Module tuning 

AV1 encoder tuning adapter.

Translates a single backend-agnostic perceptual quality target into per-encoder parameters so identical inputs yield visually consistent output across rav1e, NVENC AV1, and future backends (SVT-AV1, AMF, QSV).

See docs/av1-tuning-research.md for the source tables and docs/av1-tuning-methodology.md for how to re-calibrate when a new encoder lands.

Design

The user picks two things:

1. A QualityTarget — perceptual goal expressed in VMAF/SSIMULACRA2 bands, not encoder-native CRF. Every backend must reach roughly the same VMAF for a given target (±2 VMAF band).
2. A SpeedTier — how much wallclock to spend getting there. Maps to encoder-native speed presets.

The adapter also takes (width, height) because tile grid and lookahead sizing depend on frame size.

Structs

AmfAv1Params

Concrete parameters for AMD AMF AV1 (VCN on RDNA3+).

NvencAv1Params

Concrete parameters for NVENC AV1 (NV_ENC_CONFIG + NV_ENC_RC_PARAMS).

QsvAv1Params

Concrete parameters for Intel QSV AV1 (oneVPL on Arc / Meteor Lake+).

Rav1eParams

Concrete parameters for rav1e’s EncoderConfig.

Enums

AmfQualityPreset

AMF AV1 quality presets. Values match AMF_VIDEO_ENCODER_AV1_QUALITY_PRESET_* constants from the GPUOpen AMF wiki. Lower = better quality / more wall-clock. The transcode service never picks Speed (same rationale as NVENC: no low-latency presets in this service — see research §2.4).

AmfRateControl

AMF AV1 rate control modes actually used by this service. Values match AMF_VIDEO_ENCODER_AV1_RATE_CONTROL_METHOD_*.

NvencRateControl

NVENC rate control modes actually used by this service. The numeric value matches the SDK’s NV_ENC_PARAMS_RC_MODE.

QsvRateControl

QSV AV1 rate control mode values match MFX_RATECONTROL_* in oneVPL/include/vpl/mfxstructs.h.

QualityTarget

A single perceptual quality target, backend-agnostic.

SpeedTier

User-facing speed tier — maps to encoder-native speed presets.

Constants

MFX_CODINGOPTION_OFF

oneVPL tri-state option values (from MFX_CODINGOPTION_*). Used for LowPower and a handful of other mfxU16 toggles.

MFX_CODINGOPTION_ON

Not currently used but named so the value shows up next to OFF whenever a future code path wants explicit on-switching.

NVENC_TUNING_HIGH_QUALITY

SDK constant NV_ENC_TUNING_INFO_HIGH_QUALITY = 1.

Functions

amf_av1_params

Derive AMD AMF AV1 params for a given quality target + speed tier + resolution.

libaom_cq_for_target

libaom cq-level that corresponds to a given QualityTarget. libaom is the cross-encoder reference: we equalize other encoders to libaom’s VMAF at each CQ.

nvenc_av1_params

Derive NVENC AV1 params for a given quality target + speed tier + resolution.

qsv_av1_params

Derive Intel QSV AV1 params for a given quality target + speed tier + resolution.

rav1e_params

Derive rav1e params for a given quality target + speed tier + resolution.