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flacenc.c
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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 (channels == 3 &&
403  avctx->channel_layout != (AV_CH_LAYOUT_STEREO|AV_CH_FRONT_CENTER) ||
404  channels == 4 &&
405  avctx->channel_layout != AV_CH_LAYOUT_2_2 &&
406  avctx->channel_layout != AV_CH_LAYOUT_QUAD ||
407  channels == 5 &&
408  avctx->channel_layout != AV_CH_LAYOUT_5POINT0 &&
409  avctx->channel_layout != AV_CH_LAYOUT_5POINT0_BACK ||
410  channels == 6 &&
411  avctx->channel_layout != AV_CH_LAYOUT_5POINT1 &&
412  avctx->channel_layout != AV_CH_LAYOUT_5POINT1_BACK) {
413  if (avctx->channel_layout) {
414  av_log(avctx, AV_LOG_ERROR, "Channel layout not supported by Flac, "
415  "output stream will have incorrect "
416  "channel layout.\n");
417  } else {
418  av_log(avctx, AV_LOG_WARNING, "No channel layout specified. The encoder "
419  "will use Flac channel layout for "
420  "%d channels.\n", channels);
421  }
422  }
423 
424  ret = ff_lpc_init(&s->lpc_ctx, avctx->frame_size,
425  s->options.max_prediction_order, FF_LPC_TYPE_LEVINSON);
426 
427  ff_dsputil_init(&s->dsp, avctx);
428  ff_flacdsp_init(&s->flac_dsp, avctx->sample_fmt,
429  avctx->bits_per_raw_sample);
430 
431  dprint_compression_options(s);
432 
433  return ret;
434 }
435 
436 
437 static void init_frame(FlacEncodeContext *s, int nb_samples)
438 {
439  int i, ch;
440  FlacFrame *frame;
441 
442  frame = &s->frame;
443 
444  for (i = 0; i < 16; i++) {
445  if (nb_samples == ff_flac_blocksize_table[i]) {
446  frame->blocksize = ff_flac_blocksize_table[i];
447  frame->bs_code[0] = i;
448  frame->bs_code[1] = 0;
449  break;
450  }
451  }
452  if (i == 16) {
453  frame->blocksize = nb_samples;
454  if (frame->blocksize <= 256) {
455  frame->bs_code[0] = 6;
456  frame->bs_code[1] = frame->blocksize-1;
457  } else {
458  frame->bs_code[0] = 7;
459  frame->bs_code[1] = frame->blocksize-1;
460  }
461  }
462 
463  for (ch = 0; ch < s->channels; ch++) {
464  FlacSubframe *sub = &frame->subframes[ch];
465 
466  sub->wasted = 0;
467  sub->obits = s->avctx->bits_per_raw_sample;
468 
469  if (sub->obits > 16)
470  sub->rc.coding_mode = CODING_MODE_RICE2;
471  else
472  sub->rc.coding_mode = CODING_MODE_RICE;
473  }
474 
475  frame->verbatim_only = 0;
476 }
477 
478 
479 /**
480  * Copy channel-interleaved input samples into separate subframes.
481  */
482 static void copy_samples(FlacEncodeContext *s, const void *samples)
483 {
484  int i, j, ch;
485  FlacFrame *frame;
486  int shift = av_get_bytes_per_sample(s->avctx->sample_fmt) * 8 -
487  s->avctx->bits_per_raw_sample;
488 
489 #define COPY_SAMPLES(bits) do { \
490  const int ## bits ## _t *samples0 = samples; \
491  frame = &s->frame; \
492  for (i = 0, j = 0; i < frame->blocksize; i++) \
493  for (ch = 0; ch < s->channels; ch++, j++) \
494  frame->subframes[ch].samples[i] = samples0[j] >> shift; \
495 } while (0)
496 
497  if (s->avctx->sample_fmt == AV_SAMPLE_FMT_S16)
498  COPY_SAMPLES(16);
499  else
500  COPY_SAMPLES(32);
501 }
502 
503 
504 static uint64_t rice_count_exact(int32_t *res, int n, int k)
505 {
506  int i;
507  uint64_t count = 0;
508 
509  for (i = 0; i < n; i++) {
510  int32_t v = -2 * res[i] - 1;
511  v ^= v >> 31;
512  count += (v >> k) + 1 + k;
513  }
514  return count;
515 }
516 
517 
518 static uint64_t subframe_count_exact(FlacEncodeContext *s, FlacSubframe *sub,
519  int pred_order)
520 {
521  int p, porder, psize;
522  int i, part_end;
523  uint64_t count = 0;
524 
525  /* subframe header */
526  count += 8;
527 
528  /* subframe */
529  if (sub->type == FLAC_SUBFRAME_CONSTANT) {
530  count += sub->obits;
531  } else if (sub->type == FLAC_SUBFRAME_VERBATIM) {
532  count += s->frame.blocksize * sub->obits;
533  } else {
534  /* warm-up samples */
535  count += pred_order * sub->obits;
536 
537  /* LPC coefficients */
538  if (sub->type == FLAC_SUBFRAME_LPC)
539  count += 4 + 5 + pred_order * s->options.lpc_coeff_precision;
540 
541  /* rice-encoded block */
542  count += 2;
543 
544  /* partition order */
545  porder = sub->rc.porder;
546  psize = s->frame.blocksize >> porder;
547  count += 4;
548 
549  /* residual */
550  i = pred_order;
551  part_end = psize;
552  for (p = 0; p < 1 << porder; p++) {
553  int k = sub->rc.params[p];
554  count += sub->rc.coding_mode;
555  count += rice_count_exact(&sub->residual[i], part_end - i, k);
556  i = part_end;
557  part_end = FFMIN(s->frame.blocksize, part_end + psize);
558  }
559  }
560 
561  return count;
562 }
563 
564 
565 #define rice_encode_count(sum, n, k) (((n)*((k)+1))+((sum-(n>>1))>>(k)))
566 
567 /**
568  * Solve for d/dk(rice_encode_count) = n-((sum-(n>>1))>>(k+1)) = 0.
569  */
570 static int find_optimal_param(uint64_t sum, int n, int max_param)
571 {
572  int k;
573  uint64_t sum2;
574 
575  if (sum <= n >> 1)
576  return 0;
577  sum2 = sum - (n >> 1);
578  k = av_log2(av_clipl_int32(sum2 / n));
579  return FFMIN(k, max_param);
580 }
581 
582 
583 static uint64_t calc_optimal_rice_params(RiceContext *rc, int porder,
584  uint64_t *sums, int n, int pred_order)
585 {
586  int i;
587  int k, cnt, part, max_param;
588  uint64_t all_bits;
589 
590  max_param = (1 << rc->coding_mode) - 2;
591 
592  part = (1 << porder);
593  all_bits = 4 * part;
594 
595  cnt = (n >> porder) - pred_order;
596  for (i = 0; i < part; i++) {
597  k = find_optimal_param(sums[i], cnt, max_param);
598  rc->params[i] = k;
599  all_bits += rice_encode_count(sums[i], cnt, k);
600  cnt = n >> porder;
601  }
602 
603  rc->porder = porder;
604 
605  return all_bits;
606 }
607 
608 
609 static void calc_sums(int pmin, int pmax, uint32_t *data, int n, int pred_order,
610  uint64_t sums[][MAX_PARTITIONS])
611 {
612  int i, j;
613  int parts;
614  uint32_t *res, *res_end;
615 
616  /* sums for highest level */
617  parts = (1 << pmax);
618  res = &data[pred_order];
619  res_end = &data[n >> pmax];
620  for (i = 0; i < parts; i++) {
621  uint64_t sum = 0;
622  while (res < res_end)
623  sum += *(res++);
624  sums[pmax][i] = sum;
625  res_end += n >> pmax;
626  }
627  /* sums for lower levels */
628  for (i = pmax - 1; i >= pmin; i--) {
629  parts = (1 << i);
630  for (j = 0; j < parts; j++)
631  sums[i][j] = sums[i+1][2*j] + sums[i+1][2*j+1];
632  }
633 }
634 
635 
636 static uint64_t calc_rice_params(RiceContext *rc, int pmin, int pmax,
637  int32_t *data, int n, int pred_order)
638 {
639  int i;
640  uint64_t bits[MAX_PARTITION_ORDER+1];
641  int opt_porder;
642  RiceContext tmp_rc;
643  uint32_t *udata;
644  uint64_t sums[MAX_PARTITION_ORDER+1][MAX_PARTITIONS];
645 
646  av_assert1(pmin >= 0 && pmin <= MAX_PARTITION_ORDER);
647  av_assert1(pmax >= 0 && pmax <= MAX_PARTITION_ORDER);
648  av_assert1(pmin <= pmax);
649 
650  tmp_rc.coding_mode = rc->coding_mode;
651 
652  udata = av_malloc(n * sizeof(uint32_t));
653  for (i = 0; i < n; i++)
654  udata[i] = (2*data[i]) ^ (data[i]>>31);
655 
656  calc_sums(pmin, pmax, udata, n, pred_order, sums);
657 
658  opt_porder = pmin;
659  bits[pmin] = UINT32_MAX;
660  for (i = pmin; i <= pmax; i++) {
661  bits[i] = calc_optimal_rice_params(&tmp_rc, i, sums[i], n, pred_order);
662  if (bits[i] <= bits[opt_porder]) {
663  opt_porder = i;
664  *rc = tmp_rc;
665  }
666  }
667 
668  av_freep(&udata);
669  return bits[opt_porder];
670 }
671 
672 
673 static int get_max_p_order(int max_porder, int n, int order)
674 {
675  int porder = FFMIN(max_porder, av_log2(n^(n-1)));
676  if (order > 0)
677  porder = FFMIN(porder, av_log2(n/order));
678  return porder;
679 }
680 
681 
682 static uint64_t find_subframe_rice_params(FlacEncodeContext *s,
683  FlacSubframe *sub, int pred_order)
684 {
685  int pmin = get_max_p_order(s->options.min_partition_order,
686  s->frame.blocksize, pred_order);
687  int pmax = get_max_p_order(s->options.max_partition_order,
688  s->frame.blocksize, pred_order);
689 
690  uint64_t bits = 8 + pred_order * sub->obits + 2 + sub->rc.coding_mode;
691  if (sub->type == FLAC_SUBFRAME_LPC)
692  bits += 4 + 5 + pred_order * s->options.lpc_coeff_precision;
693  bits += calc_rice_params(&sub->rc, pmin, pmax, sub->residual,
694  s->frame.blocksize, pred_order);
695  return bits;
696 }
697 
698 
699 static void encode_residual_fixed(int32_t *res, const int32_t *smp, int n,
700  int order)
701 {
702  int i;
703 
704  for (i = 0; i < order; i++)
705  res[i] = smp[i];
706 
707  if (order == 0) {
708  for (i = order; i < n; i++)
709  res[i] = smp[i];
710  } else if (order == 1) {
711  for (i = order; i < n; i++)
712  res[i] = smp[i] - smp[i-1];
713  } else if (order == 2) {
714  int a = smp[order-1] - smp[order-2];
715  for (i = order; i < n; i += 2) {
716  int b = smp[i ] - smp[i-1];
717  res[i] = b - a;
718  a = smp[i+1] - smp[i ];
719  res[i+1] = a - b;
720  }
721  } else if (order == 3) {
722  int a = smp[order-1] - smp[order-2];
723  int c = smp[order-1] - 2*smp[order-2] + smp[order-3];
724  for (i = order; i < n; i += 2) {
725  int b = smp[i ] - smp[i-1];
726  int d = b - a;
727  res[i] = d - c;
728  a = smp[i+1] - smp[i ];
729  c = a - b;
730  res[i+1] = c - d;
731  }
732  } else {
733  int a = smp[order-1] - smp[order-2];
734  int c = smp[order-1] - 2*smp[order-2] + smp[order-3];
735  int e = smp[order-1] - 3*smp[order-2] + 3*smp[order-3] - smp[order-4];
736  for (i = order; i < n; i += 2) {
737  int b = smp[i ] - smp[i-1];
738  int d = b - a;
739  int f = d - c;
740  res[i ] = f - e;
741  a = smp[i+1] - smp[i ];
742  c = a - b;
743  e = c - d;
744  res[i+1] = e - f;
745  }
746  }
747 }
748 
749 
750 static int encode_residual_ch(FlacEncodeContext *s, int ch)
751 {
752  int i, n;
753  int min_order, max_order, opt_order, omethod;
754  FlacFrame *frame;
755  FlacSubframe *sub;
756  int32_t coefs[MAX_LPC_ORDER][MAX_LPC_ORDER];
757  int shift[MAX_LPC_ORDER];
758  int32_t *res, *smp;
759 
760  frame = &s->frame;
761  sub = &frame->subframes[ch];
762  res = sub->residual;
763  smp = sub->samples;
764  n = frame->blocksize;
765 
766  /* CONSTANT */
767  for (i = 1; i < n; i++)
768  if(smp[i] != smp[0])
769  break;
770  if (i == n) {
771  sub->type = sub->type_code = FLAC_SUBFRAME_CONSTANT;
772  res[0] = smp[0];
773  return subframe_count_exact(s, sub, 0);
774  }
775 
776  /* VERBATIM */
777  if (frame->verbatim_only || n < 5) {
778  sub->type = sub->type_code = FLAC_SUBFRAME_VERBATIM;
779  memcpy(res, smp, n * sizeof(int32_t));
780  return subframe_count_exact(s, sub, 0);
781  }
782 
783  min_order = s->options.min_prediction_order;
784  max_order = s->options.max_prediction_order;
785  omethod = s->options.prediction_order_method;
786 
787  /* FIXED */
788  sub->type = FLAC_SUBFRAME_FIXED;
789  if (s->options.lpc_type == FF_LPC_TYPE_NONE ||
790  s->options.lpc_type == FF_LPC_TYPE_FIXED || n <= max_order) {
791  uint64_t bits[MAX_FIXED_ORDER+1];
792  if (max_order > MAX_FIXED_ORDER)
793  max_order = MAX_FIXED_ORDER;
794  opt_order = 0;
795  bits[0] = UINT32_MAX;
796  for (i = min_order; i <= max_order; i++) {
797  encode_residual_fixed(res, smp, n, i);
798  bits[i] = find_subframe_rice_params(s, sub, i);
799  if (bits[i] < bits[opt_order])
800  opt_order = i;
801  }
802  sub->order = opt_order;
803  sub->type_code = sub->type | sub->order;
804  if (sub->order != max_order) {
805  encode_residual_fixed(res, smp, n, sub->order);
806  find_subframe_rice_params(s, sub, sub->order);
807  }
808  return subframe_count_exact(s, sub, sub->order);
809  }
810 
811  /* LPC */
812  sub->type = FLAC_SUBFRAME_LPC;
813  opt_order = ff_lpc_calc_coefs(&s->lpc_ctx, smp, n, min_order, max_order,
814  s->options.lpc_coeff_precision, coefs, shift, s->options.lpc_type,
815  s->options.lpc_passes, omethod,
816  MAX_LPC_SHIFT, 0);
817 
818  if (omethod == ORDER_METHOD_2LEVEL ||
819  omethod == ORDER_METHOD_4LEVEL ||
820  omethod == ORDER_METHOD_8LEVEL) {
821  int levels = 1 << omethod;
822  uint64_t bits[1 << ORDER_METHOD_8LEVEL];
823  int order = -1;
824  int opt_index = levels-1;
825  opt_order = max_order-1;
826  bits[opt_index] = UINT32_MAX;
827  for (i = levels-1; i >= 0; i--) {
828  int last_order = order;
829  order = min_order + (((max_order-min_order+1) * (i+1)) / levels)-1;
830  order = av_clip(order, min_order - 1, max_order - 1);
831  if (order == last_order)
832  continue;
833  s->flac_dsp.lpc_encode(res, smp, n, order+1, coefs[order],
834  shift[order]);
835  bits[i] = find_subframe_rice_params(s, sub, order+1);
836  if (bits[i] < bits[opt_index]) {
837  opt_index = i;
838  opt_order = order;
839  }
840  }
841  opt_order++;
842  } else if (omethod == ORDER_METHOD_SEARCH) {
843  // brute-force optimal order search
844  uint64_t bits[MAX_LPC_ORDER];
845  opt_order = 0;
846  bits[0] = UINT32_MAX;
847  for (i = min_order-1; i < max_order; i++) {
848  s->flac_dsp.lpc_encode(res, smp, n, i+1, coefs[i], shift[i]);
849  bits[i] = find_subframe_rice_params(s, sub, i+1);
850  if (bits[i] < bits[opt_order])
851  opt_order = i;
852  }
853  opt_order++;
854  } else if (omethod == ORDER_METHOD_LOG) {
855  uint64_t bits[MAX_LPC_ORDER];
856  int step;
857 
858  opt_order = min_order - 1 + (max_order-min_order)/3;
859  memset(bits, -1, sizeof(bits));
860 
861  for (step = 16; step; step >>= 1) {
862  int last = opt_order;
863  for (i = last-step; i <= last+step; i += step) {
864  if (i < min_order-1 || i >= max_order || bits[i] < UINT32_MAX)
865  continue;
866  s->flac_dsp.lpc_encode(res, smp, n, i+1, coefs[i], shift[i]);
867  bits[i] = find_subframe_rice_params(s, sub, i+1);
868  if (bits[i] < bits[opt_order])
869  opt_order = i;
870  }
871  }
872  opt_order++;
873  }
874 
875  sub->order = opt_order;
876  sub->type_code = sub->type | (sub->order-1);
877  sub->shift = shift[sub->order-1];
878  for (i = 0; i < sub->order; i++)
879  sub->coefs[i] = coefs[sub->order-1][i];
880 
881  s->flac_dsp.lpc_encode(res, smp, n, sub->order, sub->coefs, sub->shift);
882 
883  find_subframe_rice_params(s, sub, sub->order);
884 
885  return subframe_count_exact(s, sub, sub->order);
886 }
887 
888 
889 static int count_frame_header(FlacEncodeContext *s)
890 {
891  uint8_t av_unused tmp;
892  int count;
893 
894  /*
895  <14> Sync code
896  <1> Reserved
897  <1> Blocking strategy
898  <4> Block size in inter-channel samples
899  <4> Sample rate
900  <4> Channel assignment
901  <3> Sample size in bits
902  <1> Reserved
903  */
904  count = 32;
905 
906  /* coded frame number */
907  PUT_UTF8(s->frame_count, tmp, count += 8;)
908 
909  /* explicit block size */
910  if (s->frame.bs_code[0] == 6)
911  count += 8;
912  else if (s->frame.bs_code[0] == 7)
913  count += 16;
914 
915  /* explicit sample rate */
916  count += ((s->sr_code[0] == 12) + (s->sr_code[0] > 12)) * 8;
917 
918  /* frame header CRC-8 */
919  count += 8;
920 
921  return count;
922 }
923 
924 
925 static int encode_frame(FlacEncodeContext *s)
926 {
927  int ch;
928  uint64_t count;
929 
930  count = count_frame_header(s);
931 
932  for (ch = 0; ch < s->channels; ch++)
933  count += encode_residual_ch(s, ch);
934 
935  count += (8 - (count & 7)) & 7; // byte alignment
936  count += 16; // CRC-16
937 
938  count >>= 3;
939  if (count > INT_MAX)
940  return AVERROR_BUG;
941  return count;
942 }
943 
944 
945 static void remove_wasted_bits(FlacEncodeContext *s)
946 {
947  int ch, i;
948 
949  for (ch = 0; ch < s->channels; ch++) {
950  FlacSubframe *sub = &s->frame.subframes[ch];
951  int32_t v = 0;
952 
953  for (i = 0; i < s->frame.blocksize; i++) {
954  v |= sub->samples[i];
955  if (v & 1)
956  break;
957  }
958 
959  if (v && !(v & 1)) {
960  v = av_ctz(v);
961 
962  for (i = 0; i < s->frame.blocksize; i++)
963  sub->samples[i] >>= v;
964 
965  sub->wasted = v;
966  sub->obits -= v;
967 
968  /* for 24-bit, check if removing wasted bits makes the range better
969  suited for using RICE instead of RICE2 for entropy coding */
970  if (sub->obits <= 17)
971  sub->rc.coding_mode = CODING_MODE_RICE;
972  }
973  }
974 }
975 
976 
977 static int estimate_stereo_mode(int32_t *left_ch, int32_t *right_ch, int n,
978  int max_rice_param)
979 {
980  int i, best;
981  int32_t lt, rt;
982  uint64_t sum[4];
983  uint64_t score[4];
984  int k;
985 
986  /* calculate sum of 2nd order residual for each channel */
987  sum[0] = sum[1] = sum[2] = sum[3] = 0;
988  for (i = 2; i < n; i++) {
989  lt = left_ch[i] - 2*left_ch[i-1] + left_ch[i-2];
990  rt = right_ch[i] - 2*right_ch[i-1] + right_ch[i-2];
991  sum[2] += FFABS((lt + rt) >> 1);
992  sum[3] += FFABS(lt - rt);
993  sum[0] += FFABS(lt);
994  sum[1] += FFABS(rt);
995  }
996  /* estimate bit counts */
997  for (i = 0; i < 4; i++) {
998  k = find_optimal_param(2 * sum[i], n, max_rice_param);
999  sum[i] = rice_encode_count( 2 * sum[i], n, k);
1000  }
1001 
1002  /* calculate score for each mode */
1003  score[0] = sum[0] + sum[1];
1004  score[1] = sum[0] + sum[3];
1005  score[2] = sum[1] + sum[3];
1006  score[3] = sum[2] + sum[3];
1007 
1008  /* return mode with lowest score */
1009  best = 0;
1010  for (i = 1; i < 4; i++)
1011  if (score[i] < score[best])
1012  best = i;
1013 
1014  return best;
1015 }
1016 
1017 
1018 /**
1019  * Perform stereo channel decorrelation.
1020  */
1021 static void channel_decorrelation(FlacEncodeContext *s)
1022 {
1023  FlacFrame *frame;
1024  int32_t *left, *right;
1025  int i, n;
1026 
1027  frame = &s->frame;
1028  n = frame->blocksize;
1029  left = frame->subframes[0].samples;
1030  right = frame->subframes[1].samples;
1031 
1032  if (s->channels != 2) {
1033  frame->ch_mode = FLAC_CHMODE_INDEPENDENT;
1034  return;
1035  }
1036 
1037  if (s->options.ch_mode < 0) {
1038  int max_rice_param = (1 << frame->subframes[0].rc.coding_mode) - 2;
1039  frame->ch_mode = estimate_stereo_mode(left, right, n, max_rice_param);
1040  } else
1041  frame->ch_mode = s->options.ch_mode;
1042 
1043  /* perform decorrelation and adjust bits-per-sample */
1044  if (frame->ch_mode == FLAC_CHMODE_INDEPENDENT)
1045  return;
1046  if (frame->ch_mode == FLAC_CHMODE_MID_SIDE) {
1047  int32_t tmp;
1048  for (i = 0; i < n; i++) {
1049  tmp = left[i];
1050  left[i] = (tmp + right[i]) >> 1;
1051  right[i] = tmp - right[i];
1052  }
1053  frame->subframes[1].obits++;
1054  } else if (frame->ch_mode == FLAC_CHMODE_LEFT_SIDE) {
1055  for (i = 0; i < n; i++)
1056  right[i] = left[i] - right[i];
1057  frame->subframes[1].obits++;
1058  } else {
1059  for (i = 0; i < n; i++)
1060  left[i] -= right[i];
1061  frame->subframes[0].obits++;
1062  }
1063 }
1064 
1065 
1066 static void write_utf8(PutBitContext *pb, uint32_t val)
1067 {
1068  uint8_t tmp;
1069  PUT_UTF8(val, tmp, put_bits(pb, 8, tmp);)
1070 }
1071 
1072 
1073 static void write_frame_header(FlacEncodeContext *s)
1074 {
1075  FlacFrame *frame;
1076  int crc;
1077 
1078  frame = &s->frame;
1079 
1080  put_bits(&s->pb, 16, 0xFFF8);
1081  put_bits(&s->pb, 4, frame->bs_code[0]);
1082  put_bits(&s->pb, 4, s->sr_code[0]);
1083 
1084  if (frame->ch_mode == FLAC_CHMODE_INDEPENDENT)
1085  put_bits(&s->pb, 4, s->channels-1);
1086  else
1087  put_bits(&s->pb, 4, frame->ch_mode + FLAC_MAX_CHANNELS - 1);
1088 
1089  put_bits(&s->pb, 3, s->bps_code);
1090  put_bits(&s->pb, 1, 0);
1091  write_utf8(&s->pb, s->frame_count);
1092 
1093  if (frame->bs_code[0] == 6)
1094  put_bits(&s->pb, 8, frame->bs_code[1]);
1095  else if (frame->bs_code[0] == 7)
1096  put_bits(&s->pb, 16, frame->bs_code[1]);
1097 
1098  if (s->sr_code[0] == 12)
1099  put_bits(&s->pb, 8, s->sr_code[1]);
1100  else if (s->sr_code[0] > 12)
1101  put_bits(&s->pb, 16, s->sr_code[1]);
1102 
1103  flush_put_bits(&s->pb);
1104  crc = av_crc(av_crc_get_table(AV_CRC_8_ATM), 0, s->pb.buf,
1105  put_bits_count(&s->pb) >> 3);
1106  put_bits(&s->pb, 8, crc);
1107 }
1108 
1109 
1110 static void write_subframes(FlacEncodeContext *s)
1111 {
1112  int ch;
1113 
1114  for (ch = 0; ch < s->channels; ch++) {
1115  FlacSubframe *sub = &s->frame.subframes[ch];
1116  int i, p, porder, psize;
1117  int32_t *part_end;
1118  int32_t *res = sub->residual;
1119  int32_t *frame_end = &sub->residual[s->frame.blocksize];
1120 
1121  /* subframe header */
1122  put_bits(&s->pb, 1, 0);
1123  put_bits(&s->pb, 6, sub->type_code);
1124  put_bits(&s->pb, 1, !!sub->wasted);
1125  if (sub->wasted)
1126  put_bits(&s->pb, sub->wasted, 1);
1127 
1128  /* subframe */
1129  if (sub->type == FLAC_SUBFRAME_CONSTANT) {
1130  put_sbits(&s->pb, sub->obits, res[0]);
1131  } else if (sub->type == FLAC_SUBFRAME_VERBATIM) {
1132  while (res < frame_end)
1133  put_sbits(&s->pb, sub->obits, *res++);
1134  } else {
1135  /* warm-up samples */
1136  for (i = 0; i < sub->order; i++)
1137  put_sbits(&s->pb, sub->obits, *res++);
1138 
1139  /* LPC coefficients */
1140  if (sub->type == FLAC_SUBFRAME_LPC) {
1141  int cbits = s->options.lpc_coeff_precision;
1142  put_bits( &s->pb, 4, cbits-1);
1143  put_sbits(&s->pb, 5, sub->shift);
1144  for (i = 0; i < sub->order; i++)
1145  put_sbits(&s->pb, cbits, sub->coefs[i]);
1146  }
1147 
1148  /* rice-encoded block */
1149  put_bits(&s->pb, 2, sub->rc.coding_mode - 4);
1150 
1151  /* partition order */
1152  porder = sub->rc.porder;
1153  psize = s->frame.blocksize >> porder;
1154  put_bits(&s->pb, 4, porder);
1155 
1156  /* residual */
1157  part_end = &sub->residual[psize];
1158  for (p = 0; p < 1 << porder; p++) {
1159  int k = sub->rc.params[p];
1160  put_bits(&s->pb, sub->rc.coding_mode, k);
1161  while (res < part_end)
1162  set_sr_golomb_flac(&s->pb, *res++, k, INT32_MAX, 0);
1163  part_end = FFMIN(frame_end, part_end + psize);
1164  }
1165  }
1166  }
1167 }
1168 
1169 
1170 static void write_frame_footer(FlacEncodeContext *s)
1171 {
1172  int crc;
1173  flush_put_bits(&s->pb);
1174  crc = av_bswap16(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, s->pb.buf,
1175  put_bits_count(&s->pb)>>3));
1176  put_bits(&s->pb, 16, crc);
1177  flush_put_bits(&s->pb);
1178 }
1179 
1180 
1181 static int write_frame(FlacEncodeContext *s, AVPacket *avpkt)
1182 {
1183  init_put_bits(&s->pb, avpkt->data, avpkt->size);
1184  write_frame_header(s);
1185  write_subframes(s);
1186  write_frame_footer(s);
1187  return put_bits_count(&s->pb) >> 3;
1188 }
1189 
1190 
1191 static int update_md5_sum(FlacEncodeContext *s, const void *samples)
1192 {
1193  const uint8_t *buf;
1194  int buf_size = s->frame.blocksize * s->channels *
1195  ((s->avctx->bits_per_raw_sample + 7) / 8);
1196 
1197  if (s->avctx->bits_per_raw_sample > 16 || HAVE_BIGENDIAN) {
1198  av_fast_malloc(&s->md5_buffer, &s->md5_buffer_size, buf_size);
1199  if (!s->md5_buffer)
1200  return AVERROR(ENOMEM);
1201  }
1202 
1203  if (s->avctx->bits_per_raw_sample <= 16) {
1204  buf = (const uint8_t *)samples;
1205 #if HAVE_BIGENDIAN
1206  s->dsp.bswap16_buf((uint16_t *)s->md5_buffer,
1207  (const uint16_t *)samples, buf_size / 2);
1208  buf = s->md5_buffer;
1209 #endif
1210  } else {
1211  int i;
1212  const int32_t *samples0 = samples;
1213  uint8_t *tmp = s->md5_buffer;
1214 
1215  for (i = 0; i < s->frame.blocksize * s->channels; i++) {
1216  int32_t v = samples0[i] >> 8;
1217  *tmp++ = (v ) & 0xFF;
1218  *tmp++ = (v >> 8) & 0xFF;
1219  *tmp++ = (v >> 16) & 0xFF;
1220  }
1221  buf = s->md5_buffer;
1222  }
1223  av_md5_update(s->md5ctx, buf, buf_size);
1224 
1225  return 0;
1226 }
1227 
1228 
1229 static int flac_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
1230  const AVFrame *frame, int *got_packet_ptr)
1231 {
1232  FlacEncodeContext *s;
1233  int frame_bytes, out_bytes, ret;
1234 
1235  s = avctx->priv_data;
1236 
1237  /* when the last block is reached, update the header in extradata */
1238  if (!frame) {
1239  s->max_framesize = s->max_encoded_framesize;
1240  av_md5_final(s->md5ctx, s->md5sum);
1241  write_streaminfo(s, avctx->extradata);
1242  return 0;
1243  }
1244 
1245  /* change max_framesize for small final frame */
1246  if (frame->nb_samples < s->frame.blocksize) {
1247  s->max_framesize = ff_flac_get_max_frame_size(frame->nb_samples,
1248  s->channels,
1249  avctx->bits_per_raw_sample);
1250  }
1251 
1252  init_frame(s, frame->nb_samples);
1253 
1254  copy_samples(s, frame->data[0]);
1255 
1256  channel_decorrelation(s);
1257 
1258  remove_wasted_bits(s);
1259 
1260  frame_bytes = encode_frame(s);
1261 
1262  /* Fall back on verbatim mode if the compressed frame is larger than it
1263  would be if encoded uncompressed. */
1264  if (frame_bytes < 0 || frame_bytes > s->max_framesize) {
1265  s->frame.verbatim_only = 1;
1266  frame_bytes = encode_frame(s);
1267  if (frame_bytes < 0) {
1268  av_log(avctx, AV_LOG_ERROR, "Bad frame count\n");
1269  return frame_bytes;
1270  }
1271  }
1272 
1273  if ((ret = ff_alloc_packet2(avctx, avpkt, frame_bytes)) < 0)
1274  return ret;
1275 
1276  out_bytes = write_frame(s, avpkt);
1277 
1278  s->frame_count++;
1279  s->sample_count += frame->nb_samples;
1280  if ((ret = update_md5_sum(s, frame->data[0])) < 0) {
1281  av_log(avctx, AV_LOG_ERROR, "Error updating MD5 checksum\n");
1282  return ret;
1283  }
1284  if (out_bytes > s->max_encoded_framesize)
1285  s->max_encoded_framesize = out_bytes;
1286  if (out_bytes < s->min_framesize)
1287  s->min_framesize = out_bytes;
1288 
1289  avpkt->pts = frame->pts;
1290  avpkt->duration = ff_samples_to_time_base(avctx, frame->nb_samples);
1291  avpkt->size = out_bytes;
1292  *got_packet_ptr = 1;
1293  return 0;
1294 }
1295 
1296 
1297 static av_cold int flac_encode_close(AVCodecContext *avctx)
1298 {
1299  if (avctx->priv_data) {
1300  FlacEncodeContext *s = avctx->priv_data;
1301  av_freep(&s->md5ctx);
1302  av_freep(&s->md5_buffer);
1303  ff_lpc_end(&s->lpc_ctx);
1304  }
1305  av_freep(&avctx->extradata);
1306  avctx->extradata_size = 0;
1307  return 0;
1308 }
1309 
1310 #define FLAGS AV_OPT_FLAG_ENCODING_PARAM | AV_OPT_FLAG_AUDIO_PARAM
1311 static const AVOption options[] = {
1312 { "lpc_coeff_precision", "LPC coefficient precision", offsetof(FlacEncodeContext, options.lpc_coeff_precision), AV_OPT_TYPE_INT, {.i64 = 15 }, 0, MAX_LPC_PRECISION, FLAGS },
1313 { "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" },
1314 { "none", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_NONE }, INT_MIN, INT_MAX, FLAGS, "lpc_type" },
1315 { "fixed", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_FIXED }, INT_MIN, INT_MAX, FLAGS, "lpc_type" },
1316 { "levinson", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_LEVINSON }, INT_MIN, INT_MAX, FLAGS, "lpc_type" },
1317 { "cholesky", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_CHOLESKY }, INT_MIN, INT_MAX, FLAGS, "lpc_type" },
1318 { "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 },
1319 { "min_partition_order", NULL, offsetof(FlacEncodeContext, options.min_partition_order), AV_OPT_TYPE_INT, {.i64 = -1 }, -1, MAX_PARTITION_ORDER, FLAGS },
1320 { "max_partition_order", NULL, offsetof(FlacEncodeContext, options.max_partition_order), AV_OPT_TYPE_INT, {.i64 = -1 }, -1, MAX_PARTITION_ORDER, FLAGS },
1321 { "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" },
1322 { "estimation", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_EST }, INT_MIN, INT_MAX, FLAGS, "predm" },
1323 { "2level", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_2LEVEL }, INT_MIN, INT_MAX, FLAGS, "predm" },
1324 { "4level", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_4LEVEL }, INT_MIN, INT_MAX, FLAGS, "predm" },
1325 { "8level", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_8LEVEL }, INT_MIN, INT_MAX, FLAGS, "predm" },
1326 { "search", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_SEARCH }, INT_MIN, INT_MAX, FLAGS, "predm" },
1327 { "log", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_LOG }, INT_MIN, INT_MAX, FLAGS, "predm" },
1328 { "ch_mode", "Stereo decorrelation mode", offsetof(FlacEncodeContext, options.ch_mode), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, FLAC_CHMODE_MID_SIDE, FLAGS, "ch_mode" },
1329 { "auto", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = -1 }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1330 { "indep", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_INDEPENDENT }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1331 { "left_side", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_LEFT_SIDE }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1332 { "right_side", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_RIGHT_SIDE }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1333 { "mid_side", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_MID_SIDE }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1334 { NULL },
1335 };
1336 
1337 static const AVClass flac_encoder_class = {
1338  "FLAC encoder",
1339  av_default_item_name,
1340  options,
1341  LIBAVUTIL_VERSION_INT,
1342 };
1343 
1344 AVCodec ff_flac_encoder = {
1345  .name = "flac",
1346  .long_name = NULL_IF_CONFIG_SMALL("FLAC (Free Lossless Audio Codec)"),
1347  .type = AVMEDIA_TYPE_AUDIO,
1348  .id = AV_CODEC_ID_FLAC,
1349  .priv_data_size = sizeof(FlacEncodeContext),
1350  .init = flac_encode_init,
1351  .encode2 = flac_encode_frame,
1352  .close = flac_encode_close,
1353  .capabilities = CODEC_CAP_SMALL_LAST_FRAME | CODEC_CAP_DELAY | CODEC_CAP_LOSSLESS,
1354  .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
1355  AV_SAMPLE_FMT_S32,
1356  AV_SAMPLE_FMT_NONE },
1357  .priv_class = &flac_encoder_class,
1358 };
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