ref: d175848318cdadec1bda010f561b794fbe6c8ac5
parent: c6a66f1ea772a0904b8d6fa1808fa71da142406f
author: menno <menno>
date: Thu Dec 6 14:11:04 EST 2001
Fixed LTP encoder
--- a/libfaac/aacquant.c
+++ b/libfaac/aacquant.c
@@ -16,7 +16,7 @@
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
- * $Id: aacquant.c,v 1.10 2001/09/28 18:36:06 menno Exp $
+ * $Id: aacquant.c,v 1.11 2001/12/06 19:11:04 menno Exp $
*/
#include <math.h>
@@ -136,6 +136,7 @@
for ( i = 0; i < FRAME_LEN; i++ ) {sign = (xr[i] < 0) ? -1 : 1;
xi[i] *= sign;
+ coderInfo->requantFreq[i] *= sign;
}
} else {coderInfo->global_gain = 0;
--- a/libfaac/ltp.c
+++ b/libfaac/ltp.c
@@ -24,7 +24,7 @@
***************************************************************************/
/*
- * $Id: ltp.c,v 1.7 2001/09/04 18:39:36 menno Exp $
+ * $Id: ltp.c,v 1.8 2001/12/06 19:11:04 menno Exp $
*/
#include <stdio.h>
@@ -37,11 +37,13 @@
#include "filtbank.h"
#include "util.h"
+
/* short double_to_int(double sig_in); */
#define double_to_int(sig_in) \
((sig_in) > 32767 ? 32767 : ( \
(sig_in) < -32768 ? -32768 : (sig_in)))
+#define _MDCT_SCALE 512
/* Purpose: Codebook for LTP weight coefficients. */
static double codebook[CODESIZE] =
@@ -66,7 +68,6 @@
double temp1, temp2;
double energy[BLOCK_LEN_LONG], snr_p[BLOCK_LEN_LONG];
-
if (block_type != ONLY_SHORT_WINDOW)
{flen = BLOCK_LEN_LONG;
@@ -119,6 +120,7 @@
if (num_bit < side_info)
{+// printf("LTP not used!, num_bit: %f ", num_bit);num_bit = 0.0;
for (j = 0; j < flen; j++)
mdct_pred[j] = 0.0;
@@ -126,6 +128,7 @@
sfb_flag[i] = 0;
} else {num_bit -= side_info;
+// printf("LTP used!, num_bit: %f ", num_bit);}
return (num_bit);
@@ -144,9 +147,11 @@
num_samples = NOK_LT_BLEN - offset;
for(i = 0; i < num_samples; i++)
- predicted_samples[i] = *weight * buffer[offset++];
+ predicted_samples[i] = *weight * _MDCT_SCALE*buffer[offset++];
for( ; i < flen; i++)
predicted_samples[i] = 0.0;
+
+
}
static void w_quantize(double *freq, int *ltp_idx)
@@ -173,7 +178,7 @@
double *predicted_samples, double *gain, int *cb_idx)
{int i, j, delay;
- double corr1, corr2, lag_corr, corrtmp;
+ double corr1, corr2, lag_corr;
double p_max, energy, lag_energy;
/*
@@ -203,42 +208,24 @@
lag_corr = lag_energy = 0.0;
delay = lag0;
- energy = 0.0;
- corr1 = 0.0;
- for (j = lag0; j < lag1; j++)
- {- corr1 += x_buffer[NOK_LT_BLEN - j - 1] * sb_samples[flen - j - 1];
- energy += x_buffer[NOK_LT_BLEN - j - 1] * x_buffer[NOK_LT_BLEN - j - 1];
- }
- corrtmp=corr1;
- if (energy != 0.0)
- corr2 = corr1 / sqrt(energy);
- else
- corr2 = 0.0;
- if (p_max < corr2)
- {- p_max = corr2;
- delay = 0;
- lag_corr = corr1;
- lag_energy = energy;
- }
-
- /* Find the lag. */
- for (i = lag0 + 1; i < lag1; i++)
- {- energy -= x_buffer[NOK_LT_BLEN - i] * x_buffer[NOK_LT_BLEN - i];
- energy += x_buffer[NOK_LT_BLEN - i - flen] * x_buffer[NOK_LT_BLEN - i - flen];
- corr1 = corrtmp;
- corr1 -= x_buffer[NOK_LT_BLEN - i] * sb_samples[flen - 1];
- corr1 += x_buffer[NOK_LT_BLEN - i - flen] * sb_samples[0];
- corrtmp = corr1;
-
+ for (i = lag0; i<lag1; i++)
+ {+ energy = 0.0;
+ corr1 = 0.0;
+ for (j=0; j < flen; j++)
+ {+ if (j < i+BLOCK_LEN_LONG)
+ {+ corr1 += sb_samples[j] * _MDCT_SCALE * x_buffer[NOK_LT_BLEN - flen/2 - i + j];
+ energy += _MDCT_SCALE * x_buffer[NOK_LT_BLEN - flen/2 - i + j] * _MDCT_SCALE * x_buffer[NOK_LT_BLEN - flen/2 - i + j];
+ }
+ }
if (energy != 0.0)
corr2 = corr1 / sqrt(energy);
else
corr2 = 0.0;
-
+
if (p_max < corr2)
{p_max = corr2;
@@ -246,8 +233,7 @@
lag_corr = corr1;
lag_energy = energy;
}
- }
-
+ }
/* Compute the gain. */
if(lag_energy != 0.0)
*gain = lag_corr / (1.010 * lag_energy);
@@ -256,10 +242,12 @@
/* Quantize the gain. */
w_quantize(gain, cb_idx);
-
+// printf("Delay: %d, Coeff: %f", delay, *gain);+
/* Get the predicted signal. */
prediction(x_buffer, predicted_samples, gain, delay, flen);
+
return (delay);
}
@@ -274,12 +262,12 @@
/* Transform prediction to frequency domain. */
FilterBank(hEncoder, coderInfo, predicted_samples, mdct_predicted,
NULL, MNON_OVERLAPPED);
-
+
/* Apply TNS analysis filter to the predicted spectrum. */
if(tnsInfo != NULL)
TnsEncodeFilterOnly(tnsInfo, num_of_sfb, num_of_sfb, coderInfo->block_type, sfb_offset,
mdct_predicted);
-
+
/* Get the prediction gain. */
bit_gain = snr_pred(p_spectrum, mdct_predicted, sfb_prediction_used,
sfb_offset, side_info, last_band, coderInfo->nr_of_sfb);
@@ -314,7 +302,8 @@
for(i = 0; i < 2 * BLOCK_LEN_LONG; i++)
ltpInfo->mdct_predicted[i] = 0.0;
- }
+
+ }
}
void LtpEnd(faacEncHandle hEncoder)
@@ -357,6 +346,7 @@
0, 2 * BLOCK_LEN_LONG, predicted_samples, <pInfo->weight,
<pInfo->weight_idx);
+
num_bit[0] =
ltp_enc_tf(hEncoder, coderInfo, p_spectrum, predicted_samples,
ltpInfo->mdct_predicted,
@@ -364,7 +354,8 @@
last_band, ltpInfo->side_info, ltpInfo->sfb_prediction_used,
tnsInfo);
- ltpInfo->global_pred_flag = (num_bit[0] == 0.0) ? 0 : 1;
+
+ ltpInfo->global_pred_flag = (num_bit[0] == 0.0) ? 0 : 1;
if(ltpInfo->global_pred_flag)
for (i = 0; i < coderInfo->sfb_offset[last_band]; i++)