc_type;
57  int lpc_passes;
58  int lpc_coeff_precision;
59  int min_prediction_order;
60  int max_prediction_order;
61  int prediction_order_method;
62  int min_partition_order;
63  int max_partition_order;
64  int ch_mode;
65 } CompressionOptions;
66 
67 typedef struct RiceContext {
68  enum CodingMode coding_mode;
69  int porder;
70  int params[MAX_PARTITIONS];
71 } RiceContext;
72 
73 typedef struct FlacSubframe {
74  int type;
75  int type_code;
76  int obits;
77  int wasted;
78  int order;
79  int32_t coefs[MAX_LPC_ORDER];
80  int shift;
81  RiceContext rc;
82  int32_t samples[FLAC_MAX_BLOCKSIZE];
83  int32_t residual[FLAC_MAX_BLOCKSIZE+1];
84 } FlacSubframe;
85 
86 typedef struct FlacFrame {
87  FlacSubframe subframes[FLAC_MAX_CHANNELS];
88  int blocksize;
89  int bs_code[2];
90  uint8_t crc8;
91  int ch_mode;
92  int verbatim_only;
93 } FlacFrame;
94 
95 typedef struct FlacEncodeContext {
96  AVClass *class;
97  PutBitContext pb;
98  int channels;
99  int samplerate;
100  int sr_code[2];
101  int bps_code;
102  int max_blocksize;
103  int min_framesize;
104  int max_framesize;
105  int max_encoded_framesize;
106  uint32_t frame_count;
107  uint64_t sample_count;
108  uint8_t md5sum[16];
109  FlacFrame frame;
110  CompressionOptions options;
111  AVCodecContext *avctx;
112  LPCContext lpc_ctx;
113  struct AVMD5 *md5ctx;
114  uint8_t *md5_buffer;
115  unsigned int md5_buffer_size;
116  DSPContext dsp;
117  FLACDSPContext flac_dsp;
118 } FlacEncodeContext;
119 
120 
121 /**
122  * Write streaminfo metadata block to byte array.
123  */
124 static void write_streaminfo(FlacEncodeContext *s, uint8_t *header)
125 {
126  PutBitContext pb;
127 
128  memset(header, 0, FLAC_STREAMINFO_SIZE);
129  init_put_bits(&pb, header, FLAC_STREAMINFO_SIZE);
130 
131  /* streaminfo metadata block */
132  put_bits(&pb, 16, s->max_blocksize);
133  put_bits(&pb, 16, s->max_blocksize);
134  put_bits(&pb, 24, s->min_framesize);
135  put_bits(&pb, 24, s->max_framesize);
136  put_bits(&pb, 20, s->samplerate);
137  put_bits(&pb, 3, s->channels-1);
138  put_bits(&pb, 5, s->avctx->bits_per_raw_sample - 1);
139  /* write 36-bit sample count in 2 put_bits() calls */
140  put_bits(&pb, 24, (s->sample_count & 0xFFFFFF000LL) >> 12);
141  put_bits(&pb, 12, s->sample_count & 0x000000FFFLL);
142  flush_put_bits(&pb);
143  memcpy(&header[18], s->md5sum, 16);
144 }
145 
146 
147 /**
148  * Set blocksize based on samplerate.
149  * Choose the closest predefined blocksize >= BLOCK_TIME_MS milliseconds.
150  */
151 static int select_blocksize(int samplerate, int block_time_ms)
152 {
153  int i;
154  int target;
155  int blocksize;
156 
157  av_assert0(samplerate > 0);
158  blocksize = ff_flac_blocksize_table[1];
159  target = (samplerate * block_time_ms) / 1000;
160  for (i = 0; i < 16; i++) {
161  if (target >= ff_flac_blocksize_table[i] &&
162  ff_flac_blocksize_table[i] > blocksize) {
163  blocksize = ff_flac_blocksize_table[i];
164  }
165  }
166  return blocksize;
167 }
168 
169 
170 static av_cold void dprint_compression_options(FlacEncodeContext *s)
171 {
172  AVCodecContext *avctx = s->avctx;
173  CompressionOptions *opt = &s->options;
174 
175  av_log(avctx, AV_LOG_DEBUG, " compression: %d\n", opt->compression_level);
176 
177  switch (opt->lpc_type) {
178  case FF_LPC_TYPE_NONE:
179  av_log(avctx, AV_LOG_DEBUG, " lpc type: None\n");
180  break;
181  case FF_LPC_TYPE_FIXED:
182  av_log(avctx, AV_LOG_DEBUG, " lpc type: Fixed pre-defined coefficients\n");
183  break;
184  case FF_LPC_TYPE_LEVINSON:
185  av_log(avctx, AV_LOG_DEBUG, " lpc type: Levinson-Durbin recursion with Welch window\n");
186  break;
187  case FF_LPC_TYPE_CHOLESKY:
188  av_log(avctx, AV_LOG_DEBUG, " lpc type: Cholesky factorization, %d pass%s\n",
189  opt->lpc_passes, opt->lpc_passes == 1 ? "" : "es");
190  break;
191  }
192 
193  av_log(avctx, AV_LOG_DEBUG, " prediction order: %d, %d\n",
194  opt->min_prediction_order, opt->max_prediction_order);
195 
196  switch (opt->prediction_order_method) {
197  case ORDER_METHOD_EST:
198  av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "estimate");
199  break;
200  case ORDER_METHOD_2LEVEL:
201  av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "2-level");
202  break;
203  case ORDER_METHOD_4LEVEL:
204  av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "4-level");
205  break;
206  case ORDER_METHOD_8LEVEL:
207  av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "8-level");
208  break;
209  case ORDER_METHOD_SEARCH:
210  av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "full search");
211  break;
212  case ORDER_METHOD_LOG:
213  av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "log search");
214  break;
215  }
216 
217 
218  av_log(avctx, AV_LOG_DEBUG, " partition order: %d, %d\n",
219  opt->min_partition_order, opt->max_partition_order);
220 
221  av_log(avctx, AV_LOG_DEBUG, " block size: %d\n", avctx->frame_size);
222 
223  av_log(avctx, AV_LOG_DEBUG, " lpc precision: %d\n",
224  opt->lpc_coeff_precision);
225 }
226 
227 
228 static av_cold int flac_encode_init(AVCodecContext *avctx)
229 {
230  int freq = avctx->sample_rate;
231  int channels = avctx->channels;
232  FlacEncodeContext *s = avctx->priv_data;
233  int i, level, ret;
234  uint8_t *streaminfo;
235 
236  s->avctx = avctx;
237 
238  switch (avctx->sample_fmt) {
239  case AV_SAMPLE_FMT_S16:
240  avctx->bits_per_raw_sample = 16;
241  s->bps_code = 4;
242  break;
243  case AV_SAMPLE_FMT_S32:
244  if (avctx->bits_per_raw_sample != 24)
245  av_log(avctx, AV_LOG_WARNING, "encoding as 24 bits-per-sample\n");
246  avctx->bits_per_raw_sample = 24;
247  s->bps_code = 6;
248  break;
249  }
250 
251  if (channels < 1 || channels > FLAC_MAX_CHANNELS) {
252  av_log(avctx, AV_LOG_ERROR, "%d channels not supported (max %d)\n",
253  channels, FLAC_MAX_CHANNELS);
254  return AVERROR(EINVAL);
255  }
256  s->channels = channels;
257 
258  /* find samplerate in table */
259  if (freq < 1)
260  return -1;
261  for (i = 4; i < 12; i++) {
262  if (freq == ff_flac_sample_rate_table[i]) {
263  s->samplerate = ff_flac_sample_rate_table[i];
264  s->sr_code[0] = i;
265  s->sr_code[1] = 0;
266  break;
267  }
268  }
269  /* if not in table, samplerate is non-standard */
270  if (i == 12) {
271  if (freq % 1000 == 0 && freq < 255000) {
272  s->sr_code[0] = 12;
273  s->sr_code[1] = freq / 1000;
274  } else if (freq % 10 == 0 && freq < 655350) {
275  s->sr_code[0] = 14;
276  s->sr_code[1] = freq / 10;
277  } else if (freq < 65535) {
278  s->sr_code[0] = 13;
279  s->sr_code[1] = freq;
280  } else {
281  av_log(avctx, AV_LOG_ERROR, "%d Hz not supported\n", freq);
282  return AVERROR(EINVAL);
283  }
284  s->samplerate = freq;
285  }
286 
287  /* set compression option defaults based on avctx->compression_level */
288  if (avctx->compression_level < 0)
289  s->options.compression_level = 5;
290  else
291  s->options.compression_level = avctx->compression_level;
292 
293  level = s->options.compression_level;
294  if (level > 12) {
295  av_log(avctx, AV_LOG_ERROR, "invalid compression level: %d\n",
296  s->options.compression_level);
297  return AVERROR(EINVAL);
298  }
299 
300  s->options.block_time_ms = ((int[]){ 27, 27, 27,105,105,105,105,105,105,105,105,105,105})[level];
301 
302  if (s->options.lpc_type == FF_LPC_TYPE_DEFAULT)
303  s->options.lpc_type = ((int[]){ FF_LPC_TYPE_FIXED, FF_LPC_TYPE_FIXED, FF_LPC_TYPE_FIXED,
304  FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON,
305  FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON,
306  FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON,
307  FF_LPC_TYPE_LEVINSON})[level];
308 
309  s->options.min_prediction_order = ((int[]){ 2, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1})[level];
310  s->options.max_prediction_order = ((int[]){ 3, 4, 4, 6, 8, 8, 8, 8, 12, 12, 12, 32, 32})[level];
311 
312  if (s->options.prediction_order_method < 0)
313  s->options.prediction_order_method = ((int[]){ ORDER_METHOD_EST, ORDER_METHOD_EST, ORDER_METHOD_EST,
314  ORDER_METHOD_EST, ORDER_METHOD_EST, ORDER_METHOD_EST,
315  ORDER_METHOD_4LEVEL, ORDER_METHOD_LOG, ORDER_METHOD_4LEVEL,
316  ORDER_METHOD_LOG, ORDER_METHOD_SEARCH, ORDER_METHOD_LOG,
317  ORDER_METHOD_SEARCH})[level];
318 
319  if (s->options.min_partition_order > s->options.max_partition_order) {
320  av_log(avctx, AV_LOG_ERROR, "invalid partition orders: min=%d max=%d\n",
321  s->options.min_partition_order, s->options.max_partition_order);
322  return AVERROR(EINVAL);
323  }
324  if (s->options.min_partition_order < 0)
325  s->options.min_partition_order = ((int[]){ 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0})[level];
326  if (s->options.max_partition_order < 0)
327  s->options.max_partition_order = ((int[]){ 2, 2, 3, 3, 3, 8, 8, 8, 8, 8, 8, 8, 8})[level];
328 
329  if (s->options.lpc_type == FF_LPC_TYPE_NONE) {
330  s->options.min_prediction_order = 0;
331  } else if (avctx->min_prediction_order >= 0) {
332  if (s->options.lpc_type == FF_LPC_TYPE_FIXED) {
333  if (avctx->min_prediction_order > MAX_FIXED_ORDER) {
334  av_log(avctx, AV_LOG_ERROR, "invalid min prediction order: %d\n",
335  avctx->min_prediction_order);
336  return AVERROR(EINVAL);
337  }
338  } else if (avctx->min_prediction_order < MIN_LPC_ORDER ||
339  avctx->min_prediction_order > MAX_LPC_ORDER) {
340  av_log(avctx, AV_LOG_ERROR, "invalid min prediction order: %d\n",
341  avctx->min_prediction_order);
342  return AVERROR(EINVAL);
343  }
344  s->options.min_prediction_order = avctx->min_prediction_order;
345  }
346  if (s->options.lpc_type == FF_LPC_TYPE_NONE) {
347  s->options.max_prediction_order = 0;
348  } else if (avctx->max_prediction_order >= 0) {
349  if (s->options.lpc_type == FF_LPC_TYPE_FIXED) {
350  if (avctx->max_prediction_order > MAX_FIXED_ORDER) {
351  av_log(avctx, AV_LOG_ERROR, "invalid max prediction order: %d\n",
352  avctx->max_prediction_order);
353  return AVERROR(EINVAL);
354  }
355  } else if (avctx->max_prediction_order < MIN_LPC_ORDER ||
356  avctx->max_prediction_order > MAX_LPC_ORDER) {
357  av_log(avctx, AV_LOG_ERROR, "invalid max prediction order: %d\n",
358  avctx->max_prediction_order);
359  return AVERROR(EINVAL);
360  }
361  s->options.max_prediction_order = avctx->max_prediction_order;
362  }
363  if (s->options.max_prediction_order < s->options.min_prediction_order) {
364  av_log(avctx, AV_LOG_ERROR, "invalid prediction orders: min=%d max=%d\n",
365  s->options.min_prediction_order, s->options.max_prediction_order);
366  return AVERROR(EINVAL);
367  }
368 
369  if (avctx->frame_size > 0) {
370  if (avctx->frame_size < FLAC_MIN_BLOCKSIZE ||
371  avctx->frame_size > FLAC_MAX_BLOCKSIZE) {
372  av_log(avctx, AV_LOG_ERROR, "invalid block size: %d\n",
373  avctx->frame_size);
374  return AVERROR(EINVAL);
375  }
376  } else {
377  s->avctx->frame_size = select_blocksize(s->samplerate, s->options.block_time_ms);
378  }
379  s->max_blocksize = s->avctx->frame_size;
380 
381  /* set maximum encoded frame size in verbatim mode */
382  s->max_framesize = ff_flac_get_max_frame_size(s->avctx->frame_size,
383  s->channels,
384  s->avctx->bits_per_raw_sample);
385 
386  /* initialize MD5 context */
387  s->md5ctx = av_md5_alloc();
388  if (!s->md5ctx)
389  return AVERROR(ENOMEM);
390  av_md5_init(s->md5ctx);
391 
392  streaminfo = av_malloc(FLAC_STREAMINFO_SIZE);
393  if (!streaminfo)
394  return AVERROR(ENOMEM);
395  write_streaminfo(s, streaminfo);
396  avctx->extradata = streaminfo;
397  avctx->extradata_size = FLAC_STREAMINFO_SIZE;
398 
399  s->frame_count = 0;
400  s->min_framesize = s->max_framesize;
401 
402 #if FF_API_OLD_ENCODE_AUDIO
403  avctx->coded_frame = avcodec_alloc_frame();
404  if (!avctx->coded_frame)
405  return AVERROR(ENOMEM);
406 #endif
407 
408  if (channels == 3 &&
409  avctx->channel_layout != (AV_CH_LAYOUT_STEREO|AV_CH_FRONT_CENTER) ||
410  channels == 4 &&
411  avctx->channel_layout != AV_CH_LAYOUT_2_2 &&
412  avctx->channel_layout != AV_CH_LAYOUT_QUAD ||
413  channels == 5 &&
414  avctx->channel_layout != AV_CH_LAYOUT_5POINT0 &&
415  avctx->channel_layout != AV_CH_LAYOUT_5POINT0_BACK ||
416  channels == 6 &&
417  avctx->channel_layout != AV_CH_LAYOUT_5POINT1 &&
418  avctx->channel_layout != AV_CH_LAYOUT_5POINT1_BACK) {
419  if (avctx->channel_layout) {
420  av_log(avctx, AV_LOG_ERROR, "Channel layout not supported by Flac, "
421  "output stream will have incorrect "
422  "channel layout.\n");
423  } else {
424  av_log(avctx, AV_LOG_WARNING, "No channel layout specified. The encoder "
425  "will use Flac channel layout for "
426  "%d channels.\n", channels);
427  }
428  }
429 
430  ret = ff_lpc_init(&s->lpc_ctx, avctx->frame_size,
431  s->options.max_prediction_order, FF_LPC_TYPE_LEVINSON);
432 
433  ff_dsputil_init(&s->dsp, avctx);
434  ff_flacdsp_init(&s->flac_dsp, avctx->sample_fmt,
435  avctx->bits_per_raw_sample);
436 
437  dprint_compression_options(s);
438 
439  return ret;
440 }
441 
442 
443 static void init_frame(FlacEncodeContext *s, int nb_samples)
444 {
445  int i, ch;
446  FlacFrame *frame;
447 
448  frame = &s->frame;
449 
450  for (i = 0; i < 16; i++) {
451  if (nb_samples == ff_flac_blocksize_table[i]) {
452  frame->blocksize = ff_flac_blocksize_table[i];
453  frame->bs_code[0] = i;
454  frame->bs_code[1] = 0;
455  break;
456  }
457  }
458  if (i == 16) {
459  frame->blocksize = nb_samples;
460  if (frame->blocksize <= 256) {
461  frame->bs_code[0] = 6;
462  frame->bs_code[1] = frame->blocksize-1;
463  } else {
464  frame->bs_code[0] = 7;
465  frame->bs_code[1] = frame->blocksize-1;
466  }
467  }
468 
469  for (ch = 0; ch < s->channels; ch++) {
470  FlacSubframe *sub = &frame->subframes[ch];
471 
472  sub->wasted = 0;
473  sub->obits = s->avctx->bits_per_raw_sample;
474 
475  if (sub->obits > 16)
476  sub->rc.coding_mode = CODING_MODE_RICE2;
477  else
478  sub->rc.coding_mode = CODING_MODE_RICE;
479  }
480 
481  frame->verbatim_only = 0;
482 }
483 
484 
485 /**
486  * Copy channel-interleaved input samples into separate subframes.
487  */
488 static void copy_samples(FlacEncodeContext *s, const void *samples)
489 {
490  int i, j, ch;
491  FlacFrame *frame;
492  int shift = av_get_bytes_per_sample(s->avctx->sample_fmt) * 8 -
493  s->avctx->bits_per_raw_sample;
494 
495 #define COPY_SAMPLES(bits) do { \
496  const int ## bits ## _t *samples0 = samples; \
497  frame = &s->frame; \
498  for (i = 0, j = 0; i < frame->blocksize; i++) \
499  for (ch = 0; ch < s->channels; ch++, j++) \
500  frame->subframes[ch].samples[i] = samples0[j] >> shift; \
501 } while (0)
502 
503  if (s->avctx->sample_fmt == AV_SAMPLE_FMT_S16)
504  COPY_SAMPLES(16);
505  else
506  COPY_SAMPLES(32);
507 }
508 
509 
510 static uint64_t rice_count_exact(int32_t *res, int n, int k)
511 {
512  int i;
513  uint64_t count = 0;
514 
515  for (i = 0; i < n; i++) {
516  int32_t v = -2 * res[i] - 1;
517  v ^= v >> 31;
518  count += (v >> k) + 1 + k;
519  }
520  return count;
521 }
522 
523 
524 static uint64_t subframe_count_exact(FlacEncodeContext *s, FlacSubframe *sub,
525  int pred_order)
526 {
527  int p, porder, psize;
528  int i, part_end;
529  uint64_t count = 0;
530 
531  /* subframe header */
532  count += 8;
533 
534  /* subframe */
535  if (sub->type == FLAC_SUBFRAME_CONSTANT) {
536  count += sub->obits;
537  } else if (sub->type == FLAC_SUBFRAME_VERBATIM) {
538  count += s->frame.blocksize * sub->obits;
539  } else {
540  /* warm-up samples */
541  count += pred_order * sub->obits;
542 
543  /* LPC coefficients */
544  if (sub->type == FLAC_SUBFRAME_LPC)
545  count += 4 + 5 + pred_order * s->options.lpc_coeff_precision;
546 
547  /* rice-encoded block */
548  count += 2;
549 
550  /* partition order */
551  porder = sub->rc.porder;
552  psize = s->frame.blocksize >> porder;
553  count += 4;
554 
555  /* residual */
556  i = pred_order;
557  part_end = psize;
558  for (p = 0; p < 1 << porder; p++) {
559  int k = sub->rc.params[p];
560  count += sub->rc.coding_mode;
561  count += rice_count_exact(&sub->residual[i], part_end - i, k);
562  i = part_end;
563  part_end = FFMIN(s->frame.blocksize, part_end + psize);
564  }
565  }
566 
567  return count;
568 }
569 
570 
571 #define rice_encode_count(sum, n, k) (((n)*((k)+1))+((sum-(n>>1))>>(k)))
572 
573 /**
574  * Solve for d/dk(rice_encode_count) = n-((sum-(n>>1))>>(k+1)) = 0.
575  */
576 static int find_optimal_param(uint64_t sum, int n, int max_param)
577 {
578  int k;
579  uint64_t sum2;
580 
581  if (sum <= n >> 1)
582  return 0;
583  sum2 = sum - (n >> 1);
584  k = av_log2(av_clipl_int32(sum2 / n));
585  return FFMIN(k, max_param);
586 }
587 
588 
589 static uint64_t calc_optimal_rice_params(RiceContext *rc, int porder,
590  uint64_t *sums, int n, int pred_order)
591 {
592  int i;
593  int k, cnt, part, max_param;
594  uint64_t all_bits;
595 
596  max_param = (1 << rc->coding_mode) - 2;
597 
598  part = (1 << porder);
599  all_bits = 4 * part;
600 
601  cnt = (n >> porder) - pred_order;
602  for (i = 0; i < part; i++) {
603  k = find_optimal_param(sums[i], cnt, max_param);
604  rc->params[i] = k;
605  all_bits += rice_encode_count(sums[i], cnt, k);
606  cnt = n >> porder;
607  }
608 
609  rc->porder = porder;
610 
611  return all_bits;
612 }
613 
614 
615 static void calc_sums(int pmin, int pmax, uint32_t *data, int n, int pred_order,
616  uint64_t sums[][MAX_PARTITIONS])
617 {
618  int i, j;
619  int parts;
620  uint32_t *res, *res_end;
621 
622  /* sums for highest level */
623  parts = (1 << pmax);
624  res = &data[pred_order];
625  res_end = &data[n >> pmax];
626  for (i = 0; i < parts; i++) {
627  uint64_t sum = 0;
628  while (res < res_end)
629  sum += *(res++);
630  sums[pmax][i] = sum;
631  res_end += n >> pmax;
632  }
633  /* sums for lower levels */
634  for (i = pmax - 1; i >= pmin; i--) {
635  parts = (1 << i);
636  for (j = 0; j < parts; j++)
637  sums[i][j] = sums[i+1][2*j] + sums[i+1][2*j+1];
638  }
639 }
640 
641 
642 static uint64_t calc_rice_params(RiceContext *rc, int pmin, int pmax,
643  int32_t *data, int n, int pred_order)
644 {
645  int i;
646  uint64_t bits[MAX_PARTITION_ORDER+1];
647  int opt_porder;
648  RiceContext tmp_rc;
649  uint32_t *udata;
650  uint64_t sums[MAX_PARTITION_ORDER+1][MAX_PARTITIONS];
651 
652  av_assert1(pmin >= 0 && pmin <= MAX_PARTITION_ORDER);
653  av_assert1(pmax >= 0 && pmax <= MAX_PARTITION_ORDER);
654  av_assert1(pmin <= pmax);
655 
656  tmp_rc.coding_mode = rc->coding_mode;
657 
658  udata = av_malloc(n * sizeof(uint32_t));
659  for (i = 0; i < n; i++)
660  udata[i] = (2*data[i]) ^ (data[i]>>31);
661 
662  calc_sums(pmin, pmax, udata, n, pred_order, sums);
663 
664  opt_porder = pmin;
665  bits[pmin] = UINT32_MAX;
666  for (i = pmin; i <= pmax; i++) {
667  bits[i] = calc_optimal_rice_params(&tmp_rc, i, sums[i], n, pred_order);
668  if (bits[i] <= bits[opt_porder]) {
669  opt_porder = i;
670  *rc = tmp_rc;
671  }
672  }
673 
674  av_freep(&udata);
675  return bits[opt_porder];
676 }
677 
678 
679 static int get_max_p_order(int max_porder, int n, int order)
680 {
681  int porder = FFMIN(max_porder, av_log2(n^(n-1)));
682  if (order > 0)
683  porder = FFMIN(porder, av_log2(n/order));
684  return porder;
685 }
686 
687 
688 static uint64_t find_subframe_rice_params(FlacEncodeContext *s,
689  FlacSubframe *sub, int pred_order)
690 {
691  int pmin = get_max_p_order(s->options.min_partition_order,
692  s->frame.blocksize, pred_order);
693  int pmax = get_max_p_order(s->options.max_partition_order,
694  s->frame.blocksize, pred_order);
695 
696  uint64_t bits = 8 + pred_order * sub->obits + 2 + sub->rc.coding_mode;
697  if (sub->type == FLAC_SUBFRAME_LPC)
698  bits += 4 + 5 + pred_order * s->options.lpc_coeff_precision;
699  bits += calc_rice_params(&sub->rc, pmin, pmax, sub->residual,
700  s->frame.blocksize, pred_order);
701  return bits;
702 }
703 
704 
705 static void encode_residual_fixed(int32_t *res, const int32_t *smp, int n,
706  int order)
707 {
708  int i;
709 
710  for (i = 0; i < order; i++)
711  res[i] = smp[i];
712 
713  if (order == 0) {
714  for (i = order; i < n; i++)
715  res[i] = smp[i];
716  } else if (order == 1) {
717  for (i = order; i < n; i++)
718  res[i] = smp[i] - smp[i-1];
719  } else if (order == 2) {
720  int a = smp[order-1] - smp[order-2];
721  for (i = order; i < n; i += 2) {
722  int b = smp[i ] - smp[i-1];
723  res[i] = b - a;
724  a = smp[i+1] - smp[i ];
725  res[i+1] = a - b;
726  }
727  } else if (order == 3) {
728  int a = smp[order-1] - smp[order-2];
729  int c = smp[order-1] - 2*smp[order-2] + smp[order-3];
730  for (i = order; i < n; i += 2) {
731  int b = smp[i ] - smp[i-1];
732  int d = b - a;
733  res[i] = d - c;
734  a = smp[i+1] - smp[i ];
735  c = a - b;
736  res[i+1] = c - d;
737  }
738  } else {
739  int a = smp[order-1] - smp[order-2];
740  int c = smp[order-1] - 2*smp[order-2] + smp[order-3];
741  int e = smp[order-1] - 3*smp[order-2] + 3*smp[order-3] - smp[order-4];
742  for (i = order; i < n; i += 2) {
743  int b = smp[i ] - smp[i-1];
744  int d = b - a;
745  int f = d - c;
746  res[i ] = f - e;
747  a = smp[i+1] - smp[i ];
748  c = a - b;
749  e = c - d;
750  res[i+1] = e - f;
751  }
752  }
753 }
754 
755 
756 static int encode_residual_ch(FlacEncodeContext *s, int ch)
757 {
758  int i, n;
759  int min_order, max_order, opt_order, omethod;
760  FlacFrame *frame;
761  FlacSubframe *sub;
762  int32_t coefs[MAX_LPC_ORDER][MAX_LPC_ORDER];
763  int shift[MAX_LPC_ORDER];
764  int32_t *res, *smp;
765 
766  frame = &s->frame;
767  sub = &frame->subframes[ch];
768  res = sub->residual;
769  smp = sub->samples;
770  n = frame->blocksize;
771 
772  /* CONSTANT */
773  for (i = 1; i < n; i++)
774  if(smp[i] != smp[0])
775  break;
776  if (i == n) {
777  sub->type = sub->type_code = FLAC_SUBFRAME_CONSTANT;
778  res[0] = smp[0];
779  return subframe_count_exact(s, sub, 0);
780  }
781 
782  /* VERBATIM */
783  if (frame->verbatim_only || n < 5) {
784  sub->type = sub->type_code = FLAC_SUBFRAME_VERBATIM;
785  memcpy(res, smp, n * sizeof(int32_t));
786  return subframe_count_exact(s, sub, 0);
787  }
788 
789  min_order = s->options.min_prediction_order;
790  max_order = s->options.max_prediction_order;
791  omethod = s->options.prediction_order_method;
792 
793  /* FIXED */
794  sub->type = FLAC_SUBFRAME_FIXED;
795  if (s->options.lpc_type == FF_LPC_TYPE_NONE ||
796  s->options.lpc_type == FF_LPC_TYPE_FIXED || n <= max_order) {
797  uint64_t bits[MAX_FIXED_ORDER+1];
798  if (max_order > MAX_FIXED_ORDER)
799  max_order = MAX_FIXED_ORDER;
800  opt_order = 0;
801  bits[0] = UINT32_MAX;
802  for (i = min_order; i <= max_order; i++) {
803  encode_residual_fixed(res, smp, n, i);
804  bits[i] = find_subframe_rice_params(s, sub, i);
805  if (bits[i] < bits[opt_order])
806  opt_order = i;
807  }
808  sub->order = opt_order;
809  sub->type_code = sub->type | sub->order;
810  if (sub->order != max_order) {
811  encode_residual_fixed(res, smp, n, sub->order);
812  find_subframe_rice_params(s, sub, sub->order);
813  }
814  return subframe_count_exact(s, sub, sub->order);
815  }
816 
817  /* LPC */
818  sub->type = FLAC_SUBFRAME_LPC;
819  opt_order = ff_lpc_calc_coefs(&s->lpc_ctx, smp, n, min_order, max_order,
820  s->options.lpc_coeff_precision, coefs, shift, s->options.lpc_type,
821  s->options.lpc_passes, omethod,
822  MAX_LPC_SHIFT, 0);
823 
824  if (omethod == ORDER_METHOD_2LEVEL ||
825  omethod == ORDER_METHOD_4LEVEL ||
826  omethod == ORDER_METHOD_8LEVEL) {
827  int levels = 1 << omethod;
828  uint64_t bits[1 << ORDER_METHOD_8LEVEL];
829  int order = -1;
830  int opt_index = levels-1;
831  opt_order = max_order-1;
832  bits[opt_index] = UINT32_MAX;
833  for (i = levels-1; i >= 0; i--) {
834  int last_order = order;
835  order = min_order + (((max_order-min_order+1) * (i+1)) / levels)-1;
836  order = av_clip(order, min_order - 1, max_order - 1);
837  if (order == last_order)
838  continue;
839  s->flac_dsp.lpc_encode(res, smp, n, order+1, coefs[order],
840  shift[order]);
841  bits[i] = find_subframe_rice_params(s, sub, order+1);
842  if (bits[i] < bits[opt_index]) {
843  opt_index = i;
844  opt_order = order;
845  }
846  }
847  opt_order++;
848  } else if (omethod == ORDER_METHOD_SEARCH) {
849  // brute-force optimal order search
850  uint64_t bits[MAX_LPC_ORDER];
851  opt_order = 0;
852  bits[0] = UINT32_MAX;
853  for (i = min_order-1; i < max_order; i++) {
854  s->flac_dsp.lpc_encode(res, smp, n, i+1, coefs[i], shift[i]);
855  bits[i] = find_subframe_rice_params(s, sub, i+1);
856  if (bits[i] < bits[opt_order])
857  opt_order = i;
858  }
859  opt_order++;
860  } else if (omethod == ORDER_METHOD_LOG) {
861  uint64_t bits[MAX_LPC_ORDER];
862  int step;
863 
864  opt_order = min_order - 1 + (max_order-min_order)/3;
865  memset(bits, -1, sizeof(bits));
866 
867  for (step = 16; step; step >>= 1) {
868  int last = opt_order;
869  for (i = last-step; i <= last+step; i += step) {
870  if (i < min_order-1 || i >= max_order || bits[i] < UINT32_MAX)
871  continue;
872  s->flac_dsp.lpc_encode(res, smp, n, i+1, coefs[i], shift[i]);
873  bits[i] = find_subframe_rice_params(s, sub, i+1);
874  if (bits[i] < bits[opt_order])
875  opt_order = i;
876  }
877  }
878  opt_order++;
879  }
880 
881  sub->order = opt_order;
882  sub->type_code = sub->type | (sub->order-1);
883  sub->shift = shift[sub->order-1];
884  for (i = 0; i < sub->order; i++)
885  sub->coefs[i] = coefs[sub->order-1][i];
886 
887  s->flac_dsp.lpc_encode(res, smp, n, sub->order, sub->coefs, sub->shift);
888 
889  find_subframe_rice_params(s, sub, sub->order);
890 
891  return subframe_count_exact(s, sub, sub->order);
892 }
893 
894 
895 static int count_frame_header(FlacEncodeContext *s)
896 {
897  uint8_t av_unused tmp;
898  int count;
899 
900  /*
901  <14> Sync code
902  <1> Reserved
903  <1> Blocking strategy
904  <4> Block size in inter-channel samples
905  <4> Sample rate
906  <4> Channel assignment
907  <3> Sample size in bits
908  <1> Reserved
909  */
910  count = 32;
911 
912  /* coded frame number */
913  PUT_UTF8(s->frame_count, tmp, count += 8;)
914 
915  /* explicit block size */
916  if (s->frame.bs_code[0] == 6)
917  count += 8;
918  else if (s->frame.bs_code[0] == 7)
919  count += 16;
920 
921  /* explicit sample rate */
922  count += ((s->sr_code[0] == 12) + (s->sr_code[0] > 12)) * 8;
923 
924  /* frame header CRC-8 */
925  count += 8;
926 
927  return count;
928 }
929 
930 
931 static int encode_frame(FlacEncodeContext *s)
932 {
933  int ch;
934  uint64_t count;
935 
936  count = count_frame_header(s);
937 
938  for (ch = 0; ch < s->channels; ch++)
939  count += encode_residual_ch(s, ch);
940 
941  count += (8 - (count & 7)) & 7; // byte alignment
942  count += 16; // CRC-16
943 
944  count >>= 3;
945  if (count > INT_MAX)
946  return AVERROR_BUG;
947  return count;
948 }
949 
950 
951 static void remove_wasted_bits(FlacEncodeContext *s)
952 {
953  int ch, i;
954 
955  for (ch = 0; ch < s->channels; ch++) {
956  FlacSubframe *sub = &s->frame.subframes[ch];
957  int32_t v = 0;
958 
959  for (i = 0; i < s->frame.blocksize; i++) {
960  v |= sub->samples[i];
961  if (v & 1)
962  break;
963  }
964 
965  if (v && !(v & 1)) {
966  v = av_ctz(v);
967 
968  for (i = 0; i < s->frame.blocksize; i++)
969  sub->samples[i] >>= v;
970 
971  sub->wasted = v;
972  sub->obits -= v;
973 
974  /* for 24-bit, check if removing wasted bits makes the range better
975  suited for using RICE instead of RICE2 for entropy coding */
976  if (sub->obits <= 17)
977  sub->rc.coding_mode = CODING_MODE_RICE;
978  }
979  }
980 }
981 
982 
983 static int estimate_stereo_mode(int32_t *left_ch, int32_t *right_ch, int n,
984  int max_rice_param)
985 {
986  int i, best;
987  int32_t lt, rt;
988  uint64_t sum[4];
989  uint64_t score[4];
990  int k;
991 
992  /* calculate sum of 2nd order residual for each channel */
993  sum[0] = sum[1] = sum[2] = sum[3] = 0;
994  for (i = 2; i < n; i++) {
995  lt = left_ch[i] - 2*left_ch[i-1] + left_ch[i-2];
996  rt = right_ch[i] - 2*right_ch[i-1] + right_ch[i-2];
997  sum[2] += FFABS((lt + rt) >> 1);
998  sum[3] += FFABS(lt - rt);
999  sum[0] += FFABS(lt);
1000  sum[1] += FFABS(rt);
1001  }
1002  /* estimate bit counts */
1003  for (i = 0; i < 4; i++) {
1004  k = find_optimal_param(2 * sum[i], n, max_rice_param);
1005  sum[i] = rice_encode_count( 2 * sum[i], n, k);
1006  }
1007 
1008  /* calculate score for each mode */
1009  score[0] = sum[0] + sum[1];
1010  score[1] = sum[0] + sum[3];
1011  score[2] = sum[1] + sum[3];
1012  score[3] = sum[2] + sum[3];
1013 
1014  /* return mode with lowest score */
1015  best = 0;
1016  for (i = 1; i < 4; i++)
1017  if (score[i] < score[best])
1018  best = i;
1019 
1020  return best;
1021 }
1022 
1023 
1024 /**
1025  * Perform stereo channel decorrelation.
1026  */
1027 static void channel_decorrelation(FlacEncodeContext *s)
1028 {
1029  FlacFrame *frame;
1030  int32_t *left, *right;
1031  int i, n;
1032 
1033  frame = &s->frame;
1034  n = frame->blocksize;
1035  left = frame->subframes[0].samples;
1036  right = frame->subframes[1].samples;
1037 
1038  if (s->channels != 2) {
1039  frame->ch_mode = FLAC_CHMODE_INDEPENDENT;
1040  return;
1041  }
1042 
1043  if (s->options.ch_mode < 0) {
1044  int max_rice_param = (1 << frame->subframes[0].rc.coding_mode) - 2;
1045  frame->ch_mode = estimate_stereo_mode(left, right, n, max_rice_param);
1046  } else
1047  frame->ch_mode = s->options.ch_mode;
1048 
1049  /* perform decorrelation and adjust bits-per-sample */
1050  if (frame->ch_mode == FLAC_CHMODE_INDEPENDENT)
1051  return;
1052  if (frame->ch_mode == FLAC_CHMODE_MID_SIDE) {
1053  int32_t tmp;
1054  for (i = 0; i < n; i++) {
1055  tmp = left[i];
1056  left[i] = (tmp + right[i]) >> 1;
1057  right[i] = tmp - right[i];
1058  }
1059  frame->subframes[1].obits++;
1060  } else if (frame->ch_mode == FLAC_CHMODE_LEFT_SIDE) {
1061  for (i = 0; i < n; i++)
1062  right[i] = left[i] - right[i];
1063  frame->subframes[1].obits++;
1064  } else {
1065  for (i = 0; i < n; i++)
1066  left[i] -= right[i];
1067  frame->subframes[0].obits++;
1068  }
1069 }
1070 
1071 
1072 static void write_utf8(PutBitContext *pb, uint32_t val)
1073 {
1074  uint8_t tmp;
1075  PUT_UTF8(val, tmp, put_bits(pb, 8, tmp);)
1076 }
1077 
1078 
1079 static void write_frame_header(FlacEncodeContext *s)
1080 {
1081  FlacFrame *frame;
1082  int crc;
1083 
1084  frame = &s->frame;
1085 
1086  put_bits(&s->pb, 16, 0xFFF8);
1087  put_bits(&s->pb, 4, frame->bs_code[0]);
1088  put_bits(&s->pb, 4, s->sr_code[0]);
1089 
1090  if (frame->ch_mode == FLAC_CHMODE_INDEPENDENT)
1091  put_bits(&s->pb, 4, s->channels-1);
1092  else
1093  put_bits(&s->pb, 4, frame->ch_mode + FLAC_MAX_CHANNELS - 1);
1094 
1095  put_bits(&s->pb, 3, s->bps_code);
1096  put_bits(&s->pb, 1, 0);
1097  write_utf8(&s->pb, s->frame_count);
1098 
1099  if (frame->bs_code[0] == 6)
1100  put_bits(&s->pb, 8, frame->bs_code[1]);
1101  else if (frame->bs_code[0] == 7)
1102  put_bits(&s->pb, 16, frame->bs_code[1]);
1103 
1104  if (s->sr_code[0] == 12)
1105  put_bits(&s->pb, 8, s->sr_code[1]);
1106  else if (s->sr_code[0] > 12)
1107  put_bits(&s->pb, 16, s->sr_code[1]);
1108 
1109  flush_put_bits(&s->pb);
1110  crc = av_crc(av_crc_get_table(AV_CRC_8_ATM), 0, s->pb.buf,
1111  put_bits_count(&s->pb) >> 3);
1112  put_bits(&s->pb, 8, crc);
1113 }
1114 
1115 
1116 static void write_subframes(FlacEncodeContext *s)
1117 {
1118  int ch;
1119 
1120  for (ch = 0; ch < s->channels; ch++) {
1121  FlacSubframe *sub = &s->frame.subframes[ch];
1122  int i, p, porder, psize;
1123  int32_t *part_end;
1124  int32_t *res = sub->residual;
1125  int32_t *frame_end = &sub->residual[s->frame.blocksize];
1126 
1127  /* subframe header */
1128  put_bits(&s->pb, 1, 0);
1129  put_bits(&s->pb, 6, sub->type_code);
1130  put_bits(&s->pb, 1, !!sub->wasted);
1131  if (sub->wasted)
1132  put_bits(&s->pb, sub->wasted, 1);
1133 
1134  /* subframe */
1135  if (sub->type == FLAC_SUBFRAME_CONSTANT) {
1136  put_sbits(&s->pb, sub->obits, res[0]);
1137  } else if (sub->type == FLAC_SUBFRAME_VERBATIM) {
1138  while (res < frame_end)
1139  put_sbits(&s->pb, sub->obits, *res++);
1140  } else {
1141  /* warm-up samples */
1142  for (i = 0; i < sub->order; i++)
1143  put_sbits(&s->pb, sub->obits, *res++);
1144 
1145  /* LPC coefficients */
1146  if (sub->type == FLAC_SUBFRAME_LPC) {
1147  int cbits = s->options.lpc_coeff_precision;
1148  put_bits( &s->pb, 4, cbits-1);
1149  put_sbits(&s->pb, 5, sub->shift);
1150  for (i = 0; i < sub->order; i++)
1151  put_sbits(&s->pb, cbits, sub->coefs[i]);
1152  }
1153 
1154  /* rice-encoded block */
1155  put_bits(&s->pb, 2, sub->rc.coding_mode - 4);
1156 
1157  /* partition order */
1158  porder = sub->rc.porder;
1159  psize = s->frame.blocksize >> porder;
1160  put_bits(&s->pb, 4, porder);
1161 
1162  /* residual */
1163  part_end = &sub->residual[psize];
1164  for (p = 0; p < 1 << porder; p++) {
1165  int k = sub->rc.params[p];
1166  put_bits(&s->pb, sub->rc.coding_mode, k);
1167  while (res < part_end)
1168  set_sr_golomb_flac(&s->pb, *res++, k, INT32_MAX, 0);
1169  part_end = FFMIN(frame_end, part_end + psize);
1170  }
1171  }
1172  }
1173 }
1174 
1175 
1176 static void write_frame_footer(FlacEncodeContext *s)
1177 {
1178  int crc;
1179  flush_put_bits(&s->pb);
1180  crc = av_bswap16(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, s->pb.buf,
1181  put_bits_count(&s->pb)>>3));
1182  put_bits(&s->pb, 16, crc);
1183  flush_put_bits(&s->pb);
1184 }
1185 
1186 
1187 static int write_frame(FlacEncodeContext *s, AVPacket *avpkt)
1188 {
1189  init_put_bits(&s->pb, avpkt->data, avpkt->size);
1190  write_frame_header(s);
1191  write_subframes(s);
1192  write_frame_footer(s);
1193  return put_bits_count(&s->pb) >> 3;
1194 }
1195 
1196 
1197 static int update_md5_sum(FlacEncodeContext *s, const void *samples)
1198 {
1199  const uint8_t *buf;
1200  int buf_size = s->frame.blocksize * s->channels *
1201  ((s->avctx->bits_per_raw_sample + 7) / 8);
1202 
1203  if (s->avctx->bits_per_raw_sample > 16 || HAVE_BIGENDIAN) {
1204  av_fast_malloc(&s->md5_buffer, &s->md5_buffer_size, buf_size);
1205  if (!s->md5_buffer)
1206  return AVERROR(ENOMEM);
1207  }
1208 
1209  if (s->avctx->bits_per_raw_sample <= 16) {
1210  buf = (const uint8_t *)samples;
1211 #if HAVE_BIGENDIAN
1212  s->dsp.bswap16_buf((uint16_t *)s->md5_buffer,
1213  (const uint16_t *)samples, buf_size / 2);
1214  buf = s->md5_buffer;
1215 #endif
1216  } else {
1217  int i;
1218  const int32_t *samples0 = samples;
1219  uint8_t *tmp = s->md5_buffer;
1220 
1221  for (i = 0; i < s->frame.blocksize * s->channels; i++) {
1222  int32_t v = samples0[i] >> 8;
1223  *tmp++ = (v ) & 0xFF;
1224  *tmp++ = (v >> 8) & 0xFF;
1225  *tmp++ = (v >> 16) & 0xFF;
1226  }
1227  buf = s->md5_buffer;
1228  }
1229  av_md5_update(s->md5ctx, buf, buf_size);
1230 
1231  return 0;
1232 }
1233 
1234 
1235 static int flac_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
1236  const AVFrame *frame, int *got_packet_ptr)
1237 {
1238  FlacEncodeContext *s;
1239  int frame_bytes, out_bytes, ret;
1240 
1241  s = avctx->priv_data;
1242 
1243  /* when the last block is reached, update the header in extradata */
1244  if (!frame) {
1245  s->max_framesize = s->max_encoded_framesize;
1246  av_md5_final(s->md5ctx, s->md5sum);
1247  write_streaminfo(s, avctx->extradata);
1248  return 0;
1249  }
1250 
1251  /* change max_framesize for small final frame */
1252  if (frame->nb_samples < s->frame.blocksize) {
1253  s->max_framesize = ff_flac_get_max_frame_size(frame->nb_samples,
1254  s->channels,
1255  avctx->bits_per_raw_sample);
1256  }
1257 
1258  init_frame(s, frame->nb_samples);
1259 
1260  copy_samples(s, frame->data[0]);
1261 
1262  channel_decorrelation(s);
1263 
1264  remove_wasted_bits(s);
1265 
1266  frame_bytes = encode_frame(s);
1267 
1268  /* fallback to verbatim mode if the compressed frame is larger than it
1269  would be if encoded uncompressed. */
1270  if (frame_bytes < 0 || frame_bytes > s->max_framesize) {
1271  s->frame.verbatim_only = 1;
1272  frame_bytes = encode_frame(s);
1273  if (frame_bytes < 0) {
1274  av_log(avctx, AV_LOG_ERROR, "Bad frame count\n");
1275  return frame_bytes;
1276  }
1277  }
1278 
1279  if ((ret = ff_alloc_packet2(avctx, avpkt, frame_bytes)) < 0)
1280  return ret;
1281 
1282  out_bytes = write_frame(s, avpkt);
1283 
1284  s->frame_count++;
1285  s->sample_count += frame->nb_samples;
1286  if ((ret = update_md5_sum(s, frame->data[0])) < 0) {
1287  av_log(avctx, AV_LOG_ERROR, "Error updating MD5 checksum\n");
1288  return ret;
1289  }
1290  if (out_bytes > s->max_encoded_framesize)
1291  s->max_encoded_framesize = out_bytes;
1292  if (out_bytes < s->min_framesize)
1293  s->min_framesize = out_bytes;
1294 
1295  avpkt->pts = frame->pts;
1296  avpkt->duration = ff_samples_to_time_base(avctx, frame->nb_samples);
1297  avpkt->size = out_bytes;
1298  *got_packet_ptr = 1;
1299  return 0;
1300 }
1301 
1302 
1303 static av_cold int flac_encode_close(AVCodecContext *avctx)
1304 {
1305  if (avctx->priv_data) {
1306  FlacEncodeContext *s = avctx->priv_data;
1307  av_freep(&s->md5ctx);
1308  av_freep(&s->md5_buffer);
1309  ff_lpc_end(&s->lpc_ctx);
1310  }
1311  av_freep(&avctx->extradata);
1312  avctx->extradata_size = 0;
1313 #if FF_API_OLD_ENCODE_AUDIO
1314  av_freep(&avctx->coded_frame);
1315 #endif
1316  return 0;
1317 }
1318 
1319 #define FLAGS AV_OPT_FLAG_ENCODING_PARAM | AV_OPT_FLAG_AUDIO_PARAM
1320 static const AVOption options[] = {
1321 { "lpc_coeff_precision", "LPC coefficient precision", offsetof(FlacEncodeContext, options.lpc_coeff_precision), AV_OPT_TYPE_INT, {.i64 = 15 }, 0, MAX_LPC_PRECISION, FLAGS },
1322 { "lpc_type", "LPC algorithm", offsetof(FlacEncodeContext, options.lpc_type), AV_OPT_TYPE_INT, {.i64 = FF_LPC_TYPE_DEFAULT }, FF_LPC_TYPE_DEFAULT, FF_LPC_TYPE_NB-1, FLAGS, "lpc_type" },
1323 { "none", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_NONE }, INT_MIN, INT_MAX, FLAGS, "lpc_type" },
1324 { "fixed", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_FIXED }, INT_MIN, INT_MAX, FLAGS, "lpc_type" },
1325 { "levinson", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_LEVINSON }, INT_MIN, INT_MAX, FLAGS, "lpc_type" },
1326 { "cholesky", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_CHOLESKY }, INT_MIN, INT_MAX, FLAGS, "lpc_type" },
1327 { "lpc_passes", "Number of passes to use for Cholesky factorization during LPC analysis", offsetof(FlacEncodeContext, options.lpc_passes), AV_OPT_TYPE_INT, {.i64 = 2 }, 1, INT_MAX, FLAGS },
1328 { "min_partition_order", NULL, offsetof(FlacEncodeContext, options.min_partition_order), AV_OPT_TYPE_INT, {.i64 = -1 }, -1, MAX_PARTITION_ORDER, FLAGS },
1329 { "max_partition_order", NULL, offsetof(FlacEncodeContext, options.max_partition_order), AV_OPT_TYPE_INT, {.i64 = -1 }, -1, MAX_PARTITION_ORDER, FLAGS },
1330 { "prediction_order_method", "Search method for selecting prediction order", offsetof(FlacEncodeContext, options.prediction_order_method), AV_OPT_TYPE_INT, {.i64 = -1 }, -1, ORDER_METHOD_LOG, FLAGS, "predm" },
1331 { "estimation", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_EST }, INT_MIN, INT_MAX, FLAGS, "predm" },
1332 { "2level", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_2LEVEL }, INT_MIN, INT_MAX, FLAGS, "predm" },
1333 { "4level", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_4LEVEL }, INT_MIN, INT_MAX, FLAGS, "predm" },
1334 { "8level", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_8LEVEL }, INT_MIN, INT_MAX, FLAGS, "predm" },
1335 { "search", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_SEARCH }, INT_MIN, INT_MAX, FLAGS, "predm" },
1336 { "log", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_LOG }, INT_MIN, INT_MAX, FLAGS, "predm" },
1337 { "ch_mode", "Stereo decorrelation mode", offsetof(FlacEncodeContext, options.ch_mode), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, FLAC_CHMODE_MID_SIDE, FLAGS, "ch_mode" },
1338 { "auto", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = -1 }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1339 { "indep", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_INDEPENDENT }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1340 { "left_side", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_LEFT_SIDE }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1341 { "right_side", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_RIGHT_SIDE }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1342 { "mid_side", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_MID_SIDE }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1343 { NULL },
1344 };
1345 
1346 static const AVClass flac_encoder_class = {
1347  "FLAC encoder",
1348  av_default_item_name,
1349  options,
1350  LIBAVUTIL_VERSION_INT,
1351 };
1352 
1353 AVCodec ff_flac_encoder = {
1354  .name = "flac",
1355  .type = AVMEDIA_TYPE_AUDIO,
1356  .id = AV_CODEC_ID_FLAC,
1357  .priv_data_size = sizeof(FlacEncodeContext),
1358  .init = flac_encode_init,
1359  .encode2 = flac_encode_frame,
1360  .close = flac_encode_close,
1361  .capabilities = CODEC_CAP_SMALL_LAST_FRAME | CODEC_CAP_DELAY | CODEC_CAP_LOSSLESS,
1362  .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
1363  AV_SAMPLE_FMT_S32,
1364  AV_SAMPLE_FMT_NONE },
1365  .long_name = NULL_IF_CONFIG_SMALL("FLAC (Free Lossless Audio Codec)"),
1366  .priv_class = &flac_encoder_class,
1367 };
Generated on Sat May 25 2013 04:01:04 for FFmpeg by   doxygen 1.8.2