audio.c

基于DSP的实时语音信号处理系统设计实例

/*
 *  Copyright 2002 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.
 *  
 */
/* "@(#) DSP/BIOS 4.80.208 12-06-02 (barracuda-l19)" */
/*
 *  ======== audio.c ========
 */

#include <std.h>

#include <pip.h>    
#include <log.h>
#include <trc.h>
#include <hst.h>

#include <string.h>     /* memset() */
#include <stdarg.h>     /* var arg stuff */

#include "dss.h"
#include "audio.h"

Int PHASE = 0;              /* number of samples of phase difference */

static Uns allocBuf(PIP_Obj *out, Uns **buf);
static Void freeBuf(PIP_Obj *out);
static Uns getBuf(PIP_Obj *in, Uns **buf);
static Void process(Uns *src, Int size, Uns *dst);
static Void putBuf(PIP_Obj *out, Uns size);
static Void writeBuf(PIP_Obj *out, Uns *buf, Uns size);

static Int loadVal = 0;
static PIP_Obj *hostPipe = NULL;

/*
 *  ======== main ========
 */
Void main()
{
    Int size;
    Uns *buf;
    
#if AUDIO_USEHST
    hostPipe = HST_getpipe(&hostOutputProbe);
#endif
    
    DSS_init();     /* Initialize codec and serial port */

    LOG_printf(&trace, "Audio example started!!\n");    

    /* Prime output buffers with silence */
    size = allocBuf(&DSS_txPipe, &buf);
    memset(buf, 0, size * sizeof (Uns));
    putBuf(&DSS_txPipe, size);

    size = allocBuf(&DSS_txPipe, &buf);
    memset(buf, 0, size * sizeof (Uns));
    putBuf(&DSS_txPipe, size - PHASE);
    
    /* Fall into BIOS idle loop */
    return;                 
}

/*
 *  ======== audio ========
 */
Void audio(PIP_Obj *in, PIP_Obj *out)
{
    Uns *src, *dst;
    Uns size;

    if (PIP_getReaderNumFrames(in) == 0 || PIP_getWriterNumFrames(out) == 0) {
        error("Error: audio signal falsely triggered!");
    }

    /* get input data and allocate output buffer */
    size = getBuf(in, &src);
    allocBuf(out, &dst);

    /* process input data in src to output buffer dst */
    process(src, size, dst);

    /* check for real-time error */
    if (DSS_error != 0) {
        LOG_printf(&trace,
            "Error: DSS missed real-time! (DSS_error = 0x%x)", DSS_error);
        loadVal -= 1;
        DSS_error = 0;
    }
    
    /* output data and free input buffer */
    putBuf(out, size);
    freeBuf(in);
}

/*
 *  ======== error ========
 */
Void error(String msg, ...)
{
    va_list va;
    va_start(va, msg);
     
    LOG_error(msg, va_arg(va, Arg));    /* write error message to sys log */
    LOG_disable(LOG_D_system);          /* stop system log */
    
    for (;;) {
        ;                               /* loop for ever */
    }
}

/*
 *  ======== load ========
 */
Void load(Arg Arg_prd_ms)
{
    static int oldLoad = 0;
    Int prd_ms = ArgToInt(Arg_prd_ms);

    /* display confirmation of load changes */
    if (oldLoad != loadVal ) {
        oldLoad = loadVal;
        LOG_printf(&trace,
            "load: new load = %d000 instructions every %d ms", loadVal, prd_ms);
        }

    if (loadVal) {
        AUDIO_load(loadVal);
    }
}

/*
 *  ======== step ========
 */
Void step(void)
{
    static Int direction = 1;

    if (loadVal > MAXLOAD) {
        direction = -1;
    }
    if (loadVal <= 0) {
        direction = 1;
    }

    loadVal = loadVal + (100 * direction);
}

/*
 *  ======== allocBuf ========
 */
static Uns allocBuf(PIP_Obj *out, Uns **buf)
{
    PIP_alloc(out);
    *buf = PIP_getWriterAddr(out);;
    return (PIP_getWriterSize(out));
}

/*
 *  ======== freeBuf ========
 */
static Void freeBuf(PIP_Obj *out)
{
    PIP_free(out);
}

/*
 *  ======== getBuf ========
 */
static Uns getBuf(PIP_Obj *in, Uns **buf)
{
    PIP_get(in);
    *buf = PIP_getReaderAddr(in);;
    return (PIP_getReaderSize(in));
}

/*
 *  ======== process ========
 */
static Void process(Uns *src, Int size, Uns *dst)
{
    Int i;
    
    for (i = size - 1; i >= 0; i--) {
        dst[i] = src[i];
    }

    /* if hostPipe is non-NULL write data to this pipe */
    if (hostPipe != NULL) {
        writeBuf(hostPipe, dst, size);
    }
}

/*
 *  ======== putBuf ========
 */
static Void putBuf(PIP_Obj *out, Uns size)
{
    PIP_setWriterSize(out, size);
    PIP_put(out);
}

/*
 *  ======== writeBuf ========
 */
static Void writeBuf(PIP_Obj *out, Uns *buf, Uns size)
{
    Uns dstSize;
    Uns *dst;
    Int i;
    
    /* allocate outBuffer for output */
    dstSize = allocBuf(out, &dst);

    /* copy data to output buffer (but not more than output buffer size) */
    for (i = (dstSize >= size) ? size : dstSize; i > 0; i--) {
        *dst++ = *buf++;
    }

    /* put buffer to output pipe */
    putBuf(out, size);
}