LAV Filters - DirectShow Media Splitter and Decoders

[blaubart]

Ok, some progress, I'm not so often working on the 4k-PC so i've forgotten some important - the restricted output (YCbCr420) of the GTX960 on 3840*2160.
I remembered when I saw the 2 screenshots in post #20939 on a RGB outputting Intel GPU - no differences! Strange enough what code a png image, shot with 'Native' contains to show banding only through YCbCr420 and the other 'Copy-back' png not!

So next test - switching the GTX960 from 2160p to 1080p + RGB output - playing the demo and actually no more differences between DXVA2 Native and Copy-back!
What causes 'Native' to produce stronger banding through YCbCr420 using any renderer and 'Copy-back' not - no idea!

Now I hope the always remaining slight banding might vanish through a real 10-bit output into a real 10-bit TV or Monitor, that would make me and my Snake-demo happy


@ madshi
..and for a real 10-bit output we need a madVR performing a reliable 2160p! :
Naturally I always test madVR as well.
When the GTX960 was at 1080p madVR had no probs switching fullscreen with LAV 'Native'. So its just the screen resolution 2160p causing a black fullscreen. And extremely slow FSE switching at Copy-back (MPC-HC).

[madshi]

Hmmmm... So you get it working with madVR with a 1080p resolution? The problem with the black screen only occurs with 2160p? Which refresh rate are you using? At 60Hz some GPUs and/or displays are limited to YCbCr 4:2:0, but at 24Hz RGB 4:4:4 should be possible.

[nussman]

2160p RGB (4:4:4) @60hz (50hz?) @10bit is limited by hmdi bandwidth isn't it?

[blaubart]

Originally Posted by nussman

2160p RGB (4:4:4) @60hz (50hz?) @10bit is limited by hmdi bandwidth isn't it?

yes I heared sth. like HDMI 2.0a and b, only new a is 4:4:4?
My 'old' GTX960 has just HDMI 2.0 nothing known abot a/b?

Originally Posted by madshi

Hmmmm... So you get it working with madVR with a 1080p resolution? The problem with the black screen only occurs with 2160p? Which refresh rate are you using? At 60Hz some GPUs and/or displays are limited to YCbCr 4:2:0, but at 24Hz RGB 4:4:4 should be possible.

Yes, I even forgot this - just switched from 50Hz to 30Hz and now Nvidia sais 2160p 'RGB full' and 8 bpc. But with LAV at Native madVR fullscreen still black. The sound is playing and normal OSD on a black screen.

But for 10-bit FSE were needed and Copy-back needs the half demo to switch FSE. I'm not dreaming to get 10-bit 2160p out of my GTX960. I not even have a 10-bit TV (not sure) this here is all mentioned for the future..

[DragonQ]

I'm using WebMediaPortal to watch TV outside of my home and it has an option to generate an m3u file to play transcoded streams in external players. I have tried playing it in MPC-HC using LAV Filters but almost every time I end up with no video, although the audio works fine. LAV Filters doesn't even recognise there is a video track. The weird thing is that sometimes it works fine, and playing the RTSP stream directly (no transcoding) works fine every time.

Debugging this is proving difficult. Is there a way to look at debug logs or something from LAV Filters to see if it's encountering an issue with the stream, or whether the issue is purely server-side?

[madshi]

Originally Posted by blaubart

Yes, I even forgot this - just switched from 50Hz to 30Hz and now Nvidia sais 2160p 'RGB full' and 8 bpc. But with LAV at Native madVR fullscreen still black. The sound is playing and normal OSD on a black screen.

But for 10-bit FSE were needed and Copy-back needs the half demo to switch FSE. I'm not dreaming to get 10-bit 2160p out of my GTX960. I not even have a 10-bit TV (not sure) this here is all mentioned for the future..

Strange thing. If only I could reproduce any of that on my PC. I'm getting a 4K display soon, maybe that will help. But nobody else is reporting this issue atm, so I have my doubts I'll be able to reproduce it with the 4K display, either. Just to be safe: So you get a black screen even if use 1080p display resolution, correct?

[blaubart]

Originally Posted by madshi

Just to be safe: So you get a black screen even if use 1080p display resolution, correct?

No. Remember #20947 ?
>>> When the GTX960 was at 1080p madVR had no probs switching fullscreen with LAV 'Native'. So its just the screen resolution 2160p causing a black fullscreen<<<
Later I tried 2160p @ 30Hz 'RGB full' - still black fullscreen.

Just found out - naturally a GTX960 supports 2160p 50/60Hz RGB full 4:4:4 over HDMI 2.0 ! It was my LG Display just accepting YCbCr420 at 2160p 50/60Hz.

Strange thing. If only I could reproduce any of that on my PC. I'm getting a 4K display soon, maybe that will help.

Good to hear! 4k will knock you down, that's for sure! Windows complete super tiny, will need 150%..

But nobody else is reporting this issue atm, so I have my doubts I'll be able to reproduce it with the 4K display, either.

hmmm, at least one else came from the LAV chief himself:
http://www.dvbviewer.tv/forum/topic/...-4#entry432470

At this time madVR performed also windowed black. Today only 4k fullscreen remaining. Of course it may depend on numerous factors. But I'm quite confident '4k in madshis house' will soon change everything.
At <30Hz 2160p madVR performs ok (except the LAV Native fullscreen). But at 50/60hz Copy-back FSE becomes critical. And please regard also DVBViewer, he is very unstable on 4k-channels.

We could furthermore talk about this e.g in madVR topic on German DVBViewer forum (there I'm craig_s, remember? ) or whatever Forum you like. But please not in horrible doom9-madVR thread..

Thank you nevcairiel for your patience!

[madshi]

Last post on this topic in this thread: That nevcairiel post in the dvbviewer forum was from August 2015. At that time madVR did not support receiving 10bit native DXVA surfaces from the decoder yet, which is why there was a black screen. Support for 10bit native DXVA was added in madVR v0.90.0 in January 2016. So the black screen problem you have now must have a different cause. I'll follow up in the dvbviewer thread once I have that 4K screen.

[blaubart]

Just switched from Win10 to Win7, same issue. *here

[chros]

Originally Posted by blaubart

Just found out - naturally a GTX960 supports 2160p 50/60Hz RGB full 4:4:4 over HDMI 2.0 ! It was my LG Display just accepting YCbCr420 at 2160p 50/60Hz.

Originally Posted by madshi

I'm getting a 4K display soon

Can I ask which one? Monitor or TV?
Choosing the right hardware chain (!) will be more crucial then ever was. Maybe we should create a whole new thread (e.g. called "Which hardware chain for lav+madvr playback?") for this purpose with a checklist in the first post.

[mandarynek82]

So which settings in LAV and MadVR will be the best for GTX 580? Btw still I can enable hardware acceleration only in dxva copy-back mode.

[ryrynz]

Originally Posted by mandarynek82

So which settings in LAV and MadVR will be the best for GTX 580? Btw still I can enable hardware acceleration only in dxva copy-back mode.

Your settings are fine. MadVR is a whole different kettle of fish and should not be discussed here. There are plenty of guides online to assist you with making decisions with that.

[mandarynek82]

Originally Posted by ryrynz

Your settings are fine. MadVR is a whole different kettle of fish and should not be discussed here. There are plenty of guides online to assist you with making decisions with that.

OK but how I can enable hardware acceleration? I'ts working only in copy-back mode.

[strumf666]

Copy-back is the preferred mode for most, unless some special circumstances apply.

[alexacolor]

There is an old problem with the non-occurrence of sound in the rtmp stream.
Also in such streams synchronization problem.
Here is an example of the flow:
rtmp://tv-penza.ru/live/1

Flash and VLC playing this stream with sound.

[LigH]

It's pretty hard to find reliable reports about the minimum hardware requirements to decode HEVC 1080p (as used in DVB-T2 HD in Germany) without GPU acceleration. Most discussions I found so far immediately switch the topic to "better get some CPU with GPU incl. hardware decoding support". That may mean exchanging the complete PC for some... and the question was rather if existing hardware is still good enough.

So - which CPU class would you consider a minimum for decoding 1080p HEVC with LAV Filters?

In my experience, an AMD Phenom-II X4 is just not fast enough, most probably due to the lack of instruction sets much better than SSE2. I guess an FX era QuadCore may be able... And regarding intel, a Core i# Quad should be a rather safe bet; I read a Core2 Duo is not.

P.S.: Another fresh report about an E7500 DualCore being close to the threshold.

[sneaker_ger]

Originally Posted by LigH

In my experience, an AMD Phenom-II X4 is just not fast enough, most probably due to the lack of instruction sets much better than SSE2. I guess an FX era QuadCore may be able... And regarding intel, a Core i# Quad should be a rather safe bet; I read a Core2 Duo is not.

Read some reports about mobile Intel Core i5 dual core being more than sufficient. My Core i7-860 (1st gen i7, 2009) does some 500 fps on German DVB-T2 with LAV 64. Unfortunately the popular DVB Viewer is 32 bit only. Lentoid decoder is much faster on 32 bit and older hardware in general, it seems. But it may have some bugs. It's worth a try, at least.

[Nevilne]

1) on your current pc, decode a vid to -null in ffmpeg and note the speed
2) check your cpu score on cpubenchmark.net
3) do some simple math
4) see which minimal cpu score you require

[huhn]

than you have an idea for one file...

it is heavily based on the used bit rate.

and than you can't ignore CPU instractions

[sneaker_ger]

Is ffmpeg now as fast as LAV in hevc decoding? Nevcairiel cherry-picked optimizations from OpenHEVC, originally.