Splitting h264 (no re-enc.), difference mkv and mp4?

[Spiny Norman]

A few questions that I'd like advice on. When I try to split videos with VideoReDo, it sometimes refuses an h264 file when it's mkv, but accepts the same file when it's mp4. Isn't that essentially "just" a different container?


Also MyMP4Box won't split frame accurate, but VideoReDo can? Does that mean that VideoReDo is quickly re-encoding the video? Because I don't really want that to happen but it isn't always obvious if it's doing that or not.

The story: I have a h264 encoded video and it's missing the end credits. I want to reconstruct those, but I'd prefer to insert that exactly between the right frames without re-encoding the rest.


Thanks. I know that many similar questions have been asked before; but some threads are several years old and new solutions might be around and such.

[Spiny Norman]

(Oh and there is something AFTER the end credits; otherwise it'd be easier of course.)

[thymej]

VideoReDo will re-encode but it only re-encodes a small amount of frames around the cut. Gota keep those GOPs intact. In regards to what files it opens you can ask these same questions at VideoRedo's own forum.

[Spiny Norman]

VideoReDo will re-encode but it only re-encodes a small amount of frames around the cut. Gota keep those GOPs intact. In regards to what files it opens you can ask these same questions at VideoRedo's own forum.

Ah so that's how they do it. But I won't insist on videoredo if there's something better suited for this.

[PuzZLeR]

But I won't insist on videoredo if there's something better suited for this.

You don't have to insist on any particular software app, but you pretty much have to insist on the fact that for lossless, or "lossless", cuts and joins, you pretty much have two choices with a compressed format like H.264 (unlike other, say, intra-frame format like DV, etc).

1) Cut with a slight re-encoding of a few frames at the ends where the cuts (and joins) are. This is the only way you can be frame accurate to correct the video GOP in case you cut on a "frame in the group somewhere between key frames".

2) Cut without any re-encoding whatsoever. Unless this cut is exactly on a key frame, it will not be frame accurate.

Personally, I prefer the first option. It's only a few frames anyway. Furthermore, I don't care for them regardless, especially if I choose to cut/join there (and likely will apply a cross-fade if any transition is harsh.)

[Spiny Norman]

Yes, that seems good enough. I wasn't entirely up to date on how the key frames were handled but really it's more important to get frame accuracy, as you say. Thanks for the input.