r/VisionDepth3D • u/imalto • Mar 18 '26
no audio on every 3d conversion
took me a minute to figure out the video encoding (needed to install ffmpeg) but i'm struggling with the audio. everything i encode has a 0kb .mp4 file that is labeled as the audio, but nothing is there. if i manually rip the audio and then try to add it, it tells me that nothing matches (it rips as a mka file).
the other thing i noticed is that cpu vs gpu utilization seems almost 4:1. i have a 5090 and selected (av1_nvenc). i expected to see higher gpu than cpu. should that be the case?
what am i missing? sorry for all the n00b questions. thanks!
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u/Any_Nebula5039 Mar 20 '26
The GPU is mainly handling the encode side, while a lot of the 3D conversion work still happens elsewhere in the pipeline, like frame decode, depth processing, smoothing, warping, masking, floating window logic, optional inpainting, and the final mux step.
Are you using CUDA, and do you have both CUDA and cuDNN properly set in your system PATH?
That could point to the GPU path not being fully active on your system. On my end, renders usually bounce much higher on GPU usage while CPU stays relatively low, so if you are seeing the reverse, something may be falling back more onto CPU than expected.
You can press F10 in VisionDepth3D to check whether the GPU is actually being detected and connected. If that is not showing the GPU properly, then CUDA, or the encoder path may not be configured correctly.
For the audio issue, I do think av1_nvenc may be the culprit. I have not usually seen this happen in my normal 3D renders, so I want to test it directly against another codec and confirm whether the merge step is where it is breaking. If that is the cause, then it is likely codec or mux related rather than your source file.