| /** |
| * FLAC audio encoder |
| * Copyright (c) 2006 Justin Ruggles <justin.ruggles@gmail.com> |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #include "libavutil/crc.h" |
| #include "libavutil/lls.h" |
| #include "libavutil/md5.h" |
| #include "avcodec.h" |
| #include "bitstream.h" |
| #include "dsputil.h" |
| #include "golomb.h" |
| #include "lpc.h" |
| #include "flac.h" |
| #include "flacdata.h" |
| |
| #define FLAC_SUBFRAME_CONSTANT 0 |
| #define FLAC_SUBFRAME_VERBATIM 1 |
| #define FLAC_SUBFRAME_FIXED 8 |
| #define FLAC_SUBFRAME_LPC 32 |
| |
| #define MAX_FIXED_ORDER 4 |
| #define MAX_PARTITION_ORDER 8 |
| #define MAX_PARTITIONS (1 << MAX_PARTITION_ORDER) |
| #define MAX_LPC_PRECISION 15 |
| #define MAX_LPC_SHIFT 15 |
| #define MAX_RICE_PARAM 14 |
| |
| typedef struct CompressionOptions { |
| int compression_level; |
| int block_time_ms; |
| int use_lpc; |
| int lpc_coeff_precision; |
| int min_prediction_order; |
| int max_prediction_order; |
| int prediction_order_method; |
| int min_partition_order; |
| int max_partition_order; |
| } CompressionOptions; |
| |
| typedef struct RiceContext { |
| int porder; |
| int params[MAX_PARTITIONS]; |
| } RiceContext; |
| |
| typedef struct FlacSubframe { |
| int type; |
| int type_code; |
| int obits; |
| int order; |
| int32_t coefs[MAX_LPC_ORDER]; |
| int shift; |
| RiceContext rc; |
| int32_t samples[FLAC_MAX_BLOCKSIZE]; |
| int32_t residual[FLAC_MAX_BLOCKSIZE+1]; |
| } FlacSubframe; |
| |
| typedef struct FlacFrame { |
| FlacSubframe subframes[FLAC_MAX_CHANNELS]; |
| int blocksize; |
| int bs_code[2]; |
| uint8_t crc8; |
| int ch_mode; |
| } FlacFrame; |
| |
| typedef struct FlacEncodeContext { |
| PutBitContext pb; |
| int channels; |
| int samplerate; |
| int sr_code[2]; |
| int min_framesize; |
| int max_framesize; |
| int max_encoded_framesize; |
| uint32_t frame_count; |
| uint64_t sample_count; |
| uint8_t md5sum[16]; |
| FlacFrame frame; |
| CompressionOptions options; |
| AVCodecContext *avctx; |
| DSPContext dsp; |
| struct AVMD5 *md5ctx; |
| } FlacEncodeContext; |
| |
| /** |
| * Writes streaminfo metadata block to byte array |
| */ |
| static void write_streaminfo(FlacEncodeContext *s, uint8_t *header) |
| { |
| PutBitContext pb; |
| |
| memset(header, 0, FLAC_STREAMINFO_SIZE); |
| init_put_bits(&pb, header, FLAC_STREAMINFO_SIZE); |
| |
| /* streaminfo metadata block */ |
| put_bits(&pb, 16, s->avctx->frame_size); |
| put_bits(&pb, 16, s->avctx->frame_size); |
| put_bits(&pb, 24, s->min_framesize); |
| put_bits(&pb, 24, s->max_framesize); |
| put_bits(&pb, 20, s->samplerate); |
| put_bits(&pb, 3, s->channels-1); |
| put_bits(&pb, 5, 15); /* bits per sample - 1 */ |
| /* write 36-bit sample count in 2 put_bits() calls */ |
| put_bits(&pb, 24, (s->sample_count & 0xFFFFFF000LL) >> 12); |
| put_bits(&pb, 12, s->sample_count & 0x000000FFFLL); |
| flush_put_bits(&pb); |
| memcpy(&header[18], s->md5sum, 16); |
| } |
| |
| /** |
| * Sets blocksize based on samplerate |
| * Chooses the closest predefined blocksize >= BLOCK_TIME_MS milliseconds |
| */ |
| static int select_blocksize(int samplerate, int block_time_ms) |
| { |
| int i; |
| int target; |
| int blocksize; |
| |
| assert(samplerate > 0); |
| blocksize = ff_flac_blocksize_table[1]; |
| target = (samplerate * block_time_ms) / 1000; |
| for(i=0; i<16; i++) { |
| if(target >= ff_flac_blocksize_table[i] && ff_flac_blocksize_table[i] > blocksize) { |
| blocksize = ff_flac_blocksize_table[i]; |
| } |
| } |
| return blocksize; |
| } |
| |
| static av_cold int flac_encode_init(AVCodecContext *avctx) |
| { |
| int freq = avctx->sample_rate; |
| int channels = avctx->channels; |
| FlacEncodeContext *s = avctx->priv_data; |
| int i, level; |
| uint8_t *streaminfo; |
| |
| s->avctx = avctx; |
| |
| dsputil_init(&s->dsp, avctx); |
| |
| if(avctx->sample_fmt != SAMPLE_FMT_S16) { |
| return -1; |
| } |
| |
| if(channels < 1 || channels > FLAC_MAX_CHANNELS) { |
| return -1; |
| } |
| s->channels = channels; |
| |
| /* find samplerate in table */ |
| if(freq < 1) |
| return -1; |
| for(i=4; i<12; i++) { |
| if(freq == ff_flac_sample_rate_table[i]) { |
| s->samplerate = ff_flac_sample_rate_table[i]; |
| s->sr_code[0] = i; |
| s->sr_code[1] = 0; |
| break; |
| } |
| } |
| /* if not in table, samplerate is non-standard */ |
| if(i == 12) { |
| if(freq % 1000 == 0 && freq < 255000) { |
| s->sr_code[0] = 12; |
| s->sr_code[1] = freq / 1000; |
| } else if(freq % 10 == 0 && freq < 655350) { |
| s->sr_code[0] = 14; |
| s->sr_code[1] = freq / 10; |
| } else if(freq < 65535) { |
| s->sr_code[0] = 13; |
| s->sr_code[1] = freq; |
| } else { |
| return -1; |
| } |
| s->samplerate = freq; |
| } |
| |
| /* set compression option defaults based on avctx->compression_level */ |
| if(avctx->compression_level < 0) { |
| s->options.compression_level = 5; |
| } else { |
| s->options.compression_level = avctx->compression_level; |
| } |
| av_log(avctx, AV_LOG_DEBUG, " compression: %d\n", s->options.compression_level); |
| |
| level= s->options.compression_level; |
| if(level > 12) { |
| av_log(avctx, AV_LOG_ERROR, "invalid compression level: %d\n", |
| s->options.compression_level); |
| return -1; |
| } |
| |
| s->options.block_time_ms = ((int[]){ 27, 27, 27,105,105,105,105,105,105,105,105,105,105})[level]; |
| s->options.use_lpc = ((int[]){ 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1})[level]; |
| s->options.min_prediction_order= ((int[]){ 2, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1})[level]; |
| s->options.max_prediction_order= ((int[]){ 3, 4, 4, 6, 8, 8, 8, 8, 12, 12, 12, 32, 32})[level]; |
| s->options.prediction_order_method = ((int[]){ ORDER_METHOD_EST, ORDER_METHOD_EST, ORDER_METHOD_EST, |
| ORDER_METHOD_EST, ORDER_METHOD_EST, ORDER_METHOD_EST, |
| ORDER_METHOD_4LEVEL, ORDER_METHOD_LOG, ORDER_METHOD_4LEVEL, |
| ORDER_METHOD_LOG, ORDER_METHOD_SEARCH, ORDER_METHOD_LOG, |
| ORDER_METHOD_SEARCH})[level]; |
| s->options.min_partition_order = ((int[]){ 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0})[level]; |
| s->options.max_partition_order = ((int[]){ 2, 2, 3, 3, 3, 8, 8, 8, 8, 8, 8, 8, 8})[level]; |
| |
| /* set compression option overrides from AVCodecContext */ |
| if(avctx->use_lpc >= 0) { |
| s->options.use_lpc = av_clip(avctx->use_lpc, 0, 11); |
| } |
| if(s->options.use_lpc == 1) |
| av_log(avctx, AV_LOG_DEBUG, " use lpc: Levinson-Durbin recursion with Welch window\n"); |
| else if(s->options.use_lpc > 1) |
| av_log(avctx, AV_LOG_DEBUG, " use lpc: Cholesky factorization\n"); |
| |
| if(avctx->min_prediction_order >= 0) { |
| if(s->options.use_lpc) { |
| if(avctx->min_prediction_order < MIN_LPC_ORDER || |
| avctx->min_prediction_order > MAX_LPC_ORDER) { |
| av_log(avctx, AV_LOG_ERROR, "invalid min prediction order: %d\n", |
| avctx->min_prediction_order); |
| return -1; |
| } |
| } else { |
| if(avctx->min_prediction_order > MAX_FIXED_ORDER) { |
| av_log(avctx, AV_LOG_ERROR, "invalid min prediction order: %d\n", |
| avctx->min_prediction_order); |
| return -1; |
| } |
| } |
| s->options.min_prediction_order = avctx->min_prediction_order; |
| } |
| if(avctx->max_prediction_order >= 0) { |
| if(s->options.use_lpc) { |
| if(avctx->max_prediction_order < MIN_LPC_ORDER || |
| avctx->max_prediction_order > MAX_LPC_ORDER) { |
| av_log(avctx, AV_LOG_ERROR, "invalid max prediction order: %d\n", |
| avctx->max_prediction_order); |
| return -1; |
| } |
| } else { |
| if(avctx->max_prediction_order > MAX_FIXED_ORDER) { |
| av_log(avctx, AV_LOG_ERROR, "invalid max prediction order: %d\n", |
| avctx->max_prediction_order); |
| return -1; |
| } |
| } |
| s->options.max_prediction_order = avctx->max_prediction_order; |
| } |
| if(s->options.max_prediction_order < s->options.min_prediction_order) { |
| av_log(avctx, AV_LOG_ERROR, "invalid prediction orders: min=%d max=%d\n", |
| s->options.min_prediction_order, s->options.max_prediction_order); |
| return -1; |
| } |
| av_log(avctx, AV_LOG_DEBUG, " prediction order: %d, %d\n", |
| s->options.min_prediction_order, s->options.max_prediction_order); |
| |
| if(avctx->prediction_order_method >= 0) { |
| if(avctx->prediction_order_method > ORDER_METHOD_LOG) { |
| av_log(avctx, AV_LOG_ERROR, "invalid prediction order method: %d\n", |
| avctx->prediction_order_method); |
| return -1; |
| } |
| s->options.prediction_order_method = avctx->prediction_order_method; |
| } |
| switch(s->options.prediction_order_method) { |
| case ORDER_METHOD_EST: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", |
| "estimate"); break; |
| case ORDER_METHOD_2LEVEL: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", |
| "2-level"); break; |
| case ORDER_METHOD_4LEVEL: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", |
| "4-level"); break; |
| case ORDER_METHOD_8LEVEL: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", |
| "8-level"); break; |
| case ORDER_METHOD_SEARCH: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", |
| "full search"); break; |
| case ORDER_METHOD_LOG: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", |
| "log search"); break; |
| } |
| |
| if(avctx->min_partition_order >= 0) { |
| if(avctx->min_partition_order > MAX_PARTITION_ORDER) { |
| av_log(avctx, AV_LOG_ERROR, "invalid min partition order: %d\n", |
| avctx->min_partition_order); |
| return -1; |
| } |
| s->options.min_partition_order = avctx->min_partition_order; |
| } |
| if(avctx->max_partition_order >= 0) { |
| if(avctx->max_partition_order > MAX_PARTITION_ORDER) { |
| av_log(avctx, AV_LOG_ERROR, "invalid max partition order: %d\n", |
| avctx->max_partition_order); |
| return -1; |
| } |
| s->options.max_partition_order = avctx->max_partition_order; |
| } |
| if(s->options.max_partition_order < s->options.min_partition_order) { |
| av_log(avctx, AV_LOG_ERROR, "invalid partition orders: min=%d max=%d\n", |
| s->options.min_partition_order, s->options.max_partition_order); |
| return -1; |
| } |
| av_log(avctx, AV_LOG_DEBUG, " partition order: %d, %d\n", |
| s->options.min_partition_order, s->options.max_partition_order); |
| |
| if(avctx->frame_size > 0) { |
| if(avctx->frame_size < FLAC_MIN_BLOCKSIZE || |
| avctx->frame_size > FLAC_MAX_BLOCKSIZE) { |
| av_log(avctx, AV_LOG_ERROR, "invalid block size: %d\n", |
| avctx->frame_size); |
| return -1; |
| } |
| } else { |
| s->avctx->frame_size = select_blocksize(s->samplerate, s->options.block_time_ms); |
| } |
| av_log(avctx, AV_LOG_DEBUG, " block size: %d\n", s->avctx->frame_size); |
| |
| /* set LPC precision */ |
| if(avctx->lpc_coeff_precision > 0) { |
| if(avctx->lpc_coeff_precision > MAX_LPC_PRECISION) { |
| av_log(avctx, AV_LOG_ERROR, "invalid lpc coeff precision: %d\n", |
| avctx->lpc_coeff_precision); |
| return -1; |
| } |
| s->options.lpc_coeff_precision = avctx->lpc_coeff_precision; |
| } else { |
| /* default LPC precision */ |
| s->options.lpc_coeff_precision = 15; |
| } |
| av_log(avctx, AV_LOG_DEBUG, " lpc precision: %d\n", |
| s->options.lpc_coeff_precision); |
| |
| /* set maximum encoded frame size in verbatim mode */ |
| s->max_framesize = ff_flac_get_max_frame_size(s->avctx->frame_size, |
| s->channels, 16); |
| |
| /* initialize MD5 context */ |
| s->md5ctx = av_malloc(av_md5_size); |
| if(!s->md5ctx) |
| return AVERROR_NOMEM; |
| av_md5_init(s->md5ctx); |
| |
| streaminfo = av_malloc(FLAC_STREAMINFO_SIZE); |
| write_streaminfo(s, streaminfo); |
| avctx->extradata = streaminfo; |
| avctx->extradata_size = FLAC_STREAMINFO_SIZE; |
| |
| s->frame_count = 0; |
| s->min_framesize = s->max_framesize; |
| |
| avctx->coded_frame = avcodec_alloc_frame(); |
| avctx->coded_frame->key_frame = 1; |
| |
| return 0; |
| } |
| |
| static void init_frame(FlacEncodeContext *s) |
| { |
| int i, ch; |
| FlacFrame *frame; |
| |
| frame = &s->frame; |
| |
| for(i=0; i<16; i++) { |
| if(s->avctx->frame_size == ff_flac_blocksize_table[i]) { |
| frame->blocksize = ff_flac_blocksize_table[i]; |
| frame->bs_code[0] = i; |
| frame->bs_code[1] = 0; |
| break; |
| } |
| } |
| if(i == 16) { |
| frame->blocksize = s->avctx->frame_size; |
| if(frame->blocksize <= 256) { |
| frame->bs_code[0] = 6; |
| frame->bs_code[1] = frame->blocksize-1; |
| } else { |
| frame->bs_code[0] = 7; |
| frame->bs_code[1] = frame->blocksize-1; |
| } |
| } |
| |
| for(ch=0; ch<s->channels; ch++) { |
| frame->subframes[ch].obits = 16; |
| } |
| } |
| |
| /** |
| * Copy channel-interleaved input samples into separate subframes |
| */ |
| static void copy_samples(FlacEncodeContext *s, int16_t *samples) |
| { |
| int i, j, ch; |
| FlacFrame *frame; |
| |
| frame = &s->frame; |
| for(i=0,j=0; i<frame->blocksize; i++) { |
| for(ch=0; ch<s->channels; ch++,j++) { |
| frame->subframes[ch].samples[i] = samples[j]; |
| } |
| } |
| } |
| |
| |
| #define rice_encode_count(sum, n, k) (((n)*((k)+1))+((sum-(n>>1))>>(k))) |
| |
| /** |
| * Solve for d/dk(rice_encode_count) = n-((sum-(n>>1))>>(k+1)) = 0 |
| */ |
| static int find_optimal_param(uint32_t sum, int n) |
| { |
| int k; |
| uint32_t sum2; |
| |
| if(sum <= n>>1) |
| return 0; |
| sum2 = sum-(n>>1); |
| k = av_log2(n<256 ? FASTDIV(sum2,n) : sum2/n); |
| return FFMIN(k, MAX_RICE_PARAM); |
| } |
| |
| static uint32_t calc_optimal_rice_params(RiceContext *rc, int porder, |
| uint32_t *sums, int n, int pred_order) |
| { |
| int i; |
| int k, cnt, part; |
| uint32_t all_bits; |
| |
| part = (1 << porder); |
| all_bits = 4 * part; |
| |
| cnt = (n >> porder) - pred_order; |
| for(i=0; i<part; i++) { |
| k = find_optimal_param(sums[i], cnt); |
| rc->params[i] = k; |
| all_bits += rice_encode_count(sums[i], cnt, k); |
| cnt = n >> porder; |
| } |
| |
| rc->porder = porder; |
| |
| return all_bits; |
| } |
| |
| static void calc_sums(int pmin, int pmax, uint32_t *data, int n, int pred_order, |
| uint32_t sums[][MAX_PARTITIONS]) |
| { |
| int i, j; |
| int parts; |
| uint32_t *res, *res_end; |
| |
| /* sums for highest level */ |
| parts = (1 << pmax); |
| res = &data[pred_order]; |
| res_end = &data[n >> pmax]; |
| for(i=0; i<parts; i++) { |
| uint32_t sum = 0; |
| while(res < res_end){ |
| sum += *(res++); |
| } |
| sums[pmax][i] = sum; |
| res_end+= n >> pmax; |
| } |
| /* sums for lower levels */ |
| for(i=pmax-1; i>=pmin; i--) { |
| parts = (1 << i); |
| for(j=0; j<parts; j++) { |
| sums[i][j] = sums[i+1][2*j] + sums[i+1][2*j+1]; |
| } |
| } |
| } |
| |
| static uint32_t calc_rice_params(RiceContext *rc, int pmin, int pmax, |
| int32_t *data, int n, int pred_order) |
| { |
| int i; |
| uint32_t bits[MAX_PARTITION_ORDER+1]; |
| int opt_porder; |
| RiceContext tmp_rc; |
| uint32_t *udata; |
| uint32_t sums[MAX_PARTITION_ORDER+1][MAX_PARTITIONS]; |
| |
| assert(pmin >= 0 && pmin <= MAX_PARTITION_ORDER); |
| assert(pmax >= 0 && pmax <= MAX_PARTITION_ORDER); |
| assert(pmin <= pmax); |
| |
| udata = av_malloc(n * sizeof(uint32_t)); |
| for(i=0; i<n; i++) { |
| udata[i] = (2*data[i]) ^ (data[i]>>31); |
| } |
| |
| calc_sums(pmin, pmax, udata, n, pred_order, sums); |
| |
| opt_porder = pmin; |
| bits[pmin] = UINT32_MAX; |
| for(i=pmin; i<=pmax; i++) { |
| bits[i] = calc_optimal_rice_params(&tmp_rc, i, sums[i], n, pred_order); |
| if(bits[i] <= bits[opt_porder]) { |
| opt_porder = i; |
| *rc= tmp_rc; |
| } |
| } |
| |
| av_freep(&udata); |
| return bits[opt_porder]; |
| } |
| |
| static int get_max_p_order(int max_porder, int n, int order) |
| { |
| int porder = FFMIN(max_porder, av_log2(n^(n-1))); |
| if(order > 0) |
| porder = FFMIN(porder, av_log2(n/order)); |
| return porder; |
| } |
| |
| static uint32_t calc_rice_params_fixed(RiceContext *rc, int pmin, int pmax, |
| int32_t *data, int n, int pred_order, |
| int bps) |
| { |
| uint32_t bits; |
| pmin = get_max_p_order(pmin, n, pred_order); |
| pmax = get_max_p_order(pmax, n, pred_order); |
| bits = pred_order*bps + 6; |
| bits += calc_rice_params(rc, pmin, pmax, data, n, pred_order); |
| return bits; |
| } |
| |
| static uint32_t calc_rice_params_lpc(RiceContext *rc, int pmin, int pmax, |
| int32_t *data, int n, int pred_order, |
| int bps, int precision) |
| { |
| uint32_t bits; |
| pmin = get_max_p_order(pmin, n, pred_order); |
| pmax = get_max_p_order(pmax, n, pred_order); |
| bits = pred_order*bps + 4 + 5 + pred_order*precision + 6; |
| bits += calc_rice_params(rc, pmin, pmax, data, n, pred_order); |
| return bits; |
| } |
| |
| /** |
| * Apply Welch window function to audio block |
| */ |
| static void apply_welch_window(const int32_t *data, int len, double *w_data) |
| { |
| int i, n2; |
| double w; |
| double c; |
| |
| assert(!(len&1)); //the optimization in r11881 does not support odd len |
| //if someone wants odd len extend the change in r11881 |
| |
| n2 = (len >> 1); |
| c = 2.0 / (len - 1.0); |
| |
| w_data+=n2; |
| data+=n2; |
| for(i=0; i<n2; i++) { |
| w = c - n2 + i; |
| w = 1.0 - (w * w); |
| w_data[-i-1] = data[-i-1] * w; |
| w_data[+i ] = data[+i ] * w; |
| } |
| } |
| |
| /** |
| * Calculates autocorrelation data from audio samples |
| * A Welch window function is applied before calculation. |
| */ |
| void ff_flac_compute_autocorr(const int32_t *data, int len, int lag, |
| double *autoc) |
| { |
| int i, j; |
| double tmp[len + lag + 1]; |
| double *data1= tmp + lag; |
| |
| apply_welch_window(data, len, data1); |
| |
| for(j=0; j<lag; j++) |
| data1[j-lag]= 0.0; |
| data1[len] = 0.0; |
| |
| for(j=0; j<lag; j+=2){ |
| double sum0 = 1.0, sum1 = 1.0; |
| for(i=0; i<len; i++){ |
| sum0 += data1[i] * data1[i-j]; |
| sum1 += data1[i] * data1[i-j-1]; |
| } |
| autoc[j ] = sum0; |
| autoc[j+1] = sum1; |
| } |
| |
| if(j==lag){ |
| double sum = 1.0; |
| for(i=0; i<len; i+=2){ |
| sum += data1[i ] * data1[i-j ] |
| + data1[i+1] * data1[i-j+1]; |
| } |
| autoc[j] = sum; |
| } |
| } |
| |
| |
| static void encode_residual_verbatim(int32_t *res, int32_t *smp, int n) |
| { |
| assert(n > 0); |
| memcpy(res, smp, n * sizeof(int32_t)); |
| } |
| |
| static void encode_residual_fixed(int32_t *res, const int32_t *smp, int n, |
| int order) |
| { |
| int i; |
| |
| for(i=0; i<order; i++) { |
| res[i] = smp[i]; |
| } |
| |
| if(order==0){ |
| for(i=order; i<n; i++) |
| res[i]= smp[i]; |
| }else if(order==1){ |
| for(i=order; i<n; i++) |
| res[i]= smp[i] - smp[i-1]; |
| }else if(order==2){ |
| int a = smp[order-1] - smp[order-2]; |
| for(i=order; i<n; i+=2) { |
| int b = smp[i] - smp[i-1]; |
| res[i]= b - a; |
| a = smp[i+1] - smp[i]; |
| res[i+1]= a - b; |
| } |
| }else if(order==3){ |
| int a = smp[order-1] - smp[order-2]; |
| int c = smp[order-1] - 2*smp[order-2] + smp[order-3]; |
| for(i=order; i<n; i+=2) { |
| int b = smp[i] - smp[i-1]; |
| int d = b - a; |
| res[i]= d - c; |
| a = smp[i+1] - smp[i]; |
| c = a - b; |
| res[i+1]= c - d; |
| } |
| }else{ |
| int a = smp[order-1] - smp[order-2]; |
| int c = smp[order-1] - 2*smp[order-2] + smp[order-3]; |
| int e = smp[order-1] - 3*smp[order-2] + 3*smp[order-3] - smp[order-4]; |
| for(i=order; i<n; i+=2) { |
| int b = smp[i] - smp[i-1]; |
| int d = b - a; |
| int f = d - c; |
| res[i]= f - e; |
| a = smp[i+1] - smp[i]; |
| c = a - b; |
| e = c - d; |
| res[i+1]= e - f; |
| } |
| } |
| } |
| |
| #define LPC1(x) {\ |
| int c = coefs[(x)-1];\ |
| p0 += c*s;\ |
| s = smp[i-(x)+1];\ |
| p1 += c*s;\ |
| } |
| |
| static av_always_inline void encode_residual_lpc_unrolled( |
| int32_t *res, const int32_t *smp, int n, |
| int order, const int32_t *coefs, int shift, int big) |
| { |
| int i; |
| for(i=order; i<n; i+=2) { |
| int s = smp[i-order]; |
| int p0 = 0, p1 = 0; |
| if(big) { |
| switch(order) { |
| case 32: LPC1(32) |
| case 31: LPC1(31) |
| case 30: LPC1(30) |
| case 29: LPC1(29) |
| case 28: LPC1(28) |
| case 27: LPC1(27) |
| case 26: LPC1(26) |
| case 25: LPC1(25) |
| case 24: LPC1(24) |
| case 23: LPC1(23) |
| case 22: LPC1(22) |
| case 21: LPC1(21) |
| case 20: LPC1(20) |
| case 19: LPC1(19) |
| case 18: LPC1(18) |
| case 17: LPC1(17) |
| case 16: LPC1(16) |
| case 15: LPC1(15) |
| case 14: LPC1(14) |
| case 13: LPC1(13) |
| case 12: LPC1(12) |
| case 11: LPC1(11) |
| case 10: LPC1(10) |
| case 9: LPC1( 9) |
| LPC1( 8) |
| LPC1( 7) |
| LPC1( 6) |
| LPC1( 5) |
| LPC1( 4) |
| LPC1( 3) |
| LPC1( 2) |
| LPC1( 1) |
| } |
| } else { |
| switch(order) { |
| case 8: LPC1( 8) |
| case 7: LPC1( 7) |
| case 6: LPC1( 6) |
| case 5: LPC1( 5) |
| case 4: LPC1( 4) |
| case 3: LPC1( 3) |
| case 2: LPC1( 2) |
| case 1: LPC1( 1) |
| } |
| } |
| res[i ] = smp[i ] - (p0 >> shift); |
| res[i+1] = smp[i+1] - (p1 >> shift); |
| } |
| } |
| |
| static void encode_residual_lpc(int32_t *res, const int32_t *smp, int n, |
| int order, const int32_t *coefs, int shift) |
| { |
| int i; |
| for(i=0; i<order; i++) { |
| res[i] = smp[i]; |
| } |
| #if CONFIG_SMALL |
| for(i=order; i<n; i+=2) { |
| int j; |
| int s = smp[i]; |
| int p0 = 0, p1 = 0; |
| for(j=0; j<order; j++) { |
| int c = coefs[j]; |
| p1 += c*s; |
| s = smp[i-j-1]; |
| p0 += c*s; |
| } |
| res[i ] = smp[i ] - (p0 >> shift); |
| res[i+1] = smp[i+1] - (p1 >> shift); |
| } |
| #else |
| switch(order) { |
| case 1: encode_residual_lpc_unrolled(res, smp, n, 1, coefs, shift, 0); break; |
| case 2: encode_residual_lpc_unrolled(res, smp, n, 2, coefs, shift, 0); break; |
| case 3: encode_residual_lpc_unrolled(res, smp, n, 3, coefs, shift, 0); break; |
| case 4: encode_residual_lpc_unrolled(res, smp, n, 4, coefs, shift, 0); break; |
| case 5: encode_residual_lpc_unrolled(res, smp, n, 5, coefs, shift, 0); break; |
| case 6: encode_residual_lpc_unrolled(res, smp, n, 6, coefs, shift, 0); break; |
| case 7: encode_residual_lpc_unrolled(res, smp, n, 7, coefs, shift, 0); break; |
| case 8: encode_residual_lpc_unrolled(res, smp, n, 8, coefs, shift, 0); break; |
| default: encode_residual_lpc_unrolled(res, smp, n, order, coefs, shift, 1); break; |
| } |
| #endif |
| } |
| |
| static int encode_residual(FlacEncodeContext *ctx, int ch) |
| { |
| int i, n; |
| int min_order, max_order, opt_order, precision, omethod; |
| int min_porder, max_porder; |
| FlacFrame *frame; |
| FlacSubframe *sub; |
| int32_t coefs[MAX_LPC_ORDER][MAX_LPC_ORDER]; |
| int shift[MAX_LPC_ORDER]; |
| int32_t *res, *smp; |
| |
| frame = &ctx->frame; |
| sub = &frame->subframes[ch]; |
| res = sub->residual; |
| smp = sub->samples; |
| n = frame->blocksize; |
| |
| /* CONSTANT */ |
| for(i=1; i<n; i++) { |
| if(smp[i] != smp[0]) break; |
| } |
| if(i == n) { |
| sub->type = sub->type_code = FLAC_SUBFRAME_CONSTANT; |
| res[0] = smp[0]; |
| return sub->obits; |
| } |
| |
| /* VERBATIM */ |
| if(n < 5) { |
| sub->type = sub->type_code = FLAC_SUBFRAME_VERBATIM; |
| encode_residual_verbatim(res, smp, n); |
| return sub->obits * n; |
| } |
| |
| min_order = ctx->options.min_prediction_order; |
| max_order = ctx->options.max_prediction_order; |
| min_porder = ctx->options.min_partition_order; |
| max_porder = ctx->options.max_partition_order; |
| precision = ctx->options.lpc_coeff_precision; |
| omethod = ctx->options.prediction_order_method; |
| |
| /* FIXED */ |
| if(!ctx->options.use_lpc || max_order == 0 || (n <= max_order)) { |
| uint32_t bits[MAX_FIXED_ORDER+1]; |
| if(max_order > MAX_FIXED_ORDER) max_order = MAX_FIXED_ORDER; |
| opt_order = 0; |
| bits[0] = UINT32_MAX; |
| for(i=min_order; i<=max_order; i++) { |
| encode_residual_fixed(res, smp, n, i); |
| bits[i] = calc_rice_params_fixed(&sub->rc, min_porder, max_porder, res, |
| n, i, sub->obits); |
| if(bits[i] < bits[opt_order]) { |
| opt_order = i; |
| } |
| } |
| sub->order = opt_order; |
| sub->type = FLAC_SUBFRAME_FIXED; |
| sub->type_code = sub->type | sub->order; |
| if(sub->order != max_order) { |
| encode_residual_fixed(res, smp, n, sub->order); |
| return calc_rice_params_fixed(&sub->rc, min_porder, max_porder, res, n, |
| sub->order, sub->obits); |
| } |
| return bits[sub->order]; |
| } |
| |
| /* LPC */ |
| opt_order = ff_lpc_calc_coefs(&ctx->dsp, smp, n, min_order, max_order, |
| precision, coefs, shift, ctx->options.use_lpc, |
| omethod, MAX_LPC_SHIFT, 0); |
| |
| if(omethod == ORDER_METHOD_2LEVEL || |
| omethod == ORDER_METHOD_4LEVEL || |
| omethod == ORDER_METHOD_8LEVEL) { |
| int levels = 1 << omethod; |
| uint32_t bits[levels]; |
| int order; |
| int opt_index = levels-1; |
| opt_order = max_order-1; |
| bits[opt_index] = UINT32_MAX; |
| for(i=levels-1; i>=0; i--) { |
| order = min_order + (((max_order-min_order+1) * (i+1)) / levels)-1; |
| if(order < 0) order = 0; |
| encode_residual_lpc(res, smp, n, order+1, coefs[order], shift[order]); |
| bits[i] = calc_rice_params_lpc(&sub->rc, min_porder, max_porder, |
| res, n, order+1, sub->obits, precision); |
| if(bits[i] < bits[opt_index]) { |
| opt_index = i; |
| opt_order = order; |
| } |
| } |
| opt_order++; |
| } else if(omethod == ORDER_METHOD_SEARCH) { |
| // brute-force optimal order search |
| uint32_t bits[MAX_LPC_ORDER]; |
| opt_order = 0; |
| bits[0] = UINT32_MAX; |
| for(i=min_order-1; i<max_order; i++) { |
| encode_residual_lpc(res, smp, n, i+1, coefs[i], shift[i]); |
| bits[i] = calc_rice_params_lpc(&sub->rc, min_porder, max_porder, |
| res, n, i+1, sub->obits, precision); |
| if(bits[i] < bits[opt_order]) { |
| opt_order = i; |
| } |
| } |
| opt_order++; |
| } else if(omethod == ORDER_METHOD_LOG) { |
| uint32_t bits[MAX_LPC_ORDER]; |
| int step; |
| |
| opt_order= min_order - 1 + (max_order-min_order)/3; |
| memset(bits, -1, sizeof(bits)); |
| |
| for(step=16 ;step; step>>=1){ |
| int last= opt_order; |
| for(i=last-step; i<=last+step; i+= step){ |
| if(i<min_order-1 || i>=max_order || bits[i] < UINT32_MAX) |
| continue; |
| encode_residual_lpc(res, smp, n, i+1, coefs[i], shift[i]); |
| bits[i] = calc_rice_params_lpc(&sub->rc, min_porder, max_porder, |
| res, n, i+1, sub->obits, precision); |
| if(bits[i] < bits[opt_order]) |
| opt_order= i; |
| } |
| } |
| opt_order++; |
| } |
| |
| sub->order = opt_order; |
| sub->type = FLAC_SUBFRAME_LPC; |
| sub->type_code = sub->type | (sub->order-1); |
| sub->shift = shift[sub->order-1]; |
| for(i=0; i<sub->order; i++) { |
| sub->coefs[i] = coefs[sub->order-1][i]; |
| } |
| encode_residual_lpc(res, smp, n, sub->order, sub->coefs, sub->shift); |
| return calc_rice_params_lpc(&sub->rc, min_porder, max_porder, res, n, sub->order, |
| sub->obits, precision); |
| } |
| |
| static int encode_residual_v(FlacEncodeContext *ctx, int ch) |
| { |
| int i, n; |
| FlacFrame *frame; |
| FlacSubframe *sub; |
| int32_t *res, *smp; |
| |
| frame = &ctx->frame; |
| sub = &frame->subframes[ch]; |
| res = sub->residual; |
| smp = sub->samples; |
| n = frame->blocksize; |
| |
| /* CONSTANT */ |
| for(i=1; i<n; i++) { |
| if(smp[i] != smp[0]) break; |
| } |
| if(i == n) { |
| sub->type = sub->type_code = FLAC_SUBFRAME_CONSTANT; |
| res[0] = smp[0]; |
| return sub->obits; |
| } |
| |
| /* VERBATIM */ |
| sub->type = sub->type_code = FLAC_SUBFRAME_VERBATIM; |
| encode_residual_verbatim(res, smp, n); |
| return sub->obits * n; |
| } |
| |
| static int estimate_stereo_mode(int32_t *left_ch, int32_t *right_ch, int n) |
| { |
| int i, best; |
| int32_t lt, rt; |
| uint64_t sum[4]; |
| uint64_t score[4]; |
| int k; |
| |
| /* calculate sum of 2nd order residual for each channel */ |
| sum[0] = sum[1] = sum[2] = sum[3] = 0; |
| for(i=2; i<n; i++) { |
| lt = left_ch[i] - 2*left_ch[i-1] + left_ch[i-2]; |
| rt = right_ch[i] - 2*right_ch[i-1] + right_ch[i-2]; |
| sum[2] += FFABS((lt + rt) >> 1); |
| sum[3] += FFABS(lt - rt); |
| sum[0] += FFABS(lt); |
| sum[1] += FFABS(rt); |
| } |
| /* estimate bit counts */ |
| for(i=0; i<4; i++) { |
| k = find_optimal_param(2*sum[i], n); |
| sum[i] = rice_encode_count(2*sum[i], n, k); |
| } |
| |
| /* calculate score for each mode */ |
| score[0] = sum[0] + sum[1]; |
| score[1] = sum[0] + sum[3]; |
| score[2] = sum[1] + sum[3]; |
| score[3] = sum[2] + sum[3]; |
| |
| /* return mode with lowest score */ |
| best = 0; |
| for(i=1; i<4; i++) { |
| if(score[i] < score[best]) { |
| best = i; |
| } |
| } |
| if(best == 0) { |
| return FLAC_CHMODE_INDEPENDENT; |
| } else if(best == 1) { |
| return FLAC_CHMODE_LEFT_SIDE; |
| } else if(best == 2) { |
| return FLAC_CHMODE_RIGHT_SIDE; |
| } else { |
| return FLAC_CHMODE_MID_SIDE; |
| } |
| } |
| |
| /** |
| * Perform stereo channel decorrelation |
| */ |
| static void channel_decorrelation(FlacEncodeContext *ctx) |
| { |
| FlacFrame *frame; |
| int32_t *left, *right; |
| int i, n; |
| |
| frame = &ctx->frame; |
| n = frame->blocksize; |
| left = frame->subframes[0].samples; |
| right = frame->subframes[1].samples; |
| |
| if(ctx->channels != 2) { |
| frame->ch_mode = FLAC_CHMODE_INDEPENDENT; |
| return; |
| } |
| |
| frame->ch_mode = estimate_stereo_mode(left, right, n); |
| |
| /* perform decorrelation and adjust bits-per-sample */ |
| if(frame->ch_mode == FLAC_CHMODE_INDEPENDENT) { |
| return; |
| } |
| if(frame->ch_mode == FLAC_CHMODE_MID_SIDE) { |
| int32_t tmp; |
| for(i=0; i<n; i++) { |
| tmp = left[i]; |
| left[i] = (tmp + right[i]) >> 1; |
| right[i] = tmp - right[i]; |
| } |
| frame->subframes[1].obits++; |
| } else if(frame->ch_mode == FLAC_CHMODE_LEFT_SIDE) { |
| for(i=0; i<n; i++) { |
| right[i] = left[i] - right[i]; |
| } |
| frame->subframes[1].obits++; |
| } else { |
| for(i=0; i<n; i++) { |
| left[i] -= right[i]; |
| } |
| frame->subframes[0].obits++; |
| } |
| } |
| |
| static void write_utf8(PutBitContext *pb, uint32_t val) |
| { |
| uint8_t tmp; |
| PUT_UTF8(val, tmp, put_bits(pb, 8, tmp);) |
| } |
| |
| static void output_frame_header(FlacEncodeContext *s) |
| { |
| FlacFrame *frame; |
| int crc; |
| |
| frame = &s->frame; |
| |
| put_bits(&s->pb, 16, 0xFFF8); |
| put_bits(&s->pb, 4, frame->bs_code[0]); |
| put_bits(&s->pb, 4, s->sr_code[0]); |
| if(frame->ch_mode == FLAC_CHMODE_INDEPENDENT) { |
| put_bits(&s->pb, 4, s->channels-1); |
| } else { |
| put_bits(&s->pb, 4, frame->ch_mode); |
| } |
| put_bits(&s->pb, 3, 4); /* bits-per-sample code */ |
| put_bits(&s->pb, 1, 0); |
| write_utf8(&s->pb, s->frame_count); |
| if(frame->bs_code[0] == 6) { |
| put_bits(&s->pb, 8, frame->bs_code[1]); |
| } else if(frame->bs_code[0] == 7) { |
| put_bits(&s->pb, 16, frame->bs_code[1]); |
| } |
| if(s->sr_code[0] == 12) { |
| put_bits(&s->pb, 8, s->sr_code[1]); |
| } else if(s->sr_code[0] > 12) { |
| put_bits(&s->pb, 16, s->sr_code[1]); |
| } |
| flush_put_bits(&s->pb); |
| crc = av_crc(av_crc_get_table(AV_CRC_8_ATM), 0, |
| s->pb.buf, put_bits_count(&s->pb)>>3); |
| put_bits(&s->pb, 8, crc); |
| } |
| |
| static void output_subframe_constant(FlacEncodeContext *s, int ch) |
| { |
| FlacSubframe *sub; |
| int32_t res; |
| |
| sub = &s->frame.subframes[ch]; |
| res = sub->residual[0]; |
| put_sbits(&s->pb, sub->obits, res); |
| } |
| |
| static void output_subframe_verbatim(FlacEncodeContext *s, int ch) |
| { |
| int i; |
| FlacFrame *frame; |
| FlacSubframe *sub; |
| int32_t res; |
| |
| frame = &s->frame; |
| sub = &frame->subframes[ch]; |
| |
| for(i=0; i<frame->blocksize; i++) { |
| res = sub->residual[i]; |
| put_sbits(&s->pb, sub->obits, res); |
| } |
| } |
| |
| static void output_residual(FlacEncodeContext *ctx, int ch) |
| { |
| int i, j, p, n, parts; |
| int k, porder, psize, res_cnt; |
| FlacFrame *frame; |
| FlacSubframe *sub; |
| int32_t *res; |
| |
| frame = &ctx->frame; |
| sub = &frame->subframes[ch]; |
| res = sub->residual; |
| n = frame->blocksize; |
| |
| /* rice-encoded block */ |
| put_bits(&ctx->pb, 2, 0); |
| |
| /* partition order */ |
| porder = sub->rc.porder; |
| psize = n >> porder; |
| parts = (1 << porder); |
| put_bits(&ctx->pb, 4, porder); |
| res_cnt = psize - sub->order; |
| |
| /* residual */ |
| j = sub->order; |
| for(p=0; p<parts; p++) { |
| k = sub->rc.params[p]; |
| put_bits(&ctx->pb, 4, k); |
| if(p == 1) res_cnt = psize; |
| for(i=0; i<res_cnt && j<n; i++, j++) { |
| set_sr_golomb_flac(&ctx->pb, res[j], k, INT32_MAX, 0); |
| } |
| } |
| } |
| |
| static void output_subframe_fixed(FlacEncodeContext *ctx, int ch) |
| { |
| int i; |
| FlacFrame *frame; |
| FlacSubframe *sub; |
| |
| frame = &ctx->frame; |
| sub = &frame->subframes[ch]; |
| |
| /* warm-up samples */ |
| for(i=0; i<sub->order; i++) { |
| put_sbits(&ctx->pb, sub->obits, sub->residual[i]); |
| } |
| |
| /* residual */ |
| output_residual(ctx, ch); |
| } |
| |
| static void output_subframe_lpc(FlacEncodeContext *ctx, int ch) |
| { |
| int i, cbits; |
| FlacFrame *frame; |
| FlacSubframe *sub; |
| |
| frame = &ctx->frame; |
| sub = &frame->subframes[ch]; |
| |
| /* warm-up samples */ |
| for(i=0; i<sub->order; i++) { |
| put_sbits(&ctx->pb, sub->obits, sub->residual[i]); |
| } |
| |
| /* LPC coefficients */ |
| cbits = ctx->options.lpc_coeff_precision; |
| put_bits(&ctx->pb, 4, cbits-1); |
| put_sbits(&ctx->pb, 5, sub->shift); |
| for(i=0; i<sub->order; i++) { |
| put_sbits(&ctx->pb, cbits, sub->coefs[i]); |
| } |
| |
| /* residual */ |
| output_residual(ctx, ch); |
| } |
| |
| static void output_subframes(FlacEncodeContext *s) |
| { |
| FlacFrame *frame; |
| FlacSubframe *sub; |
| int ch; |
| |
| frame = &s->frame; |
| |
| for(ch=0; ch<s->channels; ch++) { |
| sub = &frame->subframes[ch]; |
| |
| /* subframe header */ |
| put_bits(&s->pb, 1, 0); |
| put_bits(&s->pb, 6, sub->type_code); |
| put_bits(&s->pb, 1, 0); /* no wasted bits */ |
| |
| /* subframe */ |
| if(sub->type == FLAC_SUBFRAME_CONSTANT) { |
| output_subframe_constant(s, ch); |
| } else if(sub->type == FLAC_SUBFRAME_VERBATIM) { |
| output_subframe_verbatim(s, ch); |
| } else if(sub->type == FLAC_SUBFRAME_FIXED) { |
| output_subframe_fixed(s, ch); |
| } else if(sub->type == FLAC_SUBFRAME_LPC) { |
| output_subframe_lpc(s, ch); |
| } |
| } |
| } |
| |
| static void output_frame_footer(FlacEncodeContext *s) |
| { |
| int crc; |
| flush_put_bits(&s->pb); |
| crc = bswap_16(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, |
| s->pb.buf, put_bits_count(&s->pb)>>3)); |
| put_bits(&s->pb, 16, crc); |
| flush_put_bits(&s->pb); |
| } |
| |
| static void update_md5_sum(FlacEncodeContext *s, int16_t *samples) |
| { |
| #ifdef WORDS_BIGENDIAN |
| int i; |
| for(i = 0; i < s->frame.blocksize*s->channels; i++) { |
| int16_t smp = le2me_16(samples[i]); |
| av_md5_update(s->md5ctx, (uint8_t *)&smp, 2); |
| } |
| #else |
| av_md5_update(s->md5ctx, (uint8_t *)samples, s->frame.blocksize*s->channels*2); |
| #endif |
| } |
| |
| static int flac_encode_frame(AVCodecContext *avctx, uint8_t *frame, |
| int buf_size, void *data) |
| { |
| int ch; |
| FlacEncodeContext *s; |
| int16_t *samples = data; |
| int out_bytes; |
| int reencoded=0; |
| |
| s = avctx->priv_data; |
| |
| if(buf_size < s->max_framesize*2) { |
| av_log(avctx, AV_LOG_ERROR, "output buffer too small\n"); |
| return 0; |
| } |
| |
| /* when the last block is reached, update the header in extradata */ |
| if (!data) { |
| s->max_framesize = s->max_encoded_framesize; |
| av_md5_final(s->md5ctx, s->md5sum); |
| write_streaminfo(s, avctx->extradata); |
| return 0; |
| } |
| |
| init_frame(s); |
| |
| copy_samples(s, samples); |
| |
| channel_decorrelation(s); |
| |
| for(ch=0; ch<s->channels; ch++) { |
| encode_residual(s, ch); |
| } |
| |
| write_frame: |
| init_put_bits(&s->pb, frame, buf_size); |
| output_frame_header(s); |
| output_subframes(s); |
| output_frame_footer(s); |
| out_bytes = put_bits_count(&s->pb) >> 3; |
| |
| if(out_bytes > s->max_framesize) { |
| if(reencoded) { |
| /* still too large. must be an error. */ |
| av_log(avctx, AV_LOG_ERROR, "error encoding frame\n"); |
| return -1; |
| } |
| |
| /* frame too large. use verbatim mode */ |
| for(ch=0; ch<s->channels; ch++) { |
| encode_residual_v(s, ch); |
| } |
| reencoded = 1; |
| goto write_frame; |
| } |
| |
| s->frame_count++; |
| s->sample_count += avctx->frame_size; |
| update_md5_sum(s, samples); |
| if (out_bytes > s->max_encoded_framesize) |
| s->max_encoded_framesize = out_bytes; |
| if (out_bytes < s->min_framesize) |
| s->min_framesize = out_bytes; |
| |
| return out_bytes; |
| } |
| |
| static av_cold int flac_encode_close(AVCodecContext *avctx) |
| { |
| if (avctx->priv_data) { |
| FlacEncodeContext *s = avctx->priv_data; |
| av_freep(&s->md5ctx); |
| } |
| av_freep(&avctx->extradata); |
| avctx->extradata_size = 0; |
| av_freep(&avctx->coded_frame); |
| return 0; |
| } |
| |
| AVCodec flac_encoder = { |
| "flac", |
| CODEC_TYPE_AUDIO, |
| CODEC_ID_FLAC, |
| sizeof(FlacEncodeContext), |
| flac_encode_init, |
| flac_encode_frame, |
| flac_encode_close, |
| NULL, |
| .capabilities = CODEC_CAP_SMALL_LAST_FRAME | CODEC_CAP_DELAY, |
| .sample_fmts = (enum SampleFormat[]){SAMPLE_FMT_S16,SAMPLE_FMT_NONE}, |
| .long_name = NULL_IF_CONFIG_SMALL("FLAC (Free Lossless Audio Codec)"), |
| }; |
