xy-VSFilter Project (High Performance VSFilter Compatible Subtitle Filters)

[cyberbeing]

Originally Posted by Gagorian

I'm having a small problem with XySubFilter. When viewed on my 119" white screen I can see some faint horizontal artifacting between letters (two very thin barely visible horizontal lines between the upper and lower parts of the letters). It seems like it's some problem with the transparency of the background. I think I had the same problem on the MPC internal filter and that's actually a reason for the switch.

I'm using MPC-HC and LAV filters with madVR (all latest versions). My GPU is the iGPU on A10-5700. I'm not using DXVA.

Any solutions to the issue?

I'm having trouble picturing what you describe. It sounds like it may be an artifact of your projector or screen, but I would need a screenshot to verify.

Disable Fullscreen Exclusive in madVR, and take a screenshot with PrtScn which shows the issue. paste that into Paint or similar, save and upload it somewhere.

[Gagorian]

Originally Posted by cyberbeing

I'm having trouble picturing what you describe. It sounds like it may be an artifact of your projector or screen, but I would need a screenshot to verify.

Disable Fullscreen Exclusive in madVR, and take a screenshot with PrtScn which shows the issue. paste that into Paint or similar, save and upload it somewhere.

Using this methodology I pinpointed the issue to the Darbee Darblet video processor I have hooked up in my video chain. It seems to create the minor artifacting. So the problem is solved, thanks.

[river1]

Can XySubFilter render subtitles in 60fps?
I use SVP to interpolate 23.976fps videos into 60fps, and xy-vsfilter will render subtitles in 60fps when I put it after ffdshow. XySubFilter seems to always render subtitles in 23.976fps and does not look as smooth as the interpolated 60fps video.

[cyberbeing]

Originally Posted by river1

Can XySubFilter render subtitles in 60fps?

Yes.

Originally Posted by river1

I use SVP to interpolate 23.976fps videos into 60fps
...
does not look as smooth as the interpolated 60fps video.

We've been discussing this issue with madshi for the past day, since technically, madVR isn't sending XySubFilter Beta the information it expects for a 60fps video when SVP interpolation is used. The issue is a bit more complex then that though. I'll reply to your comment on GoogleCode as soon as we have a definite answer, you didn't need to cross-post it here.

[Raylan Givens]

I'm using the beta subFilter at 2560x1600 resolution on a 1080p monitor, but I'd like to know if there is a way to avoid the distortion when I see a movie on lower than native resolution...

When the movie's resolution is 1280x528 for instance, the high-res fonts are being squeezed... Only when I see an HDTV serial which uses fullscreen the fonts are perfect...

I hope you get what I mean. Is there a way to keep the high-res fonts intact even when the movie ain't fullscreen?

Here you can see the settings: http://i5.minus.com/i5CDWJn9HEZQY.png

[cyberbeing]

Do not set "Customize", as it is NOT a rendering resolution setting. Leave it at the default of "Use Original Video Size" if you want proper scaling to Desktop resolution.

Also do not force YCbCr Matrix or RGB Levels PC either, leave both on the default setting of Auto or you'll have incorrect levels. Setting YCbCr Matrix to Guess will result incorrect subtitle colors in most cases, so leave that as the default setting of "Auto" as well.

Last but not least, 8x8 Bilinear sub-pixel positioning should generally not be used either, since it will make subtitles inconsistently blurry because of this old bug. It's best to leave it at the default setting of "8x8 (vsfilter)".

[Raylan Givens]

But my goal is to get 2560x1600 res fonts with Scale X 100 - Scale Y 100 on all videos... No matter the video's resolution... I'd like on all movies the same high-res fonts.

So, this ain't possible, right?

I noticed the uneven blurring, but I couldn't be sure it's a bug. Also, if I leave the Matrix to "guess" it usually says "TV.709" or "TV.601" for example... Shouldn't be PC? Just asking... Now all on "Auto" it just says "None".

[cyberbeing]

Originally Posted by Raylan Givens

But my goal is to get 2560x1600 res fonts with Scale X 100 - Scale Y 100 on all videos... No matter the video's resolution... I'd like on all movies the same high-res fonts.

Why do you want this?

Originally Posted by Raylan Givens

So, this ain't possible, right?

Correct, XySubFilter does not allow rendering at an arbitrary resolution. Fonts are always rendered at output resolution, since that yields the highest quality.

Originally Posted by Raylan Givens

Also, if I leave the Matrix to "guess" it usually says "TV.709" or "TV.601" for example... Shouldn't be PC? Just asking... Now all on "Auto" it just says "None".

No, "None" is usually what you want to see there. On ASS subtitles (assuming Auto is set) it means XySubFilter is performing color correction itself instead of madVR. On SRT subtitles it means no color correction is being performed. For the next XySubFilter release, we have already removed matrix information reported to madVR from the filter name to make this less confusing for users.

[Raylan Givens]

Originally Posted by cyberbeing

Why do you want this?

Uhm... Because it's too damn perfect? High-res fonts? Check this out and tell me...

http://i3.minus.com/ibzrKGwmBpgA7q.png

In combination with Alpha link channels, it gives very smooth results. Now when I go back even to 1080p res fonts, they seem too fat :P -but anyway.

Thanks for the Matrix-related info.

[cyberbeing]

Originally Posted by Raylan Givens

http://i3.minus.com/ibzrKGwmBpgA7q.png

In combination with Alpha link channels, it gives very smooth results.

That's because MPC-HC ISR scales subtitles with bilinear, which will give a very blurry/smooth output.

Even if we implemented a function for arbitrary output resolution in XySubFilter, madVR would scale with whatever algorithm you use for downscaling video (usually a algorithm much sharper than bilinear). MPC-HC is working on a Subtitle Consumer for XySubFilter as well, so when they finish it, maybe we'll consider adding such an option if many users prefer the appearance of blurry downscaled output.

Otherwise, we have already been considering adding an option to have XySubFilter blur the subtitles before output, which will likely yield superior results to bilinear downscaling with a lower performance penalty.

[Raylan Givens]

My point wasn't the blurriness... My point is the 2560x1600 subtitles to be rendered as-is despite video's resolution. What you see on the image is still your Subfilter with billinear. I was just trying to show the perfect resolution on a full screen video ( without being distorted 'cause of the scale ).

In a so high resolution you don't even need anti-aliasing... It's smooth anyway. You know, Potplayer does exactly what I'd prefer by your Subfilter, but unfortunately it doesn't provide higher resolutions. On Potplayer for instance, I can have 16px fonts on all videos, fullscreen or not and certainly unrelated to original video sizes.

Also, for some reason MPC HC ISR does not give me 1600p resolution anymore. I don't know why.

Anyway, thanks for the general info you provided.

P.S. Damn, I am not good at English and apparently I become tedious whilst I could make my point in one phrase or two. I apologise.

[cyberbeing]

Originally Posted by Raylan Givens

My point wasn't the blurriness... My point is the 2560x1600 subtitles to be rendered as-is despite video's resolution. What you see on the image is still your Subfilter with billinear. I was just trying to show the perfect resolution on a full screen video ( without being distorted 'cause of the scale ).

In a so high resolution you don't even need anti-aliasing... It's smooth anyway. You know, Potplayer does exactly what I'd prefer by your Subfilter, but unfortunately it doesn't provide higher resolutions. On Potplayer for instance, I can have 16px fonts on all videos, fullscreen or not and certainly unrelated to original video sizes.

Okay, so you just want to be able to set a constant (relative) font size under Styles for SRT subtitles, so you do not need to change it on videos of different resolution? Someone requested a function like this for SRT subtitles earlier in the thread, and we are considering it.

[madshi]

I think what he wants is "oversampling". Rendering to a higher resolution, then filter down. Basically similar to how "Supersampling" works for games. I think that's a valid suggestion. However, I don't like the idea to always render to a specific resolution specified by the user. That would make the options dialog more complicated than necessary. Instead I could imagine an option like "oversample 50%" and "oversample 100%" to render subtitles with 50% higher or double resolution. 50% higher for fullscreen playing with a FullHD display would be 2880x1620.

[cyberbeing]

I don't think that's the case madshi, as he seemed to make it clear that smoothness was not the primary goal in his request. He seems to just want a constant font size without degrading subtitle quality. Currently whenever the user-defined font style in settings is active, the relative font size will change whenever the original video resolution changes. This is a bit of a problem with SRT subtitles or when forcing a default subtitle style to use with all videos.

Originally Posted by madshi

Instead I could imagine an option like "oversample 50%" and "oversample 100%" to render subtitles with 50% higher or double resolution.

FWIW, all VSFilter based filters like XySubFilter already oversample font vectors to 800% output resolution. These massive vectors are then passed through a rasterizer which generates anti-aliased subtitle bitmaps at output resolution with 8x8 subpixel positioning. We have no intention of implementing game-like "supersampled" anti-aliasing of oversampled bitmaps internally, as its very expensive to do via CPU.

[madshi]

You wouldn't have to downsample via CPU. You'd just have to render subtitles to a 50% higher bitmap resolution and feed that to madVR. madVR would then automatically scale that down. At least I think it should. So basically the only added cost would be that instead of rendering to 1920x1080 you would render to 2880x1620. The rest of the work would be done by madVR, and it wouldn't cost much performance, thanks to bilinear filtering hardware in the GPU. That said, I don't know if it would look any better. Maybe it would look even worse, I don't know. It was just a thought...

[Raylan Givens]

Originally Posted by cyberbeing

He seems to just want a constant font size without degrading subtitle quality.

Exactly that... As simple as it gets. Just 2560x1600 resolution at default 18px subtitles on all videos. That's it! I'm not talking about anti-aliasing. Just the crisp high-res subs at a standard size despite video's resulution.

Also, I just found that if I set on MadVR Image Upscaling to Billinear destroys the subtitles quality when in full screen... Is it known bug? Check this image:

http://i1.minus.com/ibeZbjR0h4NTvM.png

I tried both subpixel position methods, 8x8 bilinear and 8x8 2.39 with no results. Even worse on "nearest neighbor" http://i4.minus.com/ibmA9L32N8M77X.png -so I'm even not sure whether this is a bug or not... Perhaps it might be expected.

Incidentally, could you please tell me what's the shortcut for subtitles delay +/- ( equilavent of default F1/F2 )? I can't find it...

[Soukyuu]

From what I understand, the resizing of the subtitles is handled by madvr, so the results are to be expected. Nearest neighbor, as the name implies, picks the nearest value without interpolation, so ugly results are to be expected, especially on edges. Bilinear interpolation, being linear, still has some artifacts, which is why bicubic is the lowest I would use.

[cyberbeing]

Originally Posted by Raylan Givens

Also, I just found that if I set on MadVR Image Upscaling to Billinear destroys the subtitles quality when in full screen... Is it known bug? Check this image:

http://i1.minus.com/ibeZbjR0h4NTvM.png

I tried both subpixel position methods, 8x8 bilinear and 8x8 2.39 with no results. Even worse on "nearest neighbor" http://i4.minus.com/ibmA9L32N8M77X.png -so I'm even not sure whether this is a bug or not... Perhaps it might be expected.

That's a madVR bug. It would need to be reported on madshi's bug tracker for it to be fixed.

Originally Posted by Soukyuu

From what I understand, the resizing of the subtitles is handled by madvr, so the results are to be expected. Nearest neighbor, as the name implies, picks the nearest value without interpolation, so ugly results are to be expected, especially on edges. Bilinear interpolation, being linear, still has some artifacts, which is why bicubic is the lowest I would use.

No, XySubFilter usually renders directly to output resolution without any scaling being performed by madVR. The only time madVR scales subtitles itself is when you are using a bitmap format like VOBSUB/DVB/PGS, or you have the "Render to Original Video Size" option enabled for Text subtitles.

Assuming those are text-based subtitles, appearance of those screenshots makes it look like madVR is not handling the subtitle bitmaps correctly when those "texture-based" default GPU resize algorithms are used, compared to the custom madVR "shader-based" resize algorithms. madVR is probably missing a shader pass somewhere and blending subtitles at the wrong time in the processing chain.

Originally Posted by Raylan Givens

Incidentally, could you please tell me what's the shortcut for subtitles delay +/- ( equilavent of default F1/F2 )? I can't find it...

MPC-BE nightly builds from the past couple weeks support using the default F1/F2 hotkeys with XySubFilter.

Otherwise, you'd need to ask your media player of choice to support this via the IDirectVobSub interface.

Originally Posted by madshi

You wouldn't have to downsample via CPU. You'd just have to render subtitles to a 50% higher bitmap resolution and feed that to madVR. madVR would then automatically scale that down. At least I think it should. So basically the only added cost would be that instead of rendering to 1920x1080 you would render to 2880x1620. The rest of the work would be done by madVR, and it wouldn't cost much performance, thanks to bilinear filtering hardware in the GPU. That said, I don't know if it would look any better. Maybe it would look even worse, I don't know. It was just a thought...

Yeah I know, I was just addressing why we do not perform supersampling like that within xy-VSFilter/XySubFilter. You would really need to supersample by 2x2, 4x4, or 8x8 output resolution for it to have any positive effect on quality. Even then the benefit is rather questionable considering you are increasing computation cost by an order of magnitude. In the future, there is still potential to increase the output quality of the rasterizer without resorting to this.

[Soukyuu]

Originally Posted by cyberbeing

No, XySubFilter usually renders directly to output resolution without any scaling being performed by madVR. The only time madVR scales subtitles itself is when you are using a bitmap format like VOBSUB/DVB/PGS, or you have the "Render to Original Video Size" option enabled for Text subtitles.

So I at least partially got it right for the two latter cases :P

I don't see how that's a madvr bug though, the results are to be expected unless Raylan Givens renders the subs to output resolution, not video resolution.

[cyberbeing]

Originally Posted by Soukyuu

So I at least partially got it right for the two latter cases :P

I don't see how that's a madvr bug though, the results are to be expected unless Raylan Givens renders the subs to output resolution, not video resolution.

The issue occurs when XySubFilter is passing madVR subtitle bitmaps at output resolution. madVR should not be scaling anything, so it's a bug. It's actually something I reproduced before we released XySubFilter Beta, but I forgot to mention it to madshi. So you could say it's a known issue with madVR currently.