AMF

AMF (Advanced Media Framework) is AMD’s API for the video encode/decode block (VCN) on Radeon GPUs and Ryzen APUs. FFmpeg exposes it as h264_amf, hevc_amf and av1_amf. It is mainly a Windows route: on Linux most people encode through VAAPI with Mesa instead.

Hardware or software encoder?

AMF is fast and cheap on power, but its compression efficiency has historically trailed NVENC and QSV, and all of them trail x264, x265 and SVT-AV1 at slow presets. It suits game capture, streaming and fast transcodes. For archival encodes, use a software encoder.

Which hardware supports what

Codec	Support
H.264, HEVC	AMD’s current support table starts at VCN 2.0: RDNA 1 (RX 5000), Cezanne (Ryzen 5000) APUs and everything after. H.264 is 8-bit; HEVC is 8 and 10-bit.
AV1	VCN 4.0 and newer: RDNA 3 (RX 7000), RDNA 4 (RX 9000) and Phoenix (Ryzen 7040/8040, 8000G) or newer APUs, 8 and 10-bit. RDNA 1 and RDNA 2 (RX 6000) cannot encode AV1.
VP9	No encoder.

The AMF runtime comes with the Windows Radeon driver. FFmpeg must be built with --enable-amf. On Linux the AMF runtime from the amdgpu-pro packages is required, and it initialises through Vulkan.

Quality-oriented encode

Constant QP is the simplest quality-targeted mode:

ffmpeg -i input.mkv -c:v hevc_amf -usage transcoding -quality quality -rc cqp -qp_i 24 -qp_p 24 -c:a copy output.mkv

-usage transcoding is the offline profile. -quality quality is a slow preset; high_quality is slower still. CQP makes size unpredictable; give -qp_b too when H.264 or AV1 uses B-frames. The scale is 0–51 for H.264 and HEVC and 0–255 for AV1, so AV1 values are several times higher:

ffmpeg -i input.mkv -c:v av1_amf -usage transcoding -quality high_quality -rc cqp -qp_i 100 -qp_p 100 -c:a copy output.mkv

For a size target, use peak-constrained VBR (also what FFmpeg picks when you give only -b:v):

ffmpeg -i input.mkv -c:v hevc_amf -usage transcoding -quality quality -rc vbr_peak -b:v 8M -maxrate 12M -c:a copy output.mkv

For 10-bit HEVC or AV1 pass -pix_fmt p010le. Rate control is chosen automatically if you leave -rc out: any -qp_*, -min_qp_* or -max_qp_* option means CQP, -b:v equal to -maxrate means CBR, otherwise peak VBR.

The closest thing to CRF is QVBR: -rc qvbr -qvbr_quality_level N with -preanalysis 1, since AMD’s API documentation says QVBR, HQVBR and HQCBR only work with pre-analysis enabled.

FFmpeg also has AMF filters that keep frames on the GPU, vpp_amf for scaling and format conversion and sr_amf for upscaling, but a plain command that uploads frames is the common case.

Options that matter

Option	What it does
-usage	transcoding, high_quality, lowlatency, lowlatency_high_quality, ultralowlatency, webcam. Sets the encoder’s overall tuning.
-quality	Speed/quality preset: speed, balanced, quality, high_quality. The numeric values differ between codecs, so use the names.
-rc	cqp, cbr, vbr_peak, vbr_latency, qvbr, hqvbr, hqcbr. The last three need -preanalysis 1.
-qp_i, -qp_p, -qp_b	Quantizers for -rc cqp. HEVC has no -qp_b.
-bf, -max_b_frames	B-frames (H.264 and AV1, 0–3). The HEVC wrapper has no B-frame option.
-preanalysis 1	Pre-analysis pass for better bit distribution on supported hardware. Adds latency; the -pa_* options tune it.
-vbaq 1 (H.264, HEVC), -aq_mode caq (AV1)	Adaptive quantization.
-header_insertion_mode	Repeat headers per GOP or frame; useful for streaming.

Pitfalls

• Quality presets, QP scales and -quality numbers differ between H.264, HEVC and AV1. Do not copy values across codecs.
• An accepted option does not mean the hardware used it. Many auto defaults leave the choice to the driver, and pre-analysis and B-frames depend on the GPU generation.
• If the encoder fails to open on Linux, AMF could not initialise (libamfrt64.so.1 or the amdgpu-pro runtime is missing). Switch to VAAPI.

Full option reference

Every private option of av1_amf in FFmpeg 9.0.2; h264_amf and hevc_amf have a similar but not identical set. -1 and auto leave the setting to the AMF driver. -qvbr_quality_level uses its own 0–51 scale.

Private options

Parameter	Type	Default	Meaning	Range / named values
-usage	int	-1	Use case that sets the encoder’s defaults: transcoding, high_quality, lowlatency, ultralowlatency, webcam, lowlatency_high_quality. -1 = driver default.	-1 to 5; transcoding=0, ultralowlatency=2, lowlatency=1, webcam=3, high_quality=4, lowlatency_high_quality=5
-bitdepth	int	0	Output bit depth, 8 or 10. 0 follows the input pixel format.	0 to 10; 8=8, 10=10
-profile	int	-1	AV1 profile (main); -1 = driver default.	-1 to 1; main=1
-level	int	auto	AV1 level limit; auto lets the driver choose.	-1 to 23; auto=-1, 2.0=0, 2.1=1, 2.2=2, 2.3=3, 3.0=4, 3.1=5, 3.2=6, 3.3=7, 4.0=8, 4.1=9, 4.2=10, 4.3=11, 5.0=12, 5.1=13, 5.2=14, 5.3=15, 6.0=16, 6.1=17, 6.2=18, 6.3=19, 7.0=20, 7.1=21, 7.2=22, 7.3=23
-quality	int	-1	Quality preset: high_quality, quality, balanced, speed. Same field as -preset.	-1 to 100; high_quality=0, quality=30, balanced=70, speed=100
-preset	int	-1	Alias of -quality.	-1 to 100; high_quality=0, quality=30, balanced=70, speed=100
-latency	int	-1	Latency mode: none, power_saving_real_time, real_time, lowest_latency. -1 = driver default.	-1 to 3; none=0, power_saving_real_time=1, real_time=2, lowest_latency=3
-rc	int	-1	Rate control: cqp, cbr, vbr_peak, vbr_latency, qvbr, hqvbr, hqcbr. -1 picks cqp if any QP option is set, cbr if -b:v equals -maxrate, otherwise vbr_peak.	-1 to 6; cqp=0, vbr_latency=1, vbr_peak=2, cbr=3, qvbr=4, hqvbr=5, hqcbr=6
-qvbr_quality_level	int	-1	Quality target for -rc qvbr.	-1 to 51
-header_insertion_mode	int	-1	When to repeat sequence headers: none, gop or frame. -1 = driver default.	-1 to 2; none=0, gop=1, frame=2
-async_depth	int	16	Frames queued on the GPU; higher improves throughput and adds latency.	1 to 42
-preencode	boolean	auto	Pre-encode pass that assists rate control; ignored with CQP.	-1 to 1
-enforce_hrd	boolean	auto	Enforce HRD (decoder buffer) compliance.	-1 to 1
-filler_data	boolean	auto	Insert filler data to keep CBR output at the target rate.	-1 to 1
-max_b_frames	int	-1	Maximum consecutive B-frames the encoder may use (0–3).	-1 to 3
-bf	int	-1	B-frame pattern: number of B-frames between references (0–3), if the GPU supports them.	-1 to 3
-high_motion_quality_boost_enable	boolean	auto	Spend more bits on high-motion scenes.	-1 to 1
-min_qp_i	int	-1	Lowest QP for I-frames.	-1 to 255
-max_qp_i	int	-1	Highest QP for I-frames.	-1 to 255
-min_qp_p	int	-1	Lowest QP for P-frames.	-1 to 255
-max_qp_p	int	-1	Highest QP for P-frames.	-1 to 255
-min_qp_b	int	-1	Lowest QP for B-frames.	-1 to 255
-max_qp_b	int	-1	Highest QP for B-frames.	-1 to 255
-qp_p	int	-1	Fixed QP for P-frames (CQP).	-1 to 255
-qp_i	int	-1	Fixed QP for I-frames (CQP).	-1 to 255
-qp_b	int	-1	Fixed QP for B-frames (CQP).	-1 to 255
-skip_frame	boolean	auto	Let rate control drop frames to hold the bitrate.	-1 to 1
-aq_mode	int	-1	Adaptive quantization: none or caq (content-adaptive).	-1 to 1; none=0, caq=1
-forced_idr	boolean	false	Make forced I-frames key frames.	0 to 1
-align	int	none	Resolution alignment: none, 64x16 (reject other sizes) or 1080p (64×16 plus 1920×1080).	1 to 3; 64x16=1, 1080p=2, none=3
-smart_access_video	boolean	auto	On systems with an AMD APU and GPU, use both for better performance.	-1 to 1
-preanalysis	boolean	auto	Pre-analysis stage that feeds AQ, scene-change and lookahead decisions; enables the pa_* options.	-1 to 1
-pa_activity_type	int	-1	Activity measure for pre-analysis: luma only (y) or yuv.	-1 to 1; y=0, yuv=1
-pa_scene_change_detection_enable	boolean	auto	Detect scene changes in pre-analysis.	-1 to 1
-pa_scene_change_detection_sensitivity	int	-1	Scene-change sensitivity: low, medium, high.	-1 to 2; low=0, medium=1, high=2
-pa_static_scene_detection_enable	boolean	auto	Detect static scenes in pre-analysis.	-1 to 1
-pa_static_scene_detection_sensitivity	int	-1	Static-scene sensitivity: low, medium, high.	-1 to 2; low=0, medium=1, high=2
-pa_initial_qp_after_scene_change	int	-1	QP used immediately after a scene change.	-1 to 51
-pa_max_qp_before_force_skip	int	-1	QP threshold above which a frame may be skipped.	-1 to 51
-pa_caq_strength	int	-1	Content-adaptive quantization strength: low, medium, high.	-1 to 2; low=0, medium=1, high=2
-pa_frame_sad_enable	boolean	auto	Use frame SAD (sum of absolute differences) in pre-analysis.	-1 to 1
-pa_ltr_enable	boolean	auto	Long-term reference management from pre-analysis.	-1 to 1
-pa_lookahead_buffer_depth	int	-1	Pre-analysis lookahead, in frames.	-1 to 41
-pa_paq_mode	int	-1	Perceptual AQ: none or caq.	-1 to 1; none=0, caq=1
-pa_taq_mode	int	-1	Temporal AQ: none, 1 or 2.	-1 to 2; none=0, 1=1, 2=2
-pa_high_motion_quality_boost_mode	int	-1	High-motion quality boost from pre-analysis: none or auto.	-1 to 1; none=0, auto=1
-pa_adaptive_mini_gop	boolean	auto	Adapt the number of B-frames to the content.	-1 to 1

Codec-specific generic initialization overrides

The wrapper replaces these generic FFmpeg defaults for this encoder. -b is in bits/s; -g and -bf count frames. -1, and 0 for -b and -refs, leave the value to the preset, driver or rate-control logic.

Generic parameter	Default
-refs	-1
-aspect	0
-b	0
-g	-1
-qmin	-1
-qmax	-1