This is an old problem but a constant one. Every video I render seems to "jump" right at the beginning. Sometimes it's almost unnoticeable & at the beginning I thought it was just the player (e.g. VLC) just taking a frame or two to load properly, but it only happens with ADM-rendered videos.
Does anyone else get this and do you have a solution?
I never observed such behaviour. What do you understand by "render" exactly? Saving videos in copy mode? Reencoding? Using which codec? What are the properties of the source video? Please provide at least some info, better a sample (if necessary, both a sample of the source and the target video). The version of Avidemux you are referring to must be at least the latest release, better the latest nightly (http://avidemux.org/nightly/).
Perhaps dropped frames, while
- presented incomplete video data (partial frame information) is not 1st key frame?
- possible null frame?
- ....