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+--- Thread: [HELP] AV1 NVENC B-Frames (/thread-4167.html)
AV1 NVENC B-Frames - tomek398 - 24.07.2025
I want to archive my video files from GoPro camera using AV1 format.
I have Geforce 5060ti and want to use NVENC as I heard that version supports B-Frames in AV1. I did a few tests with most recent version of Hybrid, however I didn't see any B-frames in encoded AV1 files (using NVECN)
Is there any option I need to activate to add B-frames?
Thanks
RE: AV1 NVENC B-Frames - Selur - 24.07.2025
As far as I can tell Hybrid is telling NVEncC to use '--bframes 3' by default. (assuming 'NVEncC --check-features' reported that you gpu supports using b-frames)
Looking at the output of the encoder in my quick test:
NVEncC (x64) 8.09 (r3369) by rigaya, Jul 16 2025 12:08:21 (VC 1944/Win)
OS Version Windows 11 x64 (26100) [UTF-8]
CPU AMD Ryzen 9 7950X 16-Core Processor [5.52GHz] (16C/32T)
GPU #0: NVIDIA GeForce RTX 4080 (9728 cores, 2505 MHz)[PCIe4x16][577.00]
NVENC / CUDA NVENC API 13.0, CUDA 12.9, schedule mode: sync
Input Buffers CUDA, 44 frames
Input Info y4m(yv12(10bit))->p010 [AVX2], 640x352, 25/1 fps
Vpp Filters copyDtoD
Output Info AV1 main 10bit @ Level auto
640x352p 1:1 25.000fps (25/1fps)
Encoder Preset quality
Rate Control VBR
Multipass none
Bitrate 1500 kbps (Max: 240000 kbps)
Target Quality auto
QP range I:0-255 P:0-255 B:0-255
QP Offset cb:0 cr:0
VBV buf size auto
Split Enc Mode auto
Lookahead on, 32 frames, Adaptive I Insert
GOP length 250 frames
B frames 3 frames [ref mode: middle]
Ref frames 6 frames, MultiRef L0:auto L1:auto
AQ on (spatial, temporal, strength 5)
Part size max auto / min auto
Tile num columns auto / rows auto
TemporalLayers max 0
Refs forward auto, backward auto
VUI matrix:smpte170m,rangedav1d :limited
Others mv:Q-pelFrom what I remember AV1 does not have b-frames to begin with and the 'b-frame' option in some encoders just referes to a specific combination of interframes referencing each other.
Quote:AV1 does have bi-directional predicted frames, but it is not like the way as H.264/HEVC. Instead it has so-called "mini-GOP", which includes series of inter frames that reference each other.=> https://github.com/rigaya/NVEnc/issues/438
Because of this difference, it is not counted as B frames in the log.
Cu Selur
Cu Selur
RE: AV1 NVENC B-Frames - tomek398 - 24.07.2025
Thanks for a reply.
I'm not expert on that topic. I just read that B-frames are supported for NVENC AV1 on 5000 series card and did a test. I didn't see any B frames in the output but maybe that is OK. I don't know....
When I look at the output of NVENC H.265 I can simply see B-frames....
I'm using Shutter Encoder option to "see" GOP
RE: AV1 NVENC B-Frames - Selur - 24.07.2025
H.265 and AV-1 are totally different formats,..
(shutter encoder is based on ffmpeg)
RE: AV1 NVENC B-Frames - tomek398 - 24.07.2025
(24.07.2025, 19:18)Selur Wrote: H.265 and AV-1 are totally different formats,..I know, but even NVIDIA is showing "B-Frames" in the settings of OBS for NVENC AV1 (bottom of the image)
NVIDIA NVENC Obs Guide | GeForce News | NVIDIA
It is all quite confusing....
I just want to be sure that I'm using best available settings for my hardware.
Thanks
![[Image: obs-guide-12-advanced-recording.png]](https://www.nvidia.com/content/dam/en-zz/Solutions/geforce/guides/broadcasting-guide/obs-guide-12-advanced-recording.png)
(24.07.2025, 19:18)Selur Wrote: H.265 and AV-1 are totally different formats,..
(shutter encoder is based on ffmpeg)
NVIDIA says about "...ultra-high quality (UHQ) mode to AV1..." but TBH I don't know what it means.....
Video Codec SDK | NVIDIA Developer
Quote:NVIDIA GPUs contain an on-chip hardware-accelerated video encoder (NVENC), which provides video encoding for H.264, HEVC (H.265) and AV1 codecs.
The software enhancements in SDK v13.0 enable extending ultra-high quality (UHQ) mode to AV1 encoding.. This makes AV1 encoding on Blackwell NVENC comparable to software AV1 encoding with ~3X throughput. The UHQ HEVC mode was introduced in the SDK v12.2 in the Ada generation.
RE: AV1 NVENC B-Frames - Selur - 24.07.2025
Can't really say what settings to use another tool, which might use different language.
Nor sure whether cqp should is constant or constrained and if q stands for quality or quantizer.
NVEncC uses a different naming, see: https://github.com/rigaya/NVEnc/blob/master/NVEncC_Options.en.md#encode-mode-options
RE: AV1 NVENC B-Frames - tomek398 - 25.07.2025
Quote:Professional-Grade Video for All
GeForce RTX 50 Series GPUs deliver a generational leap in NVIDIA encoders and decoders with support for the 4:2:2 pro-grade color format, multiview-HEVC (MV-HEVC) for 3D and virtual reality (VR) video, and the new AV1 Ultra High Quality mode.
GeForce RTX 50 Series GPUs Double Creative Performance | NVIDIA Blog
What is that " AV1 Ultra High Quality mode" and can I activate it in Hybrid?
RE: AV1 NVENC B-Frames - Selur - 25.07.2025
No clue what it actually does.
Since NVEncC doesn't mention it, Hybrid doesn't support it.
=> if you want it, you probably best should post a feature request over at https://github.com/rigaya/NVEnc/issues
If rigaya adds it to NVEncC I'll add support for it in Hybrid.
Cu Selur
Ps.: I added a question regarding UHQ to https://github.com/rigaya/NVEnc/issues/709
RE: AV1 NVENC B-Frames - Selur - 26.07.2025
UHQ is the same as using:
-b 7 --tf-level 4 --lookahead 32 --lookahead-level 3 --no-i-adapt --no-b-adapt --bref-mode middleCu Selur