Does Avidemux change timestamps to make them non negative like FFMpeg option?

Started by bertargomas, July 01, 2022, 05:10:59 PM

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bertargomas

I have a mp4 file which when I cut a clip from using FFMpeg with "avoid_negative_ts make_non_negative" argument has a slight freeze near the beginning when played in VLC media player, the clip plays properly when I don't use this optional argument. When I cut out the same clip using Avidemux, I get the freeze which makes me wonder whether it does alter timestamps?

eumagga0x2a

All timestamps in Avidemux are non-negative by design. Regarding the problematic file, if the issue persists with the latest Avidemux nightly build, could you please provide it as a sample (of course, only if it is innocuous enough) via WeTransfer, Mega, Dropbox or Google Drive and provide also precise editing steps.

bertargomas

Some elaboration, because I completely forgot to mention that I was doing cutting without reencoding, only copying streams. It's not about just a single problematic file, it has happened many times and also seems to be unique to VLC media player. I was first cutting clips using LosslessCut program and realized that many of them have a slight freeze near the beginning when played in VLC, LosslessCut has enabled by default option "Shift timestamps (avoid_negative_ts) - Make Zero", when I disabled this option, the resulting clips played properly in VLC. I also learned to use FFMpeg myself as LosslessCut is a GUI built to use it, and learned that it's about this "avoid_negative_ts" optional command line argument, and I can see the same thing happening when cutting the clips out with FFMpeg, when I turn it on, I get a clip with slight freeze in VLC, without it, I get good clips. Now I also tried with Avidemux and some clips have the exact same problem I had with LosslessCut initially, which is why I ask whether it does shift timestamps similarly to how LosslessCut does by default.

eumagga0x2a

Did you try the latest nightly? The release is obviously missing bugfixes from the last half of a year, so it is almost entirely pointless to waste time testing with the release.

And if the issue persists with the nightly, nothing can be done without a sample video which allows to reproduce the problem.