I'm trying to generate compressed video from within an OSG programme (the Flightgear flight simulator), getting RGB24 frames for the main window using osg::Image::readPixels(), converting to YUV420P using sws_scale() and then sending to an ffmpeg encoder+muxer similarly to the code in ffmpeg/doc/examples/muxing.c. However i'm having trouble finding an encoder/container combination that generates video that VLC can cope with, and works with the variable frame rate and also copes with the user resizing the window size while video is being generated. To cope with the variable frame rate i write to .pts and call av_packet_rescale_ts() as in the ffmpeg examples. To cope with changes to the frame size, i flush the current AVCodecContext's output, delete it and create a new AVCodecContext using the new width and height. I haven't seen this done in any examples, but it seems to work in at least a couple of cases. I'd be grateful if anyone could suggest a better way. So far i've found only three codec/container combinations that come close to what i want: codec=mpeg2video container=mpeg Works perfectly on Linux and OpenBSD, coping with variable frame rate and frame size, but compression appears to be very poor - needs 2Mb/s for decent quality output. codec=libx264 container=mpeg Appears to work with variable frame rate and size, but vlc always seems to freeze after a few seconds when replaying the video. codec=libvpx container=ogv vlc-3.0.12 on OpenBSD works fine except it opens a new window whenever the frame size changes. vlc-3.0.16 on Linux complains about 'more than 5 seconds of late video', pauses and shows corrupted frames. Does anyone have any advice on how i can make things work better? One other issue - i often see lots of output lines looking like: buffer underflow st=0 bufi=489 size=1689 Does anyone know what i can do to stop these messages appearing? Could they be related to the problems that vlc has for some of the generated videos? Just in case it's useful, here is my test code: http://op59.net/video-test.cpp It has more info on how various other codec/container combinations don't work for me. Many thanks for any help, - Jules -- http://op59.net