void audioChangeSrc(int ch, const signed char *src, unsigned int len, unsigned int loop_end, unsigned int loop_len)
{
    if (loop_len >= 4) /* 2 is the same as no loop on Amiga */
    {
        if (v[ch].index > (signed)loop_end)
        {
            v[ch].index -= loop_len;
        }

        v[ch].loop_end = loop_end;
        v[ch].loop_len = loop_len;
    }
    else
    {
        if (v[ch].index > (signed)len)
        {
            v[ch].index = 0;
        }

        v[ch].loop_end = 0;
        v[ch].loop_len = 0;
    }

    v[ch].data = src;
    v[ch].len = len;

    if (v[ch].frac > v[ch].rate)
    {
        v[ch].frac = v[ch].rate;
    }

    return;
}

void audioSetSource(int ch, const signed char *src, unsigned int len, unsigned int loop_end, unsigned int loop_len)
{
    v[ch].data  = src;
    v[ch].len   = len;
    v[ch].index = 0;
    v[ch].frac  = 0;
    v[ch].loop_end = loop_end;
    v[ch].loop_len = loop_len;

    return;
}