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by darcien 1030 days ago
>Of course, you could only re-encode only the GoPs that get broken while keeping the rest intact, and I guess this would be better and a lot faster than re-encoding everything. I don't know if any application tries to do this.

LosslessCut does have experimental support for this partial re-encode called "smart cut" [1]. Since it's using ffmpeg internally, the challenge become how to instruct ffmpeg to do this[2]?

[1]: https://github.com/mifi/lossless-cut/issues/126

[2]: https://github.com/mifi/lossless-cut/issues/1216
1 comments
runlevel1 1030 days ago
I suspect QuickTime Player.app's trim (Edit menu > Trim) does this as well when you save the result (as opposed to exporting it).

It's far too fast to be re-encoding the whole video and is too precise to be cutting at the nearest keyframe.

It has limited codec and container support, though.

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CharlesW 1030 days ago
> It's far too fast to be re-encoding the whole video and is too precise to be cutting at the nearest keyframe.

Correct! For example, if you trim the end of a video in the middle of a GOP, it includes the entire GOP as is, but only plays up to the point where you trimmed.

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j1elo 1030 days ago
Which is a very bad solution! Imagine cutting a video to remove some very privacy sensitive material, and some of those frames still ending up in the file, just not viewed because in theory the video file politely asks the player to skip until a later timestamp.

I'd for sure rather have tools that actually do what they claim to do. Using container metadata tricks feels to me as lazy and misleading to the user.

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