Trev Jackson

Thanks, that worked.

If it helps to have the original video file I've uploaded it to: http://www.staffordengineeringsystems.co.uk/Data/Laser/20260504_120205.mp4

Apart from the frames being rotated by -90 degrees (making the video match the angle the phone was at during the recording), the conversion has made no difference in the behaviour of Cinelerra - with the compositor still showing the next frame rather than the current frame.

frame timing different in compositor window

I don't know if it is related to the errors/warnings mentioned above but on some of the videos the compositor window doesn't update when I select a time position in the main program window (closing and re-opening the program sometimes fixes it).

h264 using thread count greater than 16 warning