Lecture d’une piste de disque compact
L’exemple suivant ouvre un périphérique audio CD, lit la piste spécifiée par le paramètre bTrack et ferme l’appareil une fois la lecture terminée. Il utilise la fonction mciSendCommand .
// Plays a specified audio track using MCI_OPEN, MCI_PLAY. Returns as
// soon as playback begins. The window procedure function for the
// specified window will be notified when playback is complete.
// Returns 0L on success; otherwise, returns an MCI error code.
DWORD playCDTrack(HWND hWndNotify, BYTE bTrack)
{
UINT wDeviceID;
DWORD dwReturn;
MCI_OPEN_PARMS mciOpenParms;
MCI_SET_PARMS mciSetParms;
MCI_PLAY_PARMS mciPlayParms;
// Open the CD audio device by specifying the device name.
mciOpenParms.lpstrDeviceType = "cdaudio";
if (dwReturn = mciSendCommand(NULL, MCI_OPEN,
MCI_OPEN_TYPE, (DWORD)(LPVOID) &mciOpenParms))
{
// Failed to open device. Don't close it; just return error.
return (dwReturn);
}
// The device opened successfully; get the device ID.
wDeviceID = mciOpenParms.wDeviceID;
// Set the time format to track/minute/second/frame (TMSF).
mciSetParms.dwTimeFormat = MCI_FORMAT_TMSF;
if (dwReturn = mciSendCommand(wDeviceID, MCI_SET,
MCI_SET_TIME_FORMAT, (DWORD)(LPVOID) &mciSetParms))
{
mciSendCommand(wDeviceID, MCI_CLOSE, 0, NULL);
return (dwReturn);
}
// Begin play from the specified track and play to the beginning
// of the next track. The window procedure function for the parent
// window will be notified with an MM_MCINOTIFY message when
// playback is complete. Unless the play command fails, the window
// procedure closes the device.
mciPlayParms.dwFrom = 0L;
mciPlayParms.dwTo = 0L;
mciPlayParms.dwFrom = MCI_MAKE_TMSF(bTrack, 0, 0, 0);
mciPlayParms.dwTo = MCI_MAKE_TMSF(bTrack + 1, 0, 0, 0);
mciPlayParms.dwCallback = (DWORD) hWndNotify;
if (dwReturn = mciSendCommand(wDeviceID, MCI_PLAY,
MCI_FROM | MCI_TO | MCI_NOTIFY,
(DWORD)(LPVOID) &mciPlayParms))
{
mciSendCommand(wDeviceID, MCI_CLOSE, 0, NULL);
return (dwReturn);
}
return (0L);
}
Pour spécifier une position par rapport à une piste sur un disque compact, vous devez utiliser le format d’heure track/minute/second/frame (TMSF).