ref: e62280b166b70adc335cd351d2a3d87777476409
parent: 3ec0a8fc640e88557689a72fcd99f2e5ed2691f3
author: knik <knik>
date: Sun Sep 7 12:46:22 EDT 2003
modified distortion allocation
--- a/libfaac/aacquant.c
+++ b/libfaac/aacquant.c
@@ -17,7 +17,7 @@
* 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 1.24 2003/08/18 16:23:30 knik Exp $
+ * $Id: aacquant.c,v 1.25 2003/09/07 16:46:22 knik Exp $
*/
#include <math.h>
@@ -353,10 +353,9 @@
double *xr, double *xmin, int quality)
{int sfb, start, end, l;
- const double globalthr = 39.0 / (double)quality;
+ const double globalthr = 34.7 / (double)quality;
int last = coderInfo->lastx;
int lastsb = 0;
- static const double minfix = 1.7;
int *cb_offset = coderInfo->sfb_offset;
int num_cb = coderInfo->nr_of_sfb;
double avgenrg = coderInfo->avgenrg;
@@ -384,20 +383,16 @@
for (l = start; l < end; l++)
enrg += xr[l]*xr[l];
- thr = (double)(end-start)*avgenrg/enrg;
- if (sfb == 0)
- thr = pow(thr, 0.4);
- else if ((sfb == 1) && (coderInfo->block_type != ONLY_SHORT_WINDOW))
- thr = pow(thr, 0.3);
- else
- thr = pow(thr, 0.2);
+ thr = enrg/((double)(end-start)*avgenrg);
+ thr = pow(thr, 0.4*(lastsb-sfb)/lastsb + 0.2);
- tmp = (double)start / (double)last - 0.1;
- if (tmp < 0.0)
- tmp = 0.0;
- tmp = minfix * (tmp + 0.77);
- thr = 1.0 / ((1.0 / thr) + (1.0 / tmp));
+ tmp = (double)start / (double)last;
+ if (tmp < 0.3)
+ tmp = 0.2 + 0.3333 * tmp;
+ tmp = 0.13 / tmp;
+ thr = 1.0 / (thr + tmp);
+
xmin[sfb] = ((coderInfo->block_type == ONLY_SHORT_WINDOW) ? 0.65 : 1.0)
* globalthr * thr;
}
@@ -461,23 +456,24 @@
QuantizeBand(hEncoder, xr_pow, xi, IPOW20(coderInfo->global_gain), start, end);
//printf("\tsfac: %d\n", sfac);+ quantvol = 0.0;
+ for (i = start; i < end; i++)
+ quantvol += xr[i] * xr[i];
+
calcdist:
- quantfac = pow(2.0, 0.25*(coderInfo->scale_factor[sb] - coderInfo->global_gain));
+ quantfac = pow(2.0, -0.25*(coderInfo->scale_factor[sb] - coderInfo->global_gain));
- quantvol = 0.0;
diffvol = 0.0;
for (i = start; i < end; i++)
{- tmp = hEncoder->pow43[xi[i]];
- quantvol += tmp * tmp;
-
- diffvol += fabs(fabs(xr[i]) * quantfac - tmp);
+ tmp = (hEncoder->pow43[xi[i]] * quantfac) - fabs(xr[i]);
+ diffvol += tmp * tmp;
}
- quantvol = sqrt(quantvol/(double)(end-start)) * (double)(end-start);
- //printf("\tdiffvol: %f, qvol: %f\n", diffvol, quantvol);-
- tmp = diffvol / quantvol;
+ tmp = quantvol - diffvol;
+ if (tmp < (1e-6 * quantvol))
+ tmp = 1e-6 * quantvol;
+ tmp = sqrt(diffvol / tmp);
if (fabs(fixstep) > maxstep)
{