Mac Studio Max fast enough for 4K sharpening?

[guykuo]

My Mac Mini M1 is fast enough to sharpen 1080P video without dropping frames. That works fabulously for making HD sharper before it goes to a home theater projector. However, it simply is not fast enough to sharpen 4K bluray video without dropping frames.

Does anyone have experience with sharpening 4K video on a Studio Max or Studio Ultra? Specifically, I'm interested in knowing if the VLC video stats window shows frame drops.

Gaining the ablility to sharpen 4K in VLC would bring the theater to the next level.
Also, it would save me from needing to turn sharpening on/off depending on whether the source material is 1080P vs 4K. Short of being able to keep sharpening on all the time, I'd even settle for an automatic changing of sharpening on/off upon detection of 4K vs 1080P source.

[tguillem]

There is already a GPU Shapen filter when decoding the video via videotoolbox. Could you share logs (run with vlc -vv) to see if the GPU module is used ?

Anyway, I'm not sure if the GPU plugin will be fast enough to sharpen 4K, and I don't think it is worth it for 4K content either.

What, you could do, is creating a playlist and put specific options for each item of the playlist (so ":video-filter=sharpen" for 1080p content).

cf. https://wiki.videolan.org/XSPF/ or put your options via #EXTM3U with a .m3u playlist.

[guykuo]

In my home theater room, sharpening 4K does yield a visible improvement. Then again, I'm on some higher end JVC 4K projectors and sit 1.1 screen widths away from a 150 inch screen. With that combination, sharpening in VLC is quite appreciable, even with 4K content.

VLC will do it with some 4K content files. Output looks great with a sharpening setting of 0.060 to 0.090 (the usable range for most video without excessive edge enhancement). Unfortunately, for most HD-Ultra rips, VLC can't quite keep up without dropping frames on an Mac Mini M1.

With thousands of video files, it isn't terribly effective to built a playlist to switch sharpening on/off. Ideally, I would find a machine fast enough for VLC to do sharpening without frame drops. The Mac Studio machines are faster than a Mac Mini M1, but I don't know if one actually is fast enough. Hence, my asking if anyone has tried it.

[tguillem]

OK !

Could you share logs (run with vlc -vv) to see if the sharpen GPU module is used ?

[guykuo]

I'd love to vlc -vv, but doing so in Terminal doesn't seem to find the executable. I'm assuming that is how one gets it to run with -vv option. Do I need to do something to make it runnable from the terminal command line?

I have only run VLC from it's GUI. Turning on the video sharpening either via the (command-E) video settings window, or via the preferences/show all/video & turning on the video sharpening filter there.

[tguillem]

Run "/Applications/VLC.app/Contents/MacOS/VLC -vv" from the terminal

[guykuo]

Ah.. Full pathname. Will do tonight

Given, you are asking for the GPU verification, I take it sharpening doesn't always use the GPU, but sometimes the CPU?
If it is the GPU, then we do have a better chance of a Mac Studio being fast enough. It's single CPU core speed is not that much better than a Mac Mini M1, but it certainly has a lot more GPU cores and a few more CPU cores.

Currently, my Mini M1 drops about 1 - 2 frames / second if I ask it to sharpen 4K HD-bluray MKV's.

[guykuo]

Here is the log file from playing a 4K movie mkv. Sharpening is on.
I can see the sharpen filter being added to the chain.
Also, I see the frame drops in the latter portion of the log.

I don't know how determine whether the GPU or CPU is being used for sharpening.

www.cosalient.com/picture/jvc/log%20vlc ... i%20m1.rtf

[tguillem]

Yes the GPU is used, we can't really do more to improve performances.

[guykuo]

Well, at least you confirmed it is using the GPU for sharpening rather than the CPU. This leaves hope that a Mac Studio Pro or Ultra might be able to sharpen 4K without frame drops. If performance scales with GPU and VLC was written to take advantage of more GPU cores, scaling speed should improve quite a bit going to one of those machines. Hopefully someone will try it on a Max or Utra.

My wish list to make VLC a better HTPC alternative (in the absence of better scaling performance or fast enough machine) would be to...

1. Add an option to automatically disable sharpening if 4K frame size is detected or frame drops are detected. Then one could leave sharpening on and VLC would turn it off as needed without user interaction.

2. Change the sharpening slider range to a smaller range. Presently, only a very tiny fraction of the slider scale is useful for critical viewing. It's really hard to slide it accurately. 0 to 0.3 would be more than needed. For critical viewing somewhere between 0.06 and 0.15 is about optimum for large screen viewing.

[guykuo]

I just realized, you didn't explicitly say that sharpening is being done by the GPU instead of the CPU. Back in 2018, I read that VLC was doing sharpen filter in CPU after decode by GPU.

Has that changed in the current build to using GPU to perform sharpen?

[tguillem]

Humm sorry I made a mistake reading the log, sharpen GPU is not used in your case because of the P010 format (YUV420 10 bits).

I will have a look, maybe it's easy to add P010 support.

For your question, sharpen by GPU is new in VLC 3.0, but it depends on the OS/GPU/format, so it's not always used (if compatible, it is used automatically).

[tguillem]

cf. https://code.videolan.org/videolan/vlc/-/issues/27100

[guykuo]

Thanks for circling back and correcting the CPU vs GPU sharpening device. It would be fantastic if GPU sharpening could be enabled on the Mac Mini M1.

I strongly prefer the integration of VLC for playback and desktop browser in one unit. Makes random information access MUCH faster than a streaming device. If GPU sharpening was possible, 4K playback would be improved. Still not that pefect since one can't turn off VLC's own tone mapping even when the Mini's output is set for HDR. (My JVC projector does very nice frame by frame dynamic tone mapping, So, VLC tone mapping is ironically undesirable feature)

My Zydoo 9X does a better job playing back 4K HDR purely because it can output the 4k HDR video and audio streams unmolested. AVR then can properly decode the 3d audio, and the projector handles the HDR tone mapping. Alas, it is clumsy and slow as heck to run compared to the Mac Mini & VLC. Hence, my using the Mac Mini as the main playback device for my library.