Call IMFMediaTypeHandler::SetCurrentMediaType with the modified media type.Set the MF_MT_FRAME attribute on the media type to specify the desired frame rate.The device might support other frame rates within this range. This values give the range of supported frame rates. Query the media type for the MF_MT_FRAME_RATE_RANGE_MAX and MF_MT_FRAME_RATE_RANGE_MIN attributes.Select the desired output format from the list.Enumerate the capture formats, as described in How to Set the Video Capture Format.Call IMFStreamDescriptor::GetMediaTypeHandler on the stream descriptor.Call IMFPresentationDescriptor::GetStreamDescriptorByIndex to get the stream descriptor for the video stream.Call IMFMediaSource::CreatePresentationDescriptor on the media source to get the presentation descriptor.Create the media source for the capture device.For example, at larger frame sizes, the maximum frame rate might be reduced. The range can vary depending on the capture format. If this information is available, the minimum and maximum frame rates are stored as media type attributes: Attribute A video capture device might support a range of frame rates.
0 kommentar(er)
