LAV Filters - DirectShow Media Splitter and Decoders

[Xaurus]

Originally Posted by mzso

How much are hardware deinterlacers better? (and why?) By the way, if ffdshow has yadif couldn't LAV too?

Just my 2 cents:

There is a world of difference between hardware deinterlacing and YADIF. For example, with LAV CUVID I get no combing or artefacts what so ever and it's smooth as silk except for a few panning issues (which applies to both methods). I would never go back to software deinterlacing.

[Stephen R. Savage]

Originally Posted by Xaurus

Just my 2 cents:

There is a world of difference between hardware deinterlacing and YADIF. For example, with LAV CUVID I get no combing or artefacts what so ever and it's smooth as silk except for a few panning issues (which applies to both methods). I would never go back to software deinterlacing.

Imo, there's still nothing that beats (Q)TGMC, which can even be run in realtime at up to 720p with marginally reduced quality. Unlike other deinterlacing methods, motion-compensation processes can actually recover "lost" information from adjacent frames.

@nevcairel: I want to ask r.e. the new colorspace conversions, are they free from issues with hue shift like the ones in ffdshow for 10-bit --> 8-bit conversion? I have some 10-bit H.264 encodes that were created with dithertools, and presumably free from 8->10 errors.

Edit: Never mind, downconversion is bit-exact between ffdshow and LAV, leaving the source of the ever-present hue shift still unknown.

[nevcairiel]

Originally Posted by Stephen R. Savage

Imo, there's still nothing that beats (Q)TGMC, which can even be run in realtime at up to 720p with marginally reduced quality. Unlike other deinterlacing methods, motion-compensation processes can actually recover "lost" information from adjacent frames

The only interlaced content i watch are Blu-rays, which are 1080i, and the hardware deinterlacer is the only high-quality adaptive algorithm that works in realtime on those.
It does actually do some sort of motion compensation, but the vendors are not too keen on disclosing implementation details.

Originally Posted by Stephen R. Savage

Edit: Never mind, downconversion is bit-exact between ffdshow and LAV, leaving the source of the ever-present hue shift still unknown.

Right now it is the same as ffdshows, the next version (thats when those new conversions actually make it in) will have mathematically perfect conversion from 10 to 8 (plain down-shift with dithering)

[Thunderbolt8]

can you get this one always to play fine? http://www.mediafire.com/?8y4afgs2yf20td6 (sample of South Pacific BBC 1080i25 VC-1)

seems to be acting up sometimes, not sure whether due to splitter, WMV DMOdecoder or maybe LAV audio

[hoborg]

Offtopic question:
I got new TV with HDMI input, so i connect it with my HTPC (Radeon 6450) by HDMI and set sound over HDMI.
But now i have some problems with multichanels audio - some chanels are nearly mutted. Before i used analog stereo speakers without any problem.
I am using LAV audio decoder -> ReClock on WinXP.
Is it possible somehow downmix mutlichannels to stereo? I didnt found such option anywhere in WinXP/ReClock/LAV audio decoder setting.
I think this should fix the problem.

[CruNcher]

Originally Posted by Thunderbolt8

can you get this one always to play fine? http://www.mediafire.com/?8y4afgs2yf20td6

seems to be acting up sometimes, not sure whether due to splitter, WMV DMOdecoder or maybe LAV audio

The issue looks familiar same problem as with the Beyonce sample back then it stops @ the beginning only seeking is making it to play (most probably damaged @ the beginning)
Though you should see that VC-1 Timestamp correction is on Auto else you would get a Black screen even after seeking.
But this doesn't seem like a Big problem not as heavy at least as my demonstrated MPC-HC EVR Custom & Sync problem here http://mirror05.x264.nl/CruNcher/mpc-hc/ (please wait for it to be fully loaded i still have to improve the progressive streaming @ the 1:35 mark those aren't performance issues @ recording but VBV problems with Quicksync )

[Kotik]

Originally Posted by hoborg

Offtopic question:
I got new TV with HDMI input, so i connect it with my HTPC (Radeon 6450) by HDMI and set sound over HDMI.
But now i have some problems with multichanels audio - some chanels are nearly mutted. Before i used analog stereo speakers without any problem.
I am using LAV audio decoder -> ReClock on WinXP.
Is it possible somehow downmix mutlichannels to stereo? I didnt found such option anywhere in WinXP/ReClock/LAV audio decoder setting.
I think this should fix the problem.

Yes it is possible by adding ffdshow as postprocessing and configuring it to do the downmixing to stereo.

All this till Nev adds downmixing in LavAudio.

[hoborg]

Originally Posted by Kotik

All this till Nev adds downmixing in LavAudio.

Donwmix is planned in LAV audio decoder? Good

[nevcairiel]

You can also just not use WASAPI, and let the Windows mixer do downmixing - at least on Win7 that will work pretty good.

[hoborg]

Originally Posted by nevcairiel

You can also just not use WASAPI, and let the Windows mixer do downmixing - at least on Win7 that will work pretty good.

My HTPC is based on WinXP. If i am not wrong, WASAPI is not present on WinXP.

[kalston]

Originally Posted by hoborg

My HTPC is based on WinXP. If i am not wrong, WASAPI is not present on WinXP.

Correct. For now I use ffdshow to do it.

[CruNcher]

depending on the hardware your htpc consists off you should really take a move to NT 6 Vista/Win7 into consideration it solves a lot off multimedia issues and doesn't make third party stuff needed for everything (also the possibility of less interoperability problems with different Hardware when using acceleration)
The Power saving also works much better it doesn't cause extreme spikes as on XP, that lowers the risk of unexpected framedrops also High Resolution timers are a improvement here (Hardware dependent).

[hoborg]

@CruNcher:
Yes, i known.But...
I spend a lot of time to configure my HTPC to work as i would like to be working, identify freezing durning wake up (thanks to TV card) + found a solution - for this i created "plugin" for MCE standby tools which disable/enable TV card durning standby/resume + "fullresume" while HTPC resume for recording. I even created my own "codec pack" - SAF, just to fit my HTPC needs . Setup remote contorler to work with my HTPC so even my wife can easilly control it (i dont have mouse/keybard connected), silent DVD drive even after wakeup, modify WinXP to not look like windows, media sharing ower network, be able to start/exit games by remote and control them by gamepad (like game console),etc, etc,... Right now i am very happy how it is working, moving to Win7 x86 is planned, but i really don't want to start from begin

BTW, i have two small kids home, so i really dont have much time to do such a big task

[betaking]

found a bug lavfilters can not use lavvideo to decoder this mpeg file!
Format : MPEG-PS
File size : 63.1 MiB
Duration : 4mn 13s
Overall bit rate : 2 086 Kbps

Video
ID : 224 (0xE0)
Format : MPEG Video
Format version : Version 1
Format settings, BVOP : Yes
Format settings, Matrix : Default
Duration : 4mn 13s
Bit rate : 1 789 Kbps
Maximum bit rate : 1 800 Kbps
Width : 352 pixels
Height : 240 pixels
Display aspect ratio : 4:3
Frame rate : 29.970 fps
Standard : NTSC
Color space : YUV
Bit depth : 8 bits
Scan type : Progressive
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.706
Stream size : 54.1 MiB (86%)

Audio
ID : 192 (0xC0)
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 2
Duration : 4mn 13s
Bit rate mode : Constant
Bit rate : 256 Kbps
Channel(s) : 2 channels
Sampling rate : 48.0 KHz
Compression mode : Lossy
Delay relative to video : -67ms
Stream size : 7.74 MiB (12%)
MPC-HC only use lav splitter and lav audio!

[pirlouy]

Originally Posted by Kotik

Yes it is possible by adding ffdshow as postprocessing and configuring it to do the downmixing to stereo.

All this till Nev adds downmixing in LavAudio.

Except that it does not work in my case. Even if I add ffdshow audio processor (in MPC-HC "prefer" external filter), it never
shows after LAV audio. I don't understand. :/

Originally Posted by nevcairiel

You can also just not use WASAPI, and let the Windows mixer do downmixing - at least on Win7 that will work pretty good.

Windows does that automatically or there's an option ?!!

[fastplayer]

Originally Posted by pirlouy

Windows does that automatically or there's an option ?!!

Just select the correct speaker-setup in the Control Panel settings of your sound-card and let the mixer do the rest.

[nevcairiel]

I mostly finished the implementation of the new RGB converter, roughly modelled after ffdshows HQ implementation, but with two key enhancements:

- Faster and more accurate chroma upscaling (ffdshow assumes MPEG-1 Chroma siting, while most content is using the MPEG2/H264 siting)
--- I do plan to support the MPEG1 version as well at some point in time, but its no pressing issue
- Increased processing bitdepth to natively support 9/10bit content

The code will always use dithering, because i've found that disabling dithering doesn't yield a worthy performance increase.
My implementation is not yet multi-threaded, but i'm not sure if thats actually needed. I'll see about that.

Below some performance numbers from my i7 2600k, decoding and processing a 1080p 4:2:0 H264 movie

- Decoding w/ YV12 output: 253 fps
- Old low-quality RGB conversion: 235 fps
- Old high-quality RGB conversion: 40 fps
- New RGB conversion: 180 fps
- New RGB conversion without dithering: 183 fps

And for fun:
- New RGB conversion in Debug mode: 20 fps.
Don't watch stuff with a debug version, people!

Speaking of multi-threading, anyone know a simple threadpool implementation that does not require me to use boost?

[Xaurus]

nevcairiel,

Is this anything that is beneficial for us LAV CUVID users?

[Thunderbolt8]

please add multitheading if possible, there are other tweaks like sharpening or deinterlacing (ffdshow) or VC-1 decoding which are all only single threaded and already take a good amount of power from 1 core. more of such filters & co. which only work with 1 core will eventually lead to speed problems which could be avoided with multithreading support

[nevcairiel]

I will eventually offer some post-processing, at first only the filters implemented in libavfilter (mostly for yadif), anything else .. we'll see.
I would like to do some plugin type thing, maybe it'll happen. Not soon, though.

Personally, i just don't use post-processing much.