Low FPS in preview when switching to YUY2


New Member

I wasn't sure if I should post a log file, since this is just during the preview. Basically, every time I switch from MJPEG to YUY2, my framerate goes from 30 (the listed maximum for MJPEG to 5... (the new listed maximum for YUY2)

Also, I'm mostly interested in YUY2 because a YouTube guide told me. I'm unsure the difference with encoding, or if I should care.

I suspect it's a Pc hardware problem. Looking for confirmation. Also, I have 1 bonus question down below.


Use case:
I'm using a mirrorless camera as a Webcam to connect via zoom / discord using the virtual camera option that's now native to one of the new version of OBS.

I also am looking to record this entire interaction. (bonus concern!) Best way I figured is running a 2nd instance of OBS. 1 will be broadcasting my Webcam output. The 2nd one will be framing and recording, let's say, the discord video window: a side by side grid of me consulting with my client. Also, it's very important I can record with 2 separate audio channels as output, just so I can balance them later. I don't know if YUY2 supports this or if I have to do some other work around (I'm a bit of a noob with anything to do with dual audio channels).

***CLARIFICATION: I am NOT running 2 instances when running into this framerate problem. This is merely my projected plan once I sort out the camera stuff. I've tested it and it works fine when using MJPEG encoding.



Sony A5100 -> capture card -> OBS virtual cam -> discord video calls

Also, I just upgraded my PC, so I have a new ryzen 5600x CPU, 32gb of bdie 3600mhz gskill ram, and plenty sufficient case, cooling, power supply, and mother board (can give specs if needed).

Yes, I didn't mention my graphics card... They're impossible to buy right now without a huge markup, or getting super lucky. (Trust me I looked). I'm using my old, and I'm getting substantially higher framerates in every single game I play. From stumbling at 20 to locked at 60. Needless to say, it's an MSI Radeon R9 280 Gaming card. I've overckocked it to around 1100 MHz. https://us.msi.com/Graphics-Card/R9-280-GAMING-3G


My guess:
OBS is looking at my grandpa graphics card and making assumptions that it can't actually output any higher than 5fps with YUY2, and so it just locks it at 5fos as a guess.


1) anyone know why people would recommend YUY2? Also, anyone know of a good way to parse separate audio channels so I can balance the mix after I'm done working with my clients? (also, to correct my audio/video sync delay with the virtual cam)
2) anyone know if my diagnosis is correct of the fps issue with YUY2?
3) any work arounds? (I'm still assuming I'll want YUY2, maybe I'm wrong)
4) anyone know if there's a way to both project my virtual camera feed, and then ALSO record a DIFFERENT scene (discord) using just a single instance of obs? Or is my solution of using 2 honestly easier? (seems fine, but idk if there's stability issues using 2 of them)


Thank you for reading. I know it's a solid, I tried to organize it as best I can. If you want to respond in-line, that works for me. I really appreciate the support, I've been searching everywhere for answers ❤


New Member
I looked into "native jmpeg encoders" on google and wasn't really able to understand it. Which hardware in particular has this limitation? If it's my graphics card, then it's a good thing I'm replacing it soon. If it's anything else, then I'm shocked that such a popular piece of gear doesn't have it.


My hardware? I put that in my message... unless you mean the hardware I left out. Uhh, motherboard is B550 Gigabyte Aorus Pro AC. If you still need more hardware info, please let me know which exact piece of hardware and I can get that for you.

Sorry, didn't realize the log could be helpful. https://obsproject.com/logs/LYt6i02DVV0JZMTx


Active Member
You're likely running into an issue with your capture device. What is it? If it's a USB2.0 device, that would explain why it's limited to 5fps for YUY2 -- that's an uncompressed format, which USB2.0 doesn't have the bandwidth for at reasonable framerates. MJPEG is compressed, and allows for a much higher framerate over the limited bandwidth.

The reason for YUY2 recommendations is because of the compression difference. But if your device doesn't have the bandwidth, it's useless. You need a USB3.0 capture device for this.


New Member
That makes perfect sense! I have a lower end capture device, so I'm sure you're right that I'm limited when it comes to USB throughput.

Thanks for examining why I might still want to care about upgrading, considering the YUY2 format being uncompressed. I'm gonna research more about the differences 8n quality between the two before I decide on a higher end capture card.

Thank you so much!