/*
Module : CMidiPort.cpp
Purpose: Defines the code implementation for the CMidiPort and CDirectMusic classes
Created: CJP / 08-02-2002
History: CJP / 14-07-2002
1. Fixed bug when m_pPort of CMidiPort is NULL
2. Improved CMidiPort destructor
3. Check member variables which values are NULL before performing an operation
Copyright (c) 2002 by C. Jim�nez de Parga
All rights reserved.
*/
#include "stdafx.h"
#include "CMidiPort.h"
// The constructor of the class, member variables initialization
CDirectMusic::CDirectMusic()
{
m_pMusic = NULL;
m_pMusic8 = NULL;
m_pPerformance = NULL;
// Initialize COM
CoInitialize(NULL);
}
// Intialization of CDirectMusic object.
// Creates instances of the most important interfaces
HRESULT CDirectMusic::Initialize(HWND hWnd)
{
HRESULT hr;
// Create the performance object
if (FAILED(hr = CoCreateInstance(CLSID_DirectMusicPerformance,NULL,
CLSCTX_INPROC,IID_IDirectMusicPerformance8,
(void**)&m_pPerformance))) return hr;
if (FAILED(hr = m_pPerformance->Init(&m_pMusic,NULL,hWnd))) return hr;
// Invoke the new interface pointer for IDirectMusic8 object
if (FAILED(hr = m_pMusic->QueryInterface(IID_IDirectMusic8,(LPVOID*)&m_pMusic8))) return hr;
// Release the old interface, not needed any more
SAFE_RELEASE(m_pMusic);
return S_OK;
}
// Port enumeration function
// Enumerate all the ports active in the system
HRESULT CDirectMusic::PortEnumeration(DWORD dwIndex,LPINFOPORT lpInfoPort)
{
HRESULT hr;
DMUS_PORTCAPS portinf;
// Set to 0 the DMUS_PORTCAPS structure
ZeroMemory(&portinf,sizeof(portinf));
portinf.dwSize = sizeof(DMUS_PORTCAPS);
// Call the DirectMusic8 member function to enumerate systems ports
if (FAILED(hr = m_pMusic8->EnumPort(dwIndex,&portinf))) return hr;
// Converts port description to char string
WideCharToMultiByte(CP_ACP,0,portinf.wszDescription,-1,
lpInfoPort->szPortDescription,
sizeof(lpInfoPort->szPortDescription)/
sizeof(lpInfoPort->szPortDescription[0]),0,0);
// Copy the GUID of DMUS_PORTCAP structure to CMidiMusic port structure
CopyMemory(&(lpInfoPort->guidSynthGUID),&portinf.guidPort,sizeof(GUID));
lpInfoPort->dwClass = portinf.dwClass;
lpInfoPort->dwEffectFlags = portinf.dwEffectFlags;
lpInfoPort->dwFlags = portinf.dwFlags;
lpInfoPort->dwMaxAudioChannels = portinf.dwMaxAudioChannels;
lpInfoPort->dwMaxChannelGroups = portinf.dwMaxChannelGroups;
lpInfoPort->dwMaxVoices = portinf.dwMaxVoices;
lpInfoPort->dwType = portinf.dwType;
return hr;
}
// Function to select and activate a MIDI port given a CMidiPort object
HRESULT CDirectMusic::ActivatePort(LPINFOPORT InfoPort,CMidiPort* pMidiPort)
{
HRESULT hr;
DMUS_PORTPARAMS8 dmus;
// Sets to 0 the port capabilities structure
ZeroMemory(&dmus,sizeof(DMUS_PORTPARAMS));
// Sets the params for this port
dmus.dwSize = sizeof(DMUS_PORTPARAMS);
dmus.dwValidParams = DMUS_PORTPARAMS_CHANNELGROUPS;
dmus.dwChannelGroups = 1;
// The midi port is created here
if (FAILED(hr = m_pMusic8->CreatePort(InfoPort->guidSynthGUID,&dmus,
&pMidiPort->m_pPort,NULL))) return hr;
// We have to activate it
if (FAILED(hr = pMidiPort->m_pPort->Activate(TRUE))) return hr;
// Add the port to the performance
if (FAILED(hr = m_pPerformance->AddPort(pMidiPort->m_pPort))) return hr;
// Assigns a block of 16 performance channels to the performance
if (FAILED(hr = m_pPerformance->AssignPChannelBlock(0,pMidiPort->m_pPort,1))) return hr;
pMidiPort->m_pPerformance = m_pPerformance; // Update the IDirectMusicPerformance8 reference
DMUS_BUFFERDESC BufferDesc; // Create the DirectMusic buffer to store MIDI messages
ZeroMemory(&BufferDesc,sizeof(DMUS_BUFFERDESC));
BufferDesc.dwSize = sizeof(DMUS_BUFFERDESC);
BufferDesc.guidBufferFormat = GUID_NULL;
BufferDesc.cbBuffer = 32; // at least 32 bytes to store messages
if (FAILED(hr = m_pMusic8->CreateMusicBuffer(&BufferDesc,&pMidiPort->m_pBuffer,NULL))) return hr;
return S_OK;
}
// The class destructor
// Release all the interfaces
// Closedown the performance
// Uninitialize COM
CDirectMusic::~CDirectMusic()
{
if (m_pPerformance)
m_pPerformance->CloseDown();
SAFE_RELEASE(m_pMusic);
SAFE_RELEASE(m_pMusic8);
CoUninitialize();
}
// Class constructor, member variables initialization
CMidiPort::CMidiPort()
{
m_pThru = NULL;
m_hEvent = NULL;
m_pPerformance = NULL;
m_pPort = NULL;
m_pBuffer = NULL;
m_pClock = NULL;
}
// This function removes the selected port from the performance
// and releases all their asociated objects for a new port selection
HRESULT CMidiPort::ReleasePort()
{
if (m_pPerformance)
{
if (m_pPort)
{
m_pPort->Activate(FALSE);
m_pPerformance->RemovePort(m_pPort);
}
SAFE_RELEASE(m_pPort);
SAFE_RELEASE(m_pBuffer);
SAFE_RELEASE(m_pClock);
SAFE_RELEASE(m_pThru);
}
return S_OK;
}
// Create the Event object
HRESULT CMidiPort::ActivateEvent()
{
m_hEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
if (m_hEvent) return S_OK;
else return S_FALSE;
}
// Activates the MIDI thru from an Input MIDI port to a given Output MIDI port
HRESULT CMidiPort::SetThru(CMidiPort *pdstMidiPort)
{
HRESULT hr = S_FALSE;
SAFE_RELEASE(m_pThru); // Release the old IDirectMusic thru object
if (m_pPort)
{
if (FAILED(m_pPort->QueryInterface(IID_IDirectMusicThru8,(void**)&m_pThru)))
return S_FALSE;
for (DWORD dwChannel = 0;dwChannel < 16;dwChannel++)
{
hr = m_pThru->ThruChannel(1,dwChannel,
1,dwChannel,pdstMidiPort->m_pPort);
if (FAILED(hr))
break;
}
}
return hr;
}
// Desactivates the MIDI thru
HRESULT CMidiPort::BreakThru()
{
HRESULT hr = S_FALSE;
if (m_pThru)
{
for (DWORD dwChannel = 0;dwChannel < 16;dwChannel++)
{
hr = m_pThru->ThruChannel(1,dwChannel,
1,dwChannel,NULL);
if (FAILED(hr))
break;
}
}
return hr;
}
// Activates the notification handle and starts the worker thread
HRESULT CMidiPort::SetNotification(void( __cdecl *start_address)(void *),LPVOID lpObj)
{
HRESULT hr = S_FALSE;
if (m_pPort)
{
hr = m_pPort->SetReadNotificationHandle(m_hEvent);
_beginthread(start_address,0,lpObj);
m_start_address = start_address;
}
return hr;
}
// Ends the notification and terminate the thread
HRESULT CMidiPort::TerminateNotification()
{
HRESULT hr = S_FALSE;
if (m_pPort)
{
hr = m_pPort->SetReadNotificationHandle(NULL);
TerminateThread(m_start_address,0);
CloseHandle(m_hEvent);
m_hEvent = NULL;
}
return hr;
}
// Function to fill a buffer with incoming MIDI data from the port
HRESULT CMidiPort::ReadBuffer()
{
if (m_pPort)
return m_pPort->Read(m_pBuffer);
else return S_FALSE;
}
// Sets the read pointer to the start of the data in the buffer
HRESULT CMidiPort::ResetBuffer()
{
if (m_pBuffer)
return m_pBuffer->ResetReadPtr();
else return S_FALSE;
}
// Returns information about the next message in the buffer and advances the read pointer
HRESULT CMidiPort::GetMidiEvent(REFERENCE_TIME *lprt,DWORD *lpdwGroup,DWORD *lpcb,BYTE **lppb)
{
if (m_pBuffer)
return m_pBuffer->GetNextEvent(lprt,lpdwGroup,lpcb,lppb);
else return S_FALSE;
}
// Returns the latency clock
HRESULT CMidiPort::GetLatencyClock()
{
if (m_pPort)
return m_pPort->GetLatencyClock(&m_pClock);
else return S_FALSE;
}
// Function to send a MIDI message to the selected output port
HRESULT CMidiPort::SendMidiMsg(DWORD dwMsg,DWORD dwChannel)
{
HRESULT hr = S_FALSE;
REFERENCE_TIME rt;
if ((m_pPort) && (m_pBuffer) && (m_pClock))
{
if (FAILED(hr = m_pClock->GetTime(&rt))) return hr;
if (FAILED(hr = m_pBuffer->PackStructured(rt,dwChannel,dwMsg))) return hr;
if (FAILED(hr = m_pPort->PlayBuffer(m_pBuffer))) return hr;
if (FAILED(hr = m_pBuffer->Flush())) return hr;
hr=S_OK;
}
return hr;
}
// Function to activate an effect in the port
HRESULT CMidiPort::SetEffect(BOOL bActivate,int nEffect)
{
IKsControl *pControl;
KSPROPERTY ksp;
DWORD dwEffects=0;
ULONG cb;
HRESULT hr=S_FALSE;
// Get the IKsControl interface
if (m_pPort)
{
hr = m_pPort->QueryInterface(IID_IKsControl,(void**)&pControl);
if (SUCCEEDED(hr))
{
ZeroMemory(&ksp, sizeof(ksp));
if (!bActivate)
dwEffects = 0;
else
{
// Select an audio effect
switch(nEffect)
{
case 0x1:
dwEffects = DMUS_EFFECT_REVERB;
break;
case 0x2:
dwEffects = DMUS_EFFECT_CHORUS;
break;
case 0x3:
dwEffects = DMUS_EFFECT_CHORUS | DMUS_EFFECT_REVERB;
break;
}
}
ksp.Set = GUID_DMUS_PROP_Effects;
ksp.Id = 0;
ksp.Flags = KSPROPERTY_TYPE_SET;
pControl->KsProperty(&ksp,
sizeof(ksp),
(LPVOID)&dwEffects,
sizeof(dwEffects),
&cb);
SAFE_RELEASE(pControl);
}
}
return hr;
}
// Class destructor
// Release all the interfaces
// Call TerminateNotification in case the thread is active
CMidiPort::~CMidiPort()
{
if (m_hEvent) TerminateNotification();
BreakThru();
ReleasePort();
}
Submit an article or tip