Playing MIDI Files Directly From The Resource

Introduction (back to top)

Public Interface (back to top)

// Play the MIDI file. Normally the playback will stop after
// the MIDI played off.
BOOL Play(BOOL bInfinite = FALSE);

// usually you should never set "bReOpen" to FALSE
// unless you're absolutly sure you will
// not reuse the MIDI object. Normally only the
// destructor of the class should set this flag
BOOL Stop(BOOL bReOpen = TRUE);

BOOL IsPlaying() const;

BOOL Pause();
BOOL Continue();
BOOL IsPaused() const;

// Set playback position back to the start
// normally there is no need to call this method directly.
BOOL Rewind();

// Get the number of volume channels
DWORD GetChannelCount() const;

// Set the volume of a channel in percentage. (default 100%)
// Channels can be addressed from 0 to (GetChannelCount()-1)
void SetChannelVolume(DWORD channel, DWORD percent);

// Get the volume of a channel (in percentage)
DWORD GetChannelVolume(DWORD channel) const;
 
// Set the volume for all channels in percentage
void SetVolume(DWORD percent);

// Get the average volume for all channels (in percentage)
DWORD GetVolume() const;

// Set the tempo of the playback. (default 100%)
void SetTempo(DWORD percent);

// Get the current tempo (in percentage)
DWORD GetTempo() const;

// You can (un)set an infinite loop during playback.
// Note that "Play()" overrides this setting!
void SetInfinitePlay(BOOL bSet = TRUE);

The CMIDI class sends the message WM_MIDI_VOLUMECHANGED to its owner window (if one is set via Create()), if the volume changed during playback in another way than explicitly set by the class (a MIDI stream can control its volume by itself). The WPARAM parameter of the message is a pointer to the CMIDI object that sent the message. The LOWORD of the LPARAM parameter describes the channel that changed volume and the HIWORD is the new volume in percentage. The WM_MIDI_VOLUMECHANGED message is #define'd as WM_USER+23.

Overridables (back to top)

// called when a MIDI output device is opened
virtual void OnMidiOutOpen();
 
// called when the MIDI output device is closed
virtual void OnMidiOutClose();

// called when the specified system-exclusive or stream buffer
// has been played and is being returned to the application
virtual void OnMidiOutDone(MIDIHDR &);

// called when a MEVT_F_CALLBACK event is reached in the MIDI output stream
virtual void OnMidiOutPositionCB(MIDIHDR &, MIDIEVENT &);

See the sample for how you could use these overridables. A derived CMyMidi class is inside MidiSampleDlg.h.

Usage (back to top)

Add a MIDI resource to your application (from the Menu Insert->Resource->import->*.mid->Custom Type MIDI).
"Create()" your CMIDI (derived) object giving it the resource-id of your MIDI resource. Now you can call Play(), Pause(), Stop() etc.

Download(back to top)

Download Demo Project - 44 KB

Download Sources - 14 KB