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Encoding of very old movies from the 1950s (fps?)

Posted: Sun Dec 08, 2019 6:04 am
by linuxuser
I have very old DVB-PAL-recordings with old movies from the 1950s, which have been recorded from satellite tv and an enigma2-box.

AFAIK these old movies (PAL) were taken with 25fps interlaced. But they are broadcasted with 50fps. So does it makes sense to reduce the fps from 50fps to 25fps?

I did some test encodings with 25 and 50fps, all other parameters have been the same. The result was very different to what I expected. The filesize could be the same or maybe 30% less. I expected the half size with 25fps.

Re: Encoding of very old movies from the 1950s (fps?)

Posted: Sun Dec 08, 2019 6:31 am
by BradleyS
I wouldn't expect much difference between 25 and 50 fps; surprisingly the encoders can do quite well with more frames. There's a lot less overhead than one might think with typical sources.

As far as deinterlacing, Decomb will create 25 fps and Bob will create 50 fps. The latter sacrifices a small amount of spatial resolution for temporal resolution (motion). Try both and see which suits you and your source. You will probably want to make sure you have "Same as Source" selected for FPS on the Video tab; Bob will take care of the doubling.

Re: Encoding of very old movies from the 1950s (fps?)

Posted: Sun Dec 08, 2019 6:54 am
by Deleted User 11865
I would personally go with high profile (default) and e.g. something like:

Code: Select all

ref=3:bframes=3:b-pyramid=none:weightb=0:weightp=0:cabac=0
It would most likely decode faster/better than main profile with CABAC enabled and hopefully still provide slightly better compression efficiency. Haven't done any testing of "fast decode" type settings in a while though, you might have to try it out for yourself. It may even be that disabling CABAC would not be required to get decent decoding performance.

Re: Encoding of very old movies from the 1950s (fps?)

Posted: Sun Dec 08, 2019 7:56 am
by BradleyS
@Rodeo I feel like your comments were meant for another thread regarding performance on older machines?

Re: Encoding of very old movies from the 1950s (fps?)

Posted: Sun Dec 08, 2019 8:50 am
by Deleted User 13735
The movies were probably originally 24 fps sped up for PAL, but it is now baked and can't be undone in Handbrake afaik. So Bradley's advice at 25fps is what I would use.
Bob @50fps won't be double size, because of field similarity. I also agree that Bob would not look better, partly because of the aforementioned loss of resolution, as well as slightly increased shadow noise (SNR).
I say don't try to "fix" that old-movie flicker..

Re: Encoding of very old movies from the 1950s (fps?)

Posted: Sun Dec 08, 2019 12:54 pm
by linuxuser
Until discussing this here, I did the following.

DVB-recording in HD (1280x720)

Resizing the file:
Cutting the black border
Cutting to 16:9 by cutting 64 top and the rest bottom so I get exactly 16:9 (of course this is a matter of taste)
If the result is below 1024, resizing to 1024x768
If the result is larger, than resizing to 1280x720
Anamorphic off
This is done for compatibility reasons, but in the meantime hardware-players, eg mobile phones, became better, but I keep this, had too much troubles with wrong aspect ratio. I assume too, that handbrake does a better upscaling from non standard to a standard resolution, because it is not "on the fly" and a UHD tv does a better upscaling from a known standard resolution. Of course the size will get a bit larger then.

Filters:
NLmeans / Ultraligh or Light / Grain
Unsharp / Ultralight or Light / Tune non
Decomb / Default
Deblock off

CRF 26 (less brings more details with the noise / grain, but not the picture)
25fps
Preset slow
Tune none or grain
Profile Auto
Level Auto

So please correct this, it there are better options. I know it depends on the source. My experience is, that movies from to 1950s are often better than from the 1970s. The quality of movies from the 70s are often extremely bad.

Re: Encoding of very old movies from the 1950s (fps?)

Posted: Sun Dec 08, 2019 6:13 pm
by Deleted User 11865
BradleyS wrote: Sun Dec 08, 2019 7:56 am @Rodeo I feel like your comments were meant for another thread regarding performance on older machines?
Really? :D

Re: Encoding of very old movies from the 1950s (fps?)

Posted: Sun Dec 08, 2019 8:18 pm
by BradleyS
Yes really! Thought maybe you meant to comment on viewtopic.php?f=7&t=39645

Not sure what CABAC and fast decode have to do with this topic, but maybe I'm daft.

Re: Encoding of very old movies from the 1950s (fps?)

Posted: Sun Dec 08, 2019 8:38 pm
by Deleted User 11865
Yes, you were right, hence the " :D " ;)

Re: Encoding of very old movies from the 1950s (fps?)

Posted: Sun Dec 08, 2019 9:01 pm
by BradleyS
:D