ref: 84beea1b673a6b235ac60cc4834c9e4fee1aa082
dir: /mc_enc.c/
/*******************************************************************************************
*
* Multichannel allocation module.
*
* Authors:
* CL Chuck Lueck, TI <lueck@ti.com>
* RG Ralf Geiger, FhG/IIS
*
* Changes:
* 22-jan-98 CL Initial revision.
* 07-apr-98 RG Added determination of LFE channel.
***************************************************************************************/
#include "mc_enc.h"
void DetermineChInfo(Ch_Info* chInfo, int numChannels) {
/* If LFE present */
/* Num channels # of SCE's # of CPE's #of LFE's */
/* ============ ========== ========== ========= */
/* 1 1 0 0 */
/* 2 0 1 0 */
/* 3 1 1 0 */
/* 4 1 1 1 */
/* 5 1 2 0 */
/* For more than 5 channels, use the following elements: */
/* 2*N 1 2*(N-1) 1 */
/* 2*N+1 1 2*N 0 */
/* */
/* Else: */
/* */
/* Num channels # of SCE's # of CPE's #of LFE's */
/* ============ ========== ========== ========= */
/* 1 1 0 0 */
/* 2 0 1 0 */
/* 3 1 1 0 */
/* 4 2 1 0 */
/* 5 1 2 0 */
/* For more than 5 channels, use the following elements: */
/* 2*N 2 2*(N-1) 0 */
/* 2*N+1 1 2*N 0 */
int sceTag=0;
int cpeTag=0;
int numChannelsLeft=numChannels;
/* First element is sce, except for 2 channel case */
if (numChannelsLeft!=2) {
chInfo[numChannels-numChannelsLeft].present = 1;
chInfo[numChannels-numChannelsLeft].tag=sceTag++;
chInfo[numChannels-numChannelsLeft].cpe=0;
numChannelsLeft--;
}
/* Next elements are cpe's */
while (numChannelsLeft>1) {
/* Left channel info */
chInfo[numChannels-numChannelsLeft].present = 1;
chInfo[numChannels-numChannelsLeft].tag=cpeTag++;
chInfo[numChannels-numChannelsLeft].cpe=1;
chInfo[numChannels-numChannelsLeft].common_window=0;
chInfo[numChannels-numChannelsLeft].ch_is_left=1;
chInfo[numChannels-numChannelsLeft].paired_ch=numChannels-numChannelsLeft+1;
numChannelsLeft--;
/* Right channel info */
chInfo[numChannels-numChannelsLeft].present = 1;
chInfo[numChannels-numChannelsLeft].cpe=1;
chInfo[numChannels-numChannelsLeft].common_window=0;
chInfo[numChannels-numChannelsLeft].ch_is_left=0;
chInfo[numChannels-numChannelsLeft].paired_ch=numChannels-numChannelsLeft-1;
numChannelsLeft--;
}
/* Is there another channel left ? */
if (numChannelsLeft) {
chInfo[numChannels-numChannelsLeft].present = 1;
chInfo[numChannels-numChannelsLeft].tag=sceTag++;
chInfo[numChannels-numChannelsLeft].cpe=0;
numChannelsLeft--;
}
}