Le 16 juin 2016 8:37 PM, "Duncan Palmer" <<a href="mailto:dunk.palmer@gmail.com">dunk.palmer@gmail.com</a>> a écrit : > > This problem is caused by the videobox element, which I had been using because I needed Y444 support at one point. I don't now, and can use videocrop instead, which doesn't exhibit this issue. If not already done, please file a bug. Though in general videobox is slow and can be replaced with crop and compositor. > > On 16 June 2016 at 15:41, Duncan Palmer <<a href="mailto:dunk.palmer@gmail.com">dunk.palmer@gmail.com</a>> wrote: >> >> Hi, >> >> I have a pipeline I use to compose a video stream from multiple cameras. I've found a problem whereby blacks appear as 'flickery white' in the resulting image. This problem only appears when I blend using pixel formats which contain an alpha channel, and using images below a certain height. >> >> The following example feeds a 1280x577 stream to the compositor, and does not exhibit the problem; >> >> gst-launch-1.0 uridecodebin uri=file://`pwd`/b.1.mkv ! videobox top=143 ! videorate ! 'video/x-raw,framerate=25/1,format=AYUV' ! compositor ! glimagesink >> >> The following example feeds a 1280x576 stream to the compositor, and does exhibit the problem (the '576' is a bit of a red flag perhaps?). >> >> gst-launch-1.0 uridecodebin uri=file://`pwd`/b.1.mkv ! videobox top=144 ! videorate ! 'video/x-raw,framerate=25/1,format=AYUV' ! compositor ! glimagesink >> >> I'm still digging, but feel this could take some time. Can anyone offer suggestions or point me in a direction for investigation? The problem occurs with both the software and gl compositors. >> >> Note: I force the used of an alpha pixel format in the pipeline above, to produce a small example, but in practice I insert the alpha element. I'm also showing only one video source; in practice I use more. >> >> Cheers, >> Dunk >> >> >> > > > _______________________________________________ > gstreamer-devel mailing list > <a href="mailto:gstreamer-devel@lists.freedesktop.org">gstreamer-devel@lists.freedesktop.org</a> > <a href="https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel">https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel</a> >