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More => Old Versions => JRiver Media Center 29 for Windows => Topic started by: jmone on August 05, 2022, 05:58:49 am

Title: HW Deinterlacing (SW vs HW)
Post by: jmone on August 05, 2022, 05:58:49 am
I've had more of a play with various settings in JRVR and LAV Video to see why on Interlaced Broadcast TV (from an HD Home Run) why I see relatively poor deinterlacing performance using the default JRVR settings.  With the MC JRVR default settings, I see combing issues come and go, and artefacts (like haloing) more obvious.  If I set LAV Video (under Custom) from D3D11 to CUVID the and enable "Adaptive HW Deinterlacing" rather than using SW Deinterlacing (BWDIF / Weston / YADIF) not only is the deinterlacing better but the haloing is less.

I know CUVID is deprecated, but access to nvidia's HW Deinterlacing (no idea on Intel or AMD) beats the various SW implementations on offer. 
Title: Re: HW Deinterlacing (SW vs HW)
Post by: Hendrik on August 05, 2022, 02:02:25 pm
Can you share a sample recording that shows obvious differences between CUVID and just letting JRVR deal with it? (a recording of the original TV signal, not of the differences, naturally)
Title: Re: HW Deinterlacing (SW vs HW)
Post by: jmone on August 05, 2022, 04:21:44 pm
Will do - I'll record a game and find a section
Title: Re: HW Deinterlacing (SW vs HW)
Post by: jmone on August 06, 2022, 06:52:56 pm
Here is a sample - https://behome.dyndns.info/index.php/s/dTwiHFADoBWHPQs from the original TS recorder cut into a MKV wrapper.  Yup this is the "quality" we are stuck with on some channels - 1080/50i @ 5mbps.  Nothing I can do about that, but below is a screen shot for the 14sec mark showing that on JRVR (Autoconfigured) you can see the poor deinterlacing, and with CUVID it does not (same JRVR settings, just with LAV Video set to CUVID and HW Deinterlacing turned on).

Title: Re: HW Deinterlacing (SW vs HW)
Post by: jmone on August 12, 2022, 04:03:29 am
Hi Hendrik,  Any thoughts?
Thanks
Nathan
Title: Re: HW Deinterlacing (SW vs HW)
Post by: Hendrik on August 12, 2022, 05:31:38 am
Yes, you should cancel this horrible TV service, and sue them for calling this HD.

Otherwise, not yet.
Title: Re: HW Deinterlacing (SW vs HW)
Post by: jmone on August 12, 2022, 06:26:09 am
I know..... when the FTA providers went digital they decided to launch more channels and crunch the bandwidth so they could.
Title: Re: HW Deinterlacing (SW vs HW)
Post by: jmone on August 21, 2022, 04:12:20 am
Any thoughts at this stage?
Thanks
Nathan
Title: Re: HW Deinterlacing (SW vs HW)
Post by: Hendrik on August 22, 2022, 09:17:29 am
There isn't really anything to be done. JRVR just uses D3D11 hardware deinterlacing, which is as much as a black box as CUVID deinterlacing is, and governed by the driver/GPU. You are not actually involving any software deinterlacing there.

Some work is under way to actually port YADIF or another software deinterlacer into a GPU shader, to allow it being used in combination with hardware accelerated decoding, and making use of GPU resources. It should at least provide consistent quality and resolve combing in most cases, although perhaps at the expense of a bit sharpness.
Title: Re: HW Deinterlacing (SW vs HW)
Post by: jmone on August 23, 2022, 04:12:37 am
Thanks Hendrik - I only see the combing issue (it comes and goes during playback) on poor quality interlaced material.  I first saw it on old DVD recordings of AC/DC, but then it appeared in these current DVB-T broadcasts.  It is very distracting.  Never knew it was a D3D11 issue.