ref: 103cb120b29b1b9a6290b96b0fddb1de6d24c6b6
parent: fc68b29d4f34ab444b30032638cc39a14ff7b0d9
author: menno <menno>
date: Sun Dec 19 18:32:47 EST 1999
Bugfix: MS first gave some distortion in the right channel. Because the Side channel was incorrectly formed.
--- a/ms.c
+++ b/ms.c
@@ -42,6 +42,7 @@
Ch_Info *channelInfo, /* Pointer to Ch_Info */
enum WINDOW_TYPE block_type[MAX_TIME_CHANNELS], /* Block type */
AACQuantInfo* quantInfo, /* Quant info */
+ int use_ms,
int numberOfChannels
)
{@@ -62,7 +63,7 @@
channelInfo[leftChan].common_window = 0;
/* Perform MS if block_types are the same */
- if (block_type[leftChan]==block_type[rightChan]) { + if ((block_type[leftChan]==block_type[rightChan])&&(use_ms==0)) { int numGroups;
int groupIndex = 0;
@@ -93,15 +94,15 @@
realyused = 1;
used++;
for (j = groupIndex; j < quantInfo[leftChan].window_group_length[g]+groupIndex; j++) {- p_ratio_short[0][(j*maxSfb)+sfbNum] = p_chpo_short[2][j].p_ratio[sfbNum];
- p_ratio_short[1][(j*maxSfb)+sfbNum] = p_chpo_short[3][j].p_ratio[sfbNum];
+ p_ratio_short[0][(g*maxSfb)+sfbNum] = p_chpo_short[2][j].p_ratio[sfbNum];
+ p_ratio_short[1][(g*maxSfb)+sfbNum] = p_chpo_short[3][j].p_ratio[sfbNum];
p_chpo_short[1][j].use_ms[sfbNum] = use_ms_short;
}
} else {notused++;
for (j = groupIndex; j < quantInfo[leftChan].window_group_length[g]+groupIndex; j++) {- p_ratio_short[0][(j*maxSfb)+sfbNum] = p_chpo_short[0][j].p_ratio[sfbNum];
- p_ratio_short[1][(j*maxSfb)+sfbNum] = p_chpo_short[1][j].p_ratio[sfbNum];
+ p_ratio_short[0][(g*maxSfb)+sfbNum] = p_chpo_short[0][j].p_ratio[sfbNum];
+ p_ratio_short[1][(g*maxSfb)+sfbNum] = p_chpo_short[1][j].p_ratio[sfbNum];
p_chpo_short[1][j].use_ms[sfbNum] = use_ms_short;
}
}
@@ -129,6 +130,48 @@
channelInfo[leftChan].common_window = 1; /* Use common window */
channelInfo[leftChan].ms_info.is_present=1;
}
+ } else if ((block_type[leftChan]==block_type[rightChan])&&(use_ms == 1)) {+ int chan;
+ int numGroups;
+ int groupIndex = 0;
+ int maxSfb;
+ int g,b,w, j;
+ MS_Info *msInfo;
+
+ channelInfo[0].ms_info.is_present = 1;
+ channelInfo[0].common_window = 1;
+
+ for (chan = 0; chan < 2; chan++) {+ maxSfb = quantInfo[chan].max_sfb;
+ w=0;
+
+ /* Determine which bands should be enabled */
+ msInfo = &(channelInfo[leftChan].ms_info);
+ numGroups = quantInfo[chan].num_window_groups;
+
+ for (g=0;g<numGroups;g++) {+ for (sfbNum=0;sfbNum<maxSfb;sfbNum++) {+ b = g*maxSfb+sfbNum;
+
+ if (block_type[chan] == ONLY_SHORT_WINDOW) {+
+ msInfo->ms_used[b] = 1;
+ for (j = groupIndex; j < quantInfo[chan].window_group_length[g]+groupIndex; j++) {+ p_ratio_short[chan][(g*maxSfb)+sfbNum] = p_chpo_short[chan+2][j].p_ratio[sfbNum];
+ p_chpo_short[1][j].use_ms[sfbNum] = 1;
+ }
+
+ } else {+
+ msInfo->ms_used[b] = 1;
+ p_ratio_long[chan][sfbNum] = p_chpo_long[chan+2].p_ratio[sfbNum];
+ p_chpo_long[1].use_ms[sfbNum] = 1;
+
+ }
+ }
+ groupIndex+=quantInfo[chan].window_group_length[g];
+ }
+ }
} else {int chan;
int numGroups;
@@ -153,7 +196,7 @@
msInfo->ms_used[b] = 0;
for (j = groupIndex; j < quantInfo[chan].window_group_length[g]+groupIndex; j++) {- p_ratio_short[chan][(j*maxSfb)+sfbNum] = p_chpo_short[chan][j].p_ratio[sfbNum];
+ p_ratio_short[chan][(g*maxSfb)+sfbNum] = p_chpo_short[chan][j].p_ratio[sfbNum];
p_chpo_short[1][j].use_ms[sfbNum] = 0;
}
@@ -184,18 +227,17 @@
Ch_Info *channelInfo, /* Pointer to Ch_Info */
enum WINDOW_TYPE block_type[MAX_TIME_CHANNELS], /* Block type */
AACQuantInfo* quantInfo, /* Quant info */
+ int use_ms,
int numberOfChannels
)
{int chanNum, numWindows, bandNumber;
- int otherChan, windowLength, w, j;
+ int windowLength, w, j;
int *p_use_ms;
for (chanNum=0;chanNum<numberOfChannels;chanNum++) {double dtmp;
- otherChan = !chanNum;
-
/* Compute energy in each scalefactor band of each window */
numWindows = (block_type[chanNum]==ONLY_SHORT_WINDOW) ? 8 : 1;
windowLength = 1024/8;
@@ -219,10 +261,10 @@
energy[chanNum][bandNumber] = 0.0;
width=sfb_width_table[chanNum][sfb];
for(i=offset; i<(offset+width); i++ ) {- if (p_use_ms[sfb] && (chanNum == 0))
- dtmp = (spectral_line_vector[chanNum][j]+spectral_line_vector[otherChan][j])*0.5;
- else if (p_use_ms[sfb] && (chanNum == 1))
- dtmp = (spectral_line_vector[chanNum][j]-spectral_line_vector[otherChan][j])*0.5;
+ if (((p_use_ms[sfb]||(use_ms==1)) && (chanNum == 0))&&(use_ms!=-1))
+ dtmp = (spectral_line_vector[0][j]+spectral_line_vector[1][j])*0.5;
+ else if (((p_use_ms[sfb]||(use_ms==1)) && (chanNum == 1))&&(use_ms!=-1))
+ dtmp = (spectral_line_vector[0][j]-spectral_line_vector[1][j])*0.5;
else
dtmp = spectral_line_vector[chanNum][j];
j++;
@@ -239,6 +281,87 @@
/* Perform MS encoding. Spectrum is non-interleaved. */
/* This would be a lot simpler on interleaved spectral data */
void MSEncode(double *spectrum[MAX_TIME_CHANNELS], /* array of pointers to spectral data */
+ Ch_Info *channelInfo, /* Pointer to Ch_Info */
+ int sfb_offset_table[][MAX_SCFAC_BANDS+1],
+ enum WINDOW_TYPE block_type[MAX_TIME_CHANNELS], /* Block type */
+ AACQuantInfo* quantInfo, /* Quant info */
+ int numberOfChannels) { /* Number of channels */+
+ int chanNum;
+ int sfbNum;
+ int lineNum;
+ double sum,diff;
+
+ /* Look for channel_pair_elements */
+ for (chanNum=0;chanNum<numberOfChannels;chanNum++) {+ if (channelInfo[chanNum].present) {+ if ((channelInfo[chanNum].cpe)&&(channelInfo[chanNum].ch_is_left)) {+ int leftChan=chanNum;
+ int rightChan=channelInfo[chanNum].paired_ch;
+ channelInfo[leftChan].ms_info.is_present=0;
+
+ /* Perform MS if block_types are the same */
+ if (block_type[leftChan]==block_type[rightChan]) { +
+ int numGroups;
+ int maxSfb;
+ int g,b,w,line_offset;
+ int startWindow,stopWindow;
+ IS_Info *isInfo;
+ MS_Info *msInfo;
+
+ channelInfo[leftChan].common_window = 1; /* Use common window */
+ channelInfo[leftChan].ms_info.is_present=1;
+
+ numGroups = quantInfo[leftChan].num_window_groups;
+ maxSfb = quantInfo[leftChan].max_sfb;
+ w=0;
+
+ /* Determine which bands should be enabled */
+ /* Right now, simply enable bands which do not use intensity stereo */
+ isInfo = &(channelInfo[rightChan].is_info);
+ msInfo = &(channelInfo[leftChan].ms_info);
+ for (g=0;g<numGroups;g++) {+ for (sfbNum=0;sfbNum<maxSfb;sfbNum++) {+ b = g*maxSfb+sfbNum;
+ msInfo->ms_used[b] = ( (!isInfo->is_used[b])||(!isInfo->is_present) );
+ }
+ }
+
+ /* Perform sum and differencing on bands in which ms_used flag */
+ /* has been set. */
+ line_offset=0;
+ startWindow = 0;
+ for (g=0;g<numGroups;g++) {+ int numWindows = quantInfo[leftChan].window_group_length[g];
+ stopWindow = startWindow + numWindows;
+ for (sfbNum=0;sfbNum<maxSfb;sfbNum++) {+ /* Enable MS mask */
+ if (msInfo->ms_used[g*maxSfb+sfbNum]) {+ for (w=startWindow;w<stopWindow;w++) {+ for (lineNum=sfb_offset_table[leftChan][sfbNum];
+ lineNum<sfb_offset_table[leftChan][sfbNum+1];
+ lineNum++) {+ line_offset = w*BLOCK_LEN_SHORT;
+ sum=spectrum[leftChan][line_offset+lineNum]+spectrum[rightChan][line_offset+lineNum];
+ diff=spectrum[leftChan][line_offset+lineNum]-spectrum[rightChan][line_offset+lineNum];
+ spectrum[leftChan][line_offset+lineNum] = 0.5 * sum;
+ spectrum[rightChan][line_offset+lineNum] = 0.5 * diff;
+ } /* for (lineNum... */
+ } /* for (w=... */
+ }
+ } /* for (sfbNum... */
+ startWindow = stopWindow;
+ } /* for (g... */
+ } /* if (block_type... */
+ }
+ } /* if (channelInfo[chanNum].present */
+ } /* for (chanNum... */
+}
+
+/* Perform MS encoding. Spectrum is non-interleaved. */
+/* This would be a lot simpler on interleaved spectral data */
+void MSEncodeSwitch(double *spectrum[MAX_TIME_CHANNELS], /* array of pointers to spectral data */
Ch_Info *channelInfo, /* Pointer to Ch_Info */
int sfb_offset_table[][MAX_SCFAC_BANDS+1],
enum WINDOW_TYPE block_type[MAX_TIME_CHANNELS], /* Block type */