Hello, I'm currently developing a source plugin that gets ISO MP4 streams from a server. These streams are the same video, but with different bitrate/resolution, hence different quality. I need to be able to change the stream quality, seamlessly, while the gstreamer pipeline is playing. The typical pipeline looks like this: source ! qtdemux ! ffdec_h264 ! ffmpegcolorspace ! xvimagesink I already tried 2 solutions for the change to take effect, but with no luck: 1/ send the new MP4 file header (ftyp+moov boxes), then the movie fragments (moof+mdat boxes). The problem is that qtdemux thinks it's a new video stream, hence creates a new source video pad. 2/ don't send the new MP4 header, simply send the new movie fragments. Nor qtdemux or ffdec_h264 notice the change, ffdec_h264 produces decoding errors, the output video is scrambled. Do you have any idea how I can achieve this? Cheers, Christophe Dongieux.