AviSynth+ thread Vol.2

[pinterf]

Slowly porting some function documention of Neo fork (from Japanese) to Avisynth wiki.
Achievement of January is: http://avisynth.nl/index.php/DumpFilterGraph

[tormento]

Originally Posted by DJATOM

I'll consider it based on my local prices and availability. Literally I need it for filters like eedi3/nnedi3 where 10G memory isn't really a problem. In fact, 2070 with 8G is enough for it, but eedi3 is slow.

Can you process HDR 4k material within 8GB? How many threads? Which GPU based filters do you use?

[DJATOM]

Yes, it's enough for 4k tonemap or eedi3/nnedi3 upscaling.

[tormento]

Originally Posted by DJATOM

Yes, it's enough for 4k tonemap or eedi3/nnedi3 upscaling.

Do you use any GPU based filter?

[DJATOM]

All of those filters uses GPU (tonemap is cuda-based and edi stuff is OpenCL).

[tormento]

Is there any way to determine thru AVS+ the apparent and real bit depth of a video stream?

With apparent I call the number of bits (8/10/12/16), with real the non zero part of the bits itself.

I am starting to play with > 8 bits scripts and sometimes I have doubts about their real effectiveness.

[DJATOM]

Probably ScriptClip can help with detection, but it looks obscure for me and Idk howto write proper detection with it. Vapoursynth's std.FrameEval is much easier .
With python modules we can check md5 or crc of every frame and compare hash values. For example, create few clips (8, 10, 12, 14, 16) and compare source frame's md5 with every modified clip's frame hashes, then append metrics into variable. At exit write log file from metric variable and check found values across entire clip.

[videoh]

Maybe you can source the 10-bit into a clip c1. Then source it again into c2 and apply ConvertBits(8) followed by ConvertBits(10) to it. Finally do Subtract(c1,c2).Levels(...) to visualize any difference in the two low bits. If the 10-bit source is not real (i.e., low bits all zero) then you won't be able to amp up any visible difference.

BTW, don't forget that high bit depth is not just about getting more resolution, it's also about dynamic range for HDR.

[tormento]

I thank you both for the reply. I find a bit strange that a frame server hasn't functions to analyze the frame properties.

[pinterf]

Originally Posted by tormento

I thank you both for the reply. I find a bit strange that a frame server hasn't functions to analyze the frame properties.

Extremely strange. Specify "analyze", specify "frame properties".
Did you expect a ready made function IsThisSourceReally8bitInFake10bitFormat()?

Anyway, you can look at the histogram. e.g. Histogram("levels", bits=10), it is not that wide yet, or else you can show only the histogram part with keepsource=false. Valid histogram resolutions are bits=8,9,10,11,12.

[tormento]

Originally Posted by pinterf

Extremely strange. Specify "analyze", specify "frame properties".
Did you expect a ready made function IsThisSourceReally8bitInFake10bitFormat()?

Given a single frame or a stream, the ability to detect bit depth and the capability to show the color bit value for a reasonable amount of pixels, to understand if all the bit depth is used or only “resized” to a deeper one, adding zeros only.

[pinterf]

Besides the above mentioned 10 bit Histogram you can write an expression for that in Expr.

[tormento]

Originally Posted by pinterf

Besides the above mentioned 10 bit Histogram you can write an expression for that in Expr.

Will try the histogram ASAP. For Expr, unfortunately I haven’t the capabilities to do it. Thanks, anyway.

[tormento]

Originally Posted by pinterf

Anyway, you can look at the histogram. e.g. Histogram("levels", bits=10)

I made a simple AVS script and, opening it in VirtualDub2, I can see that, when a video stream has a bit depth minor than the bits parameter, I can see "gaps" in the graph of levels.

Would be of much trouble to add an option for 16 bits too?

[pinterf]

For practical reasons the option is disabled. I hope that no one wants to display a clip with width=65536.

[tormento]

Originally Posted by pinterf

For practical reasons the option is disabled. I hope that no one wants to display a clip with width=65536.

Wait... what has bits to do with width?

[pinterf]

If we are talking about Histogram "bits": a 8 bit histogram has 2^8 (=256) horizontal columns for levels. A 10 bit histogram is shown in 1024 (2^10) columns. And a histogram with 16 bit resolution can be shown on 65536 columns.

[tormento]

Originally Posted by pinterf

If we are talking about Histogram "bits": a 8 bit histogram has 2^8 (=256) horizontal columns for levels. A 10 bit histogram is shown in 1024 (2^10) columns. And a histogram with 16 bit resolution can be shown on 65536 columns.

I am talking about "bits" parameter, i.e.

Histogram("levels", bits=12,keepsource=false)

I can find the true bitdepth of a stream just looking at histograms. That works fine for 8/10/12. How can understand if a stream is 16 bits or 10 bits without bits=16?

[pinterf]

Originally Posted by tormento

I am talking about "bits" parameter, i.e.

Histogram("levels", bits=12,keepsource=false)

I can find the true bitdepth of a stream just looking at histograms. That works fine for 8/10/12. How can understand if a stream is 16 bits or 10 bits without bits=16?

Then you have to learn Avisynth, especially Expr or masktools lut expressions, or think about other techniques. Or ask your stream sources where they obtained a 16 bit master from.

[FranceBB]

Hi Ferenc,
I have just a thing to report.

The AviSynth+ 3.7.0 release installer for Windows XP has been shipped with the "wrong" version of C++ Redistributable.
Let me explain.

There are:

- AviSynthPlus_3.7.0_20210111_vcredist_xp.exe
- AviSynthPlus_3.7.0_20210111_xp.exe

Both builds work just fine on Windows XP and they've been compiled to run on XP targeting v141_xp correctly, so no problem, however the "_vcredist_xp.exe" version isn't shipping the XP compatible Microsoft C++ Redistributable 2015-2019 installer, so what will happen is that the C++ Redistributable that is gonna be installed won't work on XP, hence it will make impossible to use Avisynth.
In order to make it work, I've installed the "vcredist" version shipped with AviSynth+ 3.6.1 and then I installed "AviSynthPlus_3.7.0_20210111_xp.exe" without re-installing the C++ Redist and it worked like a charm.
I think you should be shipping the vcredist version from AVS 3.6.1 for XP