www.pudn.com > DM642_TLV320ALC23B.rar > main.c

/* 
 *  Copyright 2003 by Texas Instruments Incorporated. 
 *  All rights reserved. Property of Texas Instruments Incorporated. 
 *  Restricted rights to use, duplicate or disclose this code are 
 *  granted through contract. 
 *   
 */ 
/* 
 *  ======== main.c ======== 
 *  
 *  This example demonstrates the use of IOM drivers with SIOs and tasks by  
 *  using the DIO class driver with a user defined device mini-driver  
 *  called "codec" and a class driver DIO instance called "dio_codec". This is  
 *  the loopback application where audio is read from an input SIO, then sent  
 *  back via an output SIO. 
 
 *  The following objects need to be created in the DSP/BIOS 
 *  configuration for this application: 
 * 
 *  * A UDEV object, which links in a user device driver. In this 
 *    case the UDEV is a codec based IOM device driver. 
 *  * A DIO object, which links the UDEV object. 
 *  * A TSK object, with the function to run set to the function demo 
 *    defined in this file. 
 *  * A LOG named trace for debug and status output. 
 */ 
#include  
 
#include  
#include  
#include  
#include  
#include  
#include  
 
#include "seeddm642.h" 
#include  
 
#define NUM_CODEC_CHANNELS	 8	/* stereo: left + right		*/ 
#define SAMPLEING_RATE		48	/* 48 samples/ms			*/ 
#define FRAME_SIZE			10	/* 10 ms					*/ 
#define	NFRAMES				100	/* 100 frames = 1 second	*/ 
#define	BUFLEN		(NUM_CODEC_CHANNELS*SAMPLEING_RATE*FRAME_SIZE) 
 
#ifdef _6x_ 
extern far LOG_Obj trace; 
 
/*  
 * Buffers placed in external memory are aligned on a 128 bytes boundary. 
 * In addition, the buffer should be of a size multiple of 128 bytes for  
 * the cache work optimally on the C6x. 
 */ 
#define BUFALIGN 128    /* alignment of buffer to allow use of L2 cache */ 
#else 
extern LOG_Obj trace; 
#define BUFALIGN 1 
#endif 
 
#define BUFSIZE (BUFLEN * sizeof(short))  
 
/* 
 *  ======== EVMDM642_DEVPARAMS ======== 
 *  This static initialization defines the default parameters used for 
 *  EVMDM642_EDMA_AIC23 IOM driver 
 */ 
EVMDM642_EDMA_AIC23_DevParams EVMDM642_CODEC_DEVPARAMS = 
        EVMDM642_EDMA_AIC23_DEFAULT_DEVPARAMS; 
 
/* inStream and outStream are SIO handles created in main */ 
SIO_Handle inStream, outStream; 
 
/* Function prototype */ 
static Void createStreams(); 
static Void prime(); 
 
 
/* 
 * ======== main ======== 
 */ 
Void main() 
{ 
    LOG_printf(&trace, "echo started"); 
} 
 
short *pEchoBuf; 
const int echoBufSize = NFRAMES * BUFLEN; 
int echoBufOffset = 0; 
int delayTime = 500; 
int echoAtt = 64; 
 
/* 
 *  ======== initEchoBuffer ======== 
 * Allocate echo buffer and fill with silence 
 */ 
int initEchoBuffer() 
{ 
	pEchoBuf = MEM_calloc(0, echoBufSize * sizeof(short), BUFALIGN); 
	return (pEchoBuf == MEM_ILLEGAL) ? -1 : 0; 
} 
 
/* 
 *  ======== copyWithEcho ======== 
 * Copy an incoming buffer with stereo audio samples into an outgoing 
 * buffer, mixing with samples from the echo buffer indexed by 
 * the parameter timeDelay.  The parameter "a" indicates the mix 
 * attenuation * 256 (i.e. 64 = 0.25). 
 */ 
void copyWithEcho(short *inBuf, short *outBuf, int timeDelay, int a) 
{ 
	int i; 
	int srcSample; 
 
	for(i = 0;i