Why the Flash Player can not find the DirectShow virtual audio device? - windows

I would like to record the microphone and the system sound(Youtube music, Media Player movie sound, keyboard type warning sound...etc.), so that publishing it to the server by Flash Player.
I found the DirectShow sample at GitHub: virtual-audio-capture-grabber-device
I register its DLL successfully.
And the filter name of this sample is "virtual-audio-capturer".
C:\Users\user\Desktop\virtual-audio-capture-grabber-device-master\virtual-aud
io-capture-grabber-device-master\source_code\Release>regsvr32 audio_sniffer.dll
I used virtual-audio-capturer filter of Audio Capture Source, WavDest Filter and File Writer Filter to record audio into the WAVE file by GraphEdt.exe. The graph is workable. And the result file is correct.
There are Microphone (VIA High Definition Audio) and Stereo Mix (VIA High Definition Audio) in the microphone list of Flash Player, but no virtual-audio-capture-grabber-device. The result is same with Action Script 3 project. But I can see the virtual-audio-capture-grabber-device at Adobe Flash Media Live Encoder 3.2. (http://img.bbs.csdn.net/upload/201311/12/1384239370_718116.png)
var deviceArray:Array = Microphone.names;
trace("Available sound input devices:");
for (var i:int = 0; i < deviceArray.length; i++) {
trace(" " + deviceArray[i]);
}
The virtual-audio-capturer filter has only one output pin, and no input pin.
const AMOVIESETUP_MEDIATYPE AMSMediaTypesVCam =
{ &MEDIATYPE_Audio, // clsMajorType
&MEDIASUBTYPE_NULL // clsMinorType
};
setup.cpp
#define CreateComObject(clsid, iid, var) CoCreateInstance( clsid, NULL, CLSCTX_INPROC_SERVER, iid, (void **)&var);
STDAPI AMovieSetupRegisterServer( CLSID clsServer, LPCWSTR szDescription, LPCWSTR szFileName, LPCWSTR szThreadingModel = L"Both", LPCWSTR szServerType = L"InprocServer32" );
STDAPI AMovieSetupUnregisterServer( CLSID clsServer );
#ifdef _WIN64
DEFINE_GUID(CLSID_VirtualCam,
0x8e146464, 0xdb61, 0x4309, 0xaf, 0xa1, 0x35, 0x78, 0xe9, 0x27, 0xe9, 0x35);
#else
DEFINE_GUID(CLSID_VirtualCam,
0x8e14549b, 0xdb61, 0x4309, 0xaf, 0xa1, 0x35, 0x78, 0xe9, 0x27, 0xe9, 0x35);
#endif
const AMOVIESETUP_MEDIATYPE AMSMediaTypesVCam = { &MEDIATYPE_Audio, &MEDIASUBTYPE_NULL };
const AMOVIESETUP_PIN AMSPinVCam = {
L"Output", // Pin string name
FALSE, // Is it rendered
TRUE, // Is it an output
FALSE, // Can we have none
FALSE, // Can we have many
&CLSID_NULL, // Connects to filter
NULL, // Connects to pin
1, // Number of types
&AMSMediaTypesVCam };
const AMOVIESETUP_FILTER AMSFilterVCam = {
&CLSID_VirtualCam, // Filter CLSID
L"virtual-audio-capturer", // String name
MERIT_DO_NOT_USE, // Filter merit
1, // Number pins
&AMSPinVCam };
CFactoryTemplate g_Templates[] = {
{
L"virtual-audio-capturer",
&CLSID_VirtualCam,
CVCam::CreateInstance,
NULL,
&AMSFilterVCam
}, };
int g_cTemplates = sizeof(g_Templates) / sizeof(g_Templates[0]);
STDAPI RegisterFilters( BOOL bRegister ) {
HRESULT hr = NOERROR;
WCHAR achFileName[MAX_PATH];
char achTemp[MAX_PATH];
ASSERT(g_hInst != 0);
if( 0 == GetModuleFileNameA(g_hInst, achTemp, sizeof(achTemp)))
return AmHresultFromWin32(GetLastError());
MultiByteToWideChar(CP_ACP, 0L, achTemp, lstrlenA(achTemp) + 1,
achFileName, NUMELMS(achFileName));
hr = CoInitialize(0);
if(bRegister) {
hr = AMovieSetupRegisterServer(CLSID_VirtualCam, L"virtual-audio-capturer", achFileName, L"Both", L"InprocServer32");
}
if( SUCCEEDED(hr) ) {
IFilterMapper2 *fm = 0;
hr = CreateComObject( CLSID_FilterMapper2, IID_IFilterMapper2, fm );
if( SUCCEEDED(hr) )
{
if(bRegister)
{
IMoniker *pMoniker = 0;
REGFILTER2 rf2;
rf2.dwVersion = 1;
rf2.dwMerit = MERIT_DO_NOT_USE;
rf2.cPins = 1;
rf2.rgPins = &AMSPinVCam;
hr = fm->RegisterFilter(CLSID_VirtualCam, L"virtual-audio-capturer", &pMoniker, &CLSID_AudioInputDeviceCategory, NULL, &rf2);
}
else
{
hr = fm->UnregisterFilter(&CLSID_AudioInputDeviceCategory, 0, CLSID_VirtualCam);
}
}
// release interface
if(fm)
fm->Release();
}
if( SUCCEEDED(hr) && !bRegister )
hr = AMovieSetupUnregisterServer( CLSID_VirtualCam );
CoFreeUnusedLibraries();
CoUninitialize();
return hr; }
#include <stdio.h>
STDAPI RegisterFilters( BOOL bRegister );
STDAPI DllRegisterServer() {
printf("hello there"); // we actually never see this...
return RegisterFilters(TRUE); }
STDAPI DllUnregisterServer() {
return RegisterFilters(FALSE); }
STDAPI DllEntryPoint(HINSTANCE, ULONG, LPVOID);
extern "C" BOOL APIENTRY DllMain(HANDLE hModule, DWORD dwReason, LPVOID lpReserved) {
return DllEntryPoint((HINSTANCE)(hModule), dwReason, lpReserved);
Please click the link to view the full DirectShow sample code.
Is the DirectShow virtual audio device available with Flash Player?
Should I add the Analog Audio input pin?
Should I implement the IAMAudioInputMixer interface?
Should I use WinDDK to make the virtual audio device first?
Win7 SP1 64Bit System;
VIA High Definition Audio;
Intel Audio;
Adobe Flash Media Live Encoder 3.2
Adobe Flash Player 11,8,800,94
Adobe Flash Builder 4.6
Microsoft Visual C++ 2010
Microsoft Windows SDK 7.1

I cannot know for sure, but Flash probably does not use DirectShow API for audio, but instead another of Windows' many audio APIs, probably DirectSound. You'll have to write an audio driver.

Related

How can I programmatically set the default input and output audio device for an application?

If I go to Settings on a Windows 10 (1803) computer, I have access to a page ("App Volume and Device Preferences") that lets me set the default input and output device for a running application.
How can I set these options programmatically?
Related:
Set audio endpoint devices application specific (programmatically)Seems to refer to a more specific problem, and is unanswered.
Controlling “App volume and device preferences” menu, from settings, with python 3.6, or any language(Windows). Automatic App audio device switchingToo broad, wrong site.
IAudioSessionControl2 and related familyAllows reading the device and setting volume and mute, but doesn't seem to allow changing the device
GitHub issue page for SoundSwitch also looking for APIImplies API is undocumented by design (default device being controlled by user)
Here you can enumerate all the playback devices
#include <windows.h>
#include <mmsystem.h>
#include <iostream>
using namespace std;
#pragma comment(lib, "Winmm.lib")
int main()
{
int nSoundCardCount = waveOutGetNumDevs();
for (int i = 0; i < nSoundCardCount; i++)
{
WAVEOUTCAPS woc;
waveOutGetDevCaps(i, &woc, sizeof(woc));
cout << woc.szPname << endl;
}
system("pause");
return 0;
}
Here you need to use PolicyConfig.h and SetDefaultAudioPlaybackDevice to add .h files and interfaces. Refer to this project
1.Add the header file PolicyConfig.h
2.Add the head file and interface.
#include "Mmdeviceapi.h"
#include "PolicyConfig.h"
#include "Propidl.h"
#include "Functiondiscoverykeys_devpkey.h"
HRESULT SetDefaultAudioPlaybackDevice( LPCWSTR devID )
{
IPolicyConfigVista *pPolicyConfig;
ERole reserved = eConsole;
HRESULT hr = CoCreateInstance(__uuidof(CPolicyConfigVistaClient),
NULL, CLSCTX_ALL, __uuidof(IPolicyConfigVista), (LPVOID *)&pPolicyConfig);
if (SUCCEEDED(hr))
{
hr = pPolicyConfig->SetDefaultEndpoint(devID, reserved);
pPolicyConfig->Release();
}
return hr;
}
3.Use the above interface to write a function to set the default output device.
It's MFC Project. Maybe you need to change.
Which output device needs to be set, you can modify the content of the macro yourself.
I get the name of output device using waveOutGetDevCaps()
//Set the default audio playback device
#define DEF_AUDIO_NAME _T("Speakers (2- Logitech USB Heads") //modify it, my device is Speakers (2- Logitech USB Heads
void InitDefaultAudioDevice()
{
HRESULT hr = CoInitialize(NULL);
if (SUCCEEDED(hr))
{
IMMDeviceEnumerator *pEnum = NULL;
// Create a multimedia device enumerator.
hr = CoCreateInstance(__uuidof(MMDeviceEnumerator), NULL,
CLSCTX_ALL, __uuidof(IMMDeviceEnumerator), (void**)&pEnum);
if (SUCCEEDED(hr))
{
//Determine if it is the default audio device
bool bExit = false;
IMMDevice *pDefDevice = NULL;
hr = pEnum->GetDefaultAudioEndpoint(eRender, eMultimedia,&pDefDevice);
if (SUCCEEDED(hr))
{
IPropertyStore *pStore;
hr = pDefDevice->OpenPropertyStore(STGM_READ, &pStore);
if (SUCCEEDED(hr))
{
PROPVARIANT friendlyName;
PropVariantInit(&friendlyName);
hr = pStore->GetValue(PKEY_Device_FriendlyName, &friendlyName);
if (SUCCEEDED(hr))
{
CString strTmp = friendlyName.pwszVal;
if (strTmp.Find(DEF_AUDIO_NAME) != -1)
{
bExit = true;
}
PropVariantClear(&friendlyName);
}
pStore->Release();
}
pDefDevice->Release();
}
if (bExit)
{
pEnum->Release();
return;
}
IMMDeviceCollection *pDevices;
// Enumerate the output devices.
hr = pEnum->EnumAudioEndpoints(eRender, DEVICE_STATE_ACTIVE, &pDevices);
if (SUCCEEDED(hr))
{
UINT count;
pDevices->GetCount(&count);
if (SUCCEEDED(hr))
{
for (int i = 0; i < count; i++)
{
bool bFind = false;
IMMDevice *pDevice;
hr = pDevices->Item(i, &pDevice);
if (SUCCEEDED(hr))
{
LPWSTR wstrID = NULL;
hr = pDevice->GetId(&wstrID);
if (SUCCEEDED(hr))
{
IPropertyStore *pStore;
hr = pDevice->OpenPropertyStore(STGM_READ, &pStore);
if (SUCCEEDED(hr))
{
PROPVARIANT friendlyName;
PropVariantInit(&friendlyName);
hr = pStore->GetValue(PKEY_Device_FriendlyName, &friendlyName);
if (SUCCEEDED(hr))
{
// if no options, print the device
// otherwise, find the selected device and set it to be default
CString strTmp = friendlyName.pwszVal;
if (strTmp.Find(DEF_AUDIO_NAME) != -1)
{
SetDefaultAudioPlaybackDevice(wstrID);
bFind = true;
}
PropVariantClear(&friendlyName);
}
pStore->Release();
}
}
pDevice->Release();
}
if (bFind)
{
break;
}
}
}
pDevices->Release();
}
pEnum->Release();
}
}
CoUninitialize();
}
This sample can only change the output of Master volume. I don't know whether it can meet your requirements? If you need to change other apps, you have to explore for a while.
So I have been using SoundVolumeView for a while that let me mute and unmute my mic for meeting with a command line and I have discovered recently (because of OBS and monitoring audio) that it can also change device for an app or global default device
http://www.nirsoft.net/utils/sound_volume_view.html
And using /SetDefault and /SetAppDefault as shown in the doc example to the bottom of the page
I have put that in a batch script and bind a macro to my keyboard and it's doing a good job so far :)

Add audio capability to Capture Filter

I'm trying to add audio capability to a capture source filter in order to make a virtual cam with audio. Beginning with the TMH's and rdp's code I extended it with another pin, called "Audio":
CUnknown * WINAPI CVCam::CreateInstance(LPUNKNOWN lpunk, HRESULT *phr)
{
ASSERT(phr);
CUnknown *punk = new CVCam(lpunk, phr);
return punk;
}
CVCam::CVCam(LPUNKNOWN lpunk, HRESULT *phr) : CSource(LPCSTR(FILTER_NAME), lpunk, CLSID_VirtualCam)
{
ASSERT(phr);
CAutoLock cAutoLock(&m_cStateLock);
m_paStreams = (CSourceStream **) new CVCamStream*[2];
m_paStreams[0] = new CVCamStream(phr, this, L"Video");
m_paStreams[1] = new CVAudioStream(phr, this, L"Audio");
}
HRESULT CVCam::QueryInterface(REFIID riid, void **ppv)
{
if (riid == _uuidof(IAMStreamConfig) || riid == _uuidof(IKsPropertySet))
{
HRESULT hr;
hr = m_paStreams[0]->QueryInterface(riid, ppv);
if (hr != S_OK) return hr;
hr = m_paStreams[1]->QueryInterface(riid, ppv);
if (hr != S_OK) return hr;
}
else return CSource::QueryInterface(riid, ppv);
return S_OK;
}
CVAudioStream::CVAudioStream(HRESULT *phr, CVCam *pParent, LPCWSTR pPinName) : CSourceStream(LPCSTR(pPinName), phr, pParent, pPinName), m_pParent(pParent)
{
GetMediaType(0, &m_mt);
}
CVAudioStream::~CVAudioStream()
{
}
HRESULT CVAudioStream::QueryInterface(REFIID riid, void **ppv)
{
if (riid == _uuidof(IAMStreamConfig)) *ppv = (IAMStreamConfig*)this;
else if (riid == _uuidof(IKsPropertySet)) *ppv = (IKsPropertySet*)this;
else if (riid == _uuidof(IAMBufferNegotiation)) *ppv = (IAMBufferNegotiation*)this;
else return CSourceStream::QueryInterface(riid, ppv);
AddRef();
return S_OK;
}
HRESULT CVAudioStream::FillBuffer(IMediaSample *pms)
{
// fill buffer with Windows audio samples
return NOERROR;
}
STDMETHODIMP CVAudioStream::Notify(IBaseFilter * pSender, Quality q)
{
return E_NOTIMPL;
}
HRESULT CVAudioStream::SetMediaType(const CMediaType *pmt)
{
HRESULT hr = CSourceStream::SetMediaType(pmt);
return hr;
}
HRESULT setupPwfex(WAVEFORMATEX *pwfex, AM_MEDIA_TYPE *pmt) {
pwfex->wFormatTag = WAVE_FORMAT_PCM;
pwfex->cbSize = 0;
pwfex->nChannels = 2;
HRESULT hr;
pwfex->nSamplesPerSec = 11025;
pwfex->wBitsPerSample = 16;
pwfex->nBlockAlign = (WORD)((pwfex->wBitsPerSample * pwfex->nChannels) / 8);
pwfex->nAvgBytesPerSec = pwfex->nSamplesPerSec * pwfex->nBlockAlign;
hr = ::CreateAudioMediaType(pwfex, pmt, FALSE);
return hr;
}
/*HRESULT CVAudioStream::setAsNormal(CMediaType *pmt)
{
WAVEFORMATEX *pwfex;
pwfex = (WAVEFORMATEX *)pmt->AllocFormatBuffer(sizeof(WAVEFORMATEX));
ZeroMemory(pwfex, sizeof(WAVEFORMATEX));
if (NULL == pwfex) return E_OUTOFMEMORY;
return setupPwfex(pwfex, pmt);
}*/
HRESULT CVAudioStream::GetMediaType(int iPosition, CMediaType *pmt)
{
if (iPosition < 0) return E_INVALIDARG;
if (iPosition > 0) return VFW_S_NO_MORE_ITEMS;
if (iPosition == 0)
{
*pmt = m_mt;
return S_OK;
}
WAVEFORMATEX *pwfex = (WAVEFORMATEX *)pmt->AllocFormatBuffer(sizeof(WAVEFORMATEX));
setupPwfex(pwfex, pmt);
return S_OK;
}
HRESULT CVAudioStream::CheckMediaType(const CMediaType *pMediaType)
{
int cbFormat = pMediaType->cbFormat;
if (*pMediaType != m_mt) return E_INVALIDARG;
return S_OK;
}
const int WaveBufferChunkSize = 16 * 1024;
HRESULT CVAudioStream::DecideBufferSize(IMemAllocator *pAlloc, ALLOCATOR_PROPERTIES *pProperties)
{
CheckPointer(pAlloc, E_POINTER);
CheckPointer(pProperties, E_POINTER);
WAVEFORMATEX *pwfexCurrent = (WAVEFORMATEX*)m_mt.Format();
pProperties->cBuffers = 1;
pProperties->cbBuffer = expectedMaxBufferSize;
ALLOCATOR_PROPERTIES Actual;
HRESULT hr = pAlloc->SetProperties(pProperties, &Actual);
if (FAILED(hr)) return hr;
if (Actual.cbBuffer < pProperties->cbBuffer) return E_FAIL;
return NOERROR;
}
HRESULT CVAudioStream::OnThreadCreate()
{
//GetMediaType(0, &m_mt);
//HRESULT hr = LoopbackCaptureSetup();
//if (FAILED(hr)) return hr;
return NOERROR;
}
HRESULT STDMETHODCALLTYPE CVAudioStream::SetFormat(AM_MEDIA_TYPE *pmt)
{
if (!pmt) return S_OK;
if (CheckMediaType((CMediaType *)pmt) != S_OK) return E_FAIL;
m_mt = *pmt;
IPin* pin;
ConnectedTo(&pin);
if (pin)
{
IFilterGraph *pGraph = m_pParent->GetGraph();
pGraph->Reconnect(this);
}
return S_OK;
}
HRESULT STDMETHODCALLTYPE CVAudioStream::GetFormat(AM_MEDIA_TYPE **ppmt)
{
*ppmt = CreateMediaType(&m_mt);
return S_OK;
}
HRESULT STDMETHODCALLTYPE CVAudioStream::GetNumberOfCapabilities(int *piCount, int *piSize)
{
*piCount = 1;
*piSize = sizeof(AUDIO_STREAM_CONFIG_CAPS);
return S_OK;
}
HRESULT STDMETHODCALLTYPE CVAudioStream::GetStreamCaps(int iIndex, AM_MEDIA_TYPE **pmt, BYTE *pSCC)
{
if (iIndex < 0) return E_INVALIDARG;
if (iIndex > 0) return S_FALSE;
if (pSCC == NULL) return E_POINTER;
*pmt = CreateMediaType(&m_mt);
if (*pmt == NULL) return E_OUTOFMEMORY;
DECLARE_PTR(WAVEFORMATEX, pAudioFormat, (*pmt)->pbFormat);
AM_MEDIA_TYPE * pm = *pmt;
setupPwfex(pAudioFormat, pm);
AUDIO_STREAM_CONFIG_CAPS* pASCC = (AUDIO_STREAM_CONFIG_CAPS*)pSCC;
ZeroMemory(pSCC, sizeof(AUDIO_STREAM_CONFIG_CAPS));
pASCC->guid = MEDIATYPE_Audio;
pASCC->MaximumChannels = pAudioFormat->nChannels;
pASCC->MinimumChannels = pAudioFormat->nChannels;
pASCC->ChannelsGranularity = 1; // doesn't matter
pASCC->MaximumSampleFrequency = pAudioFormat->nSamplesPerSec;
pASCC->MinimumSampleFrequency = pAudioFormat->nSamplesPerSec;
pASCC->SampleFrequencyGranularity = 11025; // doesn't matter
pASCC->MaximumBitsPerSample = pAudioFormat->wBitsPerSample;
pASCC->MinimumBitsPerSample = pAudioFormat->wBitsPerSample;
pASCC->BitsPerSampleGranularity = 16; // doesn't matter
return S_OK;
}
HRESULT CVAudioStream::Set(REFGUID guidPropSet, DWORD dwID, void *pInstanceData, DWORD cbInstanceData, void *pPropData, DWORD cbPropData)
{
return E_NOTIMPL;
}
HRESULT CVAudioStream::Get(
REFGUID guidPropSet,
DWORD dwPropID,
void *pInstanceData,
DWORD cbInstanceData,
void *pPropData,
DWORD cbPropData,
DWORD *pcbReturned
)
{
if (guidPropSet != AMPROPSETID_Pin) return E_PROP_SET_UNSUPPORTED;
if (dwPropID != AMPROPERTY_PIN_CATEGORY) return E_PROP_ID_UNSUPPORTED;
if (pPropData == NULL && pcbReturned == NULL) return E_POINTER;
if (pcbReturned) *pcbReturned = sizeof(GUID);
if (pPropData == NULL) return S_OK;
if (cbPropData < sizeof(GUID)) return E_UNEXPECTED;
*(GUID *)pPropData = PIN_CATEGORY_CAPTURE;
return S_OK;
}
HRESULT CVAudioStream::QuerySupported(REFGUID guidPropSet, DWORD dwPropID, DWORD *pTypeSupport)
{
if (guidPropSet != AMPROPSETID_Pin) return E_PROP_SET_UNSUPPORTED;
if (dwPropID != AMPROPERTY_PIN_CATEGORY) return E_PROP_ID_UNSUPPORTED;
if (pTypeSupport) *pTypeSupport = KSPROPERTY_SUPPORT_GET;
return S_OK;
}
My first issue is when I insert the filter in GraphStudioNext and open its properties page. The Audio pin shows the following (incorrect) information:
majorType = GUID_NULL
subType = GUID_NULL
formattype = GUID_NULL
Of course I cannot connect nothing to that pin because is not valid.
I was expecting something like MEDIATYPE_Audio because I set up it:
DEFINE_GUID(CLSID_VirtualCam, 0x8e14549a, 0xdb61, 0x4309, 0xaf, 0xa1, 0x35, 0x78, 0xe9, 0x27, 0xe9, 0x33);
const AMOVIESETUP_MEDIATYPE AMSMediaTypesVideo =
{
&MEDIATYPE_Video,
&MEDIASUBTYPE_NULL
};
const AMOVIESETUP_MEDIATYPE AMSMediaTypesAudio =
{
&MEDIATYPE_Audio,
&MEDIASUBTYPE_NULL
};
const AMOVIESETUP_PIN AMSPinVCam[] =
{
{
L"Video", // Pin string name
FALSE, // Is it rendered
TRUE, // Is it an output
FALSE, // Can we have none
FALSE, // Can we have many
&CLSID_NULL, // Connects to filter
NULL, // Connects to pin
1, // Number of types
&AMSMediaTypesVideo // Pin Media types
},
{
L"Audio", // Pin string name
FALSE, // Is it rendered
TRUE, // Is it an output
FALSE, // Can we have none
FALSE, // Can we have many
&CLSID_NULL, // Connects to filter
NULL, // Connects to pin
1, // Number of types
&AMSMediaTypesAudio // Pin Media types
}
};
const AMOVIESETUP_FILTER AMSFilterVCam =
{
&CLSID_VirtualCam, // Filter CLSID
FILTER_NAME, // String name
MERIT_DO_NOT_USE, // Filter merit
2, // Number pins
AMSPinVCam // Pin details
};
CFactoryTemplate g_Templates[] =
{
{
FILTER_NAME,
&CLSID_VirtualCam,
CVCam::CreateInstance,
NULL,
&AMSFilterVCam
},
};
int g_cTemplates = sizeof(g_Templates) / sizeof(g_Templates[0]);
STDAPI RegisterFilters( BOOL bRegister )
{
HRESULT hr = NOERROR;
WCHAR achFileName[MAX_PATH];
char achTemp[MAX_PATH];
ASSERT(g_hInst != 0);
if( 0 == GetModuleFileNameA(g_hInst, achTemp, sizeof(achTemp))) return AmHresultFromWin32(GetLastError());
MultiByteToWideChar(CP_ACP, 0L, achTemp, lstrlenA(achTemp) + 1, achFileName, NUMELMS(achFileName));
hr = CoInitialize(0);
if(bRegister)
{
hr = AMovieSetupRegisterServer(CLSID_VirtualCam, FILTER_NAME, achFileName, L"Both", L"InprocServer32");
}
if( SUCCEEDED(hr) )
{
IFilterMapper2 *fm = 0;
hr = CreateComObject( CLSID_FilterMapper2, IID_IFilterMapper2, fm );
if( SUCCEEDED(hr) )
{
if(bRegister)
{
IMoniker *pMoniker = 0;
REGFILTER2 rf2;
rf2.dwVersion = 1;
rf2.dwMerit = MERIT_DO_NOT_USE;
rf2.cPins = 2;
rf2.rgPins = AMSPinVCam;
hr = fm->RegisterFilter(CLSID_VirtualCam, FILTER_NAME, &pMoniker, &CLSID_VideoInputDeviceCategory, NULL, &rf2);
}
else
{
hr = fm->UnregisterFilter(&CLSID_VideoInputDeviceCategory, 0, CLSID_VirtualCam);
}
}
if(fm) fm->Release();
}
if( SUCCEEDED(hr) && !bRegister ) hr = AMovieSetupUnregisterServer( CLSID_VirtualCam );
CoFreeUnusedLibraries();
CoUninitialize();
return hr;
}
Second issue: there's also a "Latency" tab but when I click on it GraphStudioNext hangs forever and the VS debugger (which is attached to that process) says nothing. What piece of code control this tab?
UPDATE
Solved first issue:
HRESULT CVAudioStream::GetMediaType(int iPosition, CMediaType *pmt)
{
if (iPosition < 0) return E_INVALIDARG;
if (iPosition > 0) return VFW_S_NO_MORE_ITEMS;
WAVEFORMATEX *pwfex = (WAVEFORMATEX *)pmt->AllocFormatBuffer(sizeof(WAVEFORMATEX));
setupPwfex(pwfex, pmt);
pmt->SetType(&MEDIATYPE_Audio);
pmt->SetFormatType(&FORMAT_WaveFormatEx);
pmt->SetTemporalCompression(FALSE);
pmt->SetSubtype(&MEDIASUBTYPE_PCM);
pmt->SetSampleSize(pwfex->nBlockAlign);
return S_OK;
}
Short version: Microsoft does not really offer an API to supply virtual audio device so that it's nicely accepted by the applications as if it is a real audio capture device.
If virtual video capture filters often work for historical reasons, it is not the case with audio. A kernel level driver that implements an audio device is the way to add an audio device that applications would recognize.
Latency tab shows up because you pretended that you are implementing IAMBufferNegotiation interface:
if (riid == _uuidof(IAMBufferNegotiation)) *ppv = (IAMBufferNegotiation*)this;
The implementation is likely to be incorrect, which results in certain unexpected behavior (freeze, crash etc).
Adding audio pin on the same filter is possible but might be not the best idea, if you expect the stream to be picked as an artificial source. It makes sense in general but real devices almost never expose audio streams like this.
Long story short, the only application which could utilize audio stream like this is the one you develop yourself: no well known application attempts to locate audio pin on the video source filter. For this reason implementation of
IAMStreamConfig and especially IKsPropertySet on such pin is useless.
You will not be able to register the filter under Audio Capture Sources category because you register a filter, and this filter exposes video output pin first, and only then there is some secondary audio. If you target an application that consumes audio via DirectShow (which is already pretty rare for the reasons beyond the scope of this question), you should rather develop a separate source filter. You of course can have the two filters talk to each other behind the scenes to deliver certain feed collaboratively, but in terms of DirectShow it is typical that the filters appear as independent.
...also real webcams expose two different filters and this is why in application like Skype we have to select both under video and audio devices.
Should it be better to create two completely different projects and filters: one for video and one for audio?
Real and typical camera:
Since "real" physical cameras are typically provided with kernel level drivers, their presence in DirectShow takes place through WDM Video Capture Filter which acts as a proxy and enumerates "DirectShow wrappers" of camera drivers under the same category Video Capture Sources where you would register virtual cameras.
That is, such design enables you to mix real and virtual cameras in the list of available devices, which DirectShow based application use when it comes to video capture. This approach has its limitations, which I described earlier e.g. in this question and referenced post Applicability of Virtual DirectShow Sources.
As DirectShow's successor Media Foundation have not had good reception in general, and in addition Media Foundation offers neither good backward compatibility nor video capture extensibility, a multitude of applications including Microsoft's own are still consuming video capture via DirectShow. Vice versa those who look into video capture API for Windows are also often interested in DirectShow and not the "current" API because of availability of samples and related information, API extensibility, application integration options.
It is not the case with audio, however. DirectShow audio capture was not top-notch already at the time DirectShow development stopped. Windows Vista introduces new API for audio WASAPI and DirectShow did not receive a respective connection to the new API, neither for audio capture nor for playback. Audio is simpler itself, and WASAPI was powerful and developer friendly, so developers started switching to the new API for audio related tasks. Much fewer applications use DirectShow for audio capture and your implementing virtual audio source is likely to be a miss: your device will remain "invisible" for applications consuming audio capture via WASAPI. Even if an application has a fallback code patch for Windows XP to do audio capture via DirectShow, it will hardly be a relief for you in newer OSes.
Follow up reading on audio on StackOverflow:
Directshow.net don't detect all mics in Windows 7
Write an audio source filter for use as Lync microphone
Windows Audio and Video Capture Software Paradigm
Also, you don't have to have separate projects for video and audio filters. You can mix them in the same project, they can just be independent filters registered separately.

C++ - DirectShow - Comparison between two images captured by webcam

I'm a newbie in the DirectShow world, and I just studied the simple "playcap" sample provided by Microsoft SDK Samples. With this little program I've been able to have a window with my webcam stream.
How can I take two shots from my webcam and compare them (even without saving them on the hard disk) to find which pixels are different?
I easily did this job using Win32API capture windows, but it was very slow, and I need it to be fast.
Thank you in advance, it is very important for my project.
You'd better search here for answer or look in samples for Sample Grabber Filter.
For more details you can write me directly here.
Add the Sample Grabber filter to the graph.
IBaseFilter *pSG_Filter;
hr = CoCreateInstance(
CLSID_SampleGrabber,
NULL,
CLSCTX_INPROC_SERVER,
IID_IBaseFilter,
(void**)&pSG_Filter
);
hr = pGraph->AddFilter(pSG_Filter, L"SampleGrab");
Add the Null Renderer filter to the graph.
IBaseFilter *pNull;
hr = CoCreateInstance(
CLSID_NullRenderer,
NULL,
CLSCTX_INPROC_SERVER,
IID_IBaseFilter,
(void**)&pNull
);
hr = pGraph->AddFilter(pNull, L"NullRender");
Now you can use the ICaptureGraphBuilder2::RenderStream method to connect all three filters in one method call, going from the still pin to the Sample Grabber, and from the Sample Grabber to the Null Renderer:
hr = pBuild->RenderStream(
&PIN_CATEGORY_STILL, // Connect this pin ...
&MEDIATYPE_Video, // with this media type ...
pCap, // on this filter ...
pSG_Filter, // to the Sample Grabber ...
pNull); // ... and finally to the Null Renderer.
Now use the ISampleGrabber interface to configure the Sample Grabber so that it buffers samples:
ISampleGrabber *pSG = NULL;
hr = pSG_Filter->QueryInterface(IID_ISampleGrabber, (void**)&pSG);
if (SUCCEEDED(hr))
{
hr = pSG->SetOneShot(FALSE);
hr = pSG->SetBufferSamples(TRUE);
...
Now, you should look at method ISampleGrabber::SetOneShot and maybe set TRUE there.
Set the callback interface with a pointer to your callback object:
hr = pSG->SetCallback(&g_StillCapCB, 0); // 0 = Use the SampleCB callback method.
Get the media type that the still pin used to connect with the Sample Grabber:
// Store the media type for later use.
AM_MEDIA_TYPE g_StillMediaType;
hr = pSG->GetConnectedMediaType(&g_StillMediaType);
pSG->Release();
This media type will contain the BITMAPINFOHEADER structure that defines the format of the still image.
What follows is an example of the callback class. Note that the class implements IUnknown, which it inherits through the ISampleGrabber interface, but it does not keep a reference count. This is safe because the application creates the object on the stack, and the object remains in scope throughout the lifetime of the filter graph.
All of the work happens in the BufferCB method, which is called by the Sample Grabber whenever it gets a new sample. In the following example, the method writes the bitmap to a file:
class SampleGrabberCallback : public ISampleGrabberCB
{
public:
// Fake referance counting.
STDMETHODIMP_(ULONG) AddRef() { return 1; }
STDMETHODIMP_(ULONG) Release() { return 2; }
STDMETHODIMP QueryInterface(REFIID riid, void **ppvObject)
{
if (NULL == ppvObject) return E_POINTER;
if (riid == __uuidof(IUnknown))
{
*ppvObject = static_cast<IUnknown*>(this);
return S_OK;
}
if (riid == __uuidof(ISampleGrabberCB))
{
*ppvObject = static_cast<ISampleGrabberCB*>(this);
return S_OK;
}
return E_NOTIMPL;
}
STDMETHODIMP SampleCB(double Time, IMediaSample *pSample)
{
return E_NOTIMPL;
}
STDMETHODIMP BufferCB(double Time, BYTE *pBuffer, long BufferLen)
{
if ((g_StillMediaType.majortype != MEDIATYPE_Video) ||
(g_StillMediaType.formattype != FORMAT_VideoInfo) ||
(g_StillMediaType.cbFormat < sizeof(VIDEOINFOHEADER)) ||
(g_StillMediaType.pbFormat == NULL))
{
return VFW_E_INVALIDMEDIATYPE;
}
HANDLE hf = CreateFile("C:\\Example.bmp", GENERIC_WRITE,
FILE_SHARE_WRITE, NULL, CREATE_ALWAYS, 0, NULL);
if (hf == INVALID_HANDLE_VALUE)
{
return E_FAIL;
}
long cbBitmapInfoSize = g_StillMediaType.cbFormat - SIZE_PREHEADER;
VIDEOINFOHEADER *pVideoHeader =
(VIDEOINFOHEADER*)g_StillMediaType.pbFormat;
BITMAPFILEHEADER bfh;
ZeroMemory(&bfh, sizeof(bfh));
bfh.bfType = 'MB'; // Little-endian for "BM".
bfh.bfSize = sizeof( bfh ) + BufferLen + cbBitmapInfoSize;
bfh.bfOffBits = sizeof( BITMAPFILEHEADER ) + cbBitmapInfoSize;
// Write the file header.
DWORD dwWritten = 0;
WriteFile( hf, &bfh, sizeof( bfh ), &dwWritten, NULL );
WriteFile(hf, HEADER(pVideoHeader), cbBitmapInfoSize, &dwWritten, NULL);
WriteFile( hf, pBuffer, BufferLen, &dwWritten, NULL );
CloseHandle( hf );
return S_OK;
}
};
Free the media type before the application exits:
// On exit, remember to release the media type.
FreeMediaType(g_StillMediaType);

Detect keyboard presence in Windows 8 desktop program

For Metro apps there's Windows.Devices.Input.KeyboardCapabilities.KeyboardPresent.
Is there a way for Windows 8 desktop programs to detect whether a physical keyboard is present?
It's a bit fiddly and I don't know whether the approach I'm proposing will work in all cases, but this is the approach I ended up using:
Use SetupDiGetClassDevs to find all the keyboard devices.
Use SetupDiGetDeviceRegistryProperty to read some keyboard device properties to ignore PS/2 keyboards
Check for touch support since Win 8 touch devices always appear to have an additional HID Keyboard device.
One of the problems with PS/2 ports is that they show up as always being a keyboard device, even if nothing is plugged in. I just managed the problem by assuming no one will ever use a PS/2 keyboard and I filtered them out. I've include two separate checks to try and figure if a keyboard is PS/2 or not. I don't know how reliable either one is, but both individually seem to work okay for the machines I've tested.
The other problem (#3) is that when Windows 8 machines have touch support they have an extra HID keyboard device which you need to ignore.
PS: Something I just realised, my code is using a "buffer" class for the property queries. I left it out to keep just the relevant code, but you'll need to replace that with some appropriate buffer/memory management.
#include <algorithm>
#include <cfgmgr32.h>
#include <Setupapi.h>
#include <boost/tokenizer.hpp>
#include <boost/algorithm/string.hpp>
struct KeyboardState
{
KeyboardState() : isPS2Keyboard(false)
{ }
std::wstring deviceName; // The name of the keyboard device.
bool isPS2Keyboard; // Whether the keyboard is a PS/2 keyboard.
};
void GetKeyboardState(std::vector<KeyboardState>& result)
{
LPCWSTR PS2ServiceName = L"i8042prt";
LPCWSTR PS2CompatibleId = L"*PNP0303";
const GUID KEYBOARD_CLASS_GUID = { 0x4D36E96B, 0xE325, 0x11CE, { 0xBF, 0xC1, 0x08, 0x00, 0x2B, 0xE1, 0x03, 0x18 } };
// Query for all the keyboard devices.
HDEVINFO hDevInfo = SetupDiGetClassDevs(&KEYBOARD_CLASS_GUID, NULL, NULL, DIGCF_PRESENT);
if (hDevInfo == INVALID_HANDLE_VALUE)
{
return;
}
//
// Enumerate all the keyboards and figure out if any are PS/2 keyboards.
//
bool hasKeyboard = false;
for (int i = 0;; ++i)
{
SP_DEVINFO_DATA deviceInfoData = { 0 };
deviceInfoData.cbSize = sizeof (deviceInfoData);
if (!SetupDiEnumDeviceInfo(hDevInfo, i, &deviceInfoData))
{
break;
}
KeyboardState currentKeyboard;
// Get the device ID
WCHAR szDeviceID[MAX_DEVICE_ID_LEN];
CONFIGRET status = CM_Get_Device_ID(deviceInfoData.DevInst, szDeviceID, MAX_DEVICE_ID_LEN, 0);
if (status == CR_SUCCESS)
{
currentKeyboard.deviceName = szDeviceID;
}
//
// 1) First check the service name. If we find this device has the PS/2 service name then it is a PS/2
// keyboard.
//
DWORD size = 0;
if (!SetupDiGetDeviceRegistryProperty(hDevInfo, &deviceInfoData, SPDRP_SERVICE, NULL, NULL, NULL, &size))
{
try
{
buffer buf(size);
if (SetupDiGetDeviceRegistryProperty(hDevInfo, &deviceInfoData, SPDRP_SERVICE, NULL, buf.get(), buf.size(), &size))
{
LPCWSTR serviceName = (LPCWSTR)buf.get();
if (boost::iequals(serviceName, PS2ServiceName))
{
currentKeyboard.isPS2Keyboard = true;
}
}
}
catch (std::bad_alloc)
{
}
}
//
// 2) Fallback check for a PS/2 keyboard, if CompatibleIDs contains *PNP0303 then the keyboard is a PS/2 keyboard.
//
size = 0;
if (!currentKeyboard.isPS2Keyboard && !SetupDiGetDeviceRegistryProperty(hDevInfo, &deviceInfoData, SPDRP_COMPATIBLEIDS, NULL, NULL, NULL, &size))
{
try
{
buffer buf(size);
if (SetupDiGetDeviceRegistryProperty(hDevInfo, &deviceInfoData, SPDRP_COMPATIBLEIDS, NULL, buf.get(), buf.size(), &size))
{
std::wstring value = (LPCWSTR)buf.get();
// Split the REG_MULTI_SZ values into separate strings.
boost::char_separator<wchar_t> sep(L"\0");
typedef boost::tokenizer< boost::char_separator<wchar_t>, std::wstring::const_iterator, std::wstring > WStringTokenzier;
WStringTokenzier tokens(value, sep);
// Look for the "*PNP0303" ID that indicates a PS2 keyboard device.
for (WStringTokenzier::iterator itr = tokens.begin(); itr != tokens.end(); ++itr)
{
if (boost::iequals(itr->c_str(), PS2CompatibleId))
{
currentKeyboard.isPS2Keyboard = true;
break;
}
}
}
}
catch (std::bad_alloc)
{
}
}
result.push_back(currentKeyboard);
}
}
bool IsNonPS2Keyboard(const KeyboardState& keyboard)
{
return !keyboard.isPS2Keyboard;
}
bool HasKeyboard()
{
std::vector<KeyboardState> keyboards;
GetKeyboardState(keyboards);
int countOfNonPs2Keyboards = std::count_if(keyboards.begin(), keyboards.end(), IsNonPS2Keyboard);
// Win 8 with touch support appear to always have an extra HID keyboard device which we
// want to ignore.
if ((NID_INTEGRATED_TOUCH & GetSystemMetrics(SM_DIGITIZER)) == NID_INTEGRATED_TOUCH)
{
return countOfNonPs2Keyboards > 1;
}
else
{
return countOfNonPs2Keyboards > 0;
}
}
On Windows 10 this API is part of the UWP API and can be called from Desktop applications just fine.
To call it from C# (or other .NET languages) you need to add a few references to the project files:
<Reference Include="System.Runtime.WindowsRuntime" />
<Reference Include="Windows.Foundation.FoundationContract">
<HintPath>C:\Program Files (x86)\Windows Kits\10\References\10.0.16299.0\Windows.Foundation.FoundationContract\3.0.0.0\Windows.Foundation.FoundationContract.winmd</HintPath>
<Private>False</Private>
</Reference>
<Reference Include="Windows.Foundation.UniversalApiContract">
<HintPath>C:\Program Files (x86)\Windows Kits\10\References\10.0.16299.0\Windows.Foundation.UniversalApiContract\5.0.0.0\Windows.Foundation.UniversalApiContract.winmd</HintPath>
<Private>False</Private>
</Reference>
The first reference will be resolved against the GAC, the other two are in your VS installation (you can chose a different version if you want). Setting Private to False means to not deploy a Local Copy of those assemblies.
Console.WriteLine(new Windows.Devices.Input.KeyboardCapabilities().KeyboardPresent != 0 ? "keyboard available" : "no keyboard");
In C++ you can do it as follows:
#include <roapi.h>
#include <wrl.h>
#include <windows.devices.input.h>
#pragma comment(lib, "runtimeobject")
int APIENTRY wWinMain(
_In_ HINSTANCE hInstance,
_In_opt_ HINSTANCE hPrevInstance,
_In_ LPWSTR lpCmdLine,
_In_ int nCmdShow)
{
RoInitialize(RO_INIT_MULTITHREADED);
{
INT32 isKeyboardAvailable;
Microsoft::WRL::ComPtr<ABI::Windows::Devices::Input::IKeyboardCapabilities> pKeyboardCapabilities;
Microsoft::WRL::Wrappers::HStringReference KeyboardClass(RuntimeClass_Windows_Devices_Input_KeyboardCapabilities);
if (SUCCEEDED(RoActivateInstance(KeyboardClass.Get(), &pKeyboardCapabilities)) &&
SUCCEEDED(pKeyboardCapabilities->get_KeyboardPresent(&isKeyboardAvailable)))
{
OutputDebugStringW(isKeyboardAvailable ? L"keyboard available\n" : L"no keyboard\n");
}
}
RoUninitialize();
}
Simple : Look into HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\kbdclass

How to detect if a Microphone is present

I just had a very long tech support call because a customer didn't have a Mic on their laptop. (Stupid me: they said they'd used the mic earlier and I have never heard of a laptop not having a Mic).
I'm wondering if there is a way to detect whether there is a Microphone (recording capability) on Windows XP, Vista, 7.
(I've got error handling enabled and it logs the error and then exits the Function but the app just crashes on Windows 7 if there's no Microphone. )
I'd use IMMDeviceEnumerator::GetDefaultAudioEndpoint - this returns the default audio device for the specified role and data flow.
In particular, you would use:
CComPtr<IMMDeviceEnumerator> pEnumerator;
CComPtr<IMMDevice> pDevice;
hr = CoCreateInstance(__uuidof(MMDeviceEnumerator), NULL,
CLSCTX_ALL, IID_PPV_ARGS(&pEnumerator));
if (SUCCEEDED(hr))
{
hr = pEnumerator->GetDefaultAudioEndpoint(eCapture, eConsole, &pDevice);
}
if (!pDevice || hr == ERROR_NOT_FOUND)
{
// no microphone
}
Check out System Tray Audio Device Switcher
In this VB source code you will an example on how to enumerate audio I/O devices.
in C++
#include "stdafx.h"
#include "Mmdeviceapi.h"
#include <atlbase.h>
int _tmain(int argc, _TCHAR* argv[])
{
CoInitializeEx(NULL, COINIT_MULTITHREADED);
CComPtr<IMMDeviceEnumerator> pEnumerator = NULL;
CComPtr<IMMDevice> pDevice;
const CLSID CLSID_MMDeviceEnumerator = __uuidof(MMDeviceEnumerator);
const IID IID_IMMDeviceEnumerator = __uuidof(IMMDeviceEnumerator);
HRESULT hr = CoCreateInstance(
CLSID_MMDeviceEnumerator, NULL,
CLSCTX_ALL, IID_IMMDeviceEnumerator,
(void**)&pEnumerator);
if (FAILED(hr))
{
printf("failed");
}
else
{
hr = pEnumerator->GetDefaultAudioEndpoint(eCapture, eConsole, &pDevice);
if (!pDevice || hr == ERROR_NOT_FOUND)
{
printf("no microphone");
}
else
{
printf("microphone present");
}
}
return 0;
}
I think the only way you will be able to do this in VB 6 is through Direct X:
http://msdn.microsoft.com/en-us/library/bb318770(VS.85).aspx
You can check this out:
http://msdn.microsoft.com/en-us/library/bb280815(VS.85).aspx
CaptureDevices Collection Class (Microsoft.DirectX.DirectSound)
http://msdn.microsoft.com/en-us/library/ms810619.aspx
you can also call dxdiag..

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