Disable In-camera Noise Reduction in H.264 Video

[kyrobb]

Hi guys. I've been told that MOV video mode applies some noise reduction in camera. This could help explain why video seems to turn to mush at higher Isos on my 550D and 50D in this mode. Shooting Raw is nice, as it eliminates this problem and remains sharp, allowing me to clean up the video in post. I was curious however, to see if it was possible to disable this h.264 noise reduction? Thanks all.

[Walter Schulz]

Discussed several times before. Impossible. H.264 encoding is done by dedicated hardware.

[kyrobb]

Ok. I wasn't sure if the noise reduction was included in that, as Magic Lantern was able to disable sharpening completely with the absolute zero sharpness function. Unfortunate that the same can't be done with noise reduction.  Oh well.

[Walter Schulz]

Sorry, which "zero sharpness function" are you talking about?

[kyrobb]

It's under image fine-tuning. Absolute Zero Sharpness. Disables sharpening completely (below canons zero level). I was hoping that the same could be done to the noise reduction, but if it's done by the h.264 encoder then it's impossible. I thought I had read that it was done before the encoder though... Does anyone know for sure?

[Levas]

If you're googling how the H.264 codec works you are probably gonna find out that it is also designed to remove noise.
because noise is detail (noise is false detail, but detail cost data, so removing it, compresses the video)
So basically most codecs are designed to remove noise, because removing it helps in compressing the data.

[kyrobb]

So this is why turning up the CBR bitrate only seems to result in an actual higher bitrate at higher isos? To compress this noise detail less?

[Levas]

probably.
Low iso's on DSLR's are pretty clean, so ideal for H.264.
Also DSLR's sensors, most of the time means low depth of field, so much is out of focus(ideal for H.264 and other codecs).
Turn up the ISO and even the out of focus parts have detail (Also known as noise  )
H.264 doesn't judge if detail is noise or real detail.

Maybe we should use H.264 low bitrate output as noise reduction filter, instead of using neat filter plugins 

[kyrobb]

Haha yeah. I suppose H.264 low bitrate can also be an aliasing filter!  I guess cranking the bitrate is my best chance of saving detail at higher isos then. Well... Raw is much better. Neat video is a much better denoiser than h.264 

[Levas]

I see you have a 50d, so probably doing raw video a lot ?
I have a 6d which, like the 50d, also has a lot of aliasing problems.

I don't know your workflow, but I have tried several things, Adobe lightroom, Davinci Resolve lite etc...
And what works best for me (against aliasing and in terms of sharpness) is RawTherapee.
I develop the DNG's in RawTherapee, you can choose several demosaicing options in RawTherapee and LMMSE works best against colorful aliasing!
Sometimes I use defringe to remove the last false color and export the DNG's to TIFF's and edit them further in Davinci Resolve (which does the best upscaling to 1920 wide resolution part!!!)

[kyrobb]

Yep, lots of Raw on the 50D. I'm on a Mac currently using MLRV to apply luts and export as ProRes, but if it's available for Mac, I could certainly try developing DNGs in RawTherapee beforehand.  Thank you for all the great info! My interest in H.264 lately was simply to try and match the 50D raw as closely as possible with my 550D in H.264, but it really turns to mush above 400 iso, and that's being generous. It may be time to upgrade my B-cam. 

[Levas]

I have MLRV installed on mac for viewing MLV's (never tried the export option  )
Raw Therapee is free(open source) and also available for mac (I use version 4) Version 3 had some pink highlight problem with ML raw video, which was solved in version 4.

If you're curious, here's my workflow
http://www.magiclantern.fm/forum/index.php?topic=3904.msg123338#msg123338

Good thing too know, if you use short key CTRL-B to put all selected files to the batch queue, don't switch/click on the Queue tab, if you're in the queue tab while exporting a load of DNG's the program crashes...

[kyrobb]

Awesome! I will give it a try thanks again! And a quick test confirmed your info. Shooting 1600 iso on the 50D in 3.0X CBR retained much more detail than the standard bitrate. It came in at 117 mbit/sec, so this makes sense. So my original request, disabling h.264 noise reduction, is more or less as simple as cranking up bitrate.  Thanks for the help! Unfortunately the 550D will stop recording at this rate, and it's still inferior to raw by far! I will try out your workflow!