问题
I have 2 streams, one for Preview and one for capture in my DirectShow application. Right now, we observe that the Preview is slow for 1080P video and 1280*720 video. I would like to know if we have any method to have different resolutions for the capture and preview streams. If we have any, I can use the high resolution at capture side alone and at Preview, I am OK to display low resolutions.
Thanks
回答1:
You can connect the capture output to a Infinite Tee filter. Use one output of the tee filter to capture, connect the second output to a resize filter, and use that to preview.
On some hardware you can use preview output directly in a different resolution. But not all hardware supports that. for example some hardware does not scale the preview, so if you use a lower resolution, you only see the top left part of the video. And other hardware does not have a preview pin at all...
来源：https://stackoverflow.com/questions/10717662/can-we-have-different-resolutions-for-preview-and-capture-of-the-same-directshow