sndcvt.c

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                     float scale, float *peak)
{
    float *floats = (float *) buf1;
    unsigned char *bytes = (unsigned char *) buf2;
    int i;
    scale /= SCALE_FACTOR_TO_BYTE;
    for (i = 0; i < len2; i++) {
    *floats++ = (((int) (*bytes++)) - 128) * scale;
    }
    return len2;
}


long cvt_from_pcm_8(void *buf1, void *buf2, long len2, 
                    float scale, float *peak)
{
    float *floats = (float *) buf1;
    unsigned char *bytes = (unsigned char *) buf2;
    int i;
    scale /= SCALE_FACTOR_TO_BYTE;
    for (i = 0; i < len2; i++) {
    *floats++ = (((int) (*bytes++) ^ 128) - 128) * scale;
    }
    return len2;
}


long cvt_from_pcm_16(void *buf1, void *buf2, long len2, 
                     float scale, float *peak)
{
    float *floats = (float *) buf1;
    short *shorts = (short *) buf2;
    int i;
    scale /= SCALE_FACTOR_TO_SHORT;
    for (i = 0; i < len2; i++) {
    *floats++ = *shorts++ * scale;
    }
    return len2;
}


long cvt_from_float_32(void *buf1, void *buf2, long len2, float scale, float *peak)
{
    float *floats1 = (float *) buf1;
    float *floats2 = (float *) buf2;
    int i;
    for (i = 0; i < len2; i++) {
    *floats1++ = *floats2++ * scale;
    }
    return len2;
}


long cvt_from_pcm_32(void *buf1, void *buf2, long len2, 
                     float scale, float *peak)
{
    float *floats = (float *) buf1;
    long *longs = (long *) buf2;
    int i;
    scale /= SCALE_FACTOR_TO_LONG;
    for (i = 0; i < len2; i++) {
    *floats++ = *longs++ * scale;
    }
    return len2;
}


long cvt_from_unknown(void *buf1, void *buf2, long len2, 
                      float scale, float *peak)
{
    snd_fail("snd_convert: unknown conversion");
    return 0;
}

/* snd.h says: #define cvt_to_unknown cvt_from_unknown */


long cvt_to_alaw_8 (void *buf1, void *buf2, long len2,
                    float scale, float *peak)
{
    unsigned char *bytes = (unsigned char *) buf1;
    float *floats = (float *) buf2;
    long i;
    FASTFLOAT s, max_sample = 0.0;
    scale *= SCALE_FACTOR_TO_SHORT;

    for (i = 0; i < len2; i++) {
    s = scale * floats[i];
    if (s > 0) {
        if (s > max_sample)	{
        max_sample = s;
        }
        s += 0.5;
    } else {
        if (-s > max_sample) {
        max_sample = -s;
        }
        s -= 0.5;
    }
    bytes[i] = st_linear_to_ulaw ((int) s);
    }

    *peak = (float) (max_sample / SCALE_FACTOR_TO_SHORT);
    return len2;
}


long cvt_to_ulaw_8(void *buf1, void *buf2, long len2, 
                   float scale, float *peak)
{
    unsigned char *bytes = (unsigned char *) buf1;
    float *floats = (float *) buf2;
    int i;
    FASTFLOAT max_sample = 0.0;
    scale *= SCALE_FACTOR_TO_SHORT;
    
    for (i = 0; i < len2; i++) {
    FASTFLOAT s = *floats++ * scale;
    /* round down, e.g. -4.5 => -5: */
    if (s > 0) {
        if (s > max_sample) max_sample = s;
        s += 0.5;
    } else {
        if (-s > max_sample) max_sample = -s;
        s -= 0.5;
    }
    *bytes++ = st_linear_to_ulaw((int) s);
    }
    *peak = (float) (max_sample / SCALE_FACTOR_TO_SHORT);
    return len2;
}


long cvt_to_upcm_8(void *buf1, void *buf2, long len2, 
                   float scale, float *peak)
{
    unsigned char *bytes = (unsigned char *) buf1;
    float *floats = (float *) buf2;
    int i;
    FASTFLOAT max_sample = 0.0;
    scale *= SCALE_FACTOR_TO_BYTE;
    
    for (i = 0; i < len2; i++) {
    FASTFLOAT s = *floats++ * scale;
    /* round down, e.g. -4.5 => -5: */
    if (s > 0) {
        if (s > max_sample) max_sample = s;
        s += 0.5;
    } else {
        if (-s > max_sample) max_sample = -s;
        s -= 0.5;
    }
    *bytes++ = ((int) s) ^ 128;
    }
    *peak = (float) (max_sample / SCALE_FACTOR_TO_BYTE);
    return len2;
}


long cvt_to_pcm_8(void *buf1, void *buf2, long len2, 
                  float scale, float *peak)
{
    unsigned char *bytes = (unsigned char *) buf1;
    float *floats = (float *) buf2;
    int i;
    FASTFLOAT max_sample = 0.0;
    len2 = len2;
    scale *= SCALE_FACTOR_TO_BYTE;
    
    for (i = 0; i < len2; i++) {
    FASTFLOAT s = *floats++ * scale;
    /* round down, e.g. -4.5 => -5: */
    if (s > 0) {
        if (s > max_sample) max_sample = s;
        s += 0.5;
    } else {
        if (-s > max_sample) max_sample = -s;
        s -= 0.5;
    }
    *bytes++ = (int) s;
    }
    *peak = (float) (max_sample / SCALE_FACTOR_TO_BYTE);
    return len2;
}


long cvt_to_upcm_16(void *buf1, void *buf2, long len2,
                    float scale, float *peak)
{
    short *shorts = (short *) buf1;
    float *floats = (float *) buf2;
    int i;
    FASTFLOAT max_sample = 0.0;
    scale *= SCALE_FACTOR_TO_SHORT;
    
    for (i = 0; i < len2; i++) {
    FASTFLOAT s = *floats++ * scale;
    /* round down, e.g. -4.5 => -5: */
    if (s > 0) {
        if (s > max_sample) max_sample = s;
        s += 0.5;
    } else {
        if (-s > max_sample) max_sample = -s;
        s -= 0.5;
    }
    *shorts++ = ((short) s) ^ 32768;       // dmazzoni
    }
    *peak = (float) (max_sample / SCALE_FACTOR_TO_SHORT);
    return len2;
}


long cvt_to_pcm_16(void *buf1, void *buf2, long len2, 
                   float scale, float *peak)
{
    short *shorts = (short *) buf1;
    float *floats = (float *) buf2;
    int i;
    FASTFLOAT max_sample = 0.0;
    scale *= SCALE_FACTOR_TO_SHORT;
    
    for (i = 0; i < len2; i++) {
    FASTFLOAT s = *floats++ * scale;
    /* round down, e.g. -4.5 => -5: */
    if (s > 0) {
        if (s > max_sample) max_sample = s;
        s += 0.5;
    } else {
        if (-s > max_sample) max_sample = -s;
        s -= 0.5;
    }
    *shorts++ = (short) s;
    }
    *peak = (float) (max_sample / SCALE_FACTOR_TO_SHORT);
    return len2;
}


long cvt_to_float_32(void *buf1, void *buf2, long len2, float scale, float *peak)
{
    unsigned char *longs = (unsigned char *) buf1;
    float *floats = (float *) buf2;
    int i;
    FASTFLOAT max_sample = 0.0;
    
    for (i = 0; i < len2; i++) {
    FASTFLOAT s = *floats++ * scale;
    if (s > max_sample) max_sample = s;
    if (-s > max_sample) max_sample = -s;
    *floats++ = (float) s;
    }
    *peak = (float) max_sample;
    return len2;
}


long cvt_to_upcm_32(void *buf1, void *buf2, long len2,
                    float scale, float *peak)
{
    long *longs = (long *) buf1;
    float *floats = (float *) buf2;
    int i;
    FASTFLOAT max_sample = 0.0;
    scale *= SCALE_FACTOR_TO_LONG;
    
    for (i = 0; i < len2; i++) {
    FASTFLOAT s = *floats++ * scale;
    /* round down, e.g. -4.5 => -5: */
    if (s > 0) {
        if (s > max_sample) max_sample = s;
        s += 0.5;
    } else {
        if (-s > max_sample) max_sample = -s;
        s -= 0.5;
    }
    *longs++ = ((long) s) ^ (1 << 31); // dmazzoni
    }
    *peak = (float) (max_sample / SCALE_FACTOR_TO_LONG);
    return len2;
}


long cvt_to_pcm_32(void *buf1, void *buf2, long len2, 
                   float scale, float *peak)
{
    long *longs = (long *) buf1;
    float *floats = (float *) buf2;
    int i;
    FASTFLOAT max_sample = 0.0;
    scale *= SCALE_FACTOR_TO_LONG;
    
    for (i = 0; i < len2; i++) {
    FASTFLOAT s = *floats++ * scale;
    /* round down, e.g. -4.5 => -5: */
    if (s > 0) {
        if (s > max_sample) max_sample = s;
        s += 0.5;
    } else {
        if (-s > max_sample) max_sample = -s;
        s -= 0.5;
    }
    *longs++ = (long) s;
    }
    *peak = (float) (max_sample / SCALE_FACTOR_TO_LONG);
    return len2;
}


cvtfn_type cvt_from_8[] = { cvt_from_unknown, cvt_from_pcm_8, cvt_from_ulaw_8, cvt_from_alaw_8, cvt_from_unknown, cvt_from_upcm_8, cvt_from_unknown };

cvtfn_type cvt_from_16[] = { cvt_from_unknown, cvt_from_pcm_16, cvt_from_unknown, cvt_from_unknown, cvt_from_unknown, cvt_from_unknown, cvt_from_unknown };

cvtfn_type cvt_from_32[] = { cvt_from_unknown, cvt_from_pcm_32, cvt_from_unknown, cvt_from_unknown, cvt_from_float_32, cvt_from_unknown, cvt_from_unknown };

cvtfn_type cvt_to_8[] = { cvt_to_unknown, cvt_to_pcm_8, cvt_to_ulaw_8, cvt_to_alaw_8, cvt_to_unknown, cvt_to_upcm_8, cvt_to_unknown };

cvtfn_type cvt_to_16[] = { cvt_to_unknown, cvt_to_pcm_16, cvt_to_unknown, cvt_to_unknown, cvt_to_unknown, cvt_to_upcm_16, cvt_to_unknown };

cvtfn_type cvt_to_32[] = { cvt_to_unknown, cvt_to_pcm_32, cvt_to_unknown, cvt_to_unknown, cvt_to_float_32, cvt_to_upcm_32, cvt_to_unknown };


/* select_cvtfn -- find conversion from snd2 to snd1 */
/*
 * conversion is based on bits and mode (channels and srate
 * are ignored). Either snd1 or snd2 must be of SND_MODE_FLOAT.
 */
cvtfn_type select_cvtfn(snd_type snd1, snd_type snd2)
{
    long mode1 = snd1->format.mode;
    long mode2 = snd2->format.mode;
    if (mode1 == SND_MODE_FLOAT) {
    long bits2 = snd2->format.bits;
    /* convert_from functions */
    if (bits2 == 8) return cvt_from_8[mode2];
    else if (bits2 == 16) return cvt_from_16[mode2];
    else if (bits2 == 32) return cvt_from_32[mode2];
    else return &cvt_from_unknown;
    } else if (mode2 == SND_MODE_FLOAT) {
    long bits1 = snd1->format.bits;
    /* convert_to functions */
    if (bits1 == 8) return cvt_to_8[mode1];
    else if (bits1 == 16) return cvt_to_16[mode1];
    else if (bits1 == 32) return cvt_to_32[mode1];
    else return &cvt_to_unknown;
    } else return &cvt_from_unknown;
}