ref: 46f9c39bf931494b7e2e3bdfbcdb17dae6ea599a
dir: /audiodrivers/winmm/winmm.c/
/* winmm audio driver for ft2play ** ** Warning: This might not be 100% thread-safe or lock-safe! */ #define WIN32_LEAN_AND_MEAN #include <stdint.h> #include <stdbool.h> #include <stdlib.h> #include <windows.h> #include <mmsystem.h> #include "../../pmp_mix.h" #define MIX_BUF_NUM 4 static volatile BOOL mixerOpened, mixerBusy, mixerLocked; static uint8_t currBuffer; static int16_t *audioBuffer[MIX_BUF_NUM]; static int32_t bufferSize; static HANDLE hThread, hAudioSem; static WAVEHDR waveBlocks[MIX_BUF_NUM]; static HWAVEOUT hWave; static DWORD WINAPI mixThread(LPVOID lpParam) { SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_TIME_CRITICAL); while (mixerOpened) { WAVEHDR *waveBlock = &waveBlocks[currBuffer]; if (!mixerLocked) { mixerBusy = true; mix_UpdateBuffer((int16_t *)waveBlock->lpData, bufferSize); // pmp_mix.c function mixerBusy = false; } waveOutWrite(hWave, waveBlock, sizeof (WAVEHDR)); currBuffer = (currBuffer + 1) % MIX_BUF_NUM; WaitForSingleObject(hAudioSem, INFINITE); // wait for buffer fill request } return 0; (void)lpParam; } static void CALLBACK waveProc(HWAVEOUT hWaveOut, UINT uMsg, DWORD_PTR dwInstance, DWORD_PTR dwParam1, DWORD_PTR dwParam2) { if (uMsg == WOM_DONE) ReleaseSemaphore(hAudioSem, 1, NULL); (void)hWaveOut; (void)uMsg; (void)dwInstance; (void)dwParam1; (void)dwParam2; } void lockMixer(void) { mixerLocked = true; while (mixerBusy); } void unlockMixer(void) { mixerBusy = false; mixerLocked = false; } void closeMixer(void) { mixerOpened = false; mixerBusy = false; if (hAudioSem != NULL) ReleaseSemaphore(hAudioSem, 1, NULL); if (hThread != NULL) { WaitForSingleObject(hThread, INFINITE); CloseHandle(hThread); hThread = NULL; } if (hAudioSem != NULL) { CloseHandle(hAudioSem); hAudioSem = NULL; } if (hWave != NULL) { waveOutReset(hWave); for (int32_t i = 0; i < MIX_BUF_NUM; i++) { if (waveBlocks[i].dwUser != 0xFFFF) waveOutUnprepareHeader(hWave, &waveBlocks[i], sizeof (WAVEHDR)); } waveOutClose(hWave); hWave = NULL; } for (int32_t i = 0; i < MIX_BUF_NUM; i++) { if (audioBuffer[i] != NULL) { free(audioBuffer[i]); audioBuffer[i] = NULL; } } } bool openMixer(int32_t mixingFrequency, int32_t mixingBufferSize) { DWORD threadID; WAVEFORMATEX wfx; // don't unprepare headers on error for (int32_t i = 0; i < MIX_BUF_NUM; i++) waveBlocks[i].dwUser = 0xFFFF; closeMixer(); bufferSize = mixingBufferSize; ZeroMemory(&wfx, sizeof (wfx)); wfx.nSamplesPerSec = mixingFrequency; wfx.wBitsPerSample = 16; wfx.nChannels = 2; wfx.wFormatTag = WAVE_FORMAT_PCM; wfx.nBlockAlign = wfx.nChannels * (wfx.wBitsPerSample / 8); wfx.nAvgBytesPerSec = wfx.nSamplesPerSec * wfx.nBlockAlign; if (waveOutOpen(&hWave, WAVE_MAPPER, &wfx, (DWORD_PTR)&waveProc, 0, CALLBACK_FUNCTION) != MMSYSERR_NOERROR) goto omError; // create semaphore for buffer fill requests hAudioSem = CreateSemaphore(NULL, MIX_BUF_NUM - 1, MIX_BUF_NUM, NULL); if (hAudioSem == NULL) goto omError; // allocate WinMM mix buffers for (int32_t i = 0; i < MIX_BUF_NUM; i++) { audioBuffer[i] = (int16_t *)calloc(mixingBufferSize, wfx.nBlockAlign); if (audioBuffer[i] == NULL) goto omError; } // initialize WinMM mix headers memset(waveBlocks, 0, sizeof (waveBlocks)); for (int32_t i = 0; i < MIX_BUF_NUM; i++) { waveBlocks[i].lpData = (LPSTR)audioBuffer[i]; waveBlocks[i].dwBufferLength = mixingBufferSize * wfx.nBlockAlign; waveBlocks[i].dwFlags = WHDR_DONE; if (waveOutPrepareHeader(hWave, &waveBlocks[i], sizeof (WAVEHDR)) != MMSYSERR_NOERROR) goto omError; } currBuffer = 0; mixerOpened = true; hThread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)mixThread, NULL, 0, &threadID); if (hThread == NULL) goto omError; return TRUE; omError: closeMixer(); return FALSE; }