[FFmpeg-cvslog] r14789 - trunk/libavcodec/flacenc.c
ramiro
subversion
Sat Aug 16 19:04:00 CEST 2008
Author: ramiro
Date: Sat Aug 16 19:03:57 2008
New Revision: 14789
Log:
flacenc: Allow more flexible shift calculation in LPC.
Modified:
trunk/libavcodec/flacenc.c
Modified: trunk/libavcodec/flacenc.c
==============================================================================
--- trunk/libavcodec/flacenc.c (original)
+++ trunk/libavcodec/flacenc.c Sat Aug 16 19:03:57 2008
@@ -680,7 +680,7 @@ static void compute_lpc_coefs(const doub
* Quantize LPC coefficients
*/
static void quantize_lpc_coefs(double *lpc_in, int order, int precision,
- int32_t *lpc_out, int *shift)
+ int32_t *lpc_out, int *shift, int max_shift, int zero_shift)
{
int i;
double cmax, error;
@@ -697,14 +697,14 @@ static void quantize_lpc_coefs(double *l
}
/* if maximum value quantizes to zero, return all zeros */
- if(cmax * (1 << MAX_LPC_SHIFT) < 1.0) {
- *shift = 0;
+ if(cmax * (1 << max_shift) < 1.0) {
+ *shift = zero_shift;
memset(lpc_out, 0, sizeof(int32_t) * order);
return;
}
/* calculate level shift which scales max coeff to available bits */
- sh = MAX_LPC_SHIFT;
+ sh = max_shift;
while((cmax * (1 << sh) > qmax) && (sh > 0)) {
sh--;
}
@@ -745,10 +745,10 @@ static int estimate_best_order(double *r
/**
* Calculate LPC coefficients for multiple orders
*/
-static int lpc_calc_coefs(FlacEncodeContext *s,
+static int lpc_calc_coefs(DSPContext *s,
const int32_t *samples, int blocksize, int max_order,
int precision, int32_t coefs[][MAX_LPC_ORDER],
- int *shift, int use_lpc, int omethod)
+ int *shift, int use_lpc, int omethod, int max_shift, int zero_shift)
{
double autoc[MAX_LPC_ORDER+1];
double ref[MAX_LPC_ORDER];
@@ -759,7 +759,7 @@ static int lpc_calc_coefs(FlacEncodeCont
assert(max_order >= MIN_LPC_ORDER && max_order <= MAX_LPC_ORDER);
if(use_lpc == 1){
- s->dsp.flac_compute_autocorr(samples, blocksize, max_order, autoc);
+ s->flac_compute_autocorr(samples, blocksize, max_order, autoc);
compute_lpc_coefs(autoc, max_order, lpc, ref);
}else{
@@ -804,10 +804,10 @@ static int lpc_calc_coefs(FlacEncodeCont
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]);
+ quantize_lpc_coefs(lpc[i], i+1, precision, coefs[i], &shift[i], max_shift, zero_shift);
} else {
for(i=0; i<max_order; i++) {
- quantize_lpc_coefs(lpc[i], i+1, precision, coefs[i], &shift[i]);
+ quantize_lpc_coefs(lpc[i], i+1, precision, coefs[i], &shift[i], max_shift, zero_shift);
}
}
@@ -1042,7 +1042,8 @@ static int encode_residual(FlacEncodeCon
}
/* LPC */
- opt_order = lpc_calc_coefs(ctx, smp, n, max_order, precision, coefs, shift, ctx->options.use_lpc, omethod);
+ opt_order = lpc_calc_coefs(&ctx->dsp, smp, n, max_order, precision, coefs,
+ shift, ctx->options.use_lpc, omethod, MAX_LPC_SHIFT, 0);
if(omethod == ORDER_METHOD_2LEVEL ||
omethod == ORDER_METHOD_4LEVEL ||
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