If real-time parsing LTC is implemented,

[conducive2]

If real-time parsing LTC is implemented, I tried it. One frame will always be lost from transmission to parsing and printing, and there is a delay of about one second. This has troubled me for a long time and I don’t know how to solve it.

`
void Myltc(ltcsnd_sample_t* sound, int bufferSize) {
LTCDecoder* decoder = ltc_decoder_create(1920, 32);
LTCFrameExt frame;
ltcsnd_sample_t* soundCopy = (ltcsnd_sample_t*)malloc(bufferSize * sizeof(ltcsnd_sample_t));
if (soundCopy == NULL) {
fprintf(stderr, "Failed to allocate memory for sound copy.\n");
return;
}
memcpy(soundCopy, sound, bufferSize * sizeof(ltcsnd_sample_t));
ltc_decoder_write(decoder, soundCopy, bufferSize, 0);
while (ltc_decoder_read(decoder, &frame)) {
SMPTETimecode stime;
ltc_frame_to_time(&stime, &frame.ltc, 1);
printf("%02d:%02d:%02d%c%02d\n", stime.hours,
stime.mins, stime.secs, (frame.ltc.dfbit) ? '.' : ':',
stime.frame);
}
free(soundCopy);
ltc_decoder_free(decoder);
}
void CALLBACK waveInProc(HWAVEIN hwi, UINT uMsg, DWORD_PTR dwInstance, DWORD_PTR dwParam1, DWORD_PTR dwParam2) {
if (uMsg == WIM_DATA) {
paData* data = (paData*)dwInstance;
WAVEHDR* waveHeader = (WAVEHDR*)dwParam1;
if (waveHeader->dwBytesRecorded > 0) {
Myltc((ltcsnd_sample_t*)waveHeader->lpData, waveHeader->dwBytesRecorded / sizeof(ltcsnd_sample_t));
}
waveInAddBuffer(hwi, waveHeader, sizeof(WAVEHDR));
}
}
DWORD WINAPI RecordingThread(LPVOID lpParameter) {
paData* data = (paData*)lpParameter;
HWAVEIN hWaveIn;
WAVEHDR waveHeader;
MMRESULT result;
WAVEFORMATEX waveFormat;

waveFormat.wFormatTag = WAVE_FORMAT_PCM;
waveFormat.nChannels = NUM_CHANNELS;
waveFormat.nSamplesPerSec = SAMPLE_RATE;
waveFormat.nAvgBytesPerSec = SAMPLE_RATE * NUM_CHANNELS;
waveFormat.nBlockAlign = NUM_CHANNELS;
waveFormat.wBitsPerSample = 8;
waveFormat.cbSize = 0;
 
result = waveInOpen(&hWaveIn, WAVE_MAPPER, &waveFormat, (DWORD_PTR)waveInProc, (DWORD_PTR)&data, CALLBACK_FUNCTION);
if (result != MMSYSERR_NOERROR) {
    printf("Failed to open audio input device.\n");
    return 1;
}

int numSamples = SAMPLE_RATE * NUM_CHANNELS;
data->maxFrameIndex = numSamples;
data->frameIndex = 0;
data->recordedSamples = (float*)malloc(numSamples * sizeof(float));
if (data->recordedSamples == NULL) {
    printf("Failed to allocate memory for recording.\n");
    waveInClose(hWaveIn);
    return 1;
}

waveHeader.lpData = (LPSTR)malloc(numSamples);
waveHeader.dwBufferLength = numSamples;
waveHeader.dwFlags = 0;
waveHeader.dwLoops = 1;
waveHeader.dwUser = 0;
waveHeader.lpNext = NULL;
waveInPrepareHeader(hWaveIn, &waveHeader, sizeof(WAVEHDR));
waveInAddBuffer(hWaveIn, &waveHeader, sizeof(WAVEHDR));

result = waveInStart(hWaveIn);
if (result != MMSYSERR_NOERROR) {
    printf("Failed to start recording.\n");
    free(data->recordedSamples);
    free(waveHeader.lpData);
    waveInClose(hWaveIn);
    return 1;
}

printf("Recording...\n");
printf("Press Enter to stop recording.\n");
getchar();

waveInStop(hWaveIn);
waveInReset(hWaveIn);
waveInUnprepareHeader(hWaveIn, &waveHeader, sizeof(WAVEHDR));
free(waveHeader.lpData);
waveInClose(hWaveIn);
free(data->recordedSamples);

return 0;

}

int main() {
paData data;
HANDLE hRecordingThread;
DWORD dwThreadId;

hRecordingThread = CreateThread(NULL, 0, RecordingThread, &data, 0, &dwThreadId);
if (hRecordingThread == NULL) {
    printf("Failed to create recording thread.\n");
    return 1;
}
 
WaitForSingleObject(hRecordingThread, INFINITE);
CloseHandle(hRecordingThread);

return 0;

}`