[solved] Is it possilbe to disable deinterlacing / watch interlaced video directly on TV? (1 Viewer)

[DM153743]

Hi,

first of all thank you for a such a great piece of software. Watching TV in SDTV quality is a bit annoying, because it is stuttering. HDTV (720p) works perfectly. After some investigation I know that the SDTV video material is broadcasted in interlaced form (576i with 25fps). Unfortunately the deinterlacing on the HTPC does not output 50fps constantly. I already read a few posts in the forum, the documentation in the wiki (including the troubleshooting) guide and tried a few settings. But nothing really helped.

My HTPC is connected to my tv via hdmi and according to the manual my tv supports the following signal standards via HDMI

a) 720x480i/p 60Hz RGB
b) 720x480i/p 60Hz YCbCr 4:4:4 / 4:2:2
c) 720x576i/p 50Hz RGB
d) 720x576i/p 50Hz YCbCr 4:4:4 / 4:2:2
e) 1280x720p 50/60Hz RGB
f) 1280x720p 50/60Hz YCbCr 4:4:4 / 4:2:2
g) 1920x1080i 50/60Hz RGB
h)1920x1080i 50/60Hz YCbCr 4:4:4 / 4:2:2
i) 640x480p 60Hz RGB

So I asked me if the deinterlacing on the HTPC is really necessary? I interpret this, that my TV is able to handle video material in interlaced form and I can omit deinterlacing on my HTPC. Is this really possible or I am wrong?

If so how can I disable deinterlacing (currently using the LAV filters)?
Which component of MP decides if deinterlacing needs to be done or not?

Best regards

Joerg

 

[HomeY]

Hi and welcome Joerg,

So I asked me if the deinterlacing on the HTPC is really necessary?

Yes, for the best Picture quality. 50 fps will look (a lot) better than 25 fps on your TV. 25 fps will look like it has hiccups or stutters.

Please post some logs for us to have a look at, but the first 2 things i would check are:
- What refreshrate is the monitor set to? Based on your TV & Location, that should be 50Hz. See Dynamic Refresh Rate wiki if you also play 24Hz material on your TV (that would be better of with a refresh rate of 60Hz, since your TV doesn't support 24P).
- Check your LAV Video settings and make sure DXVA is enabled.

 

[DM153743]

Thank you for your reply. I know that the some component needs to perform the deinterlacing step. The questions is which component in a typical setup can do it:

• HTPC
  
• AV receiver
  
• TV

I was unsure how to interpret the lines in the manual. Thats why I ask if deinterlacing can be done by a TV. Using the HTPC is not sufficent so far, needs further investigation and I tend to open another thread (including proper logs) especially for this. Hope that's ok.

Here I justed wanted to clarify which options I have besides deinterlacing on the HTPC. What about AV receiver for deinterlacing / upscaling the video matieral? Which component is best suited?

Regards

Joerg

 

[HomeY]

The questions is which component in a typical setup can do it:

• HTPC
  
• AV receiver
  
• TV

All 3 of the above should be capable. Based on the 'age' and specs of the devices, both the TV and AV Receiver should have a fairly good quality hardware deinterlacer.

Using the HTPC is not sufficent so far, needs further investigation and I tend to open another thread (including proper logs) especially for this. Hope that's ok.

Perfect!

Here I justed wanted to clarify which options I have besides deinterlacing on the HTPC. What about AV receiver for deinterlacing / upscaling the video matieral? Which component is best suited?

All based on the hardware deinterlacer integrated into the device, but they probably won't be able to match up with the deinterlacing algorythms used in nowadays GPU's.
I would suggest to start the new thread describing your issues, post some logs and let's see if we can make it work with software (LAV).

 

[DM153743]

Thanks Jeroen. If I want to test it with the hardware deinterlacer of my tv, how can I disable the deinterlacing in MediaPortal / the htpc and the tv gets the interlaced video?

Regards

Joerg

 

[HomeY]

how can I disable the deinterlacing in MediaPortal / the htpc and the tv gets the interlaced video?

1. You need to disable deinterlacing in your Video Codec
2. You need to set your screen to a deinterlace mode (1080i would be best in your case)

 

[Owlsroost]

post some logs and let's see if we can make it work with software (LAV).

I agree.

JoergD, what are your HTPC system specs ?

 

[DM153743]

I played a little bit with the resolution (1080i, 576i) and checked the fps on screen display (shift + 1) as before. My cabel provider broadcoasts some channels in hdtv and others in sdtv. I recognized a strange behaviour for fps calculation:

• Channels with hdtv always had 50 fps and channels with sdtv always had 41-44 fps.
• Changing the view mode on a sdtv channel from "normal" to "stretched" the fps switched to 50. Switching back to view mode "normal" 50fps are calculated. So I would say the view mode is not the problem.
• Switching to another channel and back to the sdtv channel 41-44 fps are shown again. Switching the view mode as before shows again 50 fps.
• I can not see any difference in quality between 41-44 fps are shown or 50 fps. In both situations there is no stuttering.
• The behaviour is independent from the choosen resolution

I started to find the correct configuration when I recognized stuttering the first time. Then I used the fps to verify if I have found the best settings. It seems I searched a phantom and tried to solve a problem which does not exist anymore.

For me the behaviour is strange and seems like a bug. What do you think? Do you have any idea / explanation for this?

Best regards

Joerg

 

[Owlsroost]

Please tell us what is your PC hardware and software setup ? - we can't help you without having more information....

Pretty much any modern PC graphics hardware can easily de-interlace SDTV, so if it can't then the settings in LAV Video Decoder are probably wrong i.e. it's not set up to use hardware de-interlacing and decoding.

 

[DM153743]

As stated in my previous post there is no stuttering anymore. The only thing is the chaning fps rate, even though I did not change anything in the codec configuration, display resolution, etc. Everything works as expected, so I set the title to solved. Thanks a lot for your help.

Best regards

Joerg