Unpacking b-frames

[Hinulog]

I have source files that are Xvid encoded with packed b-frames.
This is not a Good Thing [TM].
I wish to transcode them to per spec x264 files for trouble free playback on the widest range of devices.

I'm guessing I insert bframes=0 into the "more settings" field of the video tab of the GUI from the 'Normal' preset?
Will this give me clean compliant MP4 files per the spec or should I use FFMpeg with the mpeg4_unpack_bframes filter first?
Do I need to worry about this at all IOW will 'normal' preset drop the bframes during transcoding & output per spec x264 files regardless?

H

[Ritsuka]

If you transcode (instead of remuxing), you don't have to do any additional thing.

[Hinulog]

Ok, got it.
Many thanks.

[Deleted User 11865]

More specifically, packed B-frames are strictly an AVI thing. As soon as the video track is re-encoded and written to a non-AVI container format, packed B-frames simply cannot exist.

[Hinulog]

Yes Rodeo these are AVI's encoded with the dreaded Xvid/packed b-frames. My brief non pro understanding was they are not part of x264 spec & specifically unsupported in other containers.
My question was how does Handbrake handle this. My answer is : automagically.
Thanks very much to you both for help clarifying.

[Deleted User 13735]

Just to be clear, predictive frames when decoded have nothing to to with predictive frames during encoding. The encoder does not "see" anything that was there before your material was decoded to raw bits.

"Packed" b-frames are only one kind of kludge to be able to put bipredictive interframe material inside an AVI wrapper, and that's all. Once decoded, they are no different than any other video frame. x264vfw does not use b-frames at all.

[Hinulog]

I'm all about platform agnostic, space efficient & long term playability.

My workflow was to run these AVI's through FFmpeg with the unpack filter then transcode with Handbrake into x264/AAC/MP4. But it's clear from your explanation that this extra step is not needed.

Thanks to all for clarifying for laymen.

[Deleted User 13735]

The decoders in Handbrake are "essentially" the same as ffmpeg, except that updates occasionally lag a bit.

[Hinulog]

Yes, for simple tasks (changing containers etc) I use FFmpeg in a terminal. For more complex tasks I retreat to the Handbrake GUI. I did try to parse the Handbrake cli but got lost :-/ lol!