OBS closing as soon as I click start recording with a specific encoder (SVT-AV1)

There ware no crash logs created upon app closing.


Hello,

I have recently been testing out encoders to record with to see which encoder has the least GPU usage rate, utilization and so on. From what i've heard SVT-AV1 is supposed to be a solid encoder that comes with NVIDIA GPU's, I wanted to test it out so I chose it in the encoders section in the settings and clicked apply. I went ahead and clicked start recording but after 2 seconds I did that the app froze for a second and then it closed it self. This is strange because AOM-AV1 encoder works perfectly fine.


Things I have made sure that are not causing the Issue:

I use medal but medal uses H.264 encoder so medal cant be causing any issues, any feature like Nvidia highlights or clips is turned off, XBOX gamebar is set to x264 encoder by default as far as I know and I am not trying to record with XBOX gamebar at the same time eitherway so it cant be that either. My drivers are up to date.


My guess:

Some websites say GTX 1650 does not support SVT-AV1 encoding however I am not sure about that because I think the SVT-AV1 option wouldnt appear if that was the case, right? However I have no other possible cause for this so yeah.
(source: https://videocardz.com/newz/nvidia-... 16 series utilizes,NVNEC in Ada GPUs, though.)


TL:DR:
Trying to record with SVT-AV1 encoder causes OBS to close itself, so far things i am sure that are not causing the issue;
Medal
XBOX gamebar
Nvidia highlights or anything similiar
I cant think of anything else causing this.


Laptop specs:

CPU: Intel i7-9750HF
GPU: GTX 1650 Mobile
RAM: 16GB DDR4 single stick 2400MHz ram
Disk: Samsung 512GB SSD

Reply with any extra information you need

How it Works​

Scalable Video Technology (SVT) is a software-based video coding technology that allows encoders on any x86 CPU to achieve the best-possible tradeoffs between performance, latency and visual quality. SVT also facilitates performance level scaling of encoders, given the quality and latency requirements of the target applications. The efficiency and scalability of SVT are supported through mainly architectural and algorithmic features, and also via specific optimizations for Intel® Xeon® Scalable processors and Intel® Xeon® D processors.


The SVT architecture provides multi-precision-level features like human visual system (HVS) optimized classification resulting in better rate/quality tradeoffs, and Intel® Xeon® processor-specific performance tuning.


Three modes are available:

• Visual Mode (Tune 0): Optimized for visual quality
• PSNR/SSIM Mode (Tune 1): Default encoder mode; Optimized to maximize the PSNR/SSIM BDRate performance
• VMAF Mode (Tune 2): Optimized to maximize VMAF BDRate performance

In addition, up to thirteen presets: M0-M12, provide fine granularity in the selection of the tradeoffs between quality and speed.


SVT architecture is CODEC standard-agnostic, i.e., it can be applied for the development of encoders that are compliant with different standards. Intel has created an open source SVT-HEVC and SVT-VP9 encoder core for developers to use in creating their own products and services. The SVT-HEVC encoder cores are made available to the open source community via a highly-permissive OSI approved BSD+Patent license. The same architectural advantages are available in SVT-AV1 and any other future SVT CODECs.

Anyway, it requires a fairly powerful CPU along with lots of cooling. My 12900k does A-OK with SVT but I suspect your 9750HF might be overheating immediately. Try using the fastest Preset to see if you can get any traction.

AOM is the reference encoder, it will only use a couple of threads & therefore can't be used for real time encoding. SVT on the other hand will use every thread the CPU has & that's where the overheating may start.

svt-av1 and aom-av1 are both software encoders. They run on the CPU and eat up your CPU resources. AV1 as hardware encoder is supported by Nvidia with the RTX 40 series and above.
Any Nvidia hardware encoder requires almost no GPU resources, because nvenc is a dedicated circuit within the GPU. Its secondary advantage is that just the encoded video data has to be transferred from the GPU, so it lessens pci-e bus load.
Using a software encoder requires always transferring the raw full data from GPU, so it is considerable load on the pci-e bus. Depending on the app that's using your GPU, this might be no issue (if your app loads graphics assets into the GPU once) or might lead to stutters (if your app continuously loads graphics assets into the GPU, colliding with the downloaded video data).

How it turns out for you is up to your testing, since it depends on multiple factors including the stuff you intend to record.

Why OBS closes if you use svt-av1 isn't clear. It's the first time I read about that. Without log, no chance to see what might has happened.

koala said:

svt-av1 and aom-av1 are both software encoders. They run on the CPU and eat up your CPU resources. AV1 as hardware encoder is supported by Nvidia with the RTX 40 series and above.
Any Nvidia hardware encoder requires almost no GPU resources, because nvenc is a dedicated circuit within the GPU. Its secondary advantage is that just the encoded video data has to be transferred from the GPU, so it lessens pci-e bus load.
Using a software encoder requires always transferring the raw full data from GPU, so it is considerable load on the pci-e bus. Depending on the app that's using your GPU, this might be no issue (if your app loads graphics assets into the GPU once) or might lead to stutters (if your app continuously loads graphics assets into the GPU, colliding with the downloaded video data).

How it turns out for you is up to your testing, since it depends on multiple factors including the stuff you intend to record.

Why OBS closes if you use svt-av1 isn't clear. It's the first time I read about that. Without log, no chance to see what might has happened.

Click to expand...

rockbottom said:

AOM is the reference encoder, it will only use a couple of threads & therefore can't be used for real time encoding. SVT on the other hand will use every thread the CPU has & that's where the overheating may start.

Click to expand...

Thanks for all the info! I understand way more about these encoders now, I opened up ThrottleStop to watch my CPU temp after hitting record, what happen is my CPU reached its max clock (4.2GHz) and a temp of 80°C, the load was about 50% at most. I really have no idea whats causing this, no matter what i do OBS crashes at the 2 second mark. Could it be because I have my CPU undervolted? Also is it possible to have 2 OBS instanced running at the same time so i can record whats going on? worst case i use something like medal or xbox game bar.

Hey! I tried changing the preset and it worked! though anything below 11 and 12 just gets overloaded instantly. Would it be even worth to use this encoder at these presets? I could use Nvidia nvenc encoders for an example? What would you guys recommend?

NVENC

If you have nvenc available definitely nvenc. No matter what encoder you choose (h.264, hevc, av1), not using nvenc is wasting good resources.

I get the close down bug as well, I had noticed NVENC AV1 loses detail unless CQP is really low, so I tried SVT AV1 and wow it keeps the detail at a much higher CQP, but I can only record one second of footage as OBS closes itself.

CQP is at 22 if relevant. Rest defaults 0 keyframe and seems okay (8) for preset.