Encoding Black/White Films

[amigd23]

I wonder whether there are some ground rules for encoding black and white films. Do you guys set special setting for those movies ? I guess they are easier to encode, am I right ?

[jggimi]

In my experience -- limited, but some -- they're actually more difficult.

1) A 4:3 aspect ratio means many more pixels in an individual frame -- so higher bitrates are needed. I'm currently playing with Seven Samurai, and it doesn't look good even at 512x384 and 870kbps. I'm thinking of 3-4 CDs for it.... this with DivX 5.02 and B-frames. 3-CDs takes it to 1345Kbps ... but I'm not happy with noise reduction, either.

2) These are often transferred from old prints, and need noise reduction. Because everything is shades of grey, even light noise reduction is very obvious. Settings must be played with, and sometimes a variety of smoothers and options are used in sequence, similar to anime. I haven't yet figured out a selection I'm happy with.

[Teegedeck]

XviD seems to do quite a good job on b/w encodes, too. I've done a 1-CD (XCD) encoding of a 2-hour-documentation on 20th century's opera-singers, lots of black&white footage in really bad quality (noise, 'pumping' picture, jerkiness...) and it came out very nice at 512x (aspect-ratio 4:3).

[wmansir]

B&W can be very difficult. If the source is clean (like Citizen Kane) it's not too bad, although compression defects do stand out more than with color film.

If the film quality is poor (like Seven Samurai) then it's very bad.

The worst part about SS, apart from normal noise and long run-time, is the flicker and frame judder. You can help the flicker by using Donald Graft's Anti-flicker filter. It does a great job at reducing flicker, but unfortunately it's not developed enough to be very useful. It doesn't detect scene changes, so transitions are often messed up. Also, it is difficult to use. Since it requires a first pass to collect data and then a second pass to correct the luma on each frame. The current state of the Vdub filter mechanism makes it very cumbersome to use. Adding Scene detection and porting this filter over to Avisynth would make it indispensable for encoding old B&W films. Adding Scene detection is currently on Mr. Graft's to-do list.

I don’t think there is anything you can do for judder except throw bits at it. After trying to encode this movie several months ago, I decided it would be better to buy a second copy then attempt to make a quality backup of it. This is the same conclusion I came to with SPR, it's possible to do it, but the results are not worth it.

[bb]

You probably know this already, but as nobody mentioned this: You should use a greyscale filter to ensure that there's no color noise in the video. This is always necessary for analogue captures, provided that you don't have a b&w capture card ;-).

bb

[wmansir]

I believe someone posted a plugin for avisynth that removes any color info. Someone in the avisynth forum just programmed it up real quick. It works in YUV so it's about as fast as can be.

I saved you the search, here's the thread.
http://forum.doom9.org/showthread.php?s=&threadid=9808&highlight=black+white

I see neuron2 updated the thread, now that he has the tweak plugin for avisynth. It can do the same thing and is more flexible, so your probably better off using it.

[grif_mcrenolds]

I've rippped Young Frankenstein (DivX 5.0.2, 576x304) and noticed that even though the run time is short, you still get artifacts. It was pretty good quality, still better tahn really long movies. I think it may have to do with that the encoder doesn't have the various colors to estimate motion and shape as well. Psychovisul modeling help in that kind of situation.

[Arky]

Hmmm...perhaps we should refrain from discussing this issue in case the MPAA get wind of it and decide to release ALL their future films in Black and White as a measure to deter copying!! :D


Arky ;o)

[SuperPutaMierda]

I´ve made about 6 B&W movies (Psicosis,Spellbound, Viridiana,Persona,...) using GKnot and the final quality is the same as a color movie so I don´t know what problems you might have with them. Usually the original quality is not the same as a recent movie so the final result is proportional to the source.

[duartix]

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[SuperPutaMierda]

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[Kyo]

@SuperPutaMierda
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[chemmajik]

When I did a black & white movie last year what I found was the scene changes are usually what screws up alot, because some codecs are used to using color for scene changes. I never had success with divx3.11a with b/w & at that time divx4 was only available & did a better job at it. I havent done any b/w's this year to test out xvid yet. I found if you give it a higher bitrate to work with it usually will not produce to many blocks on them scene changes. The greyscale or luma chroma filters you might want to test with also, its been awhile for me.