mirror of
https://git.videolan.org/git/ffmpeg.git
synced 2024-09-10 09:31:06 +02:00
1267 lines
38 KiB
C
1267 lines
38 KiB
C
/**
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* FLAC audio encoder
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* Copyright (c) 2006 Justin Ruggles <justin.ruggles@gmail.com>
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "libavutil/crc.h"
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#include "libavutil/md5.h"
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#include "avcodec.h"
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#include "get_bits.h"
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#include "dsputil.h"
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#include "golomb.h"
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#include "lpc.h"
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#include "flac.h"
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#include "flacdata.h"
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#define FLAC_SUBFRAME_CONSTANT 0
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#define FLAC_SUBFRAME_VERBATIM 1
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#define FLAC_SUBFRAME_FIXED 8
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#define FLAC_SUBFRAME_LPC 32
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#define MAX_FIXED_ORDER 4
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#define MAX_PARTITION_ORDER 8
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#define MAX_PARTITIONS (1 << MAX_PARTITION_ORDER)
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#define MAX_LPC_PRECISION 15
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#define MAX_LPC_SHIFT 15
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#define MAX_RICE_PARAM 14
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typedef struct CompressionOptions {
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int compression_level;
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int block_time_ms;
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int use_lpc;
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int lpc_coeff_precision;
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int min_prediction_order;
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int max_prediction_order;
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int prediction_order_method;
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int min_partition_order;
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int max_partition_order;
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} CompressionOptions;
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typedef struct RiceContext {
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int porder;
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int params[MAX_PARTITIONS];
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} RiceContext;
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typedef struct FlacSubframe {
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int type;
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int type_code;
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int obits;
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int order;
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int32_t coefs[MAX_LPC_ORDER];
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int shift;
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RiceContext rc;
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int32_t samples[FLAC_MAX_BLOCKSIZE];
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int32_t residual[FLAC_MAX_BLOCKSIZE+1];
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} FlacSubframe;
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typedef struct FlacFrame {
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FlacSubframe subframes[FLAC_MAX_CHANNELS];
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int blocksize;
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int bs_code[2];
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uint8_t crc8;
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int ch_mode;
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} FlacFrame;
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typedef struct FlacEncodeContext {
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PutBitContext pb;
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int channels;
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int samplerate;
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int sr_code[2];
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int max_blocksize;
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int min_framesize;
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int max_framesize;
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int max_encoded_framesize;
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uint32_t frame_count;
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uint64_t sample_count;
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uint8_t md5sum[16];
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FlacFrame frame;
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CompressionOptions options;
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AVCodecContext *avctx;
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DSPContext dsp;
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struct AVMD5 *md5ctx;
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} FlacEncodeContext;
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/**
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* Write streaminfo metadata block to byte array
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*/
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static void write_streaminfo(FlacEncodeContext *s, uint8_t *header)
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{
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PutBitContext pb;
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memset(header, 0, FLAC_STREAMINFO_SIZE);
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init_put_bits(&pb, header, FLAC_STREAMINFO_SIZE);
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/* streaminfo metadata block */
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put_bits(&pb, 16, s->max_blocksize);
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put_bits(&pb, 16, s->max_blocksize);
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put_bits(&pb, 24, s->min_framesize);
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put_bits(&pb, 24, s->max_framesize);
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put_bits(&pb, 20, s->samplerate);
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put_bits(&pb, 3, s->channels-1);
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put_bits(&pb, 5, 15); /* bits per sample - 1 */
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/* write 36-bit sample count in 2 put_bits() calls */
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put_bits(&pb, 24, (s->sample_count & 0xFFFFFF000LL) >> 12);
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put_bits(&pb, 12, s->sample_count & 0x000000FFFLL);
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flush_put_bits(&pb);
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memcpy(&header[18], s->md5sum, 16);
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}
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/**
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* Set blocksize based on samplerate
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* Choose the closest predefined blocksize >= BLOCK_TIME_MS milliseconds
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*/
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static int select_blocksize(int samplerate, int block_time_ms)
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{
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int i;
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int target;
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int blocksize;
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assert(samplerate > 0);
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blocksize = ff_flac_blocksize_table[1];
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target = (samplerate * block_time_ms) / 1000;
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for(i=0; i<16; i++) {
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if(target >= ff_flac_blocksize_table[i] && ff_flac_blocksize_table[i] > blocksize) {
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blocksize = ff_flac_blocksize_table[i];
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}
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}
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return blocksize;
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}
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static av_cold int flac_encode_init(AVCodecContext *avctx)
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{
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int freq = avctx->sample_rate;
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int channels = avctx->channels;
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FlacEncodeContext *s = avctx->priv_data;
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int i, level;
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uint8_t *streaminfo;
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s->avctx = avctx;
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dsputil_init(&s->dsp, avctx);
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if(avctx->sample_fmt != SAMPLE_FMT_S16) {
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return -1;
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}
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if(channels < 1 || channels > FLAC_MAX_CHANNELS) {
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return -1;
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}
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s->channels = channels;
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/* find samplerate in table */
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if(freq < 1)
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return -1;
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for(i=4; i<12; i++) {
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if(freq == ff_flac_sample_rate_table[i]) {
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s->samplerate = ff_flac_sample_rate_table[i];
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s->sr_code[0] = i;
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s->sr_code[1] = 0;
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break;
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}
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}
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/* if not in table, samplerate is non-standard */
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if(i == 12) {
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if(freq % 1000 == 0 && freq < 255000) {
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s->sr_code[0] = 12;
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s->sr_code[1] = freq / 1000;
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} else if(freq % 10 == 0 && freq < 655350) {
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s->sr_code[0] = 14;
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s->sr_code[1] = freq / 10;
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} else if(freq < 65535) {
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s->sr_code[0] = 13;
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s->sr_code[1] = freq;
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} else {
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return -1;
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}
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s->samplerate = freq;
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}
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/* set compression option defaults based on avctx->compression_level */
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if(avctx->compression_level < 0) {
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s->options.compression_level = 5;
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} else {
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s->options.compression_level = avctx->compression_level;
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}
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av_log(avctx, AV_LOG_DEBUG, " compression: %d\n", s->options.compression_level);
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level= s->options.compression_level;
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if(level > 12) {
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av_log(avctx, AV_LOG_ERROR, "invalid compression level: %d\n",
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s->options.compression_level);
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return -1;
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}
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s->options.block_time_ms = ((int[]){ 27, 27, 27,105,105,105,105,105,105,105,105,105,105})[level];
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s->options.use_lpc = ((int[]){ 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1})[level];
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s->options.min_prediction_order= ((int[]){ 2, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1})[level];
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s->options.max_prediction_order= ((int[]){ 3, 4, 4, 6, 8, 8, 8, 8, 12, 12, 12, 32, 32})[level];
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s->options.prediction_order_method = ((int[]){ ORDER_METHOD_EST, ORDER_METHOD_EST, ORDER_METHOD_EST,
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ORDER_METHOD_EST, ORDER_METHOD_EST, ORDER_METHOD_EST,
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ORDER_METHOD_4LEVEL, ORDER_METHOD_LOG, ORDER_METHOD_4LEVEL,
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ORDER_METHOD_LOG, ORDER_METHOD_SEARCH, ORDER_METHOD_LOG,
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ORDER_METHOD_SEARCH})[level];
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s->options.min_partition_order = ((int[]){ 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0})[level];
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s->options.max_partition_order = ((int[]){ 2, 2, 3, 3, 3, 8, 8, 8, 8, 8, 8, 8, 8})[level];
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/* set compression option overrides from AVCodecContext */
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if(avctx->use_lpc >= 0) {
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s->options.use_lpc = av_clip(avctx->use_lpc, 0, 11);
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}
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if(s->options.use_lpc == 1)
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av_log(avctx, AV_LOG_DEBUG, " use lpc: Levinson-Durbin recursion with Welch window\n");
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else if(s->options.use_lpc > 1)
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av_log(avctx, AV_LOG_DEBUG, " use lpc: Cholesky factorization\n");
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if(avctx->min_prediction_order >= 0) {
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if(s->options.use_lpc) {
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if(avctx->min_prediction_order < MIN_LPC_ORDER ||
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avctx->min_prediction_order > MAX_LPC_ORDER) {
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av_log(avctx, AV_LOG_ERROR, "invalid min prediction order: %d\n",
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avctx->min_prediction_order);
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return -1;
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}
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} else {
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if(avctx->min_prediction_order > MAX_FIXED_ORDER) {
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av_log(avctx, AV_LOG_ERROR, "invalid min prediction order: %d\n",
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avctx->min_prediction_order);
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return -1;
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}
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}
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s->options.min_prediction_order = avctx->min_prediction_order;
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}
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if(avctx->max_prediction_order >= 0) {
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if(s->options.use_lpc) {
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if(avctx->max_prediction_order < MIN_LPC_ORDER ||
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avctx->max_prediction_order > MAX_LPC_ORDER) {
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av_log(avctx, AV_LOG_ERROR, "invalid max prediction order: %d\n",
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avctx->max_prediction_order);
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return -1;
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}
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} else {
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if(avctx->max_prediction_order > MAX_FIXED_ORDER) {
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av_log(avctx, AV_LOG_ERROR, "invalid max prediction order: %d\n",
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avctx->max_prediction_order);
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return -1;
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}
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}
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s->options.max_prediction_order = avctx->max_prediction_order;
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}
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if(s->options.max_prediction_order < s->options.min_prediction_order) {
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av_log(avctx, AV_LOG_ERROR, "invalid prediction orders: min=%d max=%d\n",
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s->options.min_prediction_order, s->options.max_prediction_order);
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return -1;
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}
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av_log(avctx, AV_LOG_DEBUG, " prediction order: %d, %d\n",
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s->options.min_prediction_order, s->options.max_prediction_order);
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if(avctx->prediction_order_method >= 0) {
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if(avctx->prediction_order_method > ORDER_METHOD_LOG) {
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av_log(avctx, AV_LOG_ERROR, "invalid prediction order method: %d\n",
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avctx->prediction_order_method);
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return -1;
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}
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s->options.prediction_order_method = avctx->prediction_order_method;
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}
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switch(s->options.prediction_order_method) {
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case ORDER_METHOD_EST: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n",
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"estimate"); break;
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case ORDER_METHOD_2LEVEL: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n",
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"2-level"); break;
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case ORDER_METHOD_4LEVEL: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n",
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"4-level"); break;
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case ORDER_METHOD_8LEVEL: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n",
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"8-level"); break;
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case ORDER_METHOD_SEARCH: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n",
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"full search"); break;
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case ORDER_METHOD_LOG: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n",
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"log search"); break;
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}
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if(avctx->min_partition_order >= 0) {
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if(avctx->min_partition_order > MAX_PARTITION_ORDER) {
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av_log(avctx, AV_LOG_ERROR, "invalid min partition order: %d\n",
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avctx->min_partition_order);
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return -1;
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}
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s->options.min_partition_order = avctx->min_partition_order;
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}
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if(avctx->max_partition_order >= 0) {
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if(avctx->max_partition_order > MAX_PARTITION_ORDER) {
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av_log(avctx, AV_LOG_ERROR, "invalid max partition order: %d\n",
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avctx->max_partition_order);
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return -1;
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}
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s->options.max_partition_order = avctx->max_partition_order;
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}
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if(s->options.max_partition_order < s->options.min_partition_order) {
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av_log(avctx, AV_LOG_ERROR, "invalid partition orders: min=%d max=%d\n",
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s->options.min_partition_order, s->options.max_partition_order);
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return -1;
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}
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av_log(avctx, AV_LOG_DEBUG, " partition order: %d, %d\n",
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s->options.min_partition_order, s->options.max_partition_order);
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if(avctx->frame_size > 0) {
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if(avctx->frame_size < FLAC_MIN_BLOCKSIZE ||
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avctx->frame_size > FLAC_MAX_BLOCKSIZE) {
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av_log(avctx, AV_LOG_ERROR, "invalid block size: %d\n",
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avctx->frame_size);
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return -1;
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}
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} else {
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s->avctx->frame_size = select_blocksize(s->samplerate, s->options.block_time_ms);
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}
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s->max_blocksize = s->avctx->frame_size;
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av_log(avctx, AV_LOG_DEBUG, " block size: %d\n", s->avctx->frame_size);
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/* set LPC precision */
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if(avctx->lpc_coeff_precision > 0) {
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if(avctx->lpc_coeff_precision > MAX_LPC_PRECISION) {
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av_log(avctx, AV_LOG_ERROR, "invalid lpc coeff precision: %d\n",
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avctx->lpc_coeff_precision);
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return -1;
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}
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s->options.lpc_coeff_precision = avctx->lpc_coeff_precision;
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} else {
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/* default LPC precision */
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s->options.lpc_coeff_precision = 15;
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}
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av_log(avctx, AV_LOG_DEBUG, " lpc precision: %d\n",
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s->options.lpc_coeff_precision);
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/* set maximum encoded frame size in verbatim mode */
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s->max_framesize = ff_flac_get_max_frame_size(s->avctx->frame_size,
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s->channels, 16);
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/* initialize MD5 context */
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s->md5ctx = av_malloc(av_md5_size);
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if(!s->md5ctx)
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return AVERROR(ENOMEM);
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av_md5_init(s->md5ctx);
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streaminfo = av_malloc(FLAC_STREAMINFO_SIZE);
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write_streaminfo(s, streaminfo);
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avctx->extradata = streaminfo;
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avctx->extradata_size = FLAC_STREAMINFO_SIZE;
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s->frame_count = 0;
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s->min_framesize = s->max_framesize;
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avctx->coded_frame = avcodec_alloc_frame();
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avctx->coded_frame->key_frame = 1;
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return 0;
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}
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static void init_frame(FlacEncodeContext *s)
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{
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int i, ch;
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FlacFrame *frame;
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frame = &s->frame;
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for(i=0; i<16; i++) {
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if(s->avctx->frame_size == ff_flac_blocksize_table[i]) {
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frame->blocksize = ff_flac_blocksize_table[i];
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frame->bs_code[0] = i;
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frame->bs_code[1] = 0;
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break;
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}
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}
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if(i == 16) {
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frame->blocksize = s->avctx->frame_size;
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if(frame->blocksize <= 256) {
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frame->bs_code[0] = 6;
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frame->bs_code[1] = frame->blocksize-1;
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} else {
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frame->bs_code[0] = 7;
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frame->bs_code[1] = frame->blocksize-1;
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}
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}
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for(ch=0; ch<s->channels; ch++) {
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frame->subframes[ch].obits = 16;
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}
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}
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/**
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* Copy channel-interleaved input samples into separate subframes
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*/
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static void copy_samples(FlacEncodeContext *s, int16_t *samples)
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{
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int i, j, ch;
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FlacFrame *frame;
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frame = &s->frame;
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for(i=0,j=0; i<frame->blocksize; i++) {
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for(ch=0; ch<s->channels; ch++,j++) {
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frame->subframes[ch].samples[i] = samples[j];
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}
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}
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}
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#define rice_encode_count(sum, n, k) (((n)*((k)+1))+((sum-(n>>1))>>(k)))
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/**
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* Solve for d/dk(rice_encode_count) = n-((sum-(n>>1))>>(k+1)) = 0
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*/
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static int find_optimal_param(uint32_t sum, int n)
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{
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int k;
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uint32_t sum2;
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if(sum <= n>>1)
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return 0;
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sum2 = sum-(n>>1);
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k = av_log2(n<256 ? FASTDIV(sum2,n) : sum2/n);
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return FFMIN(k, MAX_RICE_PARAM);
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}
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static uint32_t calc_optimal_rice_params(RiceContext *rc, int porder,
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uint32_t *sums, int n, int pred_order)
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{
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int i;
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int k, cnt, part;
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uint32_t all_bits;
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part = (1 << porder);
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all_bits = 4 * part;
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cnt = (n >> porder) - pred_order;
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for(i=0; i<part; i++) {
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k = find_optimal_param(sums[i], cnt);
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rc->params[i] = k;
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all_bits += rice_encode_count(sums[i], cnt, k);
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cnt = n >> porder;
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}
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rc->porder = porder;
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return all_bits;
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}
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|
|
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;
|
|
}
|
|
|
|
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[1 << ORDER_METHOD_8LEVEL];
|
|
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 = av_bswap16(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)
|
|
{
|
|
#if HAVE_BIGENDIAN
|
|
int i;
|
|
for(i = 0; i < s->frame.blocksize*s->channels; i++) {
|
|
int16_t smp = av_le2ne16(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",
|
|
AVMEDIA_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 = (const enum SampleFormat[]){SAMPLE_FMT_S16,SAMPLE_FMT_NONE},
|
|
.long_name = NULL_IF_CONFIG_SMALL("FLAC (Free Lossless Audio Codec)"),
|
|
};
|