www.pudn.com > NoteBookVC++.rar > Midi.cpp

// Midi.cpp 
 
#include "stdafx.h" 
#include "Midi.h" 
 
CMidi::CMidi() 
{ 
 
	m_nDevices = midiOutGetNumDevs(); 
	m_bOpened = m_bPaused = m_bPlaying = FALSE; 
	m_wDeviceID = 0; 
 
} 
 
CMidi::~CMidi() 
{ 
 
	Close(); 
 
} 
 
int CMidi::DeviceCount( void ) 
{ 
 
	return( m_nDevices ); 
 
} 
 
BOOL CMidi::Open( const char *lpszFilename ) 
{ 
 
	if( !m_bOpened ){ 
 
		// Initialize member variables. 
		m_bPaused = m_bPlaying = FALSE; 
		m_wDeviceID = 0; 
 
		// See if the file exists. 
		CFileStatus Status; 
		if( !CFile::GetStatus( lpszFilename, Status ) ) 
			return( FALSE ); 
 
		// Open the device. 
		MCI_OPEN_PARMS OpenParms; 
		OpenParms.lpstrDeviceType = (LPCSTR) MCI_DEVTYPE_SEQUENCER; 
		OpenParms.lpstrElementName = (LPCSTR) lpszFilename; 
		OpenParms.wDeviceID = 0; 
		if( mciSendCommand( NULL, MCI_OPEN, MCI_WAIT | MCI_OPEN_TYPE | MCI_OPEN_TYPE_ID | MCI_OPEN_ELEMENT, (DWORD)(LPVOID) &OpenParms ) ) 
			return( FALSE ); 
		m_wDeviceID = OpenParms.wDeviceID; 
		m_bOpened = TRUE; 
 
		// Set the time format to milliseconds. 
		MCI_SET_PARMS SetParms; 
		SetParms.dwTimeFormat = MCI_FORMAT_MILLISECONDS; 
		if( mciSendCommand( m_wDeviceID, MCI_SET, MCI_SET_TIME_FORMAT, (DWORD)(LPVOID) &SetParms ) ){ 
			Close(); 
			return( FALSE ); 
			} 
		mciSendCommand( m_wDeviceID, MCI_SEEK, MCI_SEEK_TO_START, NULL ); 
		return( TRUE ); 
		} 
 
	return( FALSE ); 
 
} 
 
BOOL CMidi::Close( void ) 
{ 
 
	if( m_bOpened ){ 
 
		// Stop the playing and close the device. 
		if( m_bPlaying || m_bPaused ) 
			mciSendCommand( m_wDeviceID, MCI_STOP, NULL, NULL ); 
		mciSendCommand( m_wDeviceID, MCI_CLOSE, NULL, NULL ); 
 
		// Clear member variables. 
		m_bOpened = m_bPaused = m_bPlaying = FALSE; 
		m_wDeviceID = 0; 
 
		return( TRUE ); 
		} 
 
	return( FALSE ); 
 
} 
 
BOOL CMidi::Play( void ) 
{ 
 
	if( m_bOpened ){ 
 
		// Issue the 'play' command. 
		MCI_PLAY_PARMS PlayParms; 
		PlayParms.dwCallback = NULL; 
		PlayParms.dwFrom = ( ( GetMinutes() * 60 ) + GetSeconds () ) * 1000; 
		if( mciSendCommand( m_wDeviceID, MCI_PLAY, MCI_FROM, (DWORD)(LPVOID) &PlayParms ) ) 
			return( FALSE ); 
 
		// Set our class members so we know that 
		// we're currently playing. 
		m_bPlaying = TRUE; 
		m_bPaused = FALSE; 
 
		return( TRUE ); 
		} 
 
	return( FALSE ); 
 
} 
 
BOOL CMidi::Stop( void ) 
{ 
 
	if( m_bOpened && m_bPlaying ){ 
		// Issue the 'stop' command. 
		mciSendCommand( m_wDeviceID, MCI_STOP, NULL, NULL ); 
		// Issue the command that seeks back to the start. 
		mciSendCommand( m_wDeviceID, MCI_SEEK, MCI_SEEK_TO_START, NULL ); 
		m_bPaused = m_bPlaying = FALSE; 
 
		return( TRUE ); 
		} 
 
	return( FALSE ); 
 
} 
 
BOOL CMidi::Pause( void ) 
{ 
 
	if( m_bOpened && m_bPlaying ){ 
 
		// Pause the CD. 
		MCI_PLAY_PARMS PlayParms; 
		if( mciSendCommand( m_wDeviceID, MCI_PAUSE, 0, (DWORD)(LPVOID) &PlayParms ) ) 
			return( FALSE ); 
 
		m_bPaused = TRUE; 
 
		return( TRUE ); 
		} 
 
	return( FALSE ); 
 
} 
 
BOOL CMidi::IsPlaying( void ) 
{ 
 
	if( m_bOpened ){ 
 
		// Issue the 'status' command. 
		MCI_STATUS_PARMS StatusParms; 
		StatusParms.dwItem = MCI_STATUS_MODE; 
		if( mciSendCommand( m_wDeviceID, MCI_STATUS, MCI_WAIT | MCI_STATUS_ITEM, (DWORD)(LPVOID) &StatusParms ) ) 
			return( FALSE ); 
 
		if( StatusParms.dwReturn == MCI_MODE_PLAY ){ 
			m_bPlaying = TRUE; 
			m_bPaused = FALSE; 
			return( TRUE ); 
			} 
		else if( StatusParms.dwReturn == MCI_MODE_PAUSE ){ 
			m_bPlaying = TRUE; 
			m_bPaused = FALSE; 
			return( TRUE ); 
			} 
		else{ 
			m_bPlaying = FALSE; 
			m_bPaused = FALSE; 
			return( FALSE ); 
			} 
		} 
 
	return( FALSE ); 
 
} 
 
BOOL CMidi::GetLength( int *lpnMinutes, int *lpnSeconds ) 
{ 
 
	// Set minutes and seconds to -1 in 
	// case there's an error. 
	*lpnMinutes = -1; 
	*lpnSeconds = -1; 
 
	if( m_bOpened ){ 
 
		// Issue the 'status/length' command. 
		MCI_STATUS_PARMS StatusParms; 
		StatusParms.dwItem = MCI_STATUS_LENGTH; 
		if( mciSendCommand( m_wDeviceID, MCI_STATUS, MCI_WAIT | MCI_STATUS_ITEM, (DWORD)(LPVOID) &StatusParms ) ) 
			return( FALSE ); 
 
		// Store the values in *lpnMinutes and *lpnSeconds. 
		*lpnMinutes = ( StatusParms.dwReturn / 1000 ) / 60; 
		*lpnSeconds = ( StatusParms.dwReturn / 1000 ) % 60; 
 
		return( TRUE ); 
 
		} 
 
	return( FALSE ); 
 
} 
 
int CMidi::GetMinutes( void ) 
{ 
 
	if( m_bOpened ){ 
 
		// Get the current position. 
		MCI_STATUS_PARMS StatusParms; 
		StatusParms.dwItem = MCI_STATUS_POSITION; 
		if( mciSendCommand( m_wDeviceID, MCI_STATUS, MCI_WAIT | MCI_STATUS_ITEM, (DWORD)(LPVOID) &StatusParms ) ) 
			return( -1 ); 
 
		return( (int) ( ( StatusParms.dwReturn / 1000 ) / 60 ) ); 
		} 
 
	return( -1 ); 
 
} 
 
int CMidi::GetSeconds( void ) 
{ 
 
	if( m_bOpened ){ 
 
		// Get the current position. 
		MCI_STATUS_PARMS StatusParms; 
		StatusParms.dwItem = MCI_STATUS_POSITION; 
		if( mciSendCommand( m_wDeviceID, MCI_STATUS, MCI_WAIT | MCI_STATUS_ITEM, (DWORD)(LPVOID) &StatusParms ) ) 
			return( -1 ); 
 
		return( (int) ( ( StatusParms.dwReturn / 1000 ) % 60 ) ); 
		} 
 
	return( -1 ); 
 
} 
 
BOOL CMidi::SeekTo( int nMinute, int nSecond ) 
{ 
 
	if( m_bOpened ){ 
 
		// Set dwTo to the correct value. 
		MCI_SEEK_PARMS SeekParms; 
		SeekParms.dwTo = ( nMinute * 60 + nSecond ) * 1000; 
 
		// Pause if we're not paused. 
		if( m_bPlaying && !m_bPaused ) 
			mciSendCommand( m_wDeviceID, MCI_PAUSE, 0, NULL ); 
 
		// Issue the 'seek' command. 
		if( mciSendCommand( m_wDeviceID, MCI_SEEK, MCI_TO | MCI_WAIT, (DWORD)(LPVOID) &SeekParms ) ) 
			return( FALSE ); 
 
		// Restart the audio. 
		if( m_bPlaying && !m_bPaused ) 
			return( Play() ); 
 
		} 
 
	return( FALSE ); 
 
} 
 
BOOL CMidi::SkipForward( int nSeconds ) 
{ 
 
	if( m_bOpened ){ 
 
		// Get the current position. 
		MCI_STATUS_PARMS StatusParms; 
		DWORD dwPos; 
		StatusParms.dwItem = MCI_STATUS_POSITION; 
		mciSendCommand( m_wDeviceID, MCI_STATUS, MCI_WAIT | MCI_STATUS_ITEM, (DWORD)(LPVOID) &StatusParms ); 
		dwPos = StatusParms.dwReturn; 
 
		// Skip forward n milliseconds 
		dwPos += (DWORD) nSeconds * 1000; 
 
		// Pause and seek to. 
		MCI_SEEK_PARMS SeekParms; 
		SeekParms.dwTo = dwPos; 
		if( m_bPlaying && !m_bPaused ) 
			mciSendCommand( m_wDeviceID, MCI_PAUSE, 0, NULL ); 
		mciSendCommand (m_wDeviceID, MCI_SEEK, MCI_TO | MCI_WAIT, (DWORD)(LPVOID) &SeekParms); 
 
		// Restart the audio. 
		if( m_bPlaying && !m_bPaused ) 
			return( Play() ); 
 
		} 
 
	return( FALSE ); 
 
} 
 
BOOL CMidi::SkipBack( int nSeconds ) 
{ 
 
	if( m_bOpened ){ 
 
		// Get the current position. 
		MCI_STATUS_PARMS StatusParms; 
		DWORD dwPos; 
		StatusParms.dwItem = MCI_STATUS_POSITION; 
		mciSendCommand( m_wDeviceID, MCI_STATUS, MCI_WAIT | MCI_STATUS_ITEM, (DWORD)(LPVOID) &StatusParms ); 
		dwPos = StatusParms.dwReturn; 
 
		// Skip forward n milliseconds. 
		dwPos -= (DWORD) nSeconds * 1000; 
 
		// Pause and seek to. 
		MCI_SEEK_PARMS SeekParms; 
		SeekParms.dwTo = dwPos; 
		if( m_bPlaying && !m_bPaused ) 
			mciSendCommand( m_wDeviceID, MCI_PAUSE, 0, NULL ); 
		mciSendCommand( m_wDeviceID, MCI_SEEK, MCI_TO | MCI_WAIT, (DWORD)(LPVOID) &SeekParms ); 
 
		// Restart the audio. 
		if( m_bPlaying && !m_bPaused ) 
			return( Play() ); 
 
		} 
 
	return( FALSE ); 
 
} 
 
int CMidi::GetTempo( void ) 
{ 
 
	if( m_bOpened ){ 
 
		// Issue the 'status/tempo' command. 
		MCI_STATUS_PARMS StatusParms; 
		StatusParms.dwItem = MCI_SEQ_STATUS_TEMPO; 
		if( mciSendCommand( m_wDeviceID, MCI_STATUS, MCI_WAIT | MCI_STATUS_ITEM, (DWORD)(LPVOID) &StatusParms ) ) 
			return( -1 ); 
 
		return( (int) StatusParms.dwReturn ); 
		} 
 
	return( -1 ); 
 
} 
 
BOOL CMidi::SetTempo( int nTempo ) 
{ 
 
	if( m_bOpened ){ 
 
		// Set the tempo. 
		MCI_SEQ_SET_PARMS SeqSetParms; 
		SeqSetParms.dwTempo = nTempo; 
		mciSendCommand( m_wDeviceID, MCI_SET, MCI_WAIT | MCI_SEQ_SET_TEMPO, (DWORD)(LPVOID) &SeqSetParms ); 
		return( TRUE ); 
		} 
 
	return( FALSE ); 
 
}