3 * Copyright (c) 2006 Justin Ruggles <justin.ruggles@gmail.com>
5 * This file is part of FFmpeg.
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.
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.
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
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"
37 #define FLAC_SUBFRAME_CONSTANT 0
38 #define FLAC_SUBFRAME_VERBATIM 1
39 #define FLAC_SUBFRAME_FIXED 8
40 #define FLAC_SUBFRAME_LPC 32
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
50 CODING_MODE_RICE2 = 5,
53 typedef struct CompressionOptions {
54 int compression_level;
56 enum FFLPCType lpc_type;
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;
65 int exact_rice_parameters;
69 typedef struct RiceContext {
70 enum CodingMode coding_mode;
72 int params[MAX_PARTITIONS];
75 typedef struct FlacSubframe {
81 int32_t coefs[MAX_LPC_ORDER];
85 uint32_t rc_udata[FLAC_MAX_BLOCKSIZE];
86 uint64_t rc_sums[32][MAX_PARTITIONS];
88 int32_t samples[FLAC_MAX_BLOCKSIZE];
89 int32_t residual[FLAC_MAX_BLOCKSIZE+11];
92 typedef struct FlacFrame {
93 FlacSubframe subframes[FLAC_MAX_CHANNELS];
101 typedef struct FlacEncodeContext {
111 int max_encoded_framesize;
112 uint32_t frame_count;
113 uint64_t sample_count;
116 CompressionOptions options;
117 AVCodecContext *avctx;
119 struct AVMD5 *md5ctx;
121 unsigned int md5_buffer_size;
122 BswapDSPContext bdsp;
123 FLACDSPContext flac_dsp;
131 * Write streaminfo metadata block to byte array.
133 static void write_streaminfo(FlacEncodeContext *s, uint8_t *header)
137 memset(header, 0, FLAC_STREAMINFO_SIZE);
138 init_put_bits(&pb, header, FLAC_STREAMINFO_SIZE);
140 /* streaminfo metadata block */
141 put_bits(&pb, 16, s->max_blocksize);
142 put_bits(&pb, 16, s->max_blocksize);
143 put_bits(&pb, 24, s->min_framesize);
144 put_bits(&pb, 24, s->max_framesize);
145 put_bits(&pb, 20, s->samplerate);
146 put_bits(&pb, 3, s->channels-1);
147 put_bits(&pb, 5, s->avctx->bits_per_raw_sample - 1);
148 /* write 36-bit sample count in 2 put_bits() calls */
149 put_bits(&pb, 24, (s->sample_count & 0xFFFFFF000LL) >> 12);
150 put_bits(&pb, 12, s->sample_count & 0x000000FFFLL);
152 memcpy(&header[18], s->md5sum, 16);
157 * Set blocksize based on samplerate.
158 * Choose the closest predefined blocksize >= BLOCK_TIME_MS milliseconds.
160 static int select_blocksize(int samplerate, int block_time_ms)
166 av_assert0(samplerate > 0);
167 blocksize = ff_flac_blocksize_table[1];
168 target = (samplerate * block_time_ms) / 1000;
169 for (i = 0; i < 16; i++) {
170 if (target >= ff_flac_blocksize_table[i] &&
171 ff_flac_blocksize_table[i] > blocksize) {
172 blocksize = ff_flac_blocksize_table[i];
179 static av_cold void dprint_compression_options(FlacEncodeContext *s)
181 AVCodecContext *avctx = s->avctx;
182 CompressionOptions *opt = &s->options;
184 av_log(avctx, AV_LOG_DEBUG, " compression: %d\n", opt->compression_level);
186 switch (opt->lpc_type) {
187 case FF_LPC_TYPE_NONE:
188 av_log(avctx, AV_LOG_DEBUG, " lpc type: None\n");
190 case FF_LPC_TYPE_FIXED:
191 av_log(avctx, AV_LOG_DEBUG, " lpc type: Fixed pre-defined coefficients\n");
193 case FF_LPC_TYPE_LEVINSON:
194 av_log(avctx, AV_LOG_DEBUG, " lpc type: Levinson-Durbin recursion with Welch window\n");
196 case FF_LPC_TYPE_CHOLESKY:
197 av_log(avctx, AV_LOG_DEBUG, " lpc type: Cholesky factorization, %d pass%s\n",
198 opt->lpc_passes, opt->lpc_passes == 1 ? "" : "es");
202 av_log(avctx, AV_LOG_DEBUG, " prediction order: %d, %d\n",
203 opt->min_prediction_order, opt->max_prediction_order);
205 switch (opt->prediction_order_method) {
206 case ORDER_METHOD_EST:
207 av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "estimate");
209 case ORDER_METHOD_2LEVEL:
210 av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "2-level");
212 case ORDER_METHOD_4LEVEL:
213 av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "4-level");
215 case ORDER_METHOD_8LEVEL:
216 av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "8-level");
218 case ORDER_METHOD_SEARCH:
219 av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "full search");
221 case ORDER_METHOD_LOG:
222 av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "log search");
227 av_log(avctx, AV_LOG_DEBUG, " partition order: %d, %d\n",
228 opt->min_partition_order, opt->max_partition_order);
230 av_log(avctx, AV_LOG_DEBUG, " block size: %d\n", avctx->frame_size);
232 av_log(avctx, AV_LOG_DEBUG, " lpc precision: %d\n",
233 opt->lpc_coeff_precision);
237 static av_cold int flac_encode_init(AVCodecContext *avctx)
239 int freq = avctx->sample_rate;
240 int channels = avctx->channels;
241 FlacEncodeContext *s = avctx->priv_data;
247 switch (avctx->sample_fmt) {
248 case AV_SAMPLE_FMT_S16:
249 avctx->bits_per_raw_sample = 16;
252 case AV_SAMPLE_FMT_S32:
253 if (avctx->bits_per_raw_sample != 24)
254 av_log(avctx, AV_LOG_WARNING, "encoding as 24 bits-per-sample\n");
255 avctx->bits_per_raw_sample = 24;
260 if (channels < 1 || channels > FLAC_MAX_CHANNELS) {
261 av_log(avctx, AV_LOG_ERROR, "%d channels not supported (max %d)\n",
262 channels, FLAC_MAX_CHANNELS);
263 return AVERROR(EINVAL);
265 s->channels = channels;
267 /* find samplerate in table */
270 for (i = 4; i < 12; i++) {
271 if (freq == ff_flac_sample_rate_table[i]) {
272 s->samplerate = ff_flac_sample_rate_table[i];
278 /* if not in table, samplerate is non-standard */
280 if (freq % 1000 == 0 && freq < 255000) {
282 s->sr_code[1] = freq / 1000;
283 } else if (freq % 10 == 0 && freq < 655350) {
285 s->sr_code[1] = freq / 10;
286 } else if (freq < 65535) {
288 s->sr_code[1] = freq;
290 av_log(avctx, AV_LOG_ERROR, "%d Hz not supported\n", freq);
291 return AVERROR(EINVAL);
293 s->samplerate = freq;
296 /* set compression option defaults based on avctx->compression_level */
297 if (avctx->compression_level < 0)
298 s->options.compression_level = 5;
300 s->options.compression_level = avctx->compression_level;
302 level = s->options.compression_level;
304 av_log(avctx, AV_LOG_ERROR, "invalid compression level: %d\n",
305 s->options.compression_level);
306 return AVERROR(EINVAL);
309 s->options.block_time_ms = ((int[]){ 27, 27, 27,105,105,105,105,105,105,105,105,105,105})[level];
311 if (s->options.lpc_type == FF_LPC_TYPE_DEFAULT)
312 s->options.lpc_type = ((int[]){ FF_LPC_TYPE_FIXED, FF_LPC_TYPE_FIXED, FF_LPC_TYPE_FIXED,
313 FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON,
314 FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON,
315 FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON,
316 FF_LPC_TYPE_LEVINSON})[level];
318 s->options.min_prediction_order = ((int[]){ 2, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1})[level];
319 s->options.max_prediction_order = ((int[]){ 3, 4, 4, 6, 8, 8, 8, 8, 12, 12, 12, 32, 32})[level];
321 if (s->options.prediction_order_method < 0)
322 s->options.prediction_order_method = ((int[]){ ORDER_METHOD_EST, ORDER_METHOD_EST, ORDER_METHOD_EST,
323 ORDER_METHOD_EST, ORDER_METHOD_EST, ORDER_METHOD_EST,
324 ORDER_METHOD_4LEVEL, ORDER_METHOD_LOG, ORDER_METHOD_4LEVEL,
325 ORDER_METHOD_LOG, ORDER_METHOD_SEARCH, ORDER_METHOD_LOG,
326 ORDER_METHOD_SEARCH})[level];
328 if (s->options.min_partition_order > s->options.max_partition_order) {
329 av_log(avctx, AV_LOG_ERROR, "invalid partition orders: min=%d max=%d\n",
330 s->options.min_partition_order, s->options.max_partition_order);
331 return AVERROR(EINVAL);
333 if (s->options.min_partition_order < 0)
334 s->options.min_partition_order = ((int[]){ 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0})[level];
335 if (s->options.max_partition_order < 0)
336 s->options.max_partition_order = ((int[]){ 2, 2, 3, 3, 3, 8, 8, 8, 8, 8, 8, 8, 8})[level];
338 if (s->options.lpc_type == FF_LPC_TYPE_NONE) {
339 s->options.min_prediction_order = 0;
340 } else if (avctx->min_prediction_order >= 0) {
341 if (s->options.lpc_type == FF_LPC_TYPE_FIXED) {
342 if (avctx->min_prediction_order > MAX_FIXED_ORDER) {
343 av_log(avctx, AV_LOG_ERROR, "invalid min prediction order: %d\n",
344 avctx->min_prediction_order);
345 return AVERROR(EINVAL);
347 } else if (avctx->min_prediction_order < MIN_LPC_ORDER ||
348 avctx->min_prediction_order > MAX_LPC_ORDER) {
349 av_log(avctx, AV_LOG_ERROR, "invalid min prediction order: %d\n",
350 avctx->min_prediction_order);
351 return AVERROR(EINVAL);
353 s->options.min_prediction_order = avctx->min_prediction_order;
355 if (s->options.lpc_type == FF_LPC_TYPE_NONE) {
356 s->options.max_prediction_order = 0;
357 } else if (avctx->max_prediction_order >= 0) {
358 if (s->options.lpc_type == FF_LPC_TYPE_FIXED) {
359 if (avctx->max_prediction_order > MAX_FIXED_ORDER) {
360 av_log(avctx, AV_LOG_ERROR, "invalid max prediction order: %d\n",
361 avctx->max_prediction_order);
362 return AVERROR(EINVAL);
364 } else if (avctx->max_prediction_order < MIN_LPC_ORDER ||
365 avctx->max_prediction_order > MAX_LPC_ORDER) {
366 av_log(avctx, AV_LOG_ERROR, "invalid max prediction order: %d\n",
367 avctx->max_prediction_order);
368 return AVERROR(EINVAL);
370 s->options.max_prediction_order = avctx->max_prediction_order;
372 if (s->options.max_prediction_order < s->options.min_prediction_order) {
373 av_log(avctx, AV_LOG_ERROR, "invalid prediction orders: min=%d max=%d\n",
374 s->options.min_prediction_order, s->options.max_prediction_order);
375 return AVERROR(EINVAL);
378 if (avctx->frame_size > 0) {
379 if (avctx->frame_size < FLAC_MIN_BLOCKSIZE ||
380 avctx->frame_size > FLAC_MAX_BLOCKSIZE) {
381 av_log(avctx, AV_LOG_ERROR, "invalid block size: %d\n",
383 return AVERROR(EINVAL);
386 s->avctx->frame_size = select_blocksize(s->samplerate, s->options.block_time_ms);
388 s->max_blocksize = s->avctx->frame_size;
390 /* set maximum encoded frame size in verbatim mode */
391 s->max_framesize = ff_flac_get_max_frame_size(s->avctx->frame_size,
393 s->avctx->bits_per_raw_sample);
395 /* initialize MD5 context */
396 s->md5ctx = av_md5_alloc();
398 return AVERROR(ENOMEM);
399 av_md5_init(s->md5ctx);
401 streaminfo = av_malloc(FLAC_STREAMINFO_SIZE);
403 return AVERROR(ENOMEM);
404 write_streaminfo(s, streaminfo);
405 avctx->extradata = streaminfo;
406 avctx->extradata_size = FLAC_STREAMINFO_SIZE;
409 s->min_framesize = s->max_framesize;
412 avctx->channel_layout != (AV_CH_LAYOUT_STEREO|AV_CH_FRONT_CENTER) ||
414 avctx->channel_layout != AV_CH_LAYOUT_2_2 &&
415 avctx->channel_layout != AV_CH_LAYOUT_QUAD ||
417 avctx->channel_layout != AV_CH_LAYOUT_5POINT0 &&
418 avctx->channel_layout != AV_CH_LAYOUT_5POINT0_BACK ||
420 avctx->channel_layout != AV_CH_LAYOUT_5POINT1 &&
421 avctx->channel_layout != AV_CH_LAYOUT_5POINT1_BACK) {
422 if (avctx->channel_layout) {
423 av_log(avctx, AV_LOG_ERROR, "Channel layout not supported by Flac, "
424 "output stream will have incorrect "
425 "channel layout.\n");
427 av_log(avctx, AV_LOG_WARNING, "No channel layout specified. The encoder "
428 "will use Flac channel layout for "
429 "%d channels.\n", channels);
433 ret = ff_lpc_init(&s->lpc_ctx, avctx->frame_size,
434 s->options.max_prediction_order, FF_LPC_TYPE_LEVINSON);
436 ff_bswapdsp_init(&s->bdsp);
437 ff_flacdsp_init(&s->flac_dsp, avctx->sample_fmt, channels,
438 avctx->bits_per_raw_sample);
440 dprint_compression_options(s);
446 static void init_frame(FlacEncodeContext *s, int nb_samples)
453 for (i = 0; i < 16; i++) {
454 if (nb_samples == ff_flac_blocksize_table[i]) {
455 frame->blocksize = ff_flac_blocksize_table[i];
456 frame->bs_code[0] = i;
457 frame->bs_code[1] = 0;
462 frame->blocksize = nb_samples;
463 if (frame->blocksize <= 256) {
464 frame->bs_code[0] = 6;
465 frame->bs_code[1] = frame->blocksize-1;
467 frame->bs_code[0] = 7;
468 frame->bs_code[1] = frame->blocksize-1;
472 for (ch = 0; ch < s->channels; ch++) {
473 FlacSubframe *sub = &frame->subframes[ch];
476 sub->obits = s->avctx->bits_per_raw_sample;
479 sub->rc.coding_mode = CODING_MODE_RICE2;
481 sub->rc.coding_mode = CODING_MODE_RICE;
484 frame->verbatim_only = 0;
489 * Copy channel-interleaved input samples into separate subframes.
491 static void copy_samples(FlacEncodeContext *s, const void *samples)
495 int shift = av_get_bytes_per_sample(s->avctx->sample_fmt) * 8 -
496 s->avctx->bits_per_raw_sample;
498 #define COPY_SAMPLES(bits) do { \
499 const int ## bits ## _t *samples0 = samples; \
501 for (i = 0, j = 0; i < frame->blocksize; i++) \
502 for (ch = 0; ch < s->channels; ch++, j++) \
503 frame->subframes[ch].samples[i] = samples0[j] >> shift; \
506 if (s->avctx->sample_fmt == AV_SAMPLE_FMT_S16)
513 static uint64_t rice_count_exact(const int32_t *res, int n, int k)
518 for (i = 0; i < n; i++) {
519 int32_t v = -2 * res[i] - 1;
521 count += (v >> k) + 1 + k;
527 static uint64_t subframe_count_exact(FlacEncodeContext *s, FlacSubframe *sub,
530 int p, porder, psize;
534 /* subframe header */
538 count += sub->wasted;
541 if (sub->type == FLAC_SUBFRAME_CONSTANT) {
543 } else if (sub->type == FLAC_SUBFRAME_VERBATIM) {
544 count += s->frame.blocksize * sub->obits;
546 /* warm-up samples */
547 count += pred_order * sub->obits;
549 /* LPC coefficients */
550 if (sub->type == FLAC_SUBFRAME_LPC)
551 count += 4 + 5 + pred_order * s->options.lpc_coeff_precision;
553 /* rice-encoded block */
556 /* partition order */
557 porder = sub->rc.porder;
558 psize = s->frame.blocksize >> porder;
564 for (p = 0; p < 1 << porder; p++) {
565 int k = sub->rc.params[p];
566 count += sub->rc.coding_mode;
567 count += rice_count_exact(&sub->residual[i], part_end - i, k);
569 part_end = FFMIN(s->frame.blocksize, part_end + psize);
577 #define rice_encode_count(sum, n, k) (((n)*((k)+1))+((sum-(n>>1))>>(k)))
580 * Solve for d/dk(rice_encode_count) = n-((sum-(n>>1))>>(k+1)) = 0.
582 static int find_optimal_param(uint64_t sum, int n, int max_param)
589 sum2 = sum - (n >> 1);
590 k = av_log2(av_clipl_int32(sum2 / n));
591 return FFMIN(k, max_param);
594 static int find_optimal_param_exact(uint64_t sums[32][MAX_PARTITIONS], int i, int max_param)
597 int64_t bestbits = INT64_MAX;
600 for (k = 0; k <= max_param; k++) {
601 int64_t bits = sums[k][i];
602 if (bits < bestbits) {
611 static uint64_t calc_optimal_rice_params(RiceContext *rc, int porder,
612 uint64_t sums[32][MAX_PARTITIONS],
613 int n, int pred_order, int max_param, int exact)
619 part = (1 << porder);
622 cnt = (n >> porder) - pred_order;
623 for (i = 0; i < part; i++) {
625 k = find_optimal_param_exact(sums, i, max_param);
626 all_bits += sums[k][i];
628 k = find_optimal_param(sums[0][i], cnt, max_param);
629 all_bits += rice_encode_count(sums[0][i], cnt, k);
641 static void calc_sum_top(int pmax, int kmax, const uint32_t *data, int n, int pred_order,
642 uint64_t sums[32][MAX_PARTITIONS])
646 const uint32_t *res, *res_end;
648 /* sums for highest level */
651 for (k = 0; k <= kmax; k++) {
652 res = &data[pred_order];
653 res_end = &data[n >> pmax];
654 for (i = 0; i < parts; i++) {
656 uint64_t sum = (1LL + k) * (res_end - res);
657 while (res < res_end)
658 sum += *(res++) >> k;
662 while (res < res_end)
666 res_end += n >> pmax;
671 static void calc_sum_next(int level, uint64_t sums[32][MAX_PARTITIONS], int kmax)
674 int parts = (1 << level);
675 for (i = 0; i < parts; i++) {
676 for (k=0; k<=kmax; k++)
677 sums[k][i] = sums[k][2*i] + sums[k][2*i+1];
681 static uint64_t calc_rice_params(RiceContext *rc,
682 uint32_t udata[FLAC_MAX_BLOCKSIZE],
683 uint64_t sums[32][MAX_PARTITIONS],
685 const int32_t *data, int n, int pred_order, int exact)
688 uint64_t bits[MAX_PARTITION_ORDER+1];
691 int kmax = (1 << rc->coding_mode) - 2;
693 av_assert1(pmin >= 0 && pmin <= MAX_PARTITION_ORDER);
694 av_assert1(pmax >= 0 && pmax <= MAX_PARTITION_ORDER);
695 av_assert1(pmin <= pmax);
697 tmp_rc.coding_mode = rc->coding_mode;
699 for (i = 0; i < n; i++)
700 udata[i] = (2 * data[i]) ^ (data[i] >> 31);
702 calc_sum_top(pmax, exact ? kmax : 0, udata, n, pred_order, sums);
705 bits[pmin] = UINT32_MAX;
707 bits[i] = calc_optimal_rice_params(&tmp_rc, i, sums, n, pred_order, kmax, exact);
708 if (bits[i] < bits[opt_porder] || pmax == pmin) {
714 calc_sum_next(--i, sums, exact ? kmax : 0);
717 return bits[opt_porder];
721 static int get_max_p_order(int max_porder, int n, int order)
723 int porder = FFMIN(max_porder, av_log2(n^(n-1)));
725 porder = FFMIN(porder, av_log2(n/order));
730 static uint64_t find_subframe_rice_params(FlacEncodeContext *s,
731 FlacSubframe *sub, int pred_order)
733 int pmin = get_max_p_order(s->options.min_partition_order,
734 s->frame.blocksize, pred_order);
735 int pmax = get_max_p_order(s->options.max_partition_order,
736 s->frame.blocksize, pred_order);
738 uint64_t bits = 8 + pred_order * sub->obits + 2 + sub->rc.coding_mode;
739 if (sub->type == FLAC_SUBFRAME_LPC)
740 bits += 4 + 5 + pred_order * s->options.lpc_coeff_precision;
741 bits += calc_rice_params(&sub->rc, sub->rc_udata, sub->rc_sums, pmin, pmax, sub->residual,
742 s->frame.blocksize, pred_order, s->options.exact_rice_parameters);
747 static void encode_residual_fixed(int32_t *res, const int32_t *smp, int n,
752 for (i = 0; i < order; i++)
756 for (i = order; i < n; i++)
758 } else if (order == 1) {
759 for (i = order; i < n; i++)
760 res[i] = smp[i] - smp[i-1];
761 } else if (order == 2) {
762 int a = smp[order-1] - smp[order-2];
763 for (i = order; i < n; i += 2) {
764 int b = smp[i ] - smp[i-1];
766 a = smp[i+1] - smp[i ];
769 } else if (order == 3) {
770 int a = smp[order-1] - smp[order-2];
771 int c = smp[order-1] - 2*smp[order-2] + smp[order-3];
772 for (i = order; i < n; i += 2) {
773 int b = smp[i ] - smp[i-1];
776 a = smp[i+1] - smp[i ];
781 int a = smp[order-1] - smp[order-2];
782 int c = smp[order-1] - 2*smp[order-2] + smp[order-3];
783 int e = smp[order-1] - 3*smp[order-2] + 3*smp[order-3] - smp[order-4];
784 for (i = order; i < n; i += 2) {
785 int b = smp[i ] - smp[i-1];
789 a = smp[i+1] - smp[i ];
798 static int encode_residual_ch(FlacEncodeContext *s, int ch)
801 int min_order, max_order, opt_order, omethod;
804 int32_t coefs[MAX_LPC_ORDER][MAX_LPC_ORDER];
805 int shift[MAX_LPC_ORDER];
809 sub = &frame->subframes[ch];
812 n = frame->blocksize;
815 for (i = 1; i < n; i++)
819 sub->type = sub->type_code = FLAC_SUBFRAME_CONSTANT;
821 return subframe_count_exact(s, sub, 0);
825 if (frame->verbatim_only || n < 5) {
826 sub->type = sub->type_code = FLAC_SUBFRAME_VERBATIM;
827 memcpy(res, smp, n * sizeof(int32_t));
828 return subframe_count_exact(s, sub, 0);
831 min_order = s->options.min_prediction_order;
832 max_order = s->options.max_prediction_order;
833 omethod = s->options.prediction_order_method;
836 sub->type = FLAC_SUBFRAME_FIXED;
837 if (s->options.lpc_type == FF_LPC_TYPE_NONE ||
838 s->options.lpc_type == FF_LPC_TYPE_FIXED || n <= max_order) {
839 uint64_t bits[MAX_FIXED_ORDER+1];
840 if (max_order > MAX_FIXED_ORDER)
841 max_order = MAX_FIXED_ORDER;
843 bits[0] = UINT32_MAX;
844 for (i = min_order; i <= max_order; i++) {
845 encode_residual_fixed(res, smp, n, i);
846 bits[i] = find_subframe_rice_params(s, sub, i);
847 if (bits[i] < bits[opt_order])
850 sub->order = opt_order;
851 sub->type_code = sub->type | sub->order;
852 if (sub->order != max_order) {
853 encode_residual_fixed(res, smp, n, sub->order);
854 find_subframe_rice_params(s, sub, sub->order);
856 return subframe_count_exact(s, sub, sub->order);
860 sub->type = FLAC_SUBFRAME_LPC;
861 opt_order = ff_lpc_calc_coefs(&s->lpc_ctx, smp, n, min_order, max_order,
862 s->options.lpc_coeff_precision, coefs, shift, s->options.lpc_type,
863 s->options.lpc_passes, omethod,
866 if (omethod == ORDER_METHOD_2LEVEL ||
867 omethod == ORDER_METHOD_4LEVEL ||
868 omethod == ORDER_METHOD_8LEVEL) {
869 int levels = 1 << omethod;
870 uint64_t bits[1 << ORDER_METHOD_8LEVEL];
872 int opt_index = levels-1;
873 opt_order = max_order-1;
874 bits[opt_index] = UINT32_MAX;
875 for (i = levels-1; i >= 0; i--) {
876 int last_order = order;
877 order = min_order + (((max_order-min_order+1) * (i+1)) / levels)-1;
878 order = av_clip(order, min_order - 1, max_order - 1);
879 if (order == last_order)
881 if (s->bps_code * 4 + s->options.lpc_coeff_precision + av_log2(order) <= 32) {
882 s->flac_dsp.lpc16_encode(res, smp, n, order+1, coefs[order],
885 s->flac_dsp.lpc32_encode(res, smp, n, order+1, coefs[order],
888 bits[i] = find_subframe_rice_params(s, sub, order+1);
889 if (bits[i] < bits[opt_index]) {
895 } else if (omethod == ORDER_METHOD_SEARCH) {
896 // brute-force optimal order search
897 uint64_t bits[MAX_LPC_ORDER];
899 bits[0] = UINT32_MAX;
900 for (i = min_order-1; i < max_order; i++) {
901 if (s->bps_code * 4 + s->options.lpc_coeff_precision + av_log2(i) <= 32) {
902 s->flac_dsp.lpc16_encode(res, smp, n, i+1, coefs[i], shift[i]);
904 s->flac_dsp.lpc32_encode(res, smp, n, i+1, coefs[i], shift[i]);
906 bits[i] = find_subframe_rice_params(s, sub, i+1);
907 if (bits[i] < bits[opt_order])
911 } else if (omethod == ORDER_METHOD_LOG) {
912 uint64_t bits[MAX_LPC_ORDER];
915 opt_order = min_order - 1 + (max_order-min_order)/3;
916 memset(bits, -1, sizeof(bits));
918 for (step = 16; step; step >>= 1) {
919 int last = opt_order;
920 for (i = last-step; i <= last+step; i += step) {
921 if (i < min_order-1 || i >= max_order || bits[i] < UINT32_MAX)
923 if (s->bps_code * 4 + s->options.lpc_coeff_precision + av_log2(i) <= 32) {
924 s->flac_dsp.lpc32_encode(res, smp, n, i+1, coefs[i], shift[i]);
926 s->flac_dsp.lpc16_encode(res, smp, n, i+1, coefs[i], shift[i]);
928 bits[i] = find_subframe_rice_params(s, sub, i+1);
929 if (bits[i] < bits[opt_order])
936 if (s->options.multi_dim_quant) {
938 int i, step, improved;
939 int64_t best_score = INT64_MAX;
942 qmax = (1 << (s->options.lpc_coeff_precision - 1)) - 1;
944 for (i=0; i<opt_order; i++)
949 for (step = 0; step < allsteps; step++) {
951 int32_t lpc_try[MAX_LPC_ORDER];
955 for (i=0; i<opt_order; i++) {
956 int diff = ((tmp + 1) % 3) - 1;
957 lpc_try[i] = av_clip(coefs[opt_order - 1][i] + diff, -qmax, qmax);
964 if (s->bps_code * 4 + s->options.lpc_coeff_precision + av_log2(opt_order - 1) <= 32) {
965 s->flac_dsp.lpc16_encode(res, smp, n, opt_order, lpc_try, shift[opt_order-1]);
967 s->flac_dsp.lpc32_encode(res, smp, n, opt_order, lpc_try, shift[opt_order-1]);
969 score = find_subframe_rice_params(s, sub, opt_order);
970 if (score < best_score) {
972 memcpy(coefs[opt_order-1], lpc_try, sizeof(*coefs));
979 sub->order = opt_order;
980 sub->type_code = sub->type | (sub->order-1);
981 sub->shift = shift[sub->order-1];
982 for (i = 0; i < sub->order; i++)
983 sub->coefs[i] = coefs[sub->order-1][i];
985 if (s->bps_code * 4 + s->options.lpc_coeff_precision + av_log2(opt_order) <= 32) {
986 s->flac_dsp.lpc16_encode(res, smp, n, sub->order, sub->coefs, sub->shift);
988 s->flac_dsp.lpc32_encode(res, smp, n, sub->order, sub->coefs, sub->shift);
991 find_subframe_rice_params(s, sub, sub->order);
993 return subframe_count_exact(s, sub, sub->order);
997 static int count_frame_header(FlacEncodeContext *s)
999 uint8_t av_unused tmp;
1005 <1> Blocking strategy
1006 <4> Block size in inter-channel samples
1008 <4> Channel assignment
1009 <3> Sample size in bits
1014 /* coded frame number */
1015 PUT_UTF8(s->frame_count, tmp, count += 8;)
1017 /* explicit block size */
1018 if (s->frame.bs_code[0] == 6)
1020 else if (s->frame.bs_code[0] == 7)
1023 /* explicit sample rate */
1024 count += ((s->sr_code[0] == 12) + (s->sr_code[0] > 12)) * 8;
1026 /* frame header CRC-8 */
1033 static int encode_frame(FlacEncodeContext *s)
1038 count = count_frame_header(s);
1040 for (ch = 0; ch < s->channels; ch++)
1041 count += encode_residual_ch(s, ch);
1043 count += (8 - (count & 7)) & 7; // byte alignment
1044 count += 16; // CRC-16
1047 if (count > INT_MAX)
1053 static void remove_wasted_bits(FlacEncodeContext *s)
1057 for (ch = 0; ch < s->channels; ch++) {
1058 FlacSubframe *sub = &s->frame.subframes[ch];
1061 for (i = 0; i < s->frame.blocksize; i++) {
1062 v |= sub->samples[i];
1067 if (v && !(v & 1)) {
1070 for (i = 0; i < s->frame.blocksize; i++)
1071 sub->samples[i] >>= v;
1076 /* for 24-bit, check if removing wasted bits makes the range better
1077 suited for using RICE instead of RICE2 for entropy coding */
1078 if (sub->obits <= 17)
1079 sub->rc.coding_mode = CODING_MODE_RICE;
1085 static int estimate_stereo_mode(const int32_t *left_ch, const int32_t *right_ch, int n,
1094 /* calculate sum of 2nd order residual for each channel */
1095 sum[0] = sum[1] = sum[2] = sum[3] = 0;
1096 for (i = 2; i < n; i++) {
1097 lt = left_ch[i] - 2*left_ch[i-1] + left_ch[i-2];
1098 rt = right_ch[i] - 2*right_ch[i-1] + right_ch[i-2];
1099 sum[2] += FFABS((lt + rt) >> 1);
1100 sum[3] += FFABS(lt - rt);
1101 sum[0] += FFABS(lt);
1102 sum[1] += FFABS(rt);
1104 /* estimate bit counts */
1105 for (i = 0; i < 4; i++) {
1106 k = find_optimal_param(2 * sum[i], n, max_rice_param);
1107 sum[i] = rice_encode_count( 2 * sum[i], n, k);
1110 /* calculate score for each mode */
1111 score[0] = sum[0] + sum[1];
1112 score[1] = sum[0] + sum[3];
1113 score[2] = sum[1] + sum[3];
1114 score[3] = sum[2] + sum[3];
1116 /* return mode with lowest score */
1118 for (i = 1; i < 4; i++)
1119 if (score[i] < score[best])
1127 * Perform stereo channel decorrelation.
1129 static void channel_decorrelation(FlacEncodeContext *s)
1132 int32_t *left, *right;
1136 n = frame->blocksize;
1137 left = frame->subframes[0].samples;
1138 right = frame->subframes[1].samples;
1140 if (s->channels != 2) {
1141 frame->ch_mode = FLAC_CHMODE_INDEPENDENT;
1145 if (s->options.ch_mode < 0) {
1146 int max_rice_param = (1 << frame->subframes[0].rc.coding_mode) - 2;
1147 frame->ch_mode = estimate_stereo_mode(left, right, n, max_rice_param);
1149 frame->ch_mode = s->options.ch_mode;
1151 /* perform decorrelation and adjust bits-per-sample */
1152 if (frame->ch_mode == FLAC_CHMODE_INDEPENDENT)
1154 if (frame->ch_mode == FLAC_CHMODE_MID_SIDE) {
1156 for (i = 0; i < n; i++) {
1158 left[i] = (tmp + right[i]) >> 1;
1159 right[i] = tmp - right[i];
1161 frame->subframes[1].obits++;
1162 } else if (frame->ch_mode == FLAC_CHMODE_LEFT_SIDE) {
1163 for (i = 0; i < n; i++)
1164 right[i] = left[i] - right[i];
1165 frame->subframes[1].obits++;
1167 for (i = 0; i < n; i++)
1168 left[i] -= right[i];
1169 frame->subframes[0].obits++;
1174 static void write_utf8(PutBitContext *pb, uint32_t val)
1177 PUT_UTF8(val, tmp, put_bits(pb, 8, tmp);)
1181 static void write_frame_header(FlacEncodeContext *s)
1188 put_bits(&s->pb, 16, 0xFFF8);
1189 put_bits(&s->pb, 4, frame->bs_code[0]);
1190 put_bits(&s->pb, 4, s->sr_code[0]);
1192 if (frame->ch_mode == FLAC_CHMODE_INDEPENDENT)
1193 put_bits(&s->pb, 4, s->channels-1);
1195 put_bits(&s->pb, 4, frame->ch_mode + FLAC_MAX_CHANNELS - 1);
1197 put_bits(&s->pb, 3, s->bps_code);
1198 put_bits(&s->pb, 1, 0);
1199 write_utf8(&s->pb, s->frame_count);
1201 if (frame->bs_code[0] == 6)
1202 put_bits(&s->pb, 8, frame->bs_code[1]);
1203 else if (frame->bs_code[0] == 7)
1204 put_bits(&s->pb, 16, frame->bs_code[1]);
1206 if (s->sr_code[0] == 12)
1207 put_bits(&s->pb, 8, s->sr_code[1]);
1208 else if (s->sr_code[0] > 12)
1209 put_bits(&s->pb, 16, s->sr_code[1]);
1211 flush_put_bits(&s->pb);
1212 crc = av_crc(av_crc_get_table(AV_CRC_8_ATM), 0, s->pb.buf,
1213 put_bits_count(&s->pb) >> 3);
1214 put_bits(&s->pb, 8, crc);
1218 static void write_subframes(FlacEncodeContext *s)
1222 for (ch = 0; ch < s->channels; ch++) {
1223 FlacSubframe *sub = &s->frame.subframes[ch];
1224 int i, p, porder, psize;
1226 int32_t *res = sub->residual;
1227 int32_t *frame_end = &sub->residual[s->frame.blocksize];
1229 /* subframe header */
1230 put_bits(&s->pb, 1, 0);
1231 put_bits(&s->pb, 6, sub->type_code);
1232 put_bits(&s->pb, 1, !!sub->wasted);
1234 put_bits(&s->pb, sub->wasted, 1);
1237 if (sub->type == FLAC_SUBFRAME_CONSTANT) {
1238 put_sbits(&s->pb, sub->obits, res[0]);
1239 } else if (sub->type == FLAC_SUBFRAME_VERBATIM) {
1240 while (res < frame_end)
1241 put_sbits(&s->pb, sub->obits, *res++);
1243 /* warm-up samples */
1244 for (i = 0; i < sub->order; i++)
1245 put_sbits(&s->pb, sub->obits, *res++);
1247 /* LPC coefficients */
1248 if (sub->type == FLAC_SUBFRAME_LPC) {
1249 int cbits = s->options.lpc_coeff_precision;
1250 put_bits( &s->pb, 4, cbits-1);
1251 put_sbits(&s->pb, 5, sub->shift);
1252 for (i = 0; i < sub->order; i++)
1253 put_sbits(&s->pb, cbits, sub->coefs[i]);
1256 /* rice-encoded block */
1257 put_bits(&s->pb, 2, sub->rc.coding_mode - 4);
1259 /* partition order */
1260 porder = sub->rc.porder;
1261 psize = s->frame.blocksize >> porder;
1262 put_bits(&s->pb, 4, porder);
1265 part_end = &sub->residual[psize];
1266 for (p = 0; p < 1 << porder; p++) {
1267 int k = sub->rc.params[p];
1268 put_bits(&s->pb, sub->rc.coding_mode, k);
1269 while (res < part_end)
1270 set_sr_golomb_flac(&s->pb, *res++, k, INT32_MAX, 0);
1271 part_end = FFMIN(frame_end, part_end + psize);
1278 static void write_frame_footer(FlacEncodeContext *s)
1281 flush_put_bits(&s->pb);
1282 crc = av_bswap16(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, s->pb.buf,
1283 put_bits_count(&s->pb)>>3));
1284 put_bits(&s->pb, 16, crc);
1285 flush_put_bits(&s->pb);
1289 static int write_frame(FlacEncodeContext *s, AVPacket *avpkt)
1291 init_put_bits(&s->pb, avpkt->data, avpkt->size);
1292 write_frame_header(s);
1294 write_frame_footer(s);
1295 return put_bits_count(&s->pb) >> 3;
1299 static int update_md5_sum(FlacEncodeContext *s, const void *samples)
1302 int buf_size = s->frame.blocksize * s->channels *
1303 ((s->avctx->bits_per_raw_sample + 7) / 8);
1305 if (s->avctx->bits_per_raw_sample > 16 || HAVE_BIGENDIAN) {
1306 av_fast_malloc(&s->md5_buffer, &s->md5_buffer_size, buf_size);
1308 return AVERROR(ENOMEM);
1311 if (s->avctx->bits_per_raw_sample <= 16) {
1312 buf = (const uint8_t *)samples;
1314 s->bdsp.bswap16_buf((uint16_t *) s->md5_buffer,
1315 (const uint16_t *) samples, buf_size / 2);
1316 buf = s->md5_buffer;
1320 const int32_t *samples0 = samples;
1321 uint8_t *tmp = s->md5_buffer;
1323 for (i = 0; i < s->frame.blocksize * s->channels; i++) {
1324 int32_t v = samples0[i] >> 8;
1325 AV_WL24(tmp + 3*i, v);
1327 buf = s->md5_buffer;
1329 av_md5_update(s->md5ctx, buf, buf_size);
1335 static int flac_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
1336 const AVFrame *frame, int *got_packet_ptr)
1338 FlacEncodeContext *s;
1339 int frame_bytes, out_bytes, ret;
1341 s = avctx->priv_data;
1343 /* when the last block is reached, update the header in extradata */
1345 s->max_framesize = s->max_encoded_framesize;
1346 av_md5_final(s->md5ctx, s->md5sum);
1347 write_streaminfo(s, avctx->extradata);
1349 if (avctx->side_data_only_packets && !s->flushed) {
1350 uint8_t *side_data = av_packet_new_side_data(avpkt, AV_PKT_DATA_NEW_EXTRADATA,
1351 avctx->extradata_size);
1353 return AVERROR(ENOMEM);
1354 memcpy(side_data, avctx->extradata, avctx->extradata_size);
1356 avpkt->pts = s->next_pts;
1358 *got_packet_ptr = 1;
1365 /* change max_framesize for small final frame */
1366 if (frame->nb_samples < s->frame.blocksize) {
1367 s->max_framesize = ff_flac_get_max_frame_size(frame->nb_samples,
1369 avctx->bits_per_raw_sample);
1372 init_frame(s, frame->nb_samples);
1374 copy_samples(s, frame->data[0]);
1376 channel_decorrelation(s);
1378 remove_wasted_bits(s);
1380 frame_bytes = encode_frame(s);
1382 /* Fall back on verbatim mode if the compressed frame is larger than it
1383 would be if encoded uncompressed. */
1384 if (frame_bytes < 0 || frame_bytes > s->max_framesize) {
1385 s->frame.verbatim_only = 1;
1386 frame_bytes = encode_frame(s);
1387 if (frame_bytes < 0) {
1388 av_log(avctx, AV_LOG_ERROR, "Bad frame count\n");
1393 if ((ret = ff_alloc_packet2(avctx, avpkt, frame_bytes)) < 0)
1396 out_bytes = write_frame(s, avpkt);
1399 s->sample_count += frame->nb_samples;
1400 if ((ret = update_md5_sum(s, frame->data[0])) < 0) {
1401 av_log(avctx, AV_LOG_ERROR, "Error updating MD5 checksum\n");
1404 if (out_bytes > s->max_encoded_framesize)
1405 s->max_encoded_framesize = out_bytes;
1406 if (out_bytes < s->min_framesize)
1407 s->min_framesize = out_bytes;
1409 avpkt->pts = frame->pts;
1410 avpkt->duration = ff_samples_to_time_base(avctx, frame->nb_samples);
1411 avpkt->size = out_bytes;
1413 s->next_pts = avpkt->pts + avpkt->duration;
1415 *got_packet_ptr = 1;
1420 static av_cold int flac_encode_close(AVCodecContext *avctx)
1422 if (avctx->priv_data) {
1423 FlacEncodeContext *s = avctx->priv_data;
1424 av_freep(&s->md5ctx);
1425 av_freep(&s->md5_buffer);
1426 ff_lpc_end(&s->lpc_ctx);
1428 av_freep(&avctx->extradata);
1429 avctx->extradata_size = 0;
1433 #define FLAGS AV_OPT_FLAG_ENCODING_PARAM | AV_OPT_FLAG_AUDIO_PARAM
1434 static const AVOption options[] = {
1435 { "lpc_coeff_precision", "LPC coefficient precision", offsetof(FlacEncodeContext, options.lpc_coeff_precision), AV_OPT_TYPE_INT, {.i64 = 15 }, 0, MAX_LPC_PRECISION, FLAGS },
1436 { "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" },
1437 { "none", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_NONE }, INT_MIN, INT_MAX, FLAGS, "lpc_type" },
1438 { "fixed", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_FIXED }, INT_MIN, INT_MAX, FLAGS, "lpc_type" },
1439 { "levinson", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_LEVINSON }, INT_MIN, INT_MAX, FLAGS, "lpc_type" },
1440 { "cholesky", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_CHOLESKY }, INT_MIN, INT_MAX, FLAGS, "lpc_type" },
1441 { "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 },
1442 { "min_partition_order", NULL, offsetof(FlacEncodeContext, options.min_partition_order), AV_OPT_TYPE_INT, {.i64 = -1 }, -1, MAX_PARTITION_ORDER, FLAGS },
1443 { "max_partition_order", NULL, offsetof(FlacEncodeContext, options.max_partition_order), AV_OPT_TYPE_INT, {.i64 = -1 }, -1, MAX_PARTITION_ORDER, FLAGS },
1444 { "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" },
1445 { "estimation", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_EST }, INT_MIN, INT_MAX, FLAGS, "predm" },
1446 { "2level", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_2LEVEL }, INT_MIN, INT_MAX, FLAGS, "predm" },
1447 { "4level", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_4LEVEL }, INT_MIN, INT_MAX, FLAGS, "predm" },
1448 { "8level", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_8LEVEL }, INT_MIN, INT_MAX, FLAGS, "predm" },
1449 { "search", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_SEARCH }, INT_MIN, INT_MAX, FLAGS, "predm" },
1450 { "log", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_LOG }, INT_MIN, INT_MAX, FLAGS, "predm" },
1451 { "ch_mode", "Stereo decorrelation mode", offsetof(FlacEncodeContext, options.ch_mode), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, FLAC_CHMODE_MID_SIDE, FLAGS, "ch_mode" },
1452 { "auto", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = -1 }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1453 { "indep", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_INDEPENDENT }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1454 { "left_side", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_LEFT_SIDE }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1455 { "right_side", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_RIGHT_SIDE }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1456 { "mid_side", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_MID_SIDE }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1457 { "exact_rice_parameters", "Calculate rice parameters exactly", offsetof(FlacEncodeContext, options.exact_rice_parameters), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, FLAGS },
1458 { "multi_dim_quant", "Multi-dimensional quantization", offsetof(FlacEncodeContext, options.multi_dim_quant), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, FLAGS },
1462 static const AVClass flac_encoder_class = {
1464 av_default_item_name,
1466 LIBAVUTIL_VERSION_INT,
1469 AVCodec ff_flac_encoder = {
1471 .long_name = NULL_IF_CONFIG_SMALL("FLAC (Free Lossless Audio Codec)"),
1472 .type = AVMEDIA_TYPE_AUDIO,
1473 .id = AV_CODEC_ID_FLAC,
1474 .priv_data_size = sizeof(FlacEncodeContext),
1475 .init = flac_encode_init,
1476 .encode2 = flac_encode_frame,
1477 .close = flac_encode_close,
1478 .capabilities = CODEC_CAP_SMALL_LAST_FRAME | CODEC_CAP_DELAY | CODEC_CAP_LOSSLESS,
1479 .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
1481 AV_SAMPLE_FMT_NONE },
1482 .priv_class = &flac_encoder_class,