Re-encoding again from variable to constant FR

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linuxlad
Posts: 7
Joined: Mon Mar 22, 2021 3:42 am

Re-encoding again from variable to constant FR

Post by linuxlad »

Handbrake 1.3.3 Win7SP1

Is it possible to re-encode previously re-encoded videos with all the same settings except that instead of using variable framerate they will be re-encoded again with "constant framerate".

I have many videos that I recently encoded using the "variable framerate" and the original source videos are no longer available, however, due to certain reasons, I need to re-encode them again using "constant framerate" with everything else untouched and as is. Is is possible to re-encode the already re-encoded videos without having to re-encode the entire process by just simply re-encoding only the framerate using the constant framerate setting? If not then I assume that I can simply re-encode them using all the same exact settings I used previously when re-encoding from the source except changing the framerate from "variable" to "constant".
mduell
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Posts: 8187
Joined: Sat Apr 21, 2007 8:54 pm

Re: Re-encoding again from variable to constant FR

Post by mduell »

Sure, you could do that. Pick the same preset you used and pick constant framerate. The quality will be slightly worse due to the reality of lossy encoding.
linuxlad
Posts: 7
Joined: Mon Mar 22, 2021 3:42 am

Re: Re-encoding again from variable to constant FR

Post by linuxlad »

Thanks,

Yeah, the quality loss is negligible and not noticeable from any screen-size-to-distance I tested, pausing at different frames, and comparing screenshots at different frames. It does however add a few extra megabytes which is not a big-deal, I will just have to make a little extra space in all 23-drives by taking out a couple or so videos and moving them elsewhere if/when there is not enough space since the overall adds a little extra...for example, I just re-encoded 73.5GB worth of videos from the variable-framerate source to constant-framerate setting and when they completed, they all ended up at a total of about 76GB due to the few extra megabytes added to each file.

I initially started encoding all videos using constant framerate, however, on April the 15th I came across the handbrake article explaining the differences between constant and variable so I figured that it does not get any better than untouched/one-to-one exact copy of framerate and I didn't test the videos properly afterwards, so I now I have two weeks of daily encodes that I have to re-process, which I have already set aside those drives and logged all folders/files that need re-encoding; good thing that my database shows all modified dates for files/folders that can be sorted and the handbrake logs to verify them.

Good thing I caught it now instead of much later. I had two major reasons as to why I'm back-stepping and going back to "constant":

1.) I noticed that while watching those encodes with my firestick and when the camera slowly panned/moved/shifts vertical or horizontal that the videos has a stutter/shimmer effect that annoyed me (probably skipped or loss of frames) so I tested in other soft-players like MPC/VLC and I noticed the same effect so I downloaded the source videos as I initially suspected that it may be due to the source and after I came across a second set of videos with the same effect I noticed that this was only occurring for the variable-framerate encodes and not their source.

2.) I also decided to test these variable-framerate videos with my older hardware players and they would not even recognize the framerate at all as they showed up as 0fps and the videos were fast-forwarding while playing...something that I came across occasionally which I wanted to avoid at all costs and now I know exactly the cause of that. I have come across thousands of videos for films and shows and I have never came across a single video with a variable framerate flag, if however I do, I doubt that I would even need to re-encode it anyway so this will be a rare .01% probability vs 100% certainty of all a re-encoded videos that will have both issues if re-encoded with variable framerate enabled.

With constant framerate, the same re-encoded videos play smoothly and perfectly with no shimmer/stutter effect and no loss/skipped frames, they also play perfectly in my older hardware players and they show their actual framerates. After I enabled the variable setting I should have tested them in my older hardware players and the results would have been enough for me to never use that setting.
rollin_eng
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Joined: Wed May 04, 2011 11:06 pm

Re: Re-encoding again from variable to constant FR

Post by rollin_eng »

Could you please post your HB logs, instructions can be found here:

https://handbrake.fr/docs/en/latest/hel ... y-log.html
linuxlad
Posts: 7
Joined: Mon Mar 22, 2021 3:42 am

Re: Re-encoding again from variable to constant FR

Post by linuxlad »

Which one? I have a total of 226 activity logs from four separate systems starting from April the 4th to May the 4th; do you want me to post all of them?
I could copy them to four separate folders named after each machine, archive them in a zip/rar and post them somewhere like "wetransfer".
Normally when I post a single log, I use pastebin.
mduell
Veteran User
Posts: 8187
Joined: Sat Apr 21, 2007 8:54 pm

Re: Re-encoding again from variable to constant FR

Post by mduell »

An exemplar or two is all we need.
linuxlad
Posts: 7
Joined: Mon Mar 22, 2021 3:42 am

Re: Re-encoding again from variable to constant FR

Post by linuxlad »

Ok, so I chose two activity logs from one system.

The top log is from April the 13th and the 2nd one at the bottom is from April the 17th.
I changed the setting from "Constant" to "Variable" on all the systems on April the 15th so the log includes one before and one after the setting was changed.

https://pastebin.com/4BRXgrE3
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