ugfx/drivers/gaudio/Win32/gaudio_play_lld.c

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/*
* This file is subject to the terms of the GFX License. If a copy of
* the license was not distributed with this file, you can obtain one at:
*
* http://ugfx.org/license.html
*/
#include "gfx.h"
#if GFX_USE_GAUDIO && GAUDIO_NEED_PLAY
/* Include the driver defines */
#include "src/gaudio/driver_play.h"
#undef Red
#undef Green
#undef Blue
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <stdio.h>
#include <mmsystem.h>
#define MAX_WAVE_HEADERS 2 // Larger numbers enable more buffering which is good for ensuring
// there are no skips due to data not being available, however larger
// numbers of buffers also create higher latency.
static HWAVEOUT ah = 0;
static volatile int nQueuedBuffers;
static bool_t isRunning;
static WAVEHDR WaveHdrs[MAX_WAVE_HEADERS];
static HANDLE waveThread;
static DWORD threadID;
/**************************** waveProc() *******************************
* We don't use CALLBACK_FUNCTION because it is restricted to calling only
* a few particular Windows functions, namely some of the time functions,
* and a few of the Low Level MIDI API. If you violate this rule, your app can
* hang inside of the callback). One of the Windows API that a callback can't
* call is waveOutUnPrepareBuffer() which is what we need to use whenever we receive a
* MM_WOM_DONE. My callback would need to defer that job to another thread
* anyway, so instead just use CALLBACK_THREAD here instead.
*************************************************************************/
static bool_t senddata(WAVEHDR *pwh) {
GDataBuffer *paud;
// Get the next data block to send
gfxSystemLock();
paud = gaudioPlayGetDataBlockI();
if (!paud && !nQueuedBuffers)
gaudioPlayDoneI();
gfxSystemUnlock();
if (!paud)
return FALSE;
// Prepare the wave header for Windows
pwh->dwUser = (DWORD_PTR)paud;
pwh->lpData = (LPSTR)(paud+1); // The data is on the end of the structure
pwh->dwBufferLength = paud->len;
pwh->dwFlags = 0;
pwh->dwLoops = 0;
if (waveOutPrepareHeader(ah, pwh, sizeof(WAVEHDR))) {
fprintf(stderr, "GAUDIO: Failed to prepare a play buffer");
exit(-1);
}
// Send it to windows
if (waveOutWrite(ah, pwh, sizeof(WAVEHDR))) {
fprintf(stderr, "GAUDIO: Failed to write the play buffer");
exit(-1);
}
nQueuedBuffers++;
return TRUE;
}
static DWORD WINAPI waveProc(LPVOID arg) {
MSG msg;
WAVEHDR *pwh;
(void) arg;
while (GetMessage(&msg, 0, 0, 0)) {
switch (msg.message) {
case MM_WOM_DONE:
pwh = (WAVEHDR *)msg.lParam;
// Windows - Let go!
waveOutUnprepareHeader(ah, pwh, sizeof(WAVEHDR));
// Give the buffer back to the Audio Free List
gfxSystemLock();
gaudioPlayReleaseDataBlockI((GDataBuffer *)pwh->dwUser);
gfxSystemUnlock();
pwh->lpData = 0;
nQueuedBuffers--;
// Are we stopping?
if (!isRunning) {
// Have we finished yet?
if (!nQueuedBuffers) {
gfxSystemLock();
gaudioPlayDoneI();
gfxSystemUnlock();
}
break;
}
// Try and get a new block
senddata(pwh);
break;
}
}
return 0;
}
/*===========================================================================*/
/* External declarations. */
/*===========================================================================*/
bool_t gaudio_play_lld_init(uint16_t channel, uint32_t frequency, ArrayDataFormat format) {
WAVEFORMATEX wfx;
if (format != ARRAY_DATA_8BITUNSIGNED && format != ARRAY_DATA_16BITSIGNED)
return FALSE;
if (!waveThread) {
if (!(waveThread = CreateThread(0, 0, (LPTHREAD_START_ROUTINE)waveProc, 0, 0, &threadID))) {
fprintf(stderr, "GAUDIO: Can't create WAVE play-back thread\n");
exit(-1);
}
CloseHandle(waveThread);
}
wfx.wFormatTag = WAVE_FORMAT_PCM;
wfx.nChannels = channel == GAUDIO_PLAY_STEREO ? 2 : 1;
wfx.nSamplesPerSec = frequency;
wfx.nBlockAlign = wfx.nChannels * (format == ARRAY_DATA_8BITUNSIGNED ? 1 : 2);
wfx.nAvgBytesPerSec = wfx.nSamplesPerSec * wfx.nBlockAlign;
wfx.wBitsPerSample = (format == ARRAY_DATA_8BITUNSIGNED ? 8 : 16);
wfx.cbSize = 0;
if (ah) {
waveOutClose(ah);
ah = 0;
}
if (waveOutOpen(&ah, WAVE_MAPPER, &wfx, (DWORD_PTR)threadID, 0, CALLBACK_THREAD)) {
fprintf(stderr, "GAUDIO: Can't open WAVE play-back device\n");
exit(-1);
}
return TRUE;
}
bool_t gaudio_play_lld_set_volume(uint8_t vol) {
if (!ah)
return FALSE;
return waveOutSetVolume(ah, (((uint16_t)vol)<<8)|vol) != 0;
}
void gaudio_play_lld_start(void) {
WAVEHDR *pwh;
isRunning = TRUE;
while (nQueuedBuffers < MAX_WAVE_HEADERS) {
// Find the empty one - there will always be at least one.
for(pwh = WaveHdrs; pwh->lpData; pwh++);
// Grab the next audio block from the Audio Out Queue
if (!senddata(pwh))
break;
}
}
void gaudio_play_lld_stop(void) {
isRunning = FALSE;
waveOutReset(ah);
while(nQueuedBuffers) Sleep(1);
}
#endif /* GFX_USE_GAUDIO && GAUDIO_NEED_PLAY */