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Source video missing keyframes?  



Hi everyone,


I am working on a concert video, and the source video appears to be low on keyframes (I think, I don't really know much about the technical aspects).

I've set in/out points around the segment that I want to render out, and in between I've trimmed out a portion of applause between songs.  What I'm seeing is, video is frozen in the compositor when I start playback, and remains frozen for several seconds, then starts playing back normally.  Same thing happens where I trimmed out the applause.  This behavior is present both in the compositor and in the renders.  Any suggestions?

If I start playback 5-10 seconds before the in point, the freeze ends before the in point arrives, but I don't want to render the part before, and the applause has to go.

1 Answer


Too hard to guess what might be the actual problem but you could very well be right about missing keyframes.  You will get the kind of strange behavior you see if it is hard to seek and it can be hard to seek when there are insufficient keyframes.  A Settings->Transcode operation can be used to add keyframes by basically copying the original media to another file that will automatically add keyframes.

Another possibility is that the "timestamps" may be off.  There is a way to fix this using ffmpeg but I do not know the exact command.