LAV Filters - DirectShow Media Splitter and Decoders

[SeeMoreDigital]

Originally Posted by nautilus7

...I got confused (with the way Nev put it) that my file was not actual DSD, but PCM at 352KHz and LAV filters only convert it to 48KHz or 96KHz or whatever...

Yes it's a DSD stream. Which has been transcoded by LAV to a PCM stream.

Over the years there's been loads of heated discussions on various forums about 'the best way' to transcode DSD to PCM along with which sample rates and bit-depths should be used.

Personally, I'm just happy that after many years it's now possible to actually play 2-channel and multi-channel DSD streams using a software player on a PC.

Refinement of the DSD-to-PCM process probably deserves a topic of its own

[CruNcher]

Originally Posted by nevcairiel

TPDF is generally more useful with audio, imho, since the built-in high pass helps to shift noise into higher frequencies, for video I don't think the same principles apply as such.

LAV uses standard random dithering, or ordered dithering, depending on the settings, and both as weak as possible, ie. only affecting any high bit depth data that would be cut off otherwise, and as such only ever modifying at most one bit in the output.

When I introduced these two modes they have shown to be quite effective without a perceived increase in noise. That said, if you use a modern renderer like madVR, LAV wouldn't ever be in a situation where it even had to perform dithering, as the image can be passed to the renderer untouched.

But is this also currently happening in the exact scenario you describe here between Lav-Video->MadVR ?

So Lav-Video isn't going to dither then on the CPU and leaves the decision up to the Renderer in this case MadVR (so a dynamic pass it Untouched is being done and any Lav-Video dithering setting ignored automatically) ?

[nevcairiel]

LAV only ever dithers if it reduces the bitdepth of the image in any way. This just does not happen when you use madVR (and you didn't change the LAV default settings, ie. turned off output formats).
Even with other renderers it doesn't happen with the majority of content, ie. if you output normal 4:2:0 8-bit content as NV12 or YV12 to EVR, there is no dithering in LAV, because its not needed.

Thats the most basic thing about dithering, its entire purpose is to spread the "error" when you reduce the bitdepth of a signal. If you don't reduce the bitdepth, you don't dither.

[CruNcher]

so if the case is

Main10->p010->MadVR->Driver 8 bit out

CPU dithering will not take place from Lav-Videos side ?

Main10->p010->nv12/yv12->MadVR->Driver 8 bit out

CPU dithering will take place from Lav-Videos side ?

[nevcairiel]

No, since P010 is full untouched 10-bit 4:2:0.

[CruNcher]

But if you disable p010 as output format which then does a nv12/yv12 conversion so the second case then yes not No ?

in this case here Lav Video dithering takes place in this example Ordered Dithering ?



And in this case you can't avoid the dithering you just doesn't allow it to be untouched because if would cause severe visible banding in this specific example, do i understand it right and the logic behind your GUI decisions and the enforcement of the dithering option ?

[nevcairiel]

Like I said, if LAV reduces the bitdepth, then it dithers. And only then. Its really not any more complex.

[CruNcher]

Ok at least things i posted previously where valid then and i understood it correctly whats going on

Would be still nice to have the option to avoid the CPU dithering entirely in that case and get the pure untouched 8 bit output, that should look more like this untouched by the dithering

[huhn]

seriously for what?

outputting P010 is faster and cheaper...

[nevcairiel]

Originally Posted by CruNcher

Would be still nice to have the option to avoid the CPU dithering entirely in that case and get the pure untouched 8 bit output, that should look more like this untouched by the dithering

There is no "pure untouched 8 bit output" if the file is 10-bit, you have to touch it in some way to make it 8-bit, and the correct way to do that is by dithering. Disabling dithering is just wrong and should never be done, hence LAV will never allow it.
If you don't want LAV to dither, then output the proper bitdepth.

[CruNcher]

Ok i meant non dithered 8 bit output that shows banding untouched was just meant in the way of non dithered not non converted testing the debanding this way seems interesting as its very high quality banding that you can straight process with it

[nussman]

Originally Posted by CruNcher

Ok i meant non dithered 8 bit output that shows banding untouched was just meant in the way of non dithered not non converted testing the debanding this way seems interesting as its very high quality banding that you can straight process with it

And that "would be still nice to have"? Why?
Your posts about dithering all over doom9 are really hard to unterstand (pure nonsense imho).

[bongobarry]

Question on output levels for full range (0-255)

I have my TV set to accept levels from 0-255 - I know that my TV can accept and display these levels because I've sucessfully tried the AVS HD709 calibration disc on two separate blu-ray players.

However, when playing AVS HD709 files via LAV filters and MadVR, only limited range is played. I have an NVIDIA GT640, which I know is outputting full range 0-255 as desktop - I've tested it.

When I do a CTRL+J during play-back of the BTB and WTW levels on AVS HD709, MadVR reports that the input levels are Limited (says upstream).

Is LAV Video incorrectly reporting the output levels of this test file?

[huhn]

no everything is working as intended.

the video file is flagged as limited range and madVR is doing the rest.

the AVS HD709 black clipping file is created in a way that it is reporting limited range but the video signal holds full range data.
16 and lower are black else your setup is wrong.

the lavfilter range setting has nothing todo with that this is only used when lavfilter is converting to RGB and that is something that is not going to happen with madVR so it doesn't matter what you select there.

[bongobarry]

I'm not sure that I understand. The black clipping file contains video signal which goes below 16 (ie BTW). On my setup currently (LAV & MadVR), I'm unable to see 16 and below

If the signal is there in the file, why am I unable to see it on my TV? The signal from 16 and below is presented when I play the same file on a blu-ray player.

[nussman]

Unable to see 16 and below is right.

Your bluray player sends limited range (?) and you tell your TV to expect full range (=> 16 and below is visible => wrong).
If you set up your TV to expect limited range it should be ok with your bluray player (16 and below = black)

[huhn]

than your BD player chain is setup wrong.

if your BD player is outputting limited range and your TV is setup to full range you would see 16 and below.

just as a reminder this is wrong 16 and low is supposed to be black.

this has nothing todo with lavfilter.

[bongobarry]

My TV is set to expect full range. My NVIDIA card is set to output full range. MadVR is set to output full range. The AVS HD709 file contains full-range content.

If I turn-up the brightness on my TV, the black bands below 16 should be visible, if the player is outputting 0-255.

If the BTB (0-16) video content is there in the file, why is it not being sent to my TV?

[clsid]

The BTB content is present in that file so you can see if your playback chain is configured correctly or not. If it is all black then things are correct. If you can see those bars then things are configured incorrect!

[nevcairiel]

Originally Posted by bongobarry

My TV is set to expect full range. My NVIDIA card is set to output full range. MadVR is set to output full range. The AVS HD709 file contains full-range content.

Technically, the AVS HD709 files contain limited-range with BTB/WTW content. Its a distinction to actual full-range content.

Its meant to be played as limited range, so you can use BTB/WTW to calibrate the black point (ie. tune it in such a way that 1-16 all look the same - black). However, if you use full-range output, there is no room for BTB/WTW anymore, since you use the full range for the relevant image signal - and you can tune the blackpoint differently, ie. by tuning brightness so that you can barely make out the distinction between 0 and 1.

As others have said, it contains the BTB content so you can test if your playback system is setup properly - and "proper" here is that you cannot actually see 1-16, its meant to be invisible.