12.11.2026, 08:23
Got it, UHQ with HEVC failed because Hybrid’s default of 3 B-frames is too few for it.
--tune uhq turns on NVENC’s temporal filter (tfLevel: 4) for HEVC and AV1, and that filter needs at least 4 B-frames.
Hybrid always writes --bframes, and its default is 3, so NVENC rejects the setup with error 8. Testing NVEncC directly:
Tested it on my system.
=> I'll adjust Hybrid to raise bFrames minimum to 4 under uhq (HEVC/AV1). Will report back once I did the fix and uploaded a new dev.
Cu Selur
--tune uhq turns on NVENC’s temporal filter (tfLevel: 4) for HEVC and AV1, and that filter needs at least 4 B-frames.
Hybrid always writes --bframes, and its default is 3, so NVENC rejects the setup with error 8. Testing NVEncC directly:
Tested it on my system.
Codec
| --bframes 0-3
| --bframes 4
| --bframes 3 --tf-level 0
|
|---|---|---|---|
|
HEVC
|
error 8
|
works
|
works
|
|
AV1
|
error 8
|
works
|
works
|
|
H.264
|
works
|
works
|
works
|
=> I'll adjust Hybrid to raise bFrames minimum to 4 under uhq (HEVC/AV1). Will report back once I did the fix and uploaded a new dev.
Cu Selur
----
Dev versions are in the 'experimental'-folder of my GoogleDrive, which is linked on the download page.
Dev versions are in the 'experimental'-folder of my GoogleDrive, which is linked on the download page.

