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Add lpc order search. This creates new compression levels 6 to 12. 

Originally committed as revision 5762 to svn://svn.ffmpeg.org/ffmpeg/trunk
tags/v0.5
Justin Ruggles 19 years ago
parent
7e84f27693
commit
26053bdcc8
1 changed files with 66 additions and 15 deletions
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  1. +66
    -15
      libavcodec/flacenc.c

+ 66
- 15
libavcodec/flacenc.c View File

@@ -221,19 +221,23 @@ static int flac_encode_init(AVCodecContext *avctx)
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_2LEVEL, ORDER_METHOD_4LEVEL, ORDER_METHOD_4LEVEL,
ORDER_METHOD_8LEVEL, ORDER_METHOD_SEARCH, ORDER_METHOD_8LEVEL,
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) {
@@ -294,7 +298,7 @@ static int flac_encode_init(AVCodecContext *avctx)
}
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",
@@ -728,7 +732,7 @@ static int estimate_best_order(double *ref, int max_order)
*/
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 use_lpc)
int *shift, int use_lpc, int omethod)
{
double autoc[MAX_LPC_ORDER+1];
double ref[MAX_LPC_ORDER];
@@ -776,10 +780,17 @@ static int lpc_calc_coefs(const int32_t *samples, int blocksize, int max_order,
for(i=max_order-1; i>0; i--)
ref[i] = ref[i-1] - ref[i];
}
opt_order = estimate_best_order(ref, max_order);
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;
}
@@ -839,7 +850,7 @@ static void encode_residual_lpc(int32_t *res, const int32_t *smp, int n,
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;
@@ -875,6 +886,7 @@ static int encode_residual(FlacEncodeContext *ctx, int ch)
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)) {
@@ -902,7 +914,46 @@ static int encode_residual(FlacEncodeContext *ctx, int ch)
}

/* LPC */
sub->order = lpc_calc_coefs(smp, n, max_order, precision, coefs, shift, ctx->options.use_lpc);
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++;
}

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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