Windows: how to get cameras supported resolutions? - c++

Question

So to get cameras list and let user select one (C++, Boost, dshow, windows) I use such code:
#include "StdAfx.h"
#include "list.h"
#include <windows.h>
#include <dshow.h>
#include <boost/lexical_cast.hpp>
HRESULT CamerasList::EnumerateDevices( REFGUID category, IEnumMoniker **ppEnum )
{
// Create the System Device Enumerator.
ICreateDevEnum *pDevEnum;
HRESULT hr = CoCreateInstance(CLSID_SystemDeviceEnum, NULL,
CLSCTX_INPROC_SERVER, IID_PPV_ARGS(&pDevEnum));
if (SUCCEEDED(hr))
{
// Create an enumerator for the category.
hr = pDevEnum->CreateClassEnumerator(category, ppEnum, 0);
if (hr == S_FALSE)
{
hr = VFW_E_NOT_FOUND; // The category is empty. Treat as an error.
}
pDevEnum->Release();
}
return hr;
}
int CamerasList::SelectFromList()
{ int i = 0;
int SelectedIndex;
IEnumMoniker *pEnum;
printf("\nLet us select video device\n");
printf("Available Capture Devices are:\n");
HRESULT hr;
hr = EnumerateDevices(CLSID_VideoInputDeviceCategory, &pEnum);
if (SUCCEEDED(hr))
{
IMoniker *pMoniker = NULL;
while (pEnum->Next(1, &pMoniker, NULL) == S_OK)
{
IPropertyBag *pPropBag;
HRESULT hr = pMoniker->BindToStorage(0, 0, IID_PPV_ARGS(&pPropBag));
if (FAILED(hr))
{
pMoniker->Release();
continue;
}
VARIANT var;
VariantInit(&var);
// Get description or friendly name.
hr = pPropBag->Read(L"Description", &var, 0);
if (FAILED(hr))
{
hr = pPropBag->Read(L"FriendlyName", &var, 0);
}
if (SUCCEEDED(hr))
{
std::cout << i;
printf(") %S\n", var.bstrVal);
i++;
VariantClear(&var);
}
hr = pPropBag->Write(L"FriendlyName", &var);
pPropBag->Release();
pMoniker->Release();
}
SelectedIndex = 999;
if (i <= 0)
{
cout <<"No devices found. \n " << endl;
//cout <<"Please restart application." << endl;
//cin.get();
//Sleep(999999);
return 999;
}else if(i == 1){
cout <<"Default device will be used\n" << std::endl;
SelectedIndex = 0;
}else{
while(SelectedIndex > i-1 || SelectedIndex < 0)
{
try{
std::string s;
std::getline( cin, s, '\n' );
SelectedIndex = boost::lexical_cast<int>(s);
}
catch(std::exception& e){
std::cout <<"please input index from 0 to " << i-1 << std::endl;
SelectedIndex = 999;
}
}}
pEnum->Release();
}else
{
printf("no Video Devices found. \n") ;
//cout <<"Please restart application." << endl;
//cin.get();
//Sleep(999999);
return 999;
}
return SelectedIndex;
}
I need to somehow get list of camera supported resolutions for selected camera. How to do such thing?

Answer 1

Assuming that you've added the capture source filter to the graph:
One method is to get the IAMStreamConfig interface of the capture filter's output pin and then call the IAMStreamConfig::GetNumberOfCapabilities to get the number of format capabilities supported by the device. You can iterate over all formats by calling the IAMStreamConfig::GetStreamCaps with the appropriate indices.

Answer 2

You can get supported resolutions without adding the capture source to a filter graph. You need to:
bind the device moniker to a base filter
get an output pin from that filter
enumerate over media types of that output pin
Here is how to enumerate the media types given a media type enumerator:
AM_MEDIA_TYPE* mediaType = NULL;
VIDEOINFOHEADER* videoInfoHeader = NULL;
while (S_OK == mediaTypesEnumerator->Next(1, &mediaType, NULL))
{
if ((mediaType->formattype == FORMAT_VideoInfo) &&
(mediaType->cbFormat >= sizeof(VIDEOINFOHEADER)) &&
(mediaType->pbFormat != NULL))
{
videoInfoHeader = (VIDEOINFOHEADER*)mediaType->pbFormat;
videoInfoHeader->bmiHeader.biWidth; // Supported width
videoInfoHeader->bmiHeader.biHeight; // Supported height
}
FreeMediaType(*mediaType);
}