Handbrake - Use MPEG 4 or H264 for Rerender on vfr?

[Alwyn]

My Movie Edit Pro doesn't like variable-framerate videos, so I am using Handbrake to render them to constant bitrateframerate.

Some of the codec options are MPEG 4 or H264. Which should I choose/what are the advantages of either?

Thanks very much for any input.

[LigH.de]

"MPEG 4" means probably MPEG-4 ASP (like DivX, Xvid), which is a bit vintage already, and "H.264" (MPEG-4 AVC) is more modern, more efficient, thus recommendable.

I guess you mean constant framerate... to create CFR from VFR, there may be better solutions than actually recoding, but if you do it for convenience, the intermediate video should be created with a lower RF (around 12..15 should be sufficient) instead of a target bitrate, to ensure that there is a constantly low loss of quality.

[Alwyn]

Thanks very much, LigH.de. I'll have a look at the RF. The VFR video is from an iphone 11; any tips to do this without recoding would be gratefully accepted. VDub? Avisynth?

[johns0]

You have to re-encode true vfr to crf,can't do it without re-encoding.There is one way to get vrf to crf as long as the vrf has no different framerates,load the video into tsmuxer and change the framerate from to 23.976/25/29.97 depending on the real framerate it has and save as.

[Alwyn]

Thanks Johns0, the file kept crashing Tsmuxer. I'll open a new thread on the VFR/FFR topic.

[johns0]

Which version of tsmuxer did you use and please don't open a new thread,continue here.I also changed your thread title.

[Alwyn]

Version "tsMuxeR_2.6.12"

OK no worries on the threads, I thought this title no longer reflects the (new) underlying subject, which is now VFR/CFR.

I've attached a sample MOV here too.

[johns0]

Just ran it through mkvmerge and it says the file has constant frame rate,try using the mkv to see if it works that way.

[Alwyn]

Continuing framerate discussion on other thread.

[sneaker]

I've attached a sample MOV here too.

If you remux that file to a constant framerate (without re-encoding) it becomes about 1.5ms longer which is negligible.

mp4box -raw 1 20201101_105319.mov
mp4box -raw 2 20201101_105319.mov
mp4box -add 20201101_105319_track1.hvc:fps=30000/1001 -add 20201101_105319_track2.aac -new remuxed.mp4

For such a short file the 1.5ms are not a problem. If you make long videos the problem becomes bigger and then you must choose more complicated solutions (e.g. re-encode with adding or dropping video or audio frames).

[Alwyn]

Thanks Sneaker, I found that running a 10 minute MOV through MKVToolnix produced a constant FR MKV that was in sync (in Vdub and VLC). My video editor though isn't keeping the audio in sync, so I've reverted to saving the file as a LAG AVI and using that for editing.

The code in your post: is that for MP4box?

[sneaker]

The code in your post: is that for MP4box?

Yes.

[Alwyn]

I suspect the audio out-of-sync in MEP may be due to the 44100khz audio.

Is there a quick way of re-encoding the audio in MKVToolnix to 48000 while it is redoing the video framerate?

[Alwyn]

I can open the MKV in Avidemux and save it with 48khz audio, which is synced in MEP. Two steps but reasonably straight-forward and saves a re-encode.

[Cornucopia]

Hate to break it to you, but unless you are OK with a duration change, 44.1 --> 48kHz IS a re-encode. At least for the audio.

But you've gone through a bunch of tools and a bunch of filetypes in your mentions, so now it isn't really clear what you actually had vs what you now have vs what you want/need. Post clips and or mediainfo reads, please.


Scott

[Alwyn]

Couldn't detect any duration issues with changing 441 to 48k. I wouldn't say 2 is a bunch.

Source file is in post 7.

After I ran it through MKVToolnix, I get a constant FR smart-rendered MKV (according to Mediainfo) but out of sync in MEP. I say smart-rendered because a 10min MOV took 10 seconds to change to MKV.

After I run that MKV through Avidemux, setting audio to 48k, I get a 48k MKV which gives in-sync audio in MEP.

= Happy Days.

Now I need to work out how to do batch processing.

[Cornucopia]

Ok, this makes more sense now.

Source file is shot in daylight, with most of the image being of the outdoors.
= Plenty of light.
= very little need to vary the vary the framrate to compensate in maintaining good exposure.
Thus the reason the variation in framerate is less than 2fps.
BECAUSE it is that little (and remember: that is the max difference), your mis-sync between video & audio (after VFR->CFR adjustment) is probably small enough not to be noticeable. Yet it should still be there, regardless.


Scott

[Alwyn]

Thanks Scott. I did some further tests and from a dark room start to a bright outdoor finish in a single clip, the frame rate went from 4 (!) to 30 FPS. The smoothest re-render of that I got was using VDub; it was still a bit jerky though.

Looking on the net, it seems that most (all?) modern phones use VFR and it can't be turned off, even if a camera app can be set on "30FPS".

Bummer.

[Cornucopia]

Yes, that's what I've been saying for a while now.

But if you are trying to do pro-like productions, if you give the cams LOTS of light, it doesn't have as much need to cheat, and so will hover around the framerate you (or your apps) pick. And this can be fudged to be workable in editing without too much noticeable judder. As you have just found out.

Scott

[Alwyn]

Thanks Scott, Cheers.