Thread: MCI_PLAY for midis

Ok, i got it to play a midi in c++ console app using this...


[CODE]
DWORD err;
MCI_OPEN_PARMS midiParams;

midiParams.lpstrDeviceType = (LPCSTR)MCI_DEVTYPE_SEQUENCER;

midiParams.lpstrElementName = "song.mid";
int soundon=1;

if(soundon==1)
{

if ((err = mciSendCommand(0, MCI_OPEN, MCI_NOTIFY |MCI_OPEN_ELEMENT|MCI_OPEN_TYPE|MCI_OPEN_TYPE_ID, (DWORD)(LPVOID)&midiParams)))
{
/* Error */
}

if ((err = mciSendCommand(midiParams.wDeviceID, MCI_PLAY,0, (DWORD)(LPVOID)&midiParams)))
{
/* Error */
}
}


And i will close it at the end of my game loop, because i want it to be async. but my question is how do I get some type of return to let me know that the song is finished, or even how do i loop the song forever? I don't understand the concept of dwReturn and Flags.

You have three options:
[list=1][*] Create a window to receive the MM_MCINOTIFY message. Replay when the song is finished.[*] Create a thread and use the MCI_WAIT flag. Loop when the song is finished.[*] Poll regularly for the status of the device. Replay when the status indicates the song is finished.[/list=1]

Here is sample code to implement option no. 2. You call loopMIDI when you want to play a song in a loop and stopMIDI when you want the looping to finish.

The loopMIDI function creates a thread that simply plays the song over and over until the g_bContinue flag is set to false.

Code:

static volatile BOOL g_bContinue;

static DWORD WINAPI loopMIDIThread(LPVOID szMIDIFileName)
{
    UINT wDeviceID;
    DWORD dwReturn;
    MCI_OPEN_PARMS mciOpenParms      = { 0 };
    MCI_PLAY_PARMS mciPlayParms      = { 0 };

    mciOpenParms.lpstrDeviceType  = (LPCSTR) MCI_DEVTYPE_SEQUENCER;
    mciOpenParms.lpstrElementName = (LPCSTR) szMIDIFileName;

    if ((dwReturn = mciSendCommand(NULL, MCI_OPEN,
        MCI_OPEN_TYPE | MCI_OPEN_ELEMENT | MCI_OPEN_TYPE_ID,
        (DWORD_PTR) &mciOpenParms)))
    {
        return dwReturn;
    }

    wDeviceID = mciOpenParms.wDeviceID;

    while (g_bContinue)
    {
        if ((dwReturn = mciSendCommand(wDeviceID, MCI_PLAY, MCI_WAIT, 
            (DWORD_PTR) &mciPlayParms)))
        {
            mciSendCommand(wDeviceID, MCI_CLOSE, 0, NULL);
            return dwReturn;
        }
    }

    mciSendCommand(wDeviceID, MCI_CLOSE, 0, NULL);

    return 0;
}

VOID loopMIDI(LPSTR szMIDIFileName)
{
	DWORD dwThreadId;
	HANDLE hThread;

	g_bContinue = TRUE;

	hThread = CreateThread(NULL, 0, loopMIDIThread, szMIDIFileName, 0, &dwThreadId);
	CloseHandle(hThread);
}

VOID stopMIDI(VOID)
{
	g_bContinue = FALSE;
}

thanks a lot, i'll give it a try