Problems and recommendations for recording final output and raw inputs

 

I'm wondering what the recommendations are for recording potentially 4 video streams. I have three 4k inputs and the final comp being recorded with Aximmetry but it really struggles to keep up on one machine.


I've tried a few options for encoding and DnxHR seems to be the best option for CPU overhead. I have to reduce the bitrate to about 150Mbps on all streams however to get anything stable.


The three inputs seem to record ok but it really chugs when I try and also record the final comp alongside it. I can see the CPU reaching 100% and over but in task viewer it's not using all of the cores and threads. 


For reference I'm using an Intel i9-13900k with 128Gb DDR5 and an RTX4090.


I'd imagine I should just use another machine or an external recorder but we're making use of the playback module with the tracked camera setup.



   Cookseyyyyy

 
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buffos
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I would personally record inputs in atem mini iso extreme or something similar. I have not used tracking yet, but I guess you can record only tracking data if you wish so, with few modifications on the recording compound.

 
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Eifert@Aximmetry
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Hi,

Yes, you can record only tracking and do this:
Please note that in Tracking Only mode you still get a recorded video, but it's created with highly degraded quality for the minimal performance impact. It only serves as a placeholder. Later when you want to playback the material replaces this placeholder by copying the recorded file from your camera's SD card over it. More on it here: https://aximmetry.com/learn/virtual-production-workflow/preparation-of-the-production-environment-phase-i/setting-up-inputs-outputs-for-virtual-production/video/recording/how-to-record-camera-tracking-data/#recording-the-image-on-the-camera 

Also, writing 4 times 150Mbps will be more than most SATA SSD-s can handle. If your computer is running into this limitation, it might show up as high CPU usage in Aximmetry.
If this is really a limitation in your SSD, then you could consider using M.2 PCIe SSD. You can check your Disk Usage in the Task Manager:

Warmest regards,

 
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Cookseyyyyy
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Good to know. I'm good on the SSD front, I'm using an 8Tbb NVME to record to. I might try saving different clips to separate drives perhaps.


Ideally yes, I'd use an ISO recorder or hyperdeck(s) but I wasn't sure about the process of re-comping process and bringing in the clips alongside the tracking data.

If I'm reading this correctly (as long as the timecode is correct) then the clip doesn't care about start or stop it just relies on the timecode to get the tracking back in sync? Does the clip name matter at all or do you just point it at the clip you want to comp?



 
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Eifert@Aximmetry
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Hi,

Yes, it relies on the timecode.

The clip name matters. The video file's name has to be the same as the .xdata file's name: https://aximmetry.com/learn/virtual-production-workflow/preparation-of-the-production-environment-phase-i/setting-up-inputs-outputs-for-virtual-production/video/recording/how-to-record-camera-tracking-data/#playback

Warmest regards,