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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 "bswapdsp.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+11];
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  BswapDSPContext bdsp;
117  FLACDSPContext flac_dsp;
118 
119  int flushed;
120  int64_t next_pts;
121 } FlacEncodeContext;
122 
123 
124 /**
125  * Write streaminfo metadata block to byte array.
126  */
127 static void write_streaminfo(FlacEncodeContext *s, uint8_t *header)
128 {
129  PutBitContext pb;
130 
131  memset(header, 0, FLAC_STREAMINFO_SIZE);
132  init_put_bits(&pb, header, FLAC_STREAMINFO_SIZE);
133 
134  /* streaminfo metadata block */
135  put_bits(&pb, 16, s->max_blocksize);
136  put_bits(&pb, 16, s->max_blocksize);
137  put_bits(&pb, 24, s->min_framesize);
138  put_bits(&pb, 24, s->max_framesize);
139  put_bits(&pb, 20, s->samplerate);
140  put_bits(&pb, 3, s->channels-1);
141  put_bits(&pb, 5, s->avctx->bits_per_raw_sample - 1);
142  /* write 36-bit sample count in 2 put_bits() calls */
143  put_bits(&pb, 24, (s->sample_count & 0xFFFFFF000LL) >> 12);
144  put_bits(&pb, 12, s->sample_count & 0x000000FFFLL);
145  flush_put_bits(&pb);
146  memcpy(&header[18], s->md5sum, 16);
147 }
148 
149 
150 /**
151  * Set blocksize based on samplerate.
152  * Choose the closest predefined blocksize >= BLOCK_TIME_MS milliseconds.
153  */
154 static int select_blocksize(int samplerate, int block_time_ms)
155 {
156  int i;
157  int target;
158  int blocksize;
159 
160  av_assert0(samplerate > 0);
161  blocksize = ff_flac_blocksize_table[1];
162  target = (samplerate * block_time_ms) / 1000;
163  for (i = 0; i < 16; i++) {
164  if (target >= ff_flac_blocksize_table[i] &&
165  ff_flac_blocksize_table[i] > blocksize) {
166  blocksize = ff_flac_blocksize_table[i];
167  }
168  }
169  return blocksize;
170 }
171 
172 
173 static av_cold void dprint_compression_options(FlacEncodeContext *s)
174 {
175  AVCodecContext *avctx = s->avctx;
176  CompressionOptions *opt = &s->options;
177 
178  av_log(avctx, AV_LOG_DEBUG, " compression: %d\n", opt->compression_level);
179 
180  switch (opt->lpc_type) {
181  case FF_LPC_TYPE_NONE:
182  av_log(avctx, AV_LOG_DEBUG, " lpc type: None\n");
183  break;
184  case FF_LPC_TYPE_FIXED:
185  av_log(avctx, AV_LOG_DEBUG, " lpc type: Fixed pre-defined coefficients\n");
186  break;
187  case FF_LPC_TYPE_LEVINSON:
188  av_log(avctx, AV_LOG_DEBUG, " lpc type: Levinson-Durbin recursion with Welch window\n");
189  break;
190  case FF_LPC_TYPE_CHOLESKY:
191  av_log(avctx, AV_LOG_DEBUG, " lpc type: Cholesky factorization, %d pass%s\n",
192  opt->lpc_passes, opt->lpc_passes == 1 ? "" : "es");
193  break;
194  }
195 
196  av_log(avctx, AV_LOG_DEBUG, " prediction order: %d, %d\n",
197  opt->min_prediction_order, opt->max_prediction_order);
198 
199  switch (opt->prediction_order_method) {
200  case ORDER_METHOD_EST:
201  av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "estimate");
202  break;
203  case ORDER_METHOD_2LEVEL:
204  av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "2-level");
205  break;
206  case ORDER_METHOD_4LEVEL:
207  av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "4-level");
208  break;
209  case ORDER_METHOD_8LEVEL:
210  av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "8-level");
211  break;
212  case ORDER_METHOD_SEARCH:
213  av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "full search");
214  break;
215  case ORDER_METHOD_LOG:
216  av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "log search");
217  break;
218  }
219 
220 
221  av_log(avctx, AV_LOG_DEBUG, " partition order: %d, %d\n",
222  opt->min_partition_order, opt->max_partition_order);
223 
224  av_log(avctx, AV_LOG_DEBUG, " block size: %d\n", avctx->frame_size);
225 
226  av_log(avctx, AV_LOG_DEBUG, " lpc precision: %d\n",
227  opt->lpc_coeff_precision);
228 }
229 
230 
231 static av_cold int flac_encode_init(AVCodecContext *avctx)
232 {
233  int freq = avctx->sample_rate;
234  int channels = avctx->channels;
235  FlacEncodeContext *s = avctx->priv_data;
236  int i, level, ret;
237  uint8_t *streaminfo;
238 
239  s->avctx = avctx;
240 
241  switch (avctx->sample_fmt) {
242  case AV_SAMPLE_FMT_S16:
243  avctx->bits_per_raw_sample = 16;
244  s->bps_code = 4;
245  break;
246  case AV_SAMPLE_FMT_S32:
247  if (avctx->bits_per_raw_sample != 24)
248  av_log(avctx, AV_LOG_WARNING, "encoding as 24 bits-per-sample\n");
249  avctx->bits_per_raw_sample = 24;
250  s->bps_code = 6;
251  break;
252  }
253 
254  if (channels < 1 || channels > FLAC_MAX_CHANNELS) {
255  av_log(avctx, AV_LOG_ERROR, "%d channels not supported (max %d)\n",
256  channels, FLAC_MAX_CHANNELS);
257  return AVERROR(EINVAL);
258  }
259  s->channels = channels;
260 
261  /* find samplerate in table */
262  if (freq < 1)
263  return -1;
264  for (i = 4; i < 12; i++) {
265  if (freq == ff_flac_sample_rate_table[i]) {
266  s->samplerate = ff_flac_sample_rate_table[i];
267  s->sr_code[0] = i;
268  s->sr_code[1] = 0;
269  break;
270  }
271  }
272  /* if not in table, samplerate is non-standard */
273  if (i == 12) {
274  if (freq % 1000 == 0 && freq < 255000) {
275  s->sr_code[0] = 12;
276  s->sr_code[1] = freq / 1000;
277  } else if (freq % 10 == 0 && freq < 655350) {
278  s->sr_code[0] = 14;
279  s->sr_code[1] = freq / 10;
280  } else if (freq < 65535) {
281  s->sr_code[0] = 13;
282  s->sr_code[1] = freq;
283  } else {
284  av_log(avctx, AV_LOG_ERROR, "%d Hz not supported\n", freq);
285  return AVERROR(EINVAL);
286  }
287  s->samplerate = freq;
288  }
289 
290  /* set compression option defaults based on avctx->compression_level */
291  if (avctx->compression_level < 0)
292  s->options.compression_level = 5;
293  else
294  s->options.compression_level = avctx->compression_level;
295 
296  level = s->options.compression_level;
297  if (level > 12) {
298  av_log(avctx, AV_LOG_ERROR, "invalid compression level: %d\n",
299  s->options.compression_level);
300  return AVERROR(EINVAL);
301  }
302 
303  s->options.block_time_ms = ((int[]){ 27, 27, 27,105,105,105,105,105,105,105,105,105,105})[level];
304 
305  if (s->options.lpc_type == FF_LPC_TYPE_DEFAULT)
306  s->options.lpc_type = ((int[]){ FF_LPC_TYPE_FIXED, FF_LPC_TYPE_FIXED, FF_LPC_TYPE_FIXED,
307  FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON,
308  FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON,
309  FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON,
310  FF_LPC_TYPE_LEVINSON})[level];
311 
312  s->options.min_prediction_order = ((int[]){ 2, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1})[level];
313  s->options.max_prediction_order = ((int[]){ 3, 4, 4, 6, 8, 8, 8, 8, 12, 12, 12, 32, 32})[level];
314 
315  if (s->options.prediction_order_method < 0)
316  s->options.prediction_order_method = ((int[]){ ORDER_METHOD_EST, ORDER_METHOD_EST, ORDER_METHOD_EST,
317  ORDER_METHOD_EST, ORDER_METHOD_EST, ORDER_METHOD_EST,
318  ORDER_METHOD_4LEVEL, ORDER_METHOD_LOG, ORDER_METHOD_4LEVEL,
319  ORDER_METHOD_LOG, ORDER_METHOD_SEARCH, ORDER_METHOD_LOG,
320  ORDER_METHOD_SEARCH})[level];
321 
322  if (s->options.min_partition_order > s->options.max_partition_order) {
323  av_log(avctx, AV_LOG_ERROR, "invalid partition orders: min=%d max=%d\n",
324  s->options.min_partition_order, s->options.max_partition_order);
325  return AVERROR(EINVAL);
326  }
327  if (s->options.min_partition_order < 0)
328  s->options.min_partition_order = ((int[]){ 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0})[level];
329  if (s->options.max_partition_order < 0)
330  s->options.max_partition_order = ((int[]){ 2, 2, 3, 3, 3, 8, 8, 8, 8, 8, 8, 8, 8})[level];
331 
332  if (s->options.lpc_type == FF_LPC_TYPE_NONE) {
333  s->options.min_prediction_order = 0;
334  } else if (avctx->min_prediction_order >= 0) {
335  if (s->options.lpc_type == FF_LPC_TYPE_FIXED) {
336  if (avctx->min_prediction_order > MAX_FIXED_ORDER) {
337  av_log(avctx, AV_LOG_ERROR, "invalid min prediction order: %d\n",
338  avctx->min_prediction_order);
339  return AVERROR(EINVAL);
340  }
341  } else if (avctx->min_prediction_order < MIN_LPC_ORDER ||
342  avctx->min_prediction_order > MAX_LPC_ORDER) {
343  av_log(avctx, AV_LOG_ERROR, "invalid min prediction order: %d\n",
344  avctx->min_prediction_order);
345  return AVERROR(EINVAL);
346  }
347  s->options.min_prediction_order = avctx->min_prediction_order;
348  }
349  if (s->options.lpc_type == FF_LPC_TYPE_NONE) {
350  s->options.max_prediction_order = 0;
351  } else if (avctx->max_prediction_order >= 0) {
352  if (s->options.lpc_type == FF_LPC_TYPE_FIXED) {
353  if (avctx->max_prediction_order > MAX_FIXED_ORDER) {
354  av_log(avctx, AV_LOG_ERROR, "invalid max prediction order: %d\n",
355  avctx->max_prediction_order);
356  return AVERROR(EINVAL);
357  }
358  } else if (avctx->max_prediction_order < MIN_LPC_ORDER ||
359  avctx->max_prediction_order > MAX_LPC_ORDER) {
360  av_log(avctx, AV_LOG_ERROR, "invalid max prediction order: %d\n",
361  avctx->max_prediction_order);
362  return AVERROR(EINVAL);
363  }
364  s->options.max_prediction_order = avctx->max_prediction_order;
365  }
366  if (s->options.max_prediction_order < s->options.min_prediction_order) {
367  av_log(avctx, AV_LOG_ERROR, "invalid prediction orders: min=%d max=%d\n",
368  s->options.min_prediction_order, s->options.max_prediction_order);
369  return AVERROR(EINVAL);
370  }
371 
372  if (avctx->frame_size > 0) {
373  if (avctx->frame_size < FLAC_MIN_BLOCKSIZE ||
374  avctx->frame_size > FLAC_MAX_BLOCKSIZE) {
375  av_log(avctx, AV_LOG_ERROR, "invalid block size: %d\n",
376  avctx->frame_size);
377  return AVERROR(EINVAL);
378  }
379  } else {
380  s->avctx->frame_size = select_blocksize(s->samplerate, s->options.block_time_ms);
381  }
382  s->max_blocksize = s->avctx->frame_size;
383 
384  /* set maximum encoded frame size in verbatim mode */
385  s->max_framesize = ff_flac_get_max_frame_size(s->avctx->frame_size,
386  s->channels,
387  s->avctx->bits_per_raw_sample);
388 
389  /* initialize MD5 context */
390  s->md5ctx = av_md5_alloc();
391  if (!s->md5ctx)
392  return AVERROR(ENOMEM);
393  av_md5_init(s->md5ctx);
394 
395  streaminfo = av_malloc(FLAC_STREAMINFO_SIZE);
396  if (!streaminfo)
397  return AVERROR(ENOMEM);
398  write_streaminfo(s, streaminfo);
399  avctx->extradata = streaminfo;
400  avctx->extradata_size = FLAC_STREAMINFO_SIZE;
401 
402  s->frame_count = 0;
403  s->min_framesize = s->max_framesize;
404 
405  if (channels == 3 &&
406  avctx->channel_layout != (AV_CH_LAYOUT_STEREO|AV_CH_FRONT_CENTER) ||
407  channels == 4 &&
408  avctx->channel_layout != AV_CH_LAYOUT_2_2 &&
409  avctx->channel_layout != AV_CH_LAYOUT_QUAD ||
410  channels == 5 &&
411  avctx->channel_layout != AV_CH_LAYOUT_5POINT0 &&
412  avctx->channel_layout != AV_CH_LAYOUT_5POINT0_BACK ||
413  channels == 6 &&
414  avctx->channel_layout != AV_CH_LAYOUT_5POINT1 &&
415  avctx->channel_layout != AV_CH_LAYOUT_5POINT1_BACK) {
416  if (avctx->channel_layout) {
417  av_log(avctx, AV_LOG_ERROR, "Channel layout not supported by Flac, "
418  "output stream will have incorrect "
419  "channel layout.\n");
420  } else {
421  av_log(avctx, AV_LOG_WARNING, "No channel layout specified. The encoder "
422  "will use Flac channel layout for "
423  "%d channels.\n", channels);
424  }
425  }
426 
427  ret = ff_lpc_init(&s->lpc_ctx, avctx->frame_size,
428  s->options.max_prediction_order, FF_LPC_TYPE_LEVINSON);
429 
430  ff_bswapdsp_init(&s->bdsp);
431  ff_flacdsp_init(&s->flac_dsp, avctx->sample_fmt, channels,
432  avctx->bits_per_raw_sample);
433 
434  dprint_compression_options(s);
435 
436  return ret;
437 }
438 
439 
440 static void init_frame(FlacEncodeContext *s, int nb_samples)
441 {
442  int i, ch;
443  FlacFrame *frame;
444 
445  frame = &s->frame;
446 
447  for (i = 0; i < 16; i++) {
448  if (nb_samples == ff_flac_blocksize_table[i]) {
449  frame->blocksize = ff_flac_blocksize_table[i];
450  frame->bs_code[0] = i;
451  frame->bs_code[1] = 0;
452  break;
453  }
454  }
455  if (i == 16) {
456  frame->blocksize = nb_samples;
457  if (frame->blocksize <= 256) {
458  frame->bs_code[0] = 6;
459  frame->bs_code[1] = frame->blocksize-1;
460  } else {
461  frame->bs_code[0] = 7;
462  frame->bs_code[1] = frame->blocksize-1;
463  }
464  }
465 
466  for (ch = 0; ch < s->channels; ch++) {
467  FlacSubframe *sub = &frame->subframes[ch];
468 
469  sub->wasted = 0;
470  sub->obits = s->avctx->bits_per_raw_sample;
471 
472  if (sub->obits > 16)
473  sub->rc.coding_mode = CODING_MODE_RICE2;
474  else
475  sub->rc.coding_mode = CODING_MODE_RICE;
476  }
477 
478  frame->verbatim_only = 0;
479 }
480 
481 
482 /**
483  * Copy channel-interleaved input samples into separate subframes.
484  */
485 static void copy_samples(FlacEncodeContext *s, const void *samples)
486 {
487  int i, j, ch;
488  FlacFrame *frame;
489  int shift = av_get_bytes_per_sample(s->avctx->sample_fmt) * 8 -
490  s->avctx->bits_per_raw_sample;
491 
492 #define COPY_SAMPLES(bits) do { \
493  const int ## bits ## _t *samples0 = samples; \
494  frame = &s->frame; \
495  for (i = 0, j = 0; i < frame->blocksize; i++) \
496  for (ch = 0; ch < s->channels; ch++, j++) \
497  frame->subframes[ch].samples[i] = samples0[j] >> shift; \
498 } while (0)
499 
500  if (s->avctx->sample_fmt == AV_SAMPLE_FMT_S16)
501  COPY_SAMPLES(16);
502  else
503  COPY_SAMPLES(32);
504 }
505 
506 
507 static uint64_t rice_count_exact(int32_t *res, int n, int k)
508 {
509  int i;
510  uint64_t count = 0;
511 
512  for (i = 0; i < n; i++) {
513  int32_t v = -2 * res[i] - 1;
514  v ^= v >> 31;
515  count += (v >> k) + 1 + k;
516  }
517  return count;
518 }
519 
520 
521 static uint64_t subframe_count_exact(FlacEncodeContext *s, FlacSubframe *sub,
522  int pred_order)
523 {
524  int p, porder, psize;
525  int i, part_end;
526  uint64_t count = 0;
527 
528  /* subframe header */
529  count += 8;
530 
531  /* subframe */
532  if (sub->type == FLAC_SUBFRAME_CONSTANT) {
533  count += sub->obits;
534  } else if (sub->type == FLAC_SUBFRAME_VERBATIM) {
535  count += s->frame.blocksize * sub->obits;
536  } else {
537  /* warm-up samples */
538  count += pred_order * sub->obits;
539 
540  /* LPC coefficients */
541  if (sub->type == FLAC_SUBFRAME_LPC)
542  count += 4 + 5 + pred_order * s->options.lpc_coeff_precision;
543 
544  /* rice-encoded block */
545  count += 2;
546 
547  /* partition order */
548  porder = sub->rc.porder;
549  psize = s->frame.blocksize >> porder;
550  count += 4;
551 
552  /* residual */
553  i = pred_order;
554  part_end = psize;
555  for (p = 0; p < 1 << porder; p++) {
556  int k = sub->rc.params[p];
557  count += sub->rc.coding_mode;
558  count += rice_count_exact(&sub->residual[i], part_end - i, k);
559  i = part_end;
560  part_end = FFMIN(s->frame.blocksize, part_end + psize);
561  }
562  }
563 
564  return count;
565 }
566 
567 
568 #define rice_encode_count(sum, n, k) (((n)*((k)+1))+((sum-(n>>1))>>(k)))
569 
570 /**
571  * Solve for d/dk(rice_encode_count) = n-((sum-(n>>1))>>(k+1)) = 0.
572  */
573 static int find_optimal_param(uint64_t sum, int n, int max_param)
574 {
575  int k;
576  uint64_t sum2;
577 
578  if (sum <= n >> 1)
579  return 0;
580  sum2 = sum - (n >> 1);
581  k = av_log2(av_clipl_int32(sum2 / n));
582  return FFMIN(k, max_param);
583 }
584 
585 
586 static uint64_t calc_optimal_rice_params(RiceContext *rc, int porder,
587  uint64_t *sums, int n, int pred_order)
588 {
589  int i;
590  int k, cnt, part, max_param;
591  uint64_t all_bits;
592 
593  max_param = (1 << rc->coding_mode) - 2;
594 
595  part = (1 << porder);
596  all_bits = 4 * part;
597 
598  cnt = (n >> porder) - pred_order;
599  for (i = 0; i < part; i++) {
600  k = find_optimal_param(sums[i], cnt, max_param);
601  rc->params[i] = k;
602  all_bits += rice_encode_count(sums[i], cnt, k);
603  cnt = n >> porder;
604  }
605 
606  rc->porder = porder;
607 
608  return all_bits;
609 }
610 
611 
612 static void calc_sums(int pmin, int pmax, uint32_t *data, int n, int pred_order,
613  uint64_t sums[][MAX_PARTITIONS])
614 {
615  int i, j;
616  int parts;
617  uint32_t *res, *res_end;
618 
619  /* sums for highest level */
620  parts = (1 << pmax);
621  res = &data[pred_order];
622  res_end = &data[n >> pmax];
623  for (i = 0; i < parts; i++) {
624  uint64_t sum = 0;
625  while (res < res_end)
626  sum += *(res++);
627  sums[pmax][i] = sum;
628  res_end += n >> pmax;
629  }
630  /* sums for lower levels */
631  for (i = pmax - 1; i >= pmin; i--) {
632  parts = (1 << i);
633  for (j = 0; j < parts; j++)
634  sums[i][j] = sums[i+1][2*j] + sums[i+1][2*j+1];
635  }
636 }
637 
638 
639 static uint64_t calc_rice_params(RiceContext *rc, int pmin, int pmax,
640  int32_t *data, int n, int pred_order)
641 {
642  int i;
643  uint64_t bits[MAX_PARTITION_ORDER+1];
644  int opt_porder;
645  RiceContext tmp_rc;
646  uint32_t *udata;
647  uint64_t sums[MAX_PARTITION_ORDER+1][MAX_PARTITIONS];
648 
649  av_assert1(pmin >= 0 && pmin <= MAX_PARTITION_ORDER);
650  av_assert1(pmax >= 0 && pmax <= MAX_PARTITION_ORDER);
651  av_assert1(pmin <= pmax);
652 
653  tmp_rc.coding_mode = rc->coding_mode;
654 
655  udata = av_malloc_array(n, sizeof(uint32_t));
656  for (i = 0; i < n; i++)
657  udata[i] = (2*data[i]) ^ (data[i]>>31);
658 
659  calc_sums(pmin, pmax, udata, n, pred_order, sums);
660 
661  opt_porder = pmin;
662  bits[pmin] = UINT32_MAX;
663  for (i = pmin; i <= pmax; i++) {
664  bits[i] = calc_optimal_rice_params(&tmp_rc, i, sums[i], n, pred_order);
665  if (bits[i] <= bits[opt_porder]) {
666  opt_porder = i;
667  *rc = tmp_rc;
668  }
669  }
670 
671  av_freep(&udata);
672  return bits[opt_porder];
673 }
674 
675 
676 static int get_max_p_order(int max_porder, int n, int order)
677 {
678  int porder = FFMIN(max_porder, av_log2(n^(n-1)));
679  if (order > 0)
680  porder = FFMIN(porder, av_log2(n/order));
681  return porder;
682 }
683 
684 
685 static uint64_t find_subframe_rice_params(FlacEncodeContext *s,
686  FlacSubframe *sub, int pred_order)
687 {
688  int pmin = get_max_p_order(s->options.min_partition_order,
689  s->frame.blocksize, pred_order);
690  int pmax = get_max_p_order(s->options.max_partition_order,
691  s->frame.blocksize, pred_order);
692 
693  uint64_t bits = 8 + pred_order * sub->obits + 2 + sub->rc.coding_mode;
694  if (sub->type == FLAC_SUBFRAME_LPC)
695  bits += 4 + 5 + pred_order * s->options.lpc_coeff_precision;
696  bits += calc_rice_params(&sub->rc, pmin, pmax, sub->residual,
697  s->frame.blocksize, pred_order);
698  return bits;
699 }
700 
701 
702 static void encode_residual_fixed(int32_t *res, const int32_t *smp, int n,
703  int order)
704 {
705  int i;
706 
707  for (i = 0; i < order; i++)
708  res[i] = smp[i];
709 
710  if (order == 0) {
711  for (i = order; i < n; i++)
712  res[i] = smp[i];
713  } else if (order == 1) {
714  for (i = order; i < n; i++)
715  res[i] = smp[i] - smp[i-1];
716  } else if (order == 2) {
717  int a = smp[order-1] - smp[order-2];
718  for (i = order; i < n; i += 2) {
719  int b = smp[i ] - smp[i-1];
720  res[i] = b - a;
721  a = smp[i+1] - smp[i ];
722  res[i+1] = a - b;
723  }
724  } else if (order == 3) {
725  int a = smp[order-1] - smp[order-2];
726  int c = smp[order-1] - 2*smp[order-2] + smp[order-3];
727  for (i = order; i < n; i += 2) {
728  int b = smp[i ] - smp[i-1];
729  int d = b - a;
730  res[i] = d - c;
731  a = smp[i+1] - smp[i ];
732  c = a - b;
733  res[i+1] = c - d;
734  }
735  } else {
736  int a = smp[order-1] - smp[order-2];
737  int c = smp[order-1] - 2*smp[order-2] + smp[order-3];
738  int e = smp[order-1] - 3*smp[order-2] + 3*smp[order-3] - smp[order-4];
739  for (i = order; i < n; i += 2) {
740  int b = smp[i ] - smp[i-1];
741  int d = b - a;
742  int f = d - c;
743  res[i ] = f - e;
744  a = smp[i+1] - smp[i ];
745  c = a - b;
746  e = c - d;
747  res[i+1] = e - f;
748  }
749  }
750 }
751 
752 
753 static int encode_residual_ch(FlacEncodeContext *s, int ch)
754 {
755  int i, n;
756  int min_order, max_order, opt_order, omethod;
757  FlacFrame *frame;
758  FlacSubframe *sub;
759  int32_t coefs[MAX_LPC_ORDER][MAX_LPC_ORDER];
760  int shift[MAX_LPC_ORDER];
761  int32_t *res, *smp;
762 
763  frame = &s->frame;
764  sub = &frame->subframes[ch];
765  res = sub->residual;
766  smp = sub->samples;
767  n = frame->blocksize;
768 
769  /* CONSTANT */
770  for (i = 1; i < n; i++)
771  if(smp[i] != smp[0])
772  break;
773  if (i == n) {
774  sub->type = sub->type_code = FLAC_SUBFRAME_CONSTANT;
775  res[0] = smp[0];
776  return subframe_count_exact(s, sub, 0);
777  }
778 
779  /* VERBATIM */
780  if (frame->verbatim_only || n < 5) {
781  sub->type = sub->type_code = FLAC_SUBFRAME_VERBATIM;
782  memcpy(res, smp, n * sizeof(int32_t));
783  return subframe_count_exact(s, sub, 0);
784  }
785 
786  min_order = s->options.min_prediction_order;
787  max_order = s->options.max_prediction_order;
788  omethod = s->options.prediction_order_method;
789 
790  /* FIXED */
791  sub->type = FLAC_SUBFRAME_FIXED;
792  if (s->options.lpc_type == FF_LPC_TYPE_NONE ||
793  s->options.lpc_type == FF_LPC_TYPE_FIXED || n <= max_order) {
794  uint64_t bits[MAX_FIXED_ORDER+1];
795  if (max_order > MAX_FIXED_ORDER)
796  max_order = MAX_FIXED_ORDER;
797  opt_order = 0;
798  bits[0] = UINT32_MAX;
799  for (i = min_order; i <= max_order; i++) {
800  encode_residual_fixed(res, smp, n, i);
801  bits[i] = find_subframe_rice_params(s, sub, i);
802  if (bits[i] < bits[opt_order])
803  opt_order = i;
804  }
805  sub->order = opt_order;
806  sub->type_code = sub->type | sub->order;
807  if (sub->order != max_order) {
808  encode_residual_fixed(res, smp, n, sub->order);
809  find_subframe_rice_params(s, sub, sub->order);
810  }
811  return subframe_count_exact(s, sub, sub->order);
812  }
813 
814  /* LPC */
815  sub->type = FLAC_SUBFRAME_LPC;
816  opt_order = ff_lpc_calc_coefs(&s->lpc_ctx, smp, n, min_order, max_order,
817  s->options.lpc_coeff_precision, coefs, shift, s->options.lpc_type,
818  s->options.lpc_passes, omethod,
819  MAX_LPC_SHIFT, 0);
820 
821  if (omethod == ORDER_METHOD_2LEVEL ||
822  omethod == ORDER_METHOD_4LEVEL ||
823  omethod == ORDER_METHOD_8LEVEL) {
824  int levels = 1 << omethod;
825  uint64_t bits[1 << ORDER_METHOD_8LEVEL];
826  int order = -1;
827  int opt_index = levels-1;
828  opt_order = max_order-1;
829  bits[opt_index] = UINT32_MAX;
830  for (i = levels-1; i >= 0; i--) {
831  int last_order = order;
832  order = min_order + (((max_order-min_order+1) * (i+1)) / levels)-1;
833  order = av_clip(order, min_order - 1, max_order - 1);
834  if (order == last_order)
835  continue;
836  s->flac_dsp.lpc_encode(res, smp, n, order+1, coefs[order],
837  shift[order]);
838  bits[i] = find_subframe_rice_params(s, sub, order+1);
839  if (bits[i] < bits[opt_index]) {
840  opt_index = i;
841  opt_order = order;
842  }
843  }
844  opt_order++;
845  } else if (omethod == ORDER_METHOD_SEARCH) {
846  // brute-force optimal order search
847  uint64_t bits[MAX_LPC_ORDER];
848  opt_order = 0;
849  bits[0] = UINT32_MAX;
850  for (i = min_order-1; i < max_order; i++) {
851  s->flac_dsp.lpc_encode(res, smp, n, i+1, coefs[i], shift[i]);
852  bits[i] = find_subframe_rice_params(s, sub, i+1);
853  if (bits[i] < bits[opt_order])
854  opt_order = i;
855  }
856  opt_order++;
857  } else if (omethod == ORDER_METHOD_LOG) {
858  uint64_t bits[MAX_LPC_ORDER];
859  int step;
860 
861  opt_order = min_order - 1 + (max_order-min_order)/3;
862  memset(bits, -1, sizeof(bits));
863 
864  for (step = 16; step; step >>= 1) {
865  int last = opt_order;
866  for (i = last-step; i <= last+step; i += step) {
867  if (i < min_order-1 || i >= max_order || bits[i] < UINT32_MAX)
868  continue;
869  s->flac_dsp.lpc_encode(res, smp, n, i+1, coefs[i], shift[i]);
870  bits[i] = find_subframe_rice_params(s, sub, i+1);
871  if (bits[i] < bits[opt_order])
872  opt_order = i;
873  }
874  }
875  opt_order++;
876  }
877 
878  sub->order = opt_order;
879  sub->type_code = sub->type | (sub->order-1);
880  sub->shift = shift[sub->order-1];
881  for (i = 0; i < sub->order; i++)
882  sub->coefs[i] = coefs[sub->order-1][i];
883 
884  s->flac_dsp.lpc_encode(res, smp, n, sub->order, sub->coefs, sub->shift);
885 
886  find_subframe_rice_params(s, sub, sub->order);
887 
888  return subframe_count_exact(s, sub, sub->order);
889 }
890 
891 
892 static int count_frame_header(FlacEncodeContext *s)
893 {
894  uint8_t av_unused tmp;
895  int count;
896 
897  /*
898  <14> Sync code
899  <1> Reserved
900  <1> Blocking strategy
901  <4> Block size in inter-channel samples
902  <4> Sample rate
903  <4> Channel assignment
904  <3> Sample size in bits
905  <1> Reserved
906  */
907  count = 32;
908 
909  /* coded frame number */
910  PUT_UTF8(s->frame_count, tmp, count += 8;)
911 
912  /* explicit block size */
913  if (s->frame.bs_code[0] == 6)
914  count += 8;
915  else if (s->frame.bs_code[0] == 7)
916  count += 16;
917 
918  /* explicit sample rate */
919  count += ((s->sr_code[0] == 12) + (s->sr_code[0] > 12)) * 8;
920 
921  /* frame header CRC-8 */
922  count += 8;
923 
924  return count;
925 }
926 
927 
928 static int encode_frame(FlacEncodeContext *s)
929 {
930  int ch;
931  uint64_t count;
932 
933  count = count_frame_header(s);
934 
935  for (ch = 0; ch < s->channels; ch++)
936  count += encode_residual_ch(s, ch);
937 
938  count += (8 - (count & 7)) & 7; // byte alignment
939  count += 16; // CRC-16
940 
941  count >>= 3;
942  if (count > INT_MAX)
943  return AVERROR_BUG;
944  return count;
945 }
946 
947 
948 static void remove_wasted_bits(FlacEncodeContext *s)
949 {
950  int ch, i;
951 
952  for (ch = 0; ch < s->channels; ch++) {
953  FlacSubframe *sub = &s->frame.subframes[ch];
954  int32_t v = 0;
955 
956  for (i = 0; i < s->frame.blocksize; i++) {
957  v |= sub->samples[i];
958  if (v & 1)
959  break;
960  }
961 
962  if (v && !(v & 1)) {
963  v = av_ctz(v);
964 
965  for (i = 0; i < s->frame.blocksize; i++)
966  sub->samples[i] >>= v;
967 
968  sub->wasted = v;
969  sub->obits -= v;
970 
971  /* for 24-bit, check if removing wasted bits makes the range better
972  suited for using RICE instead of RICE2 for entropy coding */
973  if (sub->obits <= 17)
974  sub->rc.coding_mode = CODING_MODE_RICE;
975  }
976  }
977 }
978 
979 
980 static int estimate_stereo_mode(int32_t *left_ch, int32_t *right_ch, int n,
981  int max_rice_param)
982 {
983  int i, best;
984  int32_t lt, rt;
985  uint64_t sum[4];
986  uint64_t score[4];
987  int k;
988 
989  /* calculate sum of 2nd order residual for each channel */
990  sum[0] = sum[1] = sum[2] = sum[3] = 0;
991  for (i = 2; i < n; i++) {
992  lt = left_ch[i] - 2*left_ch[i-1] + left_ch[i-2];
993  rt = right_ch[i] - 2*right_ch[i-1] + right_ch[i-2];
994  sum[2] += FFABS((lt + rt) >> 1);
995  sum[3] += FFABS(lt - rt);
996  sum[0] += FFABS(lt);
997  sum[1] += FFABS(rt);
998  }
999  /* estimate bit counts */
1000  for (i = 0; i < 4; i++) {
1001  k = find_optimal_param(2 * sum[i], n, max_rice_param);
1002  sum[i] = rice_encode_count( 2 * sum[i], n, k);
1003  }
1004 
1005  /* calculate score for each mode */
1006  score[0] = sum[0] + sum[1];
1007  score[1] = sum[0] + sum[3];
1008  score[2] = sum[1] + sum[3];
1009  score[3] = sum[2] + sum[3];
1010 
1011  /* return mode with lowest score */
1012  best = 0;
1013  for (i = 1; i < 4; i++)
1014  if (score[i] < score[best])
1015  best = i;
1016 
1017  return best;
1018 }
1019 
1020 
1021 /**
1022  * Perform stereo channel decorrelation.
1023  */
1024 static void channel_decorrelation(FlacEncodeContext *s)
1025 {
1026  FlacFrame *frame;
1027  int32_t *left, *right;
1028  int i, n;
1029 
1030  frame = &s->frame;
1031  n = frame->blocksize;
1032  left = frame->subframes[0].samples;
1033  right = frame->subframes[1].samples;
1034 
1035  if (s->channels != 2) {
1036  frame->ch_mode = FLAC_CHMODE_INDEPENDENT;
1037  return;
1038  }
1039 
1040  if (s->options.ch_mode < 0) {
1041  int max_rice_param = (1 << frame->subframes[0].rc.coding_mode) - 2;
1042  frame->ch_mode = estimate_stereo_mode(left, right, n, max_rice_param);
1043  } else
1044  frame->ch_mode = s->options.ch_mode;
1045 
1046  /* perform decorrelation and adjust bits-per-sample */
1047  if (frame->ch_mode == FLAC_CHMODE_INDEPENDENT)
1048  return;
1049  if (frame->ch_mode == FLAC_CHMODE_MID_SIDE) {
1050  int32_t tmp;
1051  for (i = 0; i < n; i++) {
1052  tmp = left[i];
1053  left[i] = (tmp + right[i]) >> 1;
1054  right[i] = tmp - right[i];
1055  }
1056  frame->subframes[1].obits++;
1057  } else if (frame->ch_mode == FLAC_CHMODE_LEFT_SIDE) {
1058  for (i = 0; i < n; i++)
1059  right[i] = left[i] - right[i];
1060  frame->subframes[1].obits++;
1061  } else {
1062  for (i = 0; i < n; i++)
1063  left[i] -= right[i];
1064  frame->subframes[0].obits++;
1065  }
1066 }
1067 
1068 
1069 static void write_utf8(PutBitContext *pb, uint32_t val)
1070 {
1071  uint8_t tmp;
1072  PUT_UTF8(val, tmp, put_bits(pb, 8, tmp);)
1073 }
1074 
1075 
1076 static void write_frame_header(FlacEncodeContext *s)
1077 {
1078  FlacFrame *frame;
1079  int crc;
1080 
1081  frame = &s->frame;
1082 
1083  put_bits(&s->pb, 16, 0xFFF8);
1084  put_bits(&s->pb, 4, frame->bs_code[0]);
1085  put_bits(&s->pb, 4, s->sr_code[0]);
1086 
1087  if (frame->ch_mode == FLAC_CHMODE_INDEPENDENT)
1088  put_bits(&s->pb, 4, s->channels-1);
1089  else
1090  put_bits(&s->pb, 4, frame->ch_mode + FLAC_MAX_CHANNELS - 1);
1091 
1092  put_bits(&s->pb, 3, s->bps_code);
1093  put_bits(&s->pb, 1, 0);
1094  write_utf8(&s->pb, s->frame_count);
1095 
1096  if (frame->bs_code[0] == 6)
1097  put_bits(&s->pb, 8, frame->bs_code[1]);
1098  else if (frame->bs_code[0] == 7)
1099  put_bits(&s->pb, 16, frame->bs_code[1]);
1100 
1101  if (s->sr_code[0] == 12)
1102  put_bits(&s->pb, 8, s->sr_code[1]);
1103  else if (s->sr_code[0] > 12)
1104  put_bits(&s->pb, 16, s->sr_code[1]);
1105 
1106  flush_put_bits(&s->pb);
1107  crc = av_crc(av_crc_get_table(AV_CRC_8_ATM), 0, s->pb.buf,
1108  put_bits_count(&s->pb) >> 3);
1109  put_bits(&s->pb, 8, crc);
1110 }
1111 
1112 
1113 static void write_subframes(FlacEncodeContext *s)
1114 {
1115  int ch;
1116 
1117  for (ch = 0; ch < s->channels; ch++) {
1118  FlacSubframe *sub = &s->frame.subframes[ch];
1119  int i, p, porder, psize;
1120  int32_t *part_end;
1121  int32_t *res = sub->residual;
1122  int32_t *frame_end = &sub->residual[s->frame.blocksize];
1123 
1124  /* subframe header */
1125  put_bits(&s->pb, 1, 0);
1126  put_bits(&s->pb, 6, sub->type_code);
1127  put_bits(&s->pb, 1, !!sub->wasted);
1128  if (sub->wasted)
1129  put_bits(&s->pb, sub->wasted, 1);
1130 
1131  /* subframe */
1132  if (sub->type == FLAC_SUBFRAME_CONSTANT) {
1133  put_sbits(&s->pb, sub->obits, res[0]);
1134  } else if (sub->type == FLAC_SUBFRAME_VERBATIM) {
1135  while (res < frame_end)
1136  put_sbits(&s->pb, sub->obits, *res++);
1137  } else {
1138  /* warm-up samples */
1139  for (i = 0; i < sub->order; i++)
1140  put_sbits(&s->pb, sub->obits, *res++);
1141 
1142  /* LPC coefficients */
1143  if (sub->type == FLAC_SUBFRAME_LPC) {
1144  int cbits = s->options.lpc_coeff_precision;
1145  put_bits( &s->pb, 4, cbits-1);
1146  put_sbits(&s->pb, 5, sub->shift);
1147  for (i = 0; i < sub->order; i++)
1148  put_sbits(&s->pb, cbits, sub->coefs[i]);
1149  }
1150 
1151  /* rice-encoded block */
1152  put_bits(&s->pb, 2, sub->rc.coding_mode - 4);
1153 
1154  /* partition order */
1155  porder = sub->rc.porder;
1156  psize = s->frame.blocksize >> porder;
1157  put_bits(&s->pb, 4, porder);
1158 
1159  /* residual */
1160  part_end = &sub->residual[psize];
1161  for (p = 0; p < 1 << porder; p++) {
1162  int k = sub->rc.params[p];
1163  put_bits(&s->pb, sub->rc.coding_mode, k);
1164  while (res < part_end)
1165  set_sr_golomb_flac(&s->pb, *res++, k, INT32_MAX, 0);
1166  part_end = FFMIN(frame_end, part_end + psize);
1167  }
1168  }
1169  }
1170 }
1171 
1172 
1173 static void write_frame_footer(FlacEncodeContext *s)
1174 {
1175  int crc;
1176  flush_put_bits(&s->pb);
1177  crc = av_bswap16(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, s->pb.buf,
1178  put_bits_count(&s->pb)>>3));
1179  put_bits(&s->pb, 16, crc);
1180  flush_put_bits(&s->pb);
1181 }
1182 
1183 
1184 static int write_frame(FlacEncodeContext *s, AVPacket *avpkt)
1185 {
1186  init_put_bits(&s->pb, avpkt->data, avpkt->size);
1187  write_frame_header(s);
1188  write_subframes(s);
1189  write_frame_footer(s);
1190  return put_bits_count(&s->pb) >> 3;
1191 }
1192 
1193 
1194 static int update_md5_sum(FlacEncodeContext *s, const void *samples)
1195 {
1196  const uint8_t *buf;
1197  int buf_size = s->frame.blocksize * s->channels *
1198  ((s->avctx->bits_per_raw_sample + 7) / 8);
1199 
1200  if (s->avctx->bits_per_raw_sample > 16 || HAVE_BIGENDIAN) {
1201  av_fast_malloc(&s->md5_buffer, &s->md5_buffer_size, buf_size);
1202  if (!s->md5_buffer)
1203  return AVERROR(ENOMEM);
1204  }
1205 
1206  if (s->avctx->bits_per_raw_sample <= 16) {
1207  buf = (const uint8_t *)samples;
1208 #if HAVE_BIGENDIAN
1209  s->bdsp.bswap16_buf((uint16_t *) s->md5_buffer,
1210  (const uint16_t *) samples, buf_size / 2);
1211  buf = s->md5_buffer;
1212 #endif
1213  } else {
1214  int i;
1215  const int32_t *samples0 = samples;
1216  uint8_t *tmp = s->md5_buffer;
1217 
1218  for (i = 0; i < s->frame.blocksize * s->channels; i++) {
1219  int32_t v = samples0[i] >> 8;
1220  *tmp++ = (v ) & 0xFF;
1221  *tmp++ = (v >> 8) & 0xFF;
1222  *tmp++ = (v >> 16) & 0xFF;
1223  }
1224  buf = s->md5_buffer;
1225  }
1226  av_md5_update(s->md5ctx, buf, buf_size);
1227 
1228  return 0;
1229 }
1230 
1231 
1232 static int flac_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
1233  const AVFrame *frame, int *got_packet_ptr)
1234 {
1235  FlacEncodeContext *s;
1236  int frame_bytes, out_bytes, ret;
1237 
1238  s = avctx->priv_data;
1239 
1240  /* when the last block is reached, update the header in extradata */
1241  if (!frame) {
1242  s->max_framesize = s->max_encoded_framesize;
1243  av_md5_final(s->md5ctx, s->md5sum);
1244  write_streaminfo(s, avctx->extradata);
1245 
1246  if (avctx->side_data_only_packets && !s->flushed) {
1247  uint8_t *side_data = av_packet_new_side_data(avpkt, AV_PKT_DATA_NEW_EXTRADATA,
1248  avctx->extradata_size);
1249  if (!side_data)
1250  return AVERROR(ENOMEM);
1251  memcpy(side_data, avctx->extradata, avctx->extradata_size);
1252 
1253  avpkt->pts = s->next_pts;
1254 
1255  *got_packet_ptr = 1;
1256  s->flushed = 1;
1257  }
1258 
1259  return 0;
1260  }
1261 
1262  /* change max_framesize for small final frame */
1263  if (frame->nb_samples < s->frame.blocksize) {
1264  s->max_framesize = ff_flac_get_max_frame_size(frame->nb_samples,
1265  s->channels,
1266  avctx->bits_per_raw_sample);
1267  }
1268 
1269  init_frame(s, frame->nb_samples);
1270 
1271  copy_samples(s, frame->data[0]);
1272 
1273  channel_decorrelation(s);
1274 
1275  remove_wasted_bits(s);
1276 
1277  frame_bytes = encode_frame(s);
1278 
1279  /* Fall back on verbatim mode if the compressed frame is larger than it
1280  would be if encoded uncompressed. */
1281  if (frame_bytes < 0 || frame_bytes > s->max_framesize) {
1282  s->frame.verbatim_only = 1;
1283  frame_bytes = encode_frame(s);
1284  if (frame_bytes < 0) {
1285  av_log(avctx, AV_LOG_ERROR, "Bad frame count\n");
1286  return frame_bytes;
1287  }
1288  }
1289 
1290  if ((ret = ff_alloc_packet2(avctx, avpkt, frame_bytes)) < 0)
1291  return ret;
1292 
1293  out_bytes = write_frame(s, avpkt);
1294 
1295  s->frame_count++;
1296  s->sample_count += frame->nb_samples;
1297  if ((ret = update_md5_sum(s, frame->data[0])) < 0) {
1298  av_log(avctx, AV_LOG_ERROR, "Error updating MD5 checksum\n");
1299  return ret;
1300  }
1301  if (out_bytes > s->max_encoded_framesize)
1302  s->max_encoded_framesize = out_bytes;
1303  if (out_bytes < s->min_framesize)
1304  s->min_framesize = out_bytes;
1305 
1306  avpkt->pts = frame->pts;
1307  avpkt->duration = ff_samples_to_time_base(avctx, frame->nb_samples);
1308  avpkt->size = out_bytes;
1309 
1310  s->next_pts = avpkt->pts + avpkt->duration;
1311 
1312  *got_packet_ptr = 1;
1313  return 0;
1314 }
1315 
1316 
1317 static av_cold int flac_encode_close(AVCodecContext *avctx)
1318 {
1319  if (avctx->priv_data) {
1320  FlacEncodeContext *s = avctx->priv_data;
1321  av_freep(&s->md5ctx);
1322  av_freep(&s->md5_buffer);
1323  ff_lpc_end(&s->lpc_ctx);
1324  }
1325  av_freep(&avctx->extradata);
1326  avctx->extradata_size = 0;
1327  return 0;
1328 }
1329 
1330 #define FLAGS AV_OPT_FLAG_ENCODING_PARAM | AV_OPT_FLAG_AUDIO_PARAM
1331 static const AVOption options[] = {
1332 { "lpc_coeff_precision", "LPC coefficient precision", offsetof(FlacEncodeContext, options.lpc_coeff_precision), AV_OPT_TYPE_INT, {.i64 = 15 }, 0, MAX_LPC_PRECISION, FLAGS },
1333 { "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" },
1334 { "none", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_NONE }, INT_MIN, INT_MAX, FLAGS, "lpc_type" },
1335 { "fixed", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_FIXED }, INT_MIN, INT_MAX, FLAGS, "lpc_type" },
1336 { "levinson", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_LEVINSON }, INT_MIN, INT_MAX, FLAGS, "lpc_type" },
1337 { "cholesky", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_CHOLESKY }, INT_MIN, INT_MAX, FLAGS, "lpc_type" },
1338 { "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 },
1339 { "min_partition_order", NULL, offsetof(FlacEncodeContext, options.min_partition_order), AV_OPT_TYPE_INT, {.i64 = -1 }, -1, MAX_PARTITION_ORDER, FLAGS },
1340 { "max_partition_order", NULL, offsetof(FlacEncodeContext, options.max_partition_order), AV_OPT_TYPE_INT, {.i64 = -1 }, -1, MAX_PARTITION_ORDER, FLAGS },
1341 { "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" },
1342 { "estimation", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_EST }, INT_MIN, INT_MAX, FLAGS, "predm" },
1343 { "2level", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_2LEVEL }, INT_MIN, INT_MAX, FLAGS, "predm" },
1344 { "4level", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_4LEVEL }, INT_MIN, INT_MAX, FLAGS, "predm" },
1345 { "8level", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_8LEVEL }, INT_MIN, INT_MAX, FLAGS, "predm" },
1346 { "search", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_SEARCH }, INT_MIN, INT_MAX, FLAGS, "predm" },
1347 { "log", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_LOG }, INT_MIN, INT_MAX, FLAGS, "predm" },
1348 { "ch_mode", "Stereo decorrelation mode", offsetof(FlacEncodeContext, options.ch_mode), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, FLAC_CHMODE_MID_SIDE, FLAGS, "ch_mode" },
1349 { "auto", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = -1 }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1350 { "indep", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_INDEPENDENT }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1351 { "left_side", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_LEFT_SIDE }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1352 { "right_side", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_RIGHT_SIDE }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1353 { "mid_side", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_MID_SIDE }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1354 { NULL },
1355 };
1356 
1357 static const AVClass flac_encoder_class = {
1358  "FLAC encoder",
1359  av_default_item_name,
1360  options,
1361  LIBAVUTIL_VERSION_INT,
1362 };
1363 
1364 AVCodec ff_flac_encoder = {
1365  .name = "flac",
1366  .long_name = NULL_IF_CONFIG_SMALL("FLAC (Free Lossless Audio Codec)"),
1367  .type = AVMEDIA_TYPE_AUDIO,
1368  .id = AV_CODEC_ID_FLAC,
1369  .priv_data_size = sizeof(FlacEncodeContext),
1370  .init = flac_encode_init,
1371  .encode2 = flac_encode_frame,
1372  .close = flac_encode_close,
1373  .capabilities = CODEC_CAP_SMALL_LAST_FRAME | CODEC_CAP_DELAY | CODEC_CAP_LOSSLESS,
1374  .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
1375  AV_SAMPLE_FMT_S32,
1376  AV_SAMPLE_FMT_NONE },
1377  .priv_class = &flac_encoder_class,
1378 };
Generated on Fri Dec 5 2014 04:41:54 for FFmpeg by   doxygen 1.8.2