AV1 Software Encoding Problems with OBS Studio 30.1.1

Is there a way to force OBS Studio 30.1.1 to use more than 15 cpu threads? OBS said that it was skipping frames due to encoding lag with av1 AOM but the windows task manager indicated that the other 17 cpu threads were barely being utilized by OBS Studio 30.1.1 even with high process priority. (I also tested recording and live streaming with AV1 SVT encoder preset 8 with 10000 Kbps with the stable obs studio build 30.1.1 but it kept crashing the entire obs studio immediately after starting the recording or live stream. Are other people having this problem?) (I was using a separate computer for the av1 encoding with a video capture card input source)
9 Replies
Flaeri
Flaeri4mo ago
You can tell it to use more tiles, and row-mt, but it has a limit. Increase your preset if so. I suspect you'll be better off with svt-av1. More suited for realtime Not had any problems with svt crashing Nevermind... Forgot OBS already sets a very high amount of tiles and row-mt by default. Its not using more because it likely just can't, at least with that resolution, framerate, cpu+memory etc
aubade
aubade4mo ago
I tested av1 svt in obs studio 30.1.1, but it keeps crashing the entire program on any cpu that doesn't support the avx-512 instruction set. And the 1 computer that I tested AV1 svt encoding in obs studio errors out and gives this error for taking too long to encode (the 1 computer that did not have crash obs studio for trying to encode in AV1 SVT had an intel core i7 11800H)
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aubade
aubade4mo ago
I can encode with AV1 SVT in other programs such as handbrake or nmkoder without issues on my other computers that don't support AVX-512, but OBS Studio crashes when I try to do that on them. I found out the frame time latency was related to the keyframe interval setting and the encoding speed was too slow for the l444 or BGRA color format. I changed the keyframe interval to 1 s and changed the color format to l420 and it mostly solved the problem. But now it seems too easy for the computer to encode at the lowest encoder preset 7 option in obs studio and the video quality is not very good compared to Nvenc HEVC at comparable bitrates and color space and color range and color format.
aubade
aubade4mo ago
This is what the cpu usage while using AV1 AOM Encoder Preset 7 in OBS Studio looks like with a 16 core cpu that does not support AVX-512 (it only uses about 16 cpu threads effectively so the overall maximum cpu usage seems to be about 60% [similar to handbrake cpu usage]). (the dropoff at the end in cpu usage was when the recording was stopped) (This cpu supports AVX2 instruction sets and other older common instruction sets)
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Flaeri
Flaeri4mo ago
Interesting. I don't have AVX512 (R5 5500). Dosent crash for me on OBS 30.1.1, SVT-AV1. Preset: 11 Are you sure XMP/XPO is entirely stable? The software av1 encoders hits mem and cache super hardcode 😅 as for the timeout, it sounds like you need to reduce the preset I'll be honest, software av1 is not really all the great in the OBS usecase. The quality you get at the higher presets is in x264 range, and you'd be better of not going thru this pain. Just my two cents
aubade
aubade4mo ago
I tried using AV1 SVT Encoder Preset 8 with a Ryzen 5 5600x with a 4x8 GB CL16 3200 Mhz factory xmp ram kit and it just crashes for me. Oh I see. It doesn't crash obs studio if I try lowering the AV1 SVT preset to 10 or higher obs studio crashes every time I try to use AV1 SVT encoder preset 9 or lower with the cpus that don't support AVX-512. The cpu had no issues with the encoder preset 10 setting and it barely dropped any frames.
Flaeri
Flaeri4mo ago
Hmm. I see. I remember a VS compiler bug somewhat adjacent to this in my brain. Wonder if that is it... Pretty sure this has worked for me in the past Yeah, works fine in the previous version. I think I remember MS claiming it was fixed, so perhaps in the next update. I'll check my selv compiled version on the latest version of VS nope 😛 Ok, maybe the update has not yet been pushed to production. Remind me in a month, and I can check again
aubade
aubade4mo ago
ok. Thanks!
Flaeri
Flaeri4mo ago
I finally managed to compile the current deps, and it fixes the problem 🙂 So yeah, hopefully github updates their runner images before the next OBS release, and hopefully it would be fixed in the next OBS update. If you just wanna mess around (and don't care about game capture and service integrations (login to twitch/yt etc), I can send you the version I compiled, assuming you're willing to trust a stranger compiling stuff that you run (you shouldnt)