Cutpoints get corrupted when cutting HEVC videos.

Started by Felow, February 21, 2020, 09:02:25 PM

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Felow

Hello, I've been using avidemux for a while now to trim and merge my videos and it worked well. A few months ago I started encoding my videos to HEVC to save space and kept cutting and merging them using avidemux after doing so... I thought that everything was fine until yesterday when I re-visited my videos and found that all the cutpoints are artifacted and I'm pretty sure I cut at Iframes so now almost all of my collection is messed up and there's no way to fix it.

If the software isn't optimized to cut HEVC videos then you shouldn't give us the option to do so or at least give us a warning.

eumagga0x2a

Did you use Avidemux to encode original videos to HEVC? Could you please provide a sample HEVC video (uncut)? If the videos were encoded as open GOP, clean cuts are possible only if early B-frames are all dropped. This is possible only if no other frames depend on them. The required check is implemented only for H.264, for HEVC we assume that they are not droppable.

Any work on HEVC is pending a hardware upgrade which would allow me to play at least 720p in real time.

Felow

#2
Quote from: eumagga0x2a on February 22, 2020, 03:06:14 PM
Did you use Avidemux to encode original videos to HEVC? Could you please provide a sample HEVC video (uncut)? If the videos were encoded as open GOP, clean cuts are possible only if early B-frames are all dropped. This is possible only if no other frames depend on them. The required check is implemented only for H.264, for HEVC we assume that they are not droppable.

Any work on HEVC is pending a hardware upgrade which would allow me to play at least 720p in real time.

I used VidCoder and Handbrake to encode original videos to HEVC then I used Avidemux to cut and merge them and yesterday when I re-visited the videos I found that the cutpoints are corrupted (artifacted) some for about 10 seconds and some for 1 or 2 seconds. Unfortunately, my videos have a big file size and with my current upload speed I can't provide any sample. The solution that I found right now is to cut and merge the videos with Avidemux before encoding them to HEVC to avoid this problem.

https://imgur.com/a/DxdKdVe

eumagga0x2a

Quote from: Felow on February 22, 2020, 03:40:29 PM
The solution that I found right now is to cut and merge the videos with Avidemux before encoding them to HEVC to avoid this problem.

Sure, re-encoding videos in Avidemux allows also the full flexibility for placing cut points and is often the only option for IDR-less video streams with varying number of early B-frames.

Investigating issues with HEVC editing in copy mode is definitely on my todo list, but issues may be fundamental limitations due to the structure of some streams.