How to list camera available video resolution
if I have more than one camera attached to my PC ... I want to know the best available resolutions for a specific camera ...
for example some cameras are HD or FullHD (1,280×720 pixels (720p) or 1,920×1,080 pixels (1080i/1080p)) or the most common are web cameras....
I want to know at least the best video mode th开发者_如何学Cat the camera work properly...(the mode that the camera made to work with)
my work is on WPF using C# (I am using Directshow)
thanks in advance
This is a code that I wrote, its working perfectly for me
public static List<Point> GetAllAvailableResolution(DsDevice vidDev)
{
try
{
int hr;
int max = 0;
int bitCount = 0;
IBaseFilter sourceFilter = null;
var m_FilterGraph2 = new FilterGraph() as IFilterGraph2;
hr = m_FilterGraph2.AddSourceFilterForMoniker(vidDev.Mon, null, vidDev.Name, out sourceFilter);
var pRaw2 = DsFindPin.ByCategory(sourceFilter, PinCategory.Capture, 0);
var AvailableResolutions = new List<Point>();
VideoInfoHeader v = new VideoInfoHeader();
IEnumMediaTypes mediaTypeEnum;
hr = pRaw2.EnumMediaTypes(out mediaTypeEnum);
AMMediaType[] mediaTypes = new AMMediaType[1];
IntPtr fetched = IntPtr.Zero;
hr = mediaTypeEnum.Next(1, mediaTypes, fetched);
while (fetched != null && mediaTypes[0] != null)
{
Marshal.PtrToStructure(mediaTypes[0].formatPtr, v);
if (v.BmiHeader.Size != 0 && v.BmiHeader.BitCount != 0)
{
if (v.BmiHeader.BitCount > bitCount)
{
AvailableResolutions.Clear();
max = 0;
bitCount = v.BmiHeader.BitCount;
}
AvailableResolutions.Add(new Point(v.BmiHeader.Width, v.BmiHeader.Height));
if (v.BmiHeader.Width > max || v.BmiHeader.Height > max)
max = (Math.Max(v.BmiHeader.Width, v.BmiHeader.Height));
}
hr = mediaTypeEnum.Next(1, mediaTypes, fetched);
}
return AvailableResolutions;
}
catch (Exception ex)
{
Log(ex);
return new List<Point>();
}
}
(E.g. this can be added to VideoCaptureElement in WPF-MediaKit)
i use this to get max frame size, just change to suit your needs ;)
private Point GetMaxFrameSize(IPin pStill)
{
VideoInfoHeader v;
IAMStreamConfig videoStreamConfig = pStill as IAMStreamConfig;
int iCount = 0, iSize = 0;
videoStreamConfig.GetNumberOfCapabilities(out iCount, out iSize);
IntPtr TaskMemPointer = Marshal.AllocCoTaskMem(iSize);
int iMaxHeight = 0;
int iMaxWidth = 0;
for (int iFormat = 0; iFormat < iCount; iFormat++)
{
AMMediaType pmtConfig = null;
IntPtr ptr = IntPtr.Zero;
videoStreamConfig.GetStreamCaps(iFormat, out pmtConfig, TaskMemPointer);
v = (VideoInfoHeader)Marshal.PtrToStructure(pmtConfig.formatPtr, typeof(VideoInfoHeader));
if (v.BmiHeader.Width > iMaxWidth)
{
iMaxWidth = v.BmiHeader.Width;
iMaxHeight = v.BmiHeader.Height;
}
DsUtils.FreeAMMediaType(pmtConfig);
}
Marshal.FreeCoTaskMem(TaskMemPointer);
return new Point(iMaxWidth, iMaxHeight);
}
/// <summary>
/// Free the nested structures and release any
/// COM objects within an AMMediaType struct.
/// </summary>
public static void FreeAMMediaType(AMMediaType mediaType)
{
if (mediaType != null)
{
if (mediaType.formatSize != 0)
{
Marshal.FreeCoTaskMem(mediaType.formatPtr);
mediaType.formatSize = 0;
mediaType.formatPtr = IntPtr.Zero;
}
if (mediaType.unkPtr != IntPtr.Zero)
{
Marshal.Release(mediaType.unkPtr);
mediaType.unkPtr = IntPtr.Zero;
}
}
}
According to this webpage: http://www.e-consystems.com/blog/camera/?p=651, you should use this call for getting the capabilities of this device:
g_DShowCaptureGraph.GetNumberOfCapabilities(nStream, &iCount, &iSize);
g_DShowCaptureGraph.GetStreamCaps(nStream,iFormat, &pmtConfig, (BYTE*)&scc);
They are C++, however.
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