Figure out NVENC CBR GStreamer parameters

[raspi]

Clues:

• https://github.com/obsproject/obs-studio/blob/b32abbe33fb6897da4a688972cb56538e8e22677/plugins/obs-ffmpeg/obs-ffmpeg-nvenc.c
• https://docs.nvidia.com/video-technologies/video-codec-sdk/nvenc-video-encoder-api-prog-guide/index.html#recommended-nvenc-settings
• https://docs.nvidia.com/video-technologies/video-codec-sdk/nvenc-preset-migration-guide/index.html#h264-preset-migration-table
• https://www.nvidia.com/en-us/geforce/guides/broadcasting-guide/

[raspi]

GStreamer nvh264enc:

Property	Description
aq-strength	Adaptive Quantization Strength when spatial-aq is enabled from 1 (low) to 15 (aggressive), (0 = autoselect)
aud	Use AU (Access Unit) delimiter
b-adapt	Enable adaptive B-frame insert when lookahead is enabled
bframes	Number of B-frames between I and P
bitrate	Bitrate in kbit/sec (0 = from NVENC preset)
const-quality	Target Constant Quality level for VBR mode (0 = automatic)
cuda-device-id	Get the GPU device to use for operations
gop-size	Number of frames between intra frames (-1 = infinite)
i-adapt	Enable adaptive I-frame insert when lookahead is enabled
max-bitrate	Maximum Bitrate in kbit/sec (ignored for CBR mode)
min-force-key-unit-interval	Minimum interval between force-keyunit requests in nanoseconds
name	The name of the object
nonref-p	Automatic insertion of non-reference P-frames
parent	The parent of the object
preset	Encoding Preset
qos	Handle Quality-of-Service events from downstream
qp-const	Constant quantizer (-1 = from NVENC preset)
qp-const-b	Constant QP value for B frame, When >= 0, "qp-const-i" and "qp-const-p" should be also >= 0. Overwritten by "qp-const" (-1 = from NVENC preset)
qp-const-i	Constant QP value for I frame, When >= 0, "qp-const-p" and "qp-const-b" should be also >= 0. Overwritten by "qp-const" (-1 = from NVENC preset)
qp-const-p	Constant QP value for P frame, When >= 0, "qp-const-i" and "qp-const-b" should be also >= 0. Overwritten by "qp-const" (-1 = from NVENC preset)
qp-max	Maximum quantizer (-1 = from NVENC preset)
qp-max-b	Maximum QP value for B frame, When >= 0, "qp-max-i" and "qp-max-p" should be also >= 0. Overwritten by "qp-max" (-1 = from NVENC preset)
qp-max-i	Maximum QP value for I frame, When >= 0, "qp-max-p" and "qp-max-b" should be also >= 0. Overwritten by "qp-max" (-1 = from NVENC preset)
qp-max-p	Maximum QP value for P frame, When >= 0, "qp-max-i" and "qp-max-b" should be also >= 0. Overwritten by "qp-max" (-1 = from NVENC preset)
qp-min	Minimum quantizer (-1 = from NVENC preset)
qp-min-b	Minimum QP value for B frame, When >= 0, "qp-min-i" and "qp-min-p" should be also >= 0. Overwritten by "qp-min" (-1 = from NVENC preset)
qp-min-i	Minimum QP value for I frame, When >= 0, "qp-min-p" and "qp-min-b" should be also >= 0. Overwritten by "qp-min" (-1 = from NVENC preset)
qp-min-p	Minimum QP value for P frame, When >= 0, "qp-min-i" and "qp-min-b" should be also >= 0. Overwritten by "qp-min" (-1 = from NVENC preset)
rc-lookahead	Number of frames for frame type lookahead
rc-mode	Rate Control Mode
spatial-aq	Spatial Adaptive Quantization
strict-gop	Minimize GOP-to-GOP rate fluctuations
temporal-aq	Temporal Adaptive Quantization
vbv-buffer-size	VBV(HRD) Buffer Size in kbits (0 = NVENC default)
weighted-pred	Weighted Prediction
zerolatency	Zero latency operation (no reordering delay)

[raspi]

Not needed:

• cuda-device-id
• name
• parent

[raspi]

Starting point:

nvh264enc aq-strength=??? aud=??? b-adapt=??? bframes=??? bitrate=??? const-quality=??? gop-size=??? i-adapt=??? max-bitrate=??? min-force-key-unit-interval=??? nonref-p=??? preset=??? qos=??? qp-const=??? qp-const-b=??? qp-const-i=??? qp-const-p=??? qp-max=??? qp-max-b=??? qp-max-i=??? qp-max-p=??? qp-min=??? qp-min-b=??? qp-min-i=??? qp-min-p=??? rc-lookahead=??? rc-mode=??? spatial-aq=??? strict-gop=??? temporal-aq=??? vbv-buffer-size=??? weighted-pred=??? zerolatency=???