N58_HPOC/app/evrc2Pcm.c

/*
evrcPacketDecode
rtp语音包语音内容解密
*/
#include "evrc2Pcm.h"
#include <string.h>
unsigned short evrcPacketDecode(unsigned char *outBuf,unsigned char *playload, unsigned char playlen)
{
  T_BOOL fullRate;
  unsigned char index;
  unsigned char offset=0;
  unsigned char offsetN=VOICE_DATA_INDEX;
  int i;
  unsigned short retLen;

  if(playload[CNT_EVRC_FRAME_INDEX]==HAS_AMRNB_RATE){
	retLen=playlen-16;
	for(i=0;i<retLen;i++)
	outBuf[i]=playload[VOICE_DATA_INDEX+i]^playload[VOICE_MAGIC_INDEX];
	return retLen;
  }else if(playload[CNT_EVRC_FRAME_INDEX]==ALL_FULL_RATE){
  	for(index = 0; index < (UDP_VOICE_PKT_FRAME_CNT*FULL_FRAME_SIZE); index++)
		  playload[VOICE_DATA_INDEX+index] = (playload[VOICE_DATA_INDEX+index] ^ playload[VOICE_MAGIC_INDEX]);
	for(index = 0; index < UDP_VOICE_PKT_FRAME_CNT; index++){
	  outBuf[offset++] = FULL_FRAME_I;
	  outBuf[offset++] = FULL_FRAME_SIZE;
	  memcpy(&outBuf[offset],&playload[offsetN], FULL_FRAME_SIZE);
	  offsetN += FULL_FRAME_SIZE;
	  offset += FULL_FRAME_SIZE;
	}
	return offset;
  }else{
	if(HAS_FULL_RATE==playload[CNT_EVRC_FRAME_INDEX]){
	  fullRate=TRUE;
	  for(index = 0; index < (FULL_FRAME_SIZE+ (UDP_VOICE_PKT_FRAME_CNT-1)*HALF_FRAME_SIZE); index++)
		  playload[VOICE_DATA_INDEX+index] = (playload[VOICE_DATA_INDEX+index] ^ playload[VOICE_MAGIC_INDEX]);
	}else{
	  fullRate=FALSE;
	  for(index = 0; index < UDP_VOICE_PKT_FRAME_CNT*HALF_FRAME_SIZE; index++){
	    playload[VOICE_DATA_INDEX+index] = (playload[VOICE_DATA_INDEX+index] ^ playload[VOICE_MAGIC_INDEX]);
	  }
	}
	outBuf[0]=(fullRate ? FULL_FRAME_I : HALF_FRAME_I);
	outBuf[1] = (fullRate ? FULL_FRAME_SIZE : HALF_FRAME_SIZE);
	memcpy(&outBuf[2],&playload[VOICE_DATA_INDEX], (fullRate ? FULL_FRAME_SIZE : HALF_FRAME_SIZE));
	offset += (2+(fullRate ? FULL_FRAME_SIZE : HALF_FRAME_SIZE));
	offsetN += (fullRate ? FULL_FRAME_SIZE : HALF_FRAME_SIZE);

	for(index = 0; index < (UDP_VOICE_PKT_FRAME_CNT-1); index++){
	  outBuf[offset++] = HALF_FRAME_I;
	  outBuf[offset++] = HALF_FRAME_SIZE;
	  memcpy(&outBuf[offset],&playload[offsetN], HALF_FRAME_SIZE);
	  offsetN += HALF_FRAME_SIZE;
	  offset += HALF_FRAME_SIZE;
	}

	return offset;
  }
}