Question / Help Blackmagic Decklink no option for 1080p 29.97fps

[DPS_dspicer]

We are using a setup with multiple in game cameras and on screen graphics using a Blackmagic ATEM switcher. So we are looking to use OBS to be the stream encoder using a Decklink capture card to ingest the 1080p 29.97fps SDI output from the ATEM switcher. However in OBS when I try to select the correct framerate theres no option for it. I can choose 1080p 59.97/60/50/25/23.98fps but no option for 29.97fps or 30fps.

Now we have been using Wirecast because it will see 29.97fps just fine, but it's encoder is clunky as all get out, so we would rather not use it because we don't get a good quality stream from it.

Does anyone know if there is a way to get OBS to see 1080p 29.97fps from the Decklink?

Thanks,

David

 

[paibox]

IIRC, at least the Blackmagic Intensity Pro for some reason outputs 1080i at 59.97 frames per second, it keeps switching the fields around for each frame (old frame top, new frame bottom).

Selecting 59.97 and using a non-2x deinterlacer shader should work fine.

 

[DPS_dspicer]

IIRC, at least the Blackmagic Intensity Pro for some reason outputs 1080i at 59.97 frames per second, it keeps switching the fields around for each frame (old frame top, new frame bottom).

Selecting 59.97 and using a non-2x deinterlacer shader should work fine.

Thanks for the quick response! Question for you I've tried selecting 1080i 59.97 and still got a blank screen. Do I need the deinterlacer shader and is it part of OBS?

Thanks,

David

 

[paibox]

The deinterlacer shader is indeed part of OBS, you select the deinterlacing method from the "Deinterlacing" box in the properties for the capture source to pick a shader.

BlackMagic/Decklink drivers are a bit touchy, it needs to be set to the same frame rate in the BlackMagic Control Panel to not simply produce a black screen. If you set that one to 1080i 59.97 and set the same in OBS, it should work.

The Decklink WDM thing may or may not work, it all depends on what the drivers feel like, using the Decklink Video/Audio sources and matching the resolution is usually the most sure fire way to make it work.

 

[DPS_dspicer]

The deinterlacer shader is indeed part of OBS, you select the deinterlacing method from the "Deinterlacing" box in the properties for the capture source to pick a shader.

BlackMagic/Decklink drivers are a bit touchy, it needs to be set to the same frame rate in the BlackMagic Control Panel to not simply produce a black screen. If you set that one to 1080i 59.97 and set the same in OBS, it should work.

The Decklink WDM thing may or may not work, it all depends on what the drivers feel like, using the Decklink Video/Audio sources and matching the resolution is usually the most sure fire way to make it work.

Thanks! I will try that this evening.

 

[DPS_dspicer]

So this doesn't appear to work. I've set the Blackmagic Control Panel to 1080i 59.97, but when I set OBS to the same and put the deinterlace mode to blend it's still a blank screen. I do get audio but no video. What's also odd is that when I go back into settings for the capture card then the configure panel to set the framerate and size it always goes back to NTSC 8bit 4:2:2 YUV.

I also don't see a WDM option when selecting the source.

Thanks,

David

 

[DPS_dspicer]

Update,

So I was able to get it to stay on 1080i 59.97 by selecting custom resolution and setting it to 1080 29.97 and turning on deinterlacing, but still no video just audio.

Thanks,

David

 

[paibox]

Sorry, I wish I knew what was up at this point, I've only used the Intensity Pro and the Shuttle, and I figured their SDI capture card would work in a similar fashion. :(

Does it only output in 10-bit color or something? OBS doesn't support the 10-bit color modes, can't say for certain if the rewrite will be able to do it, but maybe.

 

[DPS_dspicer]

Sorry, I wish I knew what was up at this point, I've only used the Intensity Pro and the Shuttle, and I figured their SDI capture card would work in a similar fashion. :(

Does it only output in 10-bit color or something? OBS doesn't support the 10-bit color modes, can't say for certain if the rewrite will be able to do it, but maybe.

So I looked it up and the ATEM switcher outputs a 10bit color depth... So I guess OBS is out for me then... Shame because I really like the encoding. Does anyone know if the new version of OBS they've been working on will accept a 10bit color depth?

Thanks,

David

 

[paibox]

There's no setting on the ATEM to make it output 8-bit YUV instead? 10-bit color depth isn't all that easy to handle in an application like OBS, since all the scene rendering is done on the GPU, it would require a lot of rewriting to handle one specific case used by very few devices.

It is possible that it could be done in the rewrite of OBS, as long as support for 10-bit textures is added, which unfortunately isn't all that trivial, but certainly more feasible than implementing it in the current version of OBS without breaking everything else.