directshow

问题 I am new at DirectShow and found one example to capture when i ran two instances of this app it throws exceptions like camera is already in use.I having a requirement that the same camera will be shared by two Applications. Is it possible to acheive this using any filters Thanks in advance 回答1: DirectShow web cameras are typically exclusive use resources, applications cannot share them. One solution is to use a virtual camera software that creates a virtual device available to many apps,

问题 I have filters in Graphedit whose settings can be changed. I have a usb webcam which i can go to its properties and make it stream at different sizes, but im not sure how i would change these types of options programmatically without popping up the actual webcam property box. I want to keep it stream lined in a sense. .QueryFilterInfo() didn't give me any access to those types of options, and neither did .QueryPinInfo() Is there a way to get access to these options in C#? Update: http:/

问题 I have been using VMR9 to render a YUV video stream. I had some performance concern so I run a profiler and have discovered that function named _yvRgb24 takes up to 25% of CPU time. With further investigations I discovered that VMR9 uses that function to render my video stream. Does VMR9 convert my YUV video to RGB24 before rendering it? Can't it do the rendering right away? Conversion algorithm does not seem to be fast. I am using MEDIASUBTYPE_IYUV as output type for VMR9. 回答1: VMR-9 is

问题 I am creating a program that will record microphone audio and convert it into mp3 using the DirectShow API in Visual C++. There is no built in filter to convert to convert audio into MPEG Layer 3 i.e. MP3 so i want to send the mic buffer to an external library called as LAME , it will convert the data in MP3 and then i can write it to a file using a file writer. But the problem is that i dont know how to access the buffer of the microphone , please help me i am new in directshow programming..

问题 I'm writing a small application on C# (Winforms) where I am accessing a Webcam to capture some images. Does anyone know if it's possible to access and set the webcam's properties like gain, brightness and exposure using c#? (Don't pop-up Webcam's own Properties window) I've tried using the DirectShow library and it only allows me to set the exposure but no the gain nor brightness. Cheers in advance 回答1: You can set them using IAMVideoProcAmp::Set method, the settable properties include:

问题 Here is ffmpeg DirectShow options DirectShow video device options Pin "Capture" pixel_format=yuyv422 min s=720x480 fps=59.9402 max s=720x480 fps=59.9402 pixel_format=yuyv422 min s=720x480 fps=29.97 max s=720x480 fps=29.97 pixel_format=yuyv422 min s=720x576 fps=50 max s=720x576 fps=50 pixel_format=yuyv422 min s=720x576 fps=25 max s=720x576 fps=25 pixel_format=yuyv422 min s=640x480 fps=59.9402 max s=640x480 fps=59.9402 pixel_format=yuyv422 min s=1920x1080 fps=29.97 max s=1920x1080 fps=29.97

问题 Starting from the great example of Capture Source Filter here I wrote my own input capture device that works fine in Graph Studio Next, but it's not shown as a capture device (i.e. webcam) in application like Skype or similar. Because I want to understand what's happening I ask you to help me to find out what those application need to show such a device. Some relevant code: dll.cpp DEFINE_GUID(CLSID_VirtualCam, 0x8e14549a, 0xdb61, 0x4309, 0xaf, 0xa1, 0x35, 0x78, 0xe9, 0x27, 0xe9, 0x33); const

问题 I had create a simple windows form which display a video with Microsoft.DirectX.AudioVideoPlayback. When the video load to the panel, it pop up for milliseconds a activemovie window. How i could fix it because it is annoy every time start playing a video throws this activemovie window. It is like the application have delay. Here is my code : string path = Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location), @"Photos\test.avi"); var ofd = path; var video = new Video

问题 Why do all the new video/media container formats provide very little support for media foundation and more for DirectShow knowing that DirectShow is dying. 回答1: Because Media Foundation offers inferior feature set and availability to DirectShow. DirectShow is primary API for formats and codecs in Windows, nevertheless Microsoft stopped its development almost 10 years ago. The extensibility of this API is so good, and it is still so well applicable to multimedia tasks and processing. 来源： https

问题 I am using the excellent GMFBridge directshow family of filters to great effect, allowing me to close a video recording graph and open a new one, with no data-loss. My original source graph was capturing live video from standard video and audio inputs. There is an undocumented method on the GMFBridgeController filter named SetLiveTiming() . From the name, I figured that this should be set to true if we are capturing from a Live graph (not from a file) as is my case. I set this value to true