static void WSS_PlayStop(void)
{
wss.timer_callback = NULL;
wss_output(FALSE);
wss_stop_dma();
VC_PlayStop();
}
/* Start playing from DMA buffer in either 8/16 bit mono/stereo */
boolean wss_start_dma(unsigned char mode, unsigned int freq)
{
int dmabuffsize;
unsigned char format;
/* Stop DMA transfer if it is enabled */
wss_stop_dma();
/* Sanity check: we support only 8-bit unsigned and 16-bit signed formats */
if (((mode & WSSMODE_16BITS) && !(mode & WSSMODE_SIGNED))
|| (!(mode & WSSMODE_16BITS) && (mode & WSSMODE_SIGNED)))
return FALSE;
/* Find the nearest frequency divisor (rate) */
format = __wss_getrate(&freq);
wss.mode = mode;
/* Get a DMA buffer enough for a 1sec interval... 4K <= dmasize <= 32K */
dmabuffsize = freq;
if (mode & WSSMODE_STEREO)
dmabuffsize *= 2;
if (mode & WSSMODE_16BITS)
dmabuffsize *= 2;
dmabuffsize >>= 2;
if (dmabuffsize < 4096)
dmabuffsize = 4096;
if (dmabuffsize > 32768)
dmabuffsize = 32768;
dmabuffsize = (dmabuffsize + 255) & 0xffffff00;
wss.dma_buff = dma_allocate(wss.dma, dmabuffsize);
if (!wss.dma_buff)
return FALSE;
/* Fill DMA buffer with silence */
dmabuffsize = wss.dma_buff->size;
if (mode & WSSMODE_SIGNED)
memset(wss.dma_buff->linear, 0, dmabuffsize);
else
memset(wss.dma_buff->linear, 0x80, dmabuffsize);
/* Check data size and build a WSSR_PLAY_FORMAT value accordingly */
wss.samples = dmabuffsize;
if (mode & WSSMODE_16BITS) {
wss.samples >>= 1;
format |= WSSM_16BITS;
}
/* Finish working with WSS */
boolean wss_close()
{
__dpmi_meminfo struct_info;
if (!wss.open)
return FALSE;
wss.open--;
/* Stop/free DMA buffer */
wss_stop_dma();
/* Unhook IRQ */
irq_unhook(wss.irq_handle);
wss.irq_handle = NULL;
/* Unlock the wss structure */
struct_info.address = __djgpp_base_address + (unsigned long)&wss;
struct_info.size = sizeof(wss);
__dpmi_unlock_linear_region(&struct_info);
return TRUE;
}
/* Reset WSS */
void wss_reset()
{
wss_stop_dma();
__wss_reset();
}
