Question / Help Very low FPS - Blackmagic Decklink Studio 2

[Tif]

Hi all,

Trying to run a stream of an event using a GoPro Hero5 - HDMI into Blackmagic Decklink Studio 2 - via OBS.
The FPS isn't getting higher than 5.37 despite lowering the bitrate down to 800.

The mac is quite old, but I was hoping I'd be able to achieve a higher FPS than that..

Mac Pro 2009 - 2x 2.66 Quad-Core Xeon.
OS X Yosemite (10.10.5)
16GB RAM
NVIDIA GeForge GT 120 512MB Graphics,
Blackmagic Decklink Studio 2 capture card
GoPro Hero 5 - running via mini HDMI to HDMI input.

Could it be the NVIDIA that's slowing things down? All settings in OBS are default other than the bitrate which I lowered.

Any suggestions, much appreciated!

Thank you

 

[Tif]

So, I had to figure out a work around the other night, but I'll be needing to stream again a week on Friday and looking to fix this issue I'm having.

As above, I have a MacPro 4,1. The Blackmagic Decklink seems to work nicely capturing my Hero5 via HDMI, but as soon as I stream, FPS is incredibly slow and on Facebook, it glitches/fails all together.
Am I right in thinking it's the NVIDIA GPU being crap? Or is it an issue with the BlackMagic?

I'm tempted to purchase a USB 3.0 PCI card as well as a Magewell 3.0 -HDMI (or equivalent).

Can anyone suggest anything? Needing to ensure the stream works well for next week.
Ideally, it'd be fantastic if I could switch between our presentation videos (DVI output) as well as the GoPro. If anyone can recommend a card with dual inputs?

Thanks,

 

[Narcogen]

You didn't say what resolution you're trying to capture, but from what I've read if you want to do more than 720p you pretty much need USB3.

The Stats window in OBS (as well as the log) will show you where the problem is occurring, either in rendering the scene, in compressing the stream, or, if it shows nothing, the bottleneck may be i/o between the capture device and the Mac. I have a Shuttle Intensity and it's designed to work with USB3. Not sure about the Decklink.

 

[Tif]

Bah, that would have helped! Thanks Narcogen,

Yes, in an ideal world - 1080p, but I realise our mac/bandwidth wouldn't likely cope with that so I'd be more than happy with a smooth 540/720p.

I've also just realised about the logs, probably why I haven't had much of a response.

I've added a log from last night. It was during a test of both a GoPro and a cheap, Logitech USB webcam. Nothing I change within the settings seems to increase the fps making me believe it's more of a computer issue...? Anyway, hopefully someone can make more sense of it than I can.

Cheers,

 

[Narcogen]

What kind of framerate do you get with a simple scene-- just a display capture, for instance? Does it start out at 30 and then drop when you add the Decklink or the webcam?

Are you using Studio mode?

 

[FreeKillZero]

I doubt it's your GPU. I can't pinpoint any one particular thing that's going on, but in the log, it looks like the Decklink is buffering and it gets slower the longer it's going on. Is it plugged into a USB hub or directly into the Mac Pro?

Also, OBS seems to be reporting that there's an "Unknown USB Audio Device" - not sure if that's related to the buffering.

With a Mac Pro - you -could- look at getting a USB3 PCI card and a Magewell external capture card (allows for more variety with USB3), but then you could get an internal Magewell PCI card as well, which should clear up any i/o bottlenecks.

 

[Tif]

Hi guys,
Thanks for the info.
I'll check using the display iSight for fps, then add the USB webcam and see what pops up on the log.

FKZ - The Decklink is a PCI card, though we also have a USB webcam which was connected at the same time of this log.

I've ordered a USB3 PCI as well as an external USB3 capture card. I did look at the magewell but unfortunately that's out of my budget. Don't suppose anyone has any dealings with this: https://www.amazon.co.uk/dp/B0749CW...liid=I3NT2IJDWQVZRF&colid=134NZ0NKQRT8R&psc=1

I know i'm potentially making things more difficult for myself by purchasing a cheaper capture card, but the price difference is quite a chunk...

 

[Tif]

Hi all, update...

I went and purchased a USB 3.0 PCI and an AGPTEK HDMI capture device. All fit in the mac pro and seem to be picked up ok through OBS.

Unfortunately however, I'm now only getting 2 FPS no matter the source.

I'm not looking for the 60FPS it's claiming, but I'm hoping for at least double figures...!

Can anyone suggest anywhere to look? I'm baffled and need this working for an event this Friday..!

Log attached.

Thanks for any help/suggestions!

 

[Narcogen]

The logfile ends where the stream attempt starts. To get a complete log you need to start streaming, stream for a bit, and stop streaming, then grab the logfile.

 

[Tif]

The logfile ends where the stream attempt starts. To get a complete log you need to start streaming, stream for a bit, and stop streaming, then grab the logfile.

Eurgh. That'll teach me to not read through properly.
I'll try again tomorrow and UL another log.

Cheers Narcogen.