* FLAC audio encoder
* Copyright (c) 2006 Justin Ruggles <jruggle@earthlink.net>
*
- * This library is free software; you can redistribute it and/or
+ * 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 of the License, or (at your option) any later version.
+ * version 2.1 of the License, or (at your option) any later version.
*
- * This library is distributed in the hope that it will be useful,
+ * 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 this library; if not, write to the Free Software
+ * License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "bitstream.h"
#include "crc.h"
#include "golomb.h"
+#include "lls.h"
#define FLAC_MAX_CH 8
#define FLAC_MIN_BLOCKSIZE 16
#define ORDER_METHOD_4LEVEL 2
#define ORDER_METHOD_8LEVEL 3
#define ORDER_METHOD_SEARCH 4
+#define ORDER_METHOD_LOG 5
#define FLAC_STREAMINFO_SIZE 34
av_log(avctx, AV_LOG_DEBUG, " compression: %d\n", s->options.compression_level);
level= s->options.compression_level;
- if(level > 5) {
+ 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})[level];
- s->options.use_lpc = ((int[]){ 0, 0, 0, 1, 1, 1})[level];
- s->options.min_prediction_order= ((int[]){ 2, 0, 0, 1, 1, 1})[level];
- s->options.max_prediction_order= ((int[]){ 3, 4, 4, 6, 8, 8})[level];
- s->options.prediction_order_method = ORDER_METHOD_EST;
- s->options.min_partition_order = ((int[]){ 2, 2, 0, 0, 0, 0})[level];
- s->options.max_partition_order = ((int[]){ 2, 2, 3, 3, 3, 8})[level];
+ 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 = !!avctx->use_lpc;
+ s->options.use_lpc = clip(avctx->use_lpc, 0, 11);
}
- av_log(avctx, AV_LOG_DEBUG, " use lpc: %s\n",
- s->options.use_lpc? "yes" : "no");
+ 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) {
s->options.min_prediction_order, s->options.max_prediction_order);
if(avctx->prediction_order_method >= 0) {
- if(avctx->prediction_order_method > ORDER_METHOD_SEARCH) {
+ 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(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",
"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) {
int32_t *lpc_out, int *shift)
{
int i;
- double cmax;
+ double cmax, error;
int32_t qmax;
int sh;
}
/* output quantized coefficients and level shift */
+ error=0;
for(i=0; i<order; i++) {
- lpc_out[i] = (int32_t)(lpc_in[i] * (1 << sh));
+ error += lpc_in[i] * (1 << sh);
+ lpc_out[i] = clip(lrintf(error), -qmax, qmax);
+ error -= lpc_out[i];
}
*shift = sh;
}
*/
static int lpc_calc_coefs(const int32_t *samples, int blocksize, int max_order,
int precision, int32_t coefs[][MAX_LPC_ORDER],
- int *shift)
+ int *shift, int use_lpc, int omethod)
{
double autoc[MAX_LPC_ORDER+1];
double ref[MAX_LPC_ORDER];
double lpc[MAX_LPC_ORDER][MAX_LPC_ORDER];
- int i;
+ int i, j, pass;
int opt_order;
assert(max_order >= MIN_LPC_ORDER && max_order <= MAX_LPC_ORDER);
- compute_autocorr(samples, blocksize, max_order+1, autoc);
+ if(use_lpc == 1){
+ compute_autocorr(samples, blocksize, max_order+1, autoc);
- compute_lpc_coefs(autoc, max_order, lpc, ref);
+ compute_lpc_coefs(autoc, max_order, lpc, ref);
+ }else{
+ LLSModel m[2];
+ double var[MAX_LPC_ORDER+1], eval, weight;
+
+ for(pass=0; pass<use_lpc-1; pass++){
+ av_init_lls(&m[pass&1], max_order);
+
+ weight=0;
+ for(i=max_order; i<blocksize; i++){
+ for(j=0; j<=max_order; j++)
+ var[j]= samples[i-j];
+
+ if(pass){
+ eval= av_evaluate_lls(&m[(pass-1)&1], var+1, max_order-1);
+ eval= (512>>pass) + fabs(eval - var[0]);
+ for(j=0; j<=max_order; j++)
+ var[j]/= sqrt(eval);
+ weight += 1/eval;
+ }else
+ weight++;
+
+ av_update_lls(&m[pass&1], var, 1.0);
+ }
+ av_solve_lls(&m[pass&1], 0.001, 0);
+ }
- opt_order = estimate_best_order(ref, max_order);
+ for(i=0; i<max_order; i++){
+ for(j=0; j<max_order; j++)
+ lpc[i][j]= m[(pass-1)&1].coeff[i][j];
+ ref[i]= sqrt(m[(pass-1)&1].variance[i] / weight) * (blocksize - max_order) / 4000;
+ }
+ for(i=max_order-1; i>0; i--)
+ ref[i] = ref[i-1] - ref[i];
+ }
+ opt_order = max_order;
- i = opt_order-1;
- quantize_lpc_coefs(lpc[i], i+1, precision, coefs[i], &shift[i]);
+ if(omethod == ORDER_METHOD_EST) {
+ opt_order = estimate_best_order(ref, max_order);
+ i = opt_order-1;
+ quantize_lpc_coefs(lpc[i], i+1, precision, coefs[i], &shift[i]);
+ } else {
+ for(i=0; i<max_order; i++) {
+ quantize_lpc_coefs(lpc[i], i+1, precision, coefs[i], &shift[i]);
+ }
+ }
return opt_order;
}
static int encode_residual(FlacEncodeContext *ctx, int ch)
{
int i, n;
- int min_order, max_order, opt_order, precision;
+ int min_order, max_order, opt_order, precision, omethod;
int min_porder, max_porder;
FlacFrame *frame;
FlacSubframe *sub;
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)) {
}
/* LPC */
- sub->order = lpc_calc_coefs(smp, n, max_order, precision, coefs, shift);
+ opt_order = lpc_calc_coefs(smp, n, max_order, precision, coefs, shift, ctx->options.use_lpc, omethod);
+
+ 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];
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