xref: /third_party/ffmpeg/libavcodec/flacenc.c (revision cabdff1a)
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/channel_layout.h"
24#include "libavutil/crc.h"
25#include "libavutil/intmath.h"
26#include "libavutil/md5.h"
27#include "libavutil/opt.h"
28
29#include "avcodec.h"
30#include "bswapdsp.h"
31#include "codec_internal.h"
32#include "encode.h"
33#include "put_bits.h"
34#include "put_golomb.h"
35#include "internal.h"
36#include "lpc.h"
37#include "flac.h"
38#include "flacdata.h"
39#include "flacdsp.h"
40
41#define FLAC_SUBFRAME_CONSTANT  0
42#define FLAC_SUBFRAME_VERBATIM  1
43#define FLAC_SUBFRAME_FIXED     8
44#define FLAC_SUBFRAME_LPC      32
45
46#define MAX_FIXED_ORDER     4
47#define MAX_PARTITION_ORDER 8
48#define MAX_PARTITIONS     (1 << MAX_PARTITION_ORDER)
49#define MAX_LPC_PRECISION  15
50#define MIN_LPC_SHIFT       0
51#define MAX_LPC_SHIFT      15
52
53enum CodingMode {
54    CODING_MODE_RICE  = 4,
55    CODING_MODE_RICE2 = 5,
56};
57
58typedef struct CompressionOptions {
59    int compression_level;
60    int block_time_ms;
61    enum FFLPCType lpc_type;
62    int lpc_passes;
63    int lpc_coeff_precision;
64    int min_prediction_order;
65    int max_prediction_order;
66    int prediction_order_method;
67    int min_partition_order;
68    int max_partition_order;
69    int ch_mode;
70    int exact_rice_parameters;
71    int multi_dim_quant;
72} CompressionOptions;
73
74typedef struct RiceContext {
75    enum CodingMode coding_mode;
76    int porder;
77    int params[MAX_PARTITIONS];
78} RiceContext;
79
80typedef struct FlacSubframe {
81    int type;
82    int type_code;
83    int obits;
84    int wasted;
85    int order;
86    int32_t coefs[MAX_LPC_ORDER];
87    int shift;
88
89    RiceContext rc;
90    uint32_t rc_udata[FLAC_MAX_BLOCKSIZE];
91    uint64_t rc_sums[32][MAX_PARTITIONS];
92
93    int32_t samples[FLAC_MAX_BLOCKSIZE];
94    int32_t residual[FLAC_MAX_BLOCKSIZE+11];
95} FlacSubframe;
96
97typedef struct FlacFrame {
98    FlacSubframe subframes[FLAC_MAX_CHANNELS];
99    int blocksize;
100    int bs_code[2];
101    uint8_t crc8;
102    int ch_mode;
103    int verbatim_only;
104} FlacFrame;
105
106typedef struct FlacEncodeContext {
107    AVClass *class;
108    PutBitContext pb;
109    int channels;
110    int samplerate;
111    int sr_code[2];
112    int bps_code;
113    int max_blocksize;
114    int min_framesize;
115    int max_framesize;
116    int max_encoded_framesize;
117    uint32_t frame_count;
118    uint64_t sample_count;
119    uint8_t md5sum[16];
120    FlacFrame frame;
121    CompressionOptions options;
122    AVCodecContext *avctx;
123    LPCContext lpc_ctx;
124    struct AVMD5 *md5ctx;
125    uint8_t *md5_buffer;
126    unsigned int md5_buffer_size;
127    BswapDSPContext bdsp;
128    FLACDSPContext flac_dsp;
129
130    int flushed;
131    int64_t next_pts;
132} FlacEncodeContext;
133
134
135/**
136 * Write streaminfo metadata block to byte array.
137 */
138static void write_streaminfo(FlacEncodeContext *s, uint8_t *header)
139{
140    PutBitContext pb;
141
142    memset(header, 0, FLAC_STREAMINFO_SIZE);
143    init_put_bits(&pb, header, FLAC_STREAMINFO_SIZE);
144
145    /* streaminfo metadata block */
146    put_bits(&pb, 16, s->max_blocksize);
147    put_bits(&pb, 16, s->max_blocksize);
148    put_bits(&pb, 24, s->min_framesize);
149    put_bits(&pb, 24, s->max_framesize);
150    put_bits(&pb, 20, s->samplerate);
151    put_bits(&pb, 3, s->channels-1);
152    put_bits(&pb,  5, s->avctx->bits_per_raw_sample - 1);
153    /* write 36-bit sample count in 2 put_bits() calls */
154    put_bits(&pb, 24, (s->sample_count & 0xFFFFFF000LL) >> 12);
155    put_bits(&pb, 12,  s->sample_count & 0x000000FFFLL);
156    flush_put_bits(&pb);
157    memcpy(&header[18], s->md5sum, 16);
158}
159
160
161/**
162 * Set blocksize based on samplerate.
163 * Choose the closest predefined blocksize >= BLOCK_TIME_MS milliseconds.
164 */
165static int select_blocksize(int samplerate, int block_time_ms)
166{
167    int i;
168    int target;
169    int blocksize;
170
171    av_assert0(samplerate > 0);
172    blocksize = ff_flac_blocksize_table[1];
173    target    = (samplerate * block_time_ms) / 1000;
174    for (i = 0; i < 16; i++) {
175        if (target >= ff_flac_blocksize_table[i] &&
176            ff_flac_blocksize_table[i] > blocksize) {
177            blocksize = ff_flac_blocksize_table[i];
178        }
179    }
180    return blocksize;
181}
182
183
184static av_cold void dprint_compression_options(FlacEncodeContext *s)
185{
186    AVCodecContext     *avctx = s->avctx;
187    CompressionOptions *opt   = &s->options;
188
189    av_log(avctx, AV_LOG_DEBUG, " compression: %d\n", opt->compression_level);
190
191    switch (opt->lpc_type) {
192    case FF_LPC_TYPE_NONE:
193        av_log(avctx, AV_LOG_DEBUG, " lpc type: None\n");
194        break;
195    case FF_LPC_TYPE_FIXED:
196        av_log(avctx, AV_LOG_DEBUG, " lpc type: Fixed pre-defined coefficients\n");
197        break;
198    case FF_LPC_TYPE_LEVINSON:
199        av_log(avctx, AV_LOG_DEBUG, " lpc type: Levinson-Durbin recursion with Welch window\n");
200        break;
201    case FF_LPC_TYPE_CHOLESKY:
202        av_log(avctx, AV_LOG_DEBUG, " lpc type: Cholesky factorization, %d pass%s\n",
203               opt->lpc_passes, opt->lpc_passes == 1 ? "" : "es");
204        break;
205    }
206
207    av_log(avctx, AV_LOG_DEBUG, " prediction order: %d, %d\n",
208           opt->min_prediction_order, opt->max_prediction_order);
209
210    switch (opt->prediction_order_method) {
211    case ORDER_METHOD_EST:
212        av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "estimate");
213        break;
214    case ORDER_METHOD_2LEVEL:
215        av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "2-level");
216        break;
217    case ORDER_METHOD_4LEVEL:
218        av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "4-level");
219        break;
220    case ORDER_METHOD_8LEVEL:
221        av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "8-level");
222        break;
223    case ORDER_METHOD_SEARCH:
224        av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "full search");
225        break;
226    case ORDER_METHOD_LOG:
227        av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "log search");
228        break;
229    }
230
231
232    av_log(avctx, AV_LOG_DEBUG, " partition order: %d, %d\n",
233           opt->min_partition_order, opt->max_partition_order);
234
235    av_log(avctx, AV_LOG_DEBUG, " block size: %d\n", avctx->frame_size);
236
237    av_log(avctx, AV_LOG_DEBUG, " lpc precision: %d\n",
238           opt->lpc_coeff_precision);
239}
240
241
242static av_cold int flac_encode_init(AVCodecContext *avctx)
243{
244    int freq = avctx->sample_rate;
245    int channels = avctx->ch_layout.nb_channels;
246    FlacEncodeContext *s = avctx->priv_data;
247    int i, level, ret;
248    uint8_t *streaminfo;
249
250    s->avctx = avctx;
251
252    switch (avctx->sample_fmt) {
253    case AV_SAMPLE_FMT_S16:
254        avctx->bits_per_raw_sample = 16;
255        s->bps_code                = 4;
256        break;
257    case AV_SAMPLE_FMT_S32:
258        if (avctx->bits_per_raw_sample != 24)
259            av_log(avctx, AV_LOG_WARNING, "encoding as 24 bits-per-sample\n");
260        avctx->bits_per_raw_sample = 24;
261        s->bps_code                = 6;
262        break;
263    }
264
265    if (channels < 1 || channels > FLAC_MAX_CHANNELS) {
266        av_log(avctx, AV_LOG_ERROR, "%d channels not supported (max %d)\n",
267               channels, FLAC_MAX_CHANNELS);
268        return AVERROR(EINVAL);
269    }
270    s->channels = channels;
271
272    /* find samplerate in table */
273    if (freq < 1)
274        return AVERROR(EINVAL);
275    for (i = 4; i < 12; i++) {
276        if (freq == ff_flac_sample_rate_table[i]) {
277            s->samplerate = ff_flac_sample_rate_table[i];
278            s->sr_code[0] = i;
279            s->sr_code[1] = 0;
280            break;
281        }
282    }
283    /* if not in table, samplerate is non-standard */
284    if (i == 12) {
285        if (freq % 1000 == 0 && freq < 255000) {
286            s->sr_code[0] = 12;
287            s->sr_code[1] = freq / 1000;
288        } else if (freq % 10 == 0 && freq < 655350) {
289            s->sr_code[0] = 14;
290            s->sr_code[1] = freq / 10;
291        } else if (freq < 65535) {
292            s->sr_code[0] = 13;
293            s->sr_code[1] = freq;
294        } else {
295            av_log(avctx, AV_LOG_ERROR, "%d Hz not supported\n", freq);
296            return AVERROR(EINVAL);
297        }
298        s->samplerate = freq;
299    }
300
301    /* set compression option defaults based on avctx->compression_level */
302    if (avctx->compression_level < 0)
303        s->options.compression_level = 5;
304    else
305        s->options.compression_level = avctx->compression_level;
306
307    level = s->options.compression_level;
308    if (level > 12) {
309        av_log(avctx, AV_LOG_ERROR, "invalid compression level: %d\n",
310               s->options.compression_level);
311        return AVERROR(EINVAL);
312    }
313
314    s->options.block_time_ms = ((int[]){ 27, 27, 27,105,105,105,105,105,105,105,105,105,105})[level];
315
316    if (s->options.lpc_type == FF_LPC_TYPE_DEFAULT)
317        s->options.lpc_type  = ((int[]){ FF_LPC_TYPE_FIXED,    FF_LPC_TYPE_FIXED,    FF_LPC_TYPE_FIXED,
318                                         FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON,
319                                         FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON,
320                                         FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON,
321                                         FF_LPC_TYPE_LEVINSON})[level];
322
323    if (s->options.min_prediction_order < 0)
324        s->options.min_prediction_order = ((int[]){  2,  0,  0,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1})[level];
325    if (s->options.max_prediction_order < 0)
326        s->options.max_prediction_order = ((int[]){  3,  4,  4,  6,  8,  8,  8,  8, 12, 12, 12, 32, 32})[level];
327
328    if (s->options.prediction_order_method < 0)
329        s->options.prediction_order_method = ((int[]){ ORDER_METHOD_EST,    ORDER_METHOD_EST,    ORDER_METHOD_EST,
330                                                       ORDER_METHOD_EST,    ORDER_METHOD_EST,    ORDER_METHOD_EST,
331                                                       ORDER_METHOD_4LEVEL, ORDER_METHOD_LOG,    ORDER_METHOD_4LEVEL,
332                                                       ORDER_METHOD_LOG,    ORDER_METHOD_SEARCH, ORDER_METHOD_LOG,
333                                                       ORDER_METHOD_SEARCH})[level];
334
335    if (s->options.min_partition_order > s->options.max_partition_order) {
336        av_log(avctx, AV_LOG_ERROR, "invalid partition orders: min=%d max=%d\n",
337               s->options.min_partition_order, s->options.max_partition_order);
338        return AVERROR(EINVAL);
339    }
340    if (s->options.min_partition_order < 0)
341        s->options.min_partition_order = ((int[]){  2,  2,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0})[level];
342    if (s->options.max_partition_order < 0)
343        s->options.max_partition_order = ((int[]){  2,  2,  3,  3,  3,  8,  8,  8,  8,  8,  8,  8,  8})[level];
344
345    if (s->options.lpc_type == FF_LPC_TYPE_NONE) {
346        s->options.min_prediction_order = 0;
347        s->options.max_prediction_order = 0;
348    } else if (s->options.lpc_type == FF_LPC_TYPE_FIXED) {
349        if (s->options.min_prediction_order > MAX_FIXED_ORDER) {
350            av_log(avctx, AV_LOG_WARNING,
351                   "invalid min prediction order %d, clamped to %d\n",
352                   s->options.min_prediction_order, MAX_FIXED_ORDER);
353            s->options.min_prediction_order = MAX_FIXED_ORDER;
354        }
355        if (s->options.max_prediction_order > MAX_FIXED_ORDER) {
356            av_log(avctx, AV_LOG_WARNING,
357                   "invalid max prediction order %d, clamped to %d\n",
358                   s->options.max_prediction_order, MAX_FIXED_ORDER);
359            s->options.max_prediction_order = MAX_FIXED_ORDER;
360        }
361    }
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         av_channel_layout_compare(&avctx->ch_layout, &(AVChannelLayout)AV_CHANNEL_LAYOUT_SURROUND)) ||
404        (channels == 4 &&
405         av_channel_layout_compare(&avctx->ch_layout, &(AVChannelLayout)AV_CHANNEL_LAYOUT_2_2) &&
406         av_channel_layout_compare(&avctx->ch_layout, &(AVChannelLayout)AV_CHANNEL_LAYOUT_QUAD)) ||
407        (channels == 5 &&
408         av_channel_layout_compare(&avctx->ch_layout, &(AVChannelLayout)AV_CHANNEL_LAYOUT_5POINT0) &&
409         av_channel_layout_compare(&avctx->ch_layout, &(AVChannelLayout)AV_CHANNEL_LAYOUT_5POINT0_BACK)) ||
410        (channels == 6 &&
411         av_channel_layout_compare(&avctx->ch_layout, &(AVChannelLayout)AV_CHANNEL_LAYOUT_5POINT1) &&
412         av_channel_layout_compare(&avctx->ch_layout, &(AVChannelLayout)AV_CHANNEL_LAYOUT_5POINT1_BACK))) {
413        if (avctx->ch_layout.order != AV_CHANNEL_ORDER_UNSPEC) {
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_bswapdsp_init(&s->bdsp);
428    ff_flacdsp_init(&s->flac_dsp, avctx->sample_fmt, channels,
429                    avctx->bits_per_raw_sample);
430
431    dprint_compression_options(s);
432
433    return ret;
434}
435
436
437static 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 */
482static 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
504static uint64_t rice_count_exact(const 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
518static 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    if (sub->wasted)
529        count += sub->wasted;
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 */
573static 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
585static int find_optimal_param_exact(uint64_t sums[32][MAX_PARTITIONS], int i, int max_param)
586{
587    int bestk = 0;
588    int64_t bestbits = INT64_MAX;
589    int k;
590
591    for (k = 0; k <= max_param; k++) {
592        int64_t bits = sums[k][i];
593        if (bits < bestbits) {
594            bestbits = bits;
595            bestk = k;
596        }
597    }
598
599    return bestk;
600}
601
602static uint64_t calc_optimal_rice_params(RiceContext *rc, int porder,
603                                         uint64_t sums[32][MAX_PARTITIONS],
604                                         int n, int pred_order, int max_param, int exact)
605{
606    int i;
607    int k, cnt, part;
608    uint64_t all_bits;
609
610    part     = (1 << porder);
611    all_bits = 4 * part;
612
613    cnt = (n >> porder) - pred_order;
614    for (i = 0; i < part; i++) {
615        if (exact) {
616            k = find_optimal_param_exact(sums, i, max_param);
617            all_bits += sums[k][i];
618        } else {
619            k = find_optimal_param(sums[0][i], cnt, max_param);
620            all_bits += rice_encode_count(sums[0][i], cnt, k);
621        }
622        rc->params[i] = k;
623        cnt = n >> porder;
624    }
625
626    rc->porder = porder;
627
628    return all_bits;
629}
630
631
632static void calc_sum_top(int pmax, int kmax, const uint32_t *data, int n, int pred_order,
633                         uint64_t sums[32][MAX_PARTITIONS])
634{
635    int i, k;
636    int parts;
637    const uint32_t *res, *res_end;
638
639    /* sums for highest level */
640    parts   = (1 << pmax);
641
642    for (k = 0; k <= kmax; k++) {
643        res     = &data[pred_order];
644        res_end = &data[n >> pmax];
645        for (i = 0; i < parts; i++) {
646            if (kmax) {
647                uint64_t sum = (1LL + k) * (res_end - res);
648                while (res < res_end)
649                    sum += *(res++) >> k;
650                sums[k][i] = sum;
651            } else {
652                uint64_t sum = 0;
653                while (res < res_end)
654                    sum += *(res++);
655                sums[k][i] = sum;
656            }
657            res_end += n >> pmax;
658        }
659    }
660}
661
662static void calc_sum_next(int level, uint64_t sums[32][MAX_PARTITIONS], int kmax)
663{
664    int i, k;
665    int parts = (1 << level);
666    for (i = 0; i < parts; i++) {
667        for (k=0; k<=kmax; k++)
668            sums[k][i] = sums[k][2*i] + sums[k][2*i+1];
669    }
670}
671
672static uint64_t calc_rice_params(RiceContext *rc,
673                                 uint32_t udata[FLAC_MAX_BLOCKSIZE],
674                                 uint64_t sums[32][MAX_PARTITIONS],
675                                 int pmin, int pmax,
676                                 const int32_t *data, int n, int pred_order, int exact)
677{
678    int i;
679    uint64_t bits[MAX_PARTITION_ORDER+1];
680    int opt_porder;
681    RiceContext tmp_rc;
682    int kmax = (1 << rc->coding_mode) - 2;
683
684    av_assert1(pmin >= 0 && pmin <= MAX_PARTITION_ORDER);
685    av_assert1(pmax >= 0 && pmax <= MAX_PARTITION_ORDER);
686    av_assert1(pmin <= pmax);
687
688    tmp_rc.coding_mode = rc->coding_mode;
689
690    for (i = 0; i < n; i++)
691        udata[i] = (2 * data[i]) ^ (data[i] >> 31);
692
693    calc_sum_top(pmax, exact ? kmax : 0, udata, n, pred_order, sums);
694
695    opt_porder = pmin;
696    bits[pmin] = UINT32_MAX;
697    for (i = pmax; ; ) {
698        bits[i] = calc_optimal_rice_params(&tmp_rc, i, sums, n, pred_order, kmax, exact);
699        if (bits[i] < bits[opt_porder] || pmax == pmin) {
700            opt_porder = i;
701            *rc = tmp_rc;
702        }
703        if (i == pmin)
704            break;
705        calc_sum_next(--i, sums, exact ? kmax : 0);
706    }
707
708    return bits[opt_porder];
709}
710
711
712static int get_max_p_order(int max_porder, int n, int order)
713{
714    int porder = FFMIN(max_porder, av_log2(n^(n-1)));
715    if (order > 0)
716        porder = FFMIN(porder, av_log2(n/order));
717    return porder;
718}
719
720
721static uint64_t find_subframe_rice_params(FlacEncodeContext *s,
722                                          FlacSubframe *sub, int pred_order)
723{
724    int pmin = get_max_p_order(s->options.min_partition_order,
725                               s->frame.blocksize, pred_order);
726    int pmax = get_max_p_order(s->options.max_partition_order,
727                               s->frame.blocksize, pred_order);
728
729    uint64_t bits = 8 + pred_order * sub->obits + 2 + sub->rc.coding_mode;
730    if (sub->type == FLAC_SUBFRAME_LPC)
731        bits += 4 + 5 + pred_order * s->options.lpc_coeff_precision;
732    bits += calc_rice_params(&sub->rc, sub->rc_udata, sub->rc_sums, pmin, pmax, sub->residual,
733                             s->frame.blocksize, pred_order, s->options.exact_rice_parameters);
734    return bits;
735}
736
737
738static void encode_residual_fixed(int32_t *res, const int32_t *smp, int n,
739                                  int order)
740{
741    int i;
742
743    for (i = 0; i < order; i++)
744        res[i] = smp[i];
745
746    if (order == 0) {
747        for (i = order; i < n; i++)
748            res[i] = smp[i];
749    } else if (order == 1) {
750        for (i = order; i < n; i++)
751            res[i] = smp[i] - smp[i-1];
752    } else if (order == 2) {
753        int a = smp[order-1] - smp[order-2];
754        for (i = order; i < n; i += 2) {
755            int b    = smp[i  ] - smp[i-1];
756            res[i]   = b - a;
757            a        = smp[i+1] - smp[i  ];
758            res[i+1] = a - b;
759        }
760    } else if (order == 3) {
761        int a = smp[order-1] -   smp[order-2];
762        int c = smp[order-1] - 2*smp[order-2] + smp[order-3];
763        for (i = order; i < n; i += 2) {
764            int b    = smp[i  ] - smp[i-1];
765            int d    = b - a;
766            res[i]   = d - c;
767            a        = smp[i+1] - smp[i  ];
768            c        = a - b;
769            res[i+1] = c - d;
770        }
771    } else {
772        int a = smp[order-1] -   smp[order-2];
773        int c = smp[order-1] - 2*smp[order-2] +   smp[order-3];
774        int e = smp[order-1] - 3*smp[order-2] + 3*smp[order-3] - smp[order-4];
775        for (i = order; i < n; i += 2) {
776            int b    = smp[i  ] - smp[i-1];
777            int d    = b - a;
778            int f    = d - c;
779            res[i  ] = f - e;
780            a        = smp[i+1] - smp[i  ];
781            c        = a - b;
782            e        = c - d;
783            res[i+1] = e - f;
784        }
785    }
786}
787
788
789static int encode_residual_ch(FlacEncodeContext *s, int ch)
790{
791    int i, n;
792    int min_order, max_order, opt_order, omethod;
793    FlacFrame *frame;
794    FlacSubframe *sub;
795    int32_t coefs[MAX_LPC_ORDER][MAX_LPC_ORDER];
796    int shift[MAX_LPC_ORDER];
797    int32_t *res, *smp;
798
799    frame = &s->frame;
800    sub   = &frame->subframes[ch];
801    res   = sub->residual;
802    smp   = sub->samples;
803    n     = frame->blocksize;
804
805    /* CONSTANT */
806    for (i = 1; i < n; i++)
807        if(smp[i] != smp[0])
808            break;
809    if (i == n) {
810        sub->type = sub->type_code = FLAC_SUBFRAME_CONSTANT;
811        res[0] = smp[0];
812        return subframe_count_exact(s, sub, 0);
813    }
814
815    /* VERBATIM */
816    if (frame->verbatim_only || n < 5) {
817        sub->type = sub->type_code = FLAC_SUBFRAME_VERBATIM;
818        memcpy(res, smp, n * sizeof(int32_t));
819        return subframe_count_exact(s, sub, 0);
820    }
821
822    min_order  = s->options.min_prediction_order;
823    max_order  = s->options.max_prediction_order;
824    omethod    = s->options.prediction_order_method;
825
826    /* FIXED */
827    sub->type = FLAC_SUBFRAME_FIXED;
828    if (s->options.lpc_type == FF_LPC_TYPE_NONE  ||
829        s->options.lpc_type == FF_LPC_TYPE_FIXED || n <= max_order) {
830        uint64_t bits[MAX_FIXED_ORDER+1];
831        if (max_order > MAX_FIXED_ORDER)
832            max_order = MAX_FIXED_ORDER;
833        opt_order = 0;
834        bits[0]   = UINT32_MAX;
835        for (i = min_order; i <= max_order; i++) {
836            encode_residual_fixed(res, smp, n, i);
837            bits[i] = find_subframe_rice_params(s, sub, i);
838            if (bits[i] < bits[opt_order])
839                opt_order = i;
840        }
841        sub->order     = opt_order;
842        sub->type_code = sub->type | sub->order;
843        if (sub->order != max_order) {
844            encode_residual_fixed(res, smp, n, sub->order);
845            find_subframe_rice_params(s, sub, sub->order);
846        }
847        return subframe_count_exact(s, sub, sub->order);
848    }
849
850    /* LPC */
851    sub->type = FLAC_SUBFRAME_LPC;
852    opt_order = ff_lpc_calc_coefs(&s->lpc_ctx, smp, n, min_order, max_order,
853                                  s->options.lpc_coeff_precision, coefs, shift, s->options.lpc_type,
854                                  s->options.lpc_passes, omethod,
855                                  MIN_LPC_SHIFT, MAX_LPC_SHIFT, 0);
856
857    if (omethod == ORDER_METHOD_2LEVEL ||
858        omethod == ORDER_METHOD_4LEVEL ||
859        omethod == ORDER_METHOD_8LEVEL) {
860        int levels = 1 << omethod;
861        uint64_t bits[1 << ORDER_METHOD_8LEVEL];
862        int order       = -1;
863        int opt_index   = levels-1;
864        opt_order       = max_order-1;
865        bits[opt_index] = UINT32_MAX;
866        for (i = levels-1; i >= 0; i--) {
867            int last_order = order;
868            order = min_order + (((max_order-min_order+1) * (i+1)) / levels)-1;
869            order = av_clip(order, min_order - 1, max_order - 1);
870            if (order == last_order)
871                continue;
872            if (s->bps_code * 4 + s->options.lpc_coeff_precision + av_log2(order) <= 32) {
873                s->flac_dsp.lpc16_encode(res, smp, n, order+1, coefs[order],
874                                         shift[order]);
875            } else {
876                s->flac_dsp.lpc32_encode(res, smp, n, order+1, coefs[order],
877                                         shift[order]);
878            }
879            bits[i] = find_subframe_rice_params(s, sub, order+1);
880            if (bits[i] < bits[opt_index]) {
881                opt_index = i;
882                opt_order = order;
883            }
884        }
885        opt_order++;
886    } else if (omethod == ORDER_METHOD_SEARCH) {
887        // brute-force optimal order search
888        uint64_t bits[MAX_LPC_ORDER];
889        opt_order = 0;
890        bits[0]   = UINT32_MAX;
891        for (i = min_order-1; i < max_order; i++) {
892            if (s->bps_code * 4 + s->options.lpc_coeff_precision + av_log2(i) <= 32) {
893                s->flac_dsp.lpc16_encode(res, smp, n, i+1, coefs[i], shift[i]);
894            } else {
895                s->flac_dsp.lpc32_encode(res, smp, n, i+1, coefs[i], shift[i]);
896            }
897            bits[i] = find_subframe_rice_params(s, sub, i+1);
898            if (bits[i] < bits[opt_order])
899                opt_order = i;
900        }
901        opt_order++;
902    } else if (omethod == ORDER_METHOD_LOG) {
903        uint64_t bits[MAX_LPC_ORDER];
904        int step;
905
906        opt_order = min_order - 1 + (max_order-min_order)/3;
907        memset(bits, -1, sizeof(bits));
908
909        for (step = 16; step; step >>= 1) {
910            int last = opt_order;
911            for (i = last-step; i <= last+step; i += step) {
912                if (i < min_order-1 || i >= max_order || bits[i] < UINT32_MAX)
913                    continue;
914                if (s->bps_code * 4 + s->options.lpc_coeff_precision + av_log2(i) <= 32) {
915                    s->flac_dsp.lpc32_encode(res, smp, n, i+1, coefs[i], shift[i]);
916                } else {
917                    s->flac_dsp.lpc16_encode(res, smp, n, i+1, coefs[i], shift[i]);
918                }
919                bits[i] = find_subframe_rice_params(s, sub, i+1);
920                if (bits[i] < bits[opt_order])
921                    opt_order = i;
922            }
923        }
924        opt_order++;
925    }
926
927    if (s->options.multi_dim_quant) {
928        int allsteps = 1;
929        int i, step, improved;
930        int64_t best_score = INT64_MAX;
931        int32_t qmax;
932
933        qmax = (1 << (s->options.lpc_coeff_precision - 1)) - 1;
934
935        for (i=0; i<opt_order; i++)
936            allsteps *= 3;
937
938        do {
939            improved = 0;
940            for (step = 0; step < allsteps; step++) {
941                int tmp = step;
942                int32_t lpc_try[MAX_LPC_ORDER];
943                int64_t score = 0;
944                int diffsum = 0;
945
946                for (i=0; i<opt_order; i++) {
947                    int diff = ((tmp + 1) % 3) - 1;
948                    lpc_try[i] = av_clip(coefs[opt_order - 1][i] + diff, -qmax, qmax);
949                    tmp /= 3;
950                    diffsum += !!diff;
951                }
952                if (diffsum >8)
953                    continue;
954
955                if (s->bps_code * 4 + s->options.lpc_coeff_precision + av_log2(opt_order - 1) <= 32) {
956                    s->flac_dsp.lpc16_encode(res, smp, n, opt_order, lpc_try, shift[opt_order-1]);
957                } else {
958                    s->flac_dsp.lpc32_encode(res, smp, n, opt_order, lpc_try, shift[opt_order-1]);
959                }
960                score = find_subframe_rice_params(s, sub, opt_order);
961                if (score < best_score) {
962                    best_score = score;
963                    memcpy(coefs[opt_order-1], lpc_try, sizeof(*coefs));
964                    improved=1;
965                }
966            }
967        } while(improved);
968    }
969
970    sub->order     = opt_order;
971    sub->type_code = sub->type | (sub->order-1);
972    sub->shift     = shift[sub->order-1];
973    for (i = 0; i < sub->order; i++)
974        sub->coefs[i] = coefs[sub->order-1][i];
975
976    if (s->bps_code * 4 + s->options.lpc_coeff_precision + av_log2(opt_order) <= 32) {
977        s->flac_dsp.lpc16_encode(res, smp, n, sub->order, sub->coefs, sub->shift);
978    } else {
979        s->flac_dsp.lpc32_encode(res, smp, n, sub->order, sub->coefs, sub->shift);
980    }
981
982    find_subframe_rice_params(s, sub, sub->order);
983
984    return subframe_count_exact(s, sub, sub->order);
985}
986
987
988static int count_frame_header(FlacEncodeContext *s)
989{
990    uint8_t av_unused tmp;
991    int count;
992
993    /*
994    <14> Sync code
995    <1>  Reserved
996    <1>  Blocking strategy
997    <4>  Block size in inter-channel samples
998    <4>  Sample rate
999    <4>  Channel assignment
1000    <3>  Sample size in bits
1001    <1>  Reserved
1002    */
1003    count = 32;
1004
1005    /* coded frame number */
1006    PUT_UTF8(s->frame_count, tmp, count += 8;)
1007
1008    /* explicit block size */
1009    if (s->frame.bs_code[0] == 6)
1010        count += 8;
1011    else if (s->frame.bs_code[0] == 7)
1012        count += 16;
1013
1014    /* explicit sample rate */
1015    count += ((s->sr_code[0] == 12) + (s->sr_code[0] > 12) * 2) * 8;
1016
1017    /* frame header CRC-8 */
1018    count += 8;
1019
1020    return count;
1021}
1022
1023
1024static int encode_frame(FlacEncodeContext *s)
1025{
1026    int ch;
1027    uint64_t count;
1028
1029    count = count_frame_header(s);
1030
1031    for (ch = 0; ch < s->channels; ch++)
1032        count += encode_residual_ch(s, ch);
1033
1034    count += (8 - (count & 7)) & 7; // byte alignment
1035    count += 16;                    // CRC-16
1036
1037    count >>= 3;
1038    if (count > INT_MAX)
1039        return AVERROR_BUG;
1040    return count;
1041}
1042
1043
1044static void remove_wasted_bits(FlacEncodeContext *s)
1045{
1046    int ch, i;
1047
1048    for (ch = 0; ch < s->channels; ch++) {
1049        FlacSubframe *sub = &s->frame.subframes[ch];
1050        int32_t v         = 0;
1051
1052        for (i = 0; i < s->frame.blocksize; i++) {
1053            v |= sub->samples[i];
1054            if (v & 1)
1055                break;
1056        }
1057
1058        if (v && !(v & 1)) {
1059            v = ff_ctz(v);
1060
1061            for (i = 0; i < s->frame.blocksize; i++)
1062                sub->samples[i] >>= v;
1063
1064            sub->wasted = v;
1065            sub->obits -= v;
1066
1067            /* for 24-bit, check if removing wasted bits makes the range better
1068               suited for using RICE instead of RICE2 for entropy coding */
1069            if (sub->obits <= 17)
1070                sub->rc.coding_mode = CODING_MODE_RICE;
1071        }
1072    }
1073}
1074
1075
1076static int estimate_stereo_mode(const int32_t *left_ch, const int32_t *right_ch, int n,
1077                                int max_rice_param)
1078{
1079    int i, best;
1080    int32_t lt, rt;
1081    uint64_t sum[4];
1082    uint64_t score[4];
1083    int k;
1084
1085    /* calculate sum of 2nd order residual for each channel */
1086    sum[0] = sum[1] = sum[2] = sum[3] = 0;
1087    for (i = 2; i < n; i++) {
1088        lt = left_ch[i]  - 2*left_ch[i-1]  + left_ch[i-2];
1089        rt = right_ch[i] - 2*right_ch[i-1] + right_ch[i-2];
1090        sum[2] += FFABS((lt + rt) >> 1);
1091        sum[3] += FFABS(lt - rt);
1092        sum[0] += FFABS(lt);
1093        sum[1] += FFABS(rt);
1094    }
1095    /* estimate bit counts */
1096    for (i = 0; i < 4; i++) {
1097        k      = find_optimal_param(2 * sum[i], n, max_rice_param);
1098        sum[i] = rice_encode_count( 2 * sum[i], n, k);
1099    }
1100
1101    /* calculate score for each mode */
1102    score[0] = sum[0] + sum[1];
1103    score[1] = sum[0] + sum[3];
1104    score[2] = sum[1] + sum[3];
1105    score[3] = sum[2] + sum[3];
1106
1107    /* return mode with lowest score */
1108    best = 0;
1109    for (i = 1; i < 4; i++)
1110        if (score[i] < score[best])
1111            best = i;
1112
1113    return best;
1114}
1115
1116
1117/**
1118 * Perform stereo channel decorrelation.
1119 */
1120static void channel_decorrelation(FlacEncodeContext *s)
1121{
1122    FlacFrame *frame;
1123    int32_t *left, *right;
1124    int i, n;
1125
1126    frame = &s->frame;
1127    n     = frame->blocksize;
1128    left  = frame->subframes[0].samples;
1129    right = frame->subframes[1].samples;
1130
1131    if (s->channels != 2) {
1132        frame->ch_mode = FLAC_CHMODE_INDEPENDENT;
1133        return;
1134    }
1135
1136    if (s->options.ch_mode < 0) {
1137        int max_rice_param = (1 << frame->subframes[0].rc.coding_mode) - 2;
1138        frame->ch_mode = estimate_stereo_mode(left, right, n, max_rice_param);
1139    } else
1140        frame->ch_mode = s->options.ch_mode;
1141
1142    /* perform decorrelation and adjust bits-per-sample */
1143    if (frame->ch_mode == FLAC_CHMODE_INDEPENDENT)
1144        return;
1145    if (frame->ch_mode == FLAC_CHMODE_MID_SIDE) {
1146        int32_t tmp;
1147        for (i = 0; i < n; i++) {
1148            tmp      = left[i];
1149            left[i]  = (tmp + right[i]) >> 1;
1150            right[i] =  tmp - right[i];
1151        }
1152        frame->subframes[1].obits++;
1153    } else if (frame->ch_mode == FLAC_CHMODE_LEFT_SIDE) {
1154        for (i = 0; i < n; i++)
1155            right[i] = left[i] - right[i];
1156        frame->subframes[1].obits++;
1157    } else {
1158        for (i = 0; i < n; i++)
1159            left[i] -= right[i];
1160        frame->subframes[0].obits++;
1161    }
1162}
1163
1164
1165static void write_utf8(PutBitContext *pb, uint32_t val)
1166{
1167    uint8_t tmp;
1168    PUT_UTF8(val, tmp, put_bits(pb, 8, tmp);)
1169}
1170
1171
1172static void write_frame_header(FlacEncodeContext *s)
1173{
1174    FlacFrame *frame;
1175    int crc;
1176
1177    frame = &s->frame;
1178
1179    put_bits(&s->pb, 16, 0xFFF8);
1180    put_bits(&s->pb, 4, frame->bs_code[0]);
1181    put_bits(&s->pb, 4, s->sr_code[0]);
1182
1183    if (frame->ch_mode == FLAC_CHMODE_INDEPENDENT)
1184        put_bits(&s->pb, 4, s->channels-1);
1185    else
1186        put_bits(&s->pb, 4, frame->ch_mode + FLAC_MAX_CHANNELS - 1);
1187
1188    put_bits(&s->pb, 3, s->bps_code);
1189    put_bits(&s->pb, 1, 0);
1190    write_utf8(&s->pb, s->frame_count);
1191
1192    if (frame->bs_code[0] == 6)
1193        put_bits(&s->pb, 8, frame->bs_code[1]);
1194    else if (frame->bs_code[0] == 7)
1195        put_bits(&s->pb, 16, frame->bs_code[1]);
1196
1197    if (s->sr_code[0] == 12)
1198        put_bits(&s->pb, 8, s->sr_code[1]);
1199    else if (s->sr_code[0] > 12)
1200        put_bits(&s->pb, 16, s->sr_code[1]);
1201
1202    flush_put_bits(&s->pb);
1203    crc = av_crc(av_crc_get_table(AV_CRC_8_ATM), 0, s->pb.buf,
1204                 put_bytes_output(&s->pb));
1205    put_bits(&s->pb, 8, crc);
1206}
1207
1208
1209static void write_subframes(FlacEncodeContext *s)
1210{
1211    int ch;
1212
1213    for (ch = 0; ch < s->channels; ch++) {
1214        FlacSubframe *sub = &s->frame.subframes[ch];
1215        int i, p, porder, psize;
1216        int32_t *part_end;
1217        int32_t *res       =  sub->residual;
1218        int32_t *frame_end = &sub->residual[s->frame.blocksize];
1219
1220        /* subframe header */
1221        put_bits(&s->pb, 1, 0);
1222        put_bits(&s->pb, 6, sub->type_code);
1223        put_bits(&s->pb, 1, !!sub->wasted);
1224        if (sub->wasted)
1225            put_bits(&s->pb, sub->wasted, 1);
1226
1227        /* subframe */
1228        if (sub->type == FLAC_SUBFRAME_CONSTANT) {
1229            put_sbits(&s->pb, sub->obits, res[0]);
1230        } else if (sub->type == FLAC_SUBFRAME_VERBATIM) {
1231            while (res < frame_end)
1232                put_sbits(&s->pb, sub->obits, *res++);
1233        } else {
1234            /* warm-up samples */
1235            for (i = 0; i < sub->order; i++)
1236                put_sbits(&s->pb, sub->obits, *res++);
1237
1238            /* LPC coefficients */
1239            if (sub->type == FLAC_SUBFRAME_LPC) {
1240                int cbits = s->options.lpc_coeff_precision;
1241                put_bits( &s->pb, 4, cbits-1);
1242                put_sbits(&s->pb, 5, sub->shift);
1243                for (i = 0; i < sub->order; i++)
1244                    put_sbits(&s->pb, cbits, sub->coefs[i]);
1245            }
1246
1247            /* rice-encoded block */
1248            put_bits(&s->pb, 2, sub->rc.coding_mode - 4);
1249
1250            /* partition order */
1251            porder  = sub->rc.porder;
1252            psize   = s->frame.blocksize >> porder;
1253            put_bits(&s->pb, 4, porder);
1254
1255            /* residual */
1256            part_end  = &sub->residual[psize];
1257            for (p = 0; p < 1 << porder; p++) {
1258                int k = sub->rc.params[p];
1259                put_bits(&s->pb, sub->rc.coding_mode, k);
1260                while (res < part_end)
1261                    set_sr_golomb_flac(&s->pb, *res++, k, INT32_MAX, 0);
1262                part_end = FFMIN(frame_end, part_end + psize);
1263            }
1264        }
1265    }
1266}
1267
1268
1269static void write_frame_footer(FlacEncodeContext *s)
1270{
1271    int crc;
1272    flush_put_bits(&s->pb);
1273    crc = av_bswap16(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, s->pb.buf,
1274                            put_bytes_output(&s->pb)));
1275    put_bits(&s->pb, 16, crc);
1276    flush_put_bits(&s->pb);
1277}
1278
1279
1280static int write_frame(FlacEncodeContext *s, AVPacket *avpkt)
1281{
1282    init_put_bits(&s->pb, avpkt->data, avpkt->size);
1283    write_frame_header(s);
1284    write_subframes(s);
1285    write_frame_footer(s);
1286    return put_bytes_output(&s->pb);
1287}
1288
1289
1290static int update_md5_sum(FlacEncodeContext *s, const void *samples)
1291{
1292    const uint8_t *buf;
1293    int buf_size = s->frame.blocksize * s->channels *
1294                   ((s->avctx->bits_per_raw_sample + 7) / 8);
1295
1296    if (s->avctx->bits_per_raw_sample > 16 || HAVE_BIGENDIAN) {
1297        av_fast_malloc(&s->md5_buffer, &s->md5_buffer_size, buf_size);
1298        if (!s->md5_buffer)
1299            return AVERROR(ENOMEM);
1300    }
1301
1302    if (s->avctx->bits_per_raw_sample <= 16) {
1303        buf = (const uint8_t *)samples;
1304#if HAVE_BIGENDIAN
1305        s->bdsp.bswap16_buf((uint16_t *) s->md5_buffer,
1306                            (const uint16_t *) samples, buf_size / 2);
1307        buf = s->md5_buffer;
1308#endif
1309    } else {
1310        int i;
1311        const int32_t *samples0 = samples;
1312        uint8_t *tmp            = s->md5_buffer;
1313
1314        for (i = 0; i < s->frame.blocksize * s->channels; i++) {
1315            int32_t v = samples0[i] >> 8;
1316            AV_WL24(tmp + 3*i, v);
1317        }
1318        buf = s->md5_buffer;
1319    }
1320    av_md5_update(s->md5ctx, buf, buf_size);
1321
1322    return 0;
1323}
1324
1325
1326static int flac_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
1327                             const AVFrame *frame, int *got_packet_ptr)
1328{
1329    FlacEncodeContext *s;
1330    int frame_bytes, out_bytes, ret;
1331
1332    s = avctx->priv_data;
1333
1334    /* when the last block is reached, update the header in extradata */
1335    if (!frame) {
1336        s->max_framesize = s->max_encoded_framesize;
1337        av_md5_final(s->md5ctx, s->md5sum);
1338        write_streaminfo(s, avctx->extradata);
1339
1340        if (!s->flushed) {
1341            uint8_t *side_data = av_packet_new_side_data(avpkt, AV_PKT_DATA_NEW_EXTRADATA,
1342                                                         avctx->extradata_size);
1343            if (!side_data)
1344                return AVERROR(ENOMEM);
1345            memcpy(side_data, avctx->extradata, avctx->extradata_size);
1346
1347            avpkt->pts = s->next_pts;
1348
1349            *got_packet_ptr = 1;
1350            s->flushed = 1;
1351        }
1352
1353        return 0;
1354    }
1355
1356    /* change max_framesize for small final frame */
1357    if (frame->nb_samples < s->frame.blocksize) {
1358        s->max_framesize = ff_flac_get_max_frame_size(frame->nb_samples,
1359                                                      s->channels,
1360                                                      avctx->bits_per_raw_sample);
1361    }
1362
1363    init_frame(s, frame->nb_samples);
1364
1365    copy_samples(s, frame->data[0]);
1366
1367    channel_decorrelation(s);
1368
1369    remove_wasted_bits(s);
1370
1371    frame_bytes = encode_frame(s);
1372
1373    /* Fall back on verbatim mode if the compressed frame is larger than it
1374       would be if encoded uncompressed. */
1375    if (frame_bytes < 0 || frame_bytes > s->max_framesize) {
1376        s->frame.verbatim_only = 1;
1377        frame_bytes = encode_frame(s);
1378        if (frame_bytes < 0) {
1379            av_log(avctx, AV_LOG_ERROR, "Bad frame count\n");
1380            return frame_bytes;
1381        }
1382    }
1383
1384    if ((ret = ff_get_encode_buffer(avctx, avpkt, frame_bytes, 0)) < 0)
1385        return ret;
1386
1387    out_bytes = write_frame(s, avpkt);
1388
1389    s->frame_count++;
1390    s->sample_count += frame->nb_samples;
1391    if ((ret = update_md5_sum(s, frame->data[0])) < 0) {
1392        av_log(avctx, AV_LOG_ERROR, "Error updating MD5 checksum\n");
1393        return ret;
1394    }
1395    if (out_bytes > s->max_encoded_framesize)
1396        s->max_encoded_framesize = out_bytes;
1397    if (out_bytes < s->min_framesize)
1398        s->min_framesize = out_bytes;
1399
1400    avpkt->pts      = frame->pts;
1401    avpkt->duration = ff_samples_to_time_base(avctx, frame->nb_samples);
1402
1403    s->next_pts = avpkt->pts + avpkt->duration;
1404
1405    av_shrink_packet(avpkt, out_bytes);
1406
1407    *got_packet_ptr = 1;
1408    return 0;
1409}
1410
1411
1412static av_cold int flac_encode_close(AVCodecContext *avctx)
1413{
1414    FlacEncodeContext *s = avctx->priv_data;
1415
1416    av_freep(&s->md5ctx);
1417    av_freep(&s->md5_buffer);
1418    ff_lpc_end(&s->lpc_ctx);
1419    return 0;
1420}
1421
1422#define FLAGS AV_OPT_FLAG_ENCODING_PARAM | AV_OPT_FLAG_AUDIO_PARAM
1423static const AVOption options[] = {
1424{ "lpc_coeff_precision", "LPC coefficient precision", offsetof(FlacEncodeContext, options.lpc_coeff_precision), AV_OPT_TYPE_INT, {.i64 = 15 }, 0, MAX_LPC_PRECISION, FLAGS },
1425{ "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" },
1426{ "none",     NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_NONE },     INT_MIN, INT_MAX, FLAGS, "lpc_type" },
1427{ "fixed",    NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_FIXED },    INT_MIN, INT_MAX, FLAGS, "lpc_type" },
1428{ "levinson", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_LEVINSON }, INT_MIN, INT_MAX, FLAGS, "lpc_type" },
1429{ "cholesky", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_CHOLESKY }, INT_MIN, INT_MAX, FLAGS, "lpc_type" },
1430{ "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 },
1431{ "min_partition_order",  NULL, offsetof(FlacEncodeContext, options.min_partition_order),  AV_OPT_TYPE_INT, {.i64 = -1 },      -1, MAX_PARTITION_ORDER, FLAGS },
1432{ "max_partition_order",  NULL, offsetof(FlacEncodeContext, options.max_partition_order),  AV_OPT_TYPE_INT, {.i64 = -1 },      -1, MAX_PARTITION_ORDER, FLAGS },
1433{ "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" },
1434{ "estimation", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_EST },    INT_MIN, INT_MAX, FLAGS, "predm" },
1435{ "2level",     NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_2LEVEL }, INT_MIN, INT_MAX, FLAGS, "predm" },
1436{ "4level",     NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_4LEVEL }, INT_MIN, INT_MAX, FLAGS, "predm" },
1437{ "8level",     NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_8LEVEL }, INT_MIN, INT_MAX, FLAGS, "predm" },
1438{ "search",     NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_SEARCH }, INT_MIN, INT_MAX, FLAGS, "predm" },
1439{ "log",        NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_LOG },    INT_MIN, INT_MAX, FLAGS, "predm" },
1440{ "ch_mode", "Stereo decorrelation mode", offsetof(FlacEncodeContext, options.ch_mode), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, FLAC_CHMODE_MID_SIDE, FLAGS, "ch_mode" },
1441{ "auto",       NULL, 0, AV_OPT_TYPE_CONST, { .i64 = -1                      }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1442{ "indep",      NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_INDEPENDENT }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1443{ "left_side",  NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_LEFT_SIDE   }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1444{ "right_side", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_RIGHT_SIDE  }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1445{ "mid_side",   NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_MID_SIDE    }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
1446{ "exact_rice_parameters", "Calculate rice parameters exactly", offsetof(FlacEncodeContext, options.exact_rice_parameters), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS },
1447{ "multi_dim_quant",       "Multi-dimensional quantization",    offsetof(FlacEncodeContext, options.multi_dim_quant),       AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS },
1448{ "min_prediction_order", NULL, offsetof(FlacEncodeContext, options.min_prediction_order), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, MAX_LPC_ORDER, FLAGS },
1449{ "max_prediction_order", NULL, offsetof(FlacEncodeContext, options.max_prediction_order), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, MAX_LPC_ORDER, FLAGS },
1450
1451{ NULL },
1452};
1453
1454static const AVClass flac_encoder_class = {
1455    .class_name = "FLAC encoder",
1456    .item_name  = av_default_item_name,
1457    .option     = options,
1458    .version    = LIBAVUTIL_VERSION_INT,
1459};
1460
1461const FFCodec ff_flac_encoder = {
1462    .p.name         = "flac",
1463    .p.long_name    = NULL_IF_CONFIG_SMALL("FLAC (Free Lossless Audio Codec)"),
1464    .p.type         = AVMEDIA_TYPE_AUDIO,
1465    .p.id           = AV_CODEC_ID_FLAC,
1466    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY |
1467                      AV_CODEC_CAP_SMALL_LAST_FRAME,
1468    .priv_data_size = sizeof(FlacEncodeContext),
1469    .init           = flac_encode_init,
1470    FF_CODEC_ENCODE_CB(flac_encode_frame),
1471    .close          = flac_encode_close,
1472    .p.sample_fmts  = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
1473                                                     AV_SAMPLE_FMT_S32,
1474                                                     AV_SAMPLE_FMT_NONE },
1475    .p.priv_class   = &flac_encoder_class,
1476    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
1477};
1478