Hello Everyone,

I used Selur MKV cutter to frame accurately and losslessly cut a few segments followed by joining the kept segments using MKV Merge. All segments are from the same file so resolution, codec, frame rate and aspect ratio are the same. The file plays fine on the computer but I what I really need is to create a Bluray Structure so for that I've used tsmuxer and here's where I run into a problem. While muxing tsmuxer starts posting h264 warnings about unexpected pic order lsb slice type B and P, etc. When done the resulting file plays fine until the cut points then freezes, alternating a few frames and then proceeds as normal but of course loses audio sync. So here's what I tried.

When setting "Do not change SEI and VUI data" in tsmuxer, it then gives a single warning and the resulting file plays fine in VLC for example but my goal is to have it play using Dune 4K where it completely chokes with only the audio playing and the video skips as well as freezes.

For my next attempt I tried concatenating the file segments using ffmpeg like so.

ffmpeg -f concat -i file.txt -c copy -fflags +genpts output.mkv

When put that file into tsmuxer it showed a weird frame rate of 11 dot something even though the mkv does appear to play at its source frame rate of 23.976. But anyway I forced the fps to 23.976 and muxed the file normally with the "Insert SEI and VUI data if absent" but again tsmuxer spits out the same warnings about h264 with the resulting playback being just as bad as before.

So is this a header issue that can be fixed losslessly or is re-encoding after joining the clips my only option?

I really like the concept of smart lossless cutting but unfortunately it only seems to work great for when you just need to trim out a section but when joining clips together that's where trouble starts.

Thanks in advance.