[HELP] AOMEnc Disscusion

[Selur]

if i go back from constant quantizer as example. going back to 2-pass, its still greyed out.

That's correct, since using constant quantizer enforces '--auto-alt-ref=0', but 2pass does not enforce '--auto-alt-ref=1' or similar, so alternate references get disabled when switching to constant quantizer and not enabled when switching to 2pass.
-> this is as expected (given the assumption that altrefs require 2pass)

So the only question is: Do alt refs require 2pass or not?
Calling:

ffmpeg -y -loglevel fatal -noautorotate -nostdin -threads 8 -i "G:\TestClips&Co\files\test.avi" -map 0:0 -an -sn -vf zscale=rangein=tv:range=tv -pix_fmt yuv420p -vsync 0 -f yuv4mpegpipe - | aomenc --passes=1 --pass=1 --end-usage=q --cq-level=10 --profile=0 --cpu-used=8 --undershoot-pct=0 --overshoot-pct=0 --buf-sz=6 --buf-initial-sz=4 --buf-optimal-sz=5 --drop-frame=0 --kf-min-dist=0 --kf-max-dist=250 --auto-alt-ref=0 --sharpness=0 --static-thresh=0 --noise-sensitivity=0 --denoise-noise-level=0 --tune-content=default --tile-columns=0 --tile-rows=0 --mtu-size=0 --frame-boost=0 --min-gf-interval=0 --max-gf-interval=2 --gf-min-pyr-height=0 --gf-max-pyr-height=5 --threads=64 --width=640 --height=352 --input-bit-depth=8 --bit-depth=8 --denoise-noise-level=0 --min-partition-size=4 --max-partition-size=128 --fp-mt=1 --sb-size=dynamic --max-reference-frames=7 --disable-trellis-quant=0 --enable-tpl-model=1 --enable-keyframe-filtering=0 --force-video-mode=1 --reduced-tx-type-set=1 --use-intra-dct-only=0 --use-inter-dct-only=0 --use-intra-default-tx-only=0 --quant-b-adapt=1 --coeff-cost-upd-freq=0 --mode-cost-upd-freq=0 --mv-cost-upd-freq=0 -o "G:\output\without.ivf" -

and

ffmpeg -y -loglevel fatal -noautorotate -nostdin -threads 8 -i "G:\TestClips&Co\files\test.avi" -map 0:0 -an -sn -vf zscale=rangein=tv:range=tv -pix_fmt yuv420p -vsync 0 -f yuv4mpegpipe - | aomenc --passes=1 --pass=1 --end-usage=q --cq-level=10 --profile=0 --cpu-used=8 --undershoot-pct=0 --overshoot-pct=0 --buf-sz=6 --buf-initial-sz=4 --buf-optimal-sz=5 --drop-frame=0 --kf-min-dist=0 --kf-max-dist=250 --auto-alt-ref=1 --sharpness=0 --static-thresh=0 --noise-sensitivity=0 --denoise-noise-level=0 --tune-content=default --tile-columns=0 --tile-rows=0 --mtu-size=0 --frame-boost=0 --min-gf-interval=0 --max-gf-interval=2 --gf-min-pyr-height=0 --gf-max-pyr-height=5 --threads=64 --width=640 --height=352 --input-bit-depth=8 --bit-depth=8 --denoise-noise-level=0 --min-partition-size=4 --max-partition-size=128 --fp-mt=1 --sb-size=dynamic --max-reference-frames=7 --disable-trellis-quant=0 --enable-tpl-model=1 --enable-keyframe-filtering=0 --force-video-mode=1 --reduced-tx-type-set=1 --use-intra-dct-only=0 --use-inter-dct-only=0 --use-intra-default-tx-only=0 --quant-b-adapt=1 --coeff-cost-upd-freq=0 --mode-cost-upd-freq=0 --mv-cost-upd-freq=0 -o "G:\output\with.ivf" -

(only difference are the output file names and '--auto-alt-ref' value)
For three short clips I used, the output of these two was identical for each clip.

the same happens when I compare:

ffmpeg -y -loglevel fatal -noautorotate -nostdin -threads 8 -i "G:\TestClips&Co\files\test.avi" -map 0:0 -an -sn -vf zscale=rangein=tv:range=tv -pix_fmt yuv420p -vsync 0 -f yuv4mpegpipe - | aomenc --passes=1 --pass=1 --end-usage=cq --cq-level=20 --target-bitrate=15000 --profile=0 --cpu-used=8 --min-q=1 --max-q=63 --undershoot-pct=0 --overshoot-pct=0 --buf-sz=6 --buf-initial-sz=4 --buf-optimal-sz=5 --drop-frame=0 --kf-min-dist=0 --kf-max-dist=250 --auto-alt-ref=1 --sharpness=0 --static-thresh=0 --noise-sensitivity=0 --denoise-noise-level=0 --tune-content=default --tile-columns=0 --tile-rows=0 --mtu-size=0 --frame-boost=0 --aq-mode=1 --min-gf-interval=0 --max-gf-interval=2 --gf-min-pyr-height=0 --gf-max-pyr-height=5 --threads=64 --width=640 --height=352 --input-bit-depth=8 --bit-depth=8 --denoise-noise-level=0 --min-partition-size=4 --max-partition-size=128 --fp-mt=1 --sb-size=dynamic --max-reference-frames=7 --disable-trellis-quant=0 --enable-tpl-model=1 --enable-keyframe-filtering=0 --force-video-mode=1 --reduced-tx-type-set=1 --use-intra-dct-only=0 --use-inter-dct-only=0 --use-intra-default-tx-only=0 --quant-b-adapt=1 --coeff-cost-upd-freq=0 --mode-cost-upd-freq=0 --mv-cost-upd-freq=0 -o "G:\Output\crf_with.ivf" -

and

ffmpeg -y -loglevel fatal -noautorotate -nostdin -threads 8 -i "G:\TestClips&Co\files\test.avi" -map 0:0 -an -sn -vf zscale=rangein=tv:range=tv -pix_fmt yuv420p -vsync 0 -f yuv4mpegpipe - | aomenc --passes=1 --pass=1 --end-usage=cq --cq-level=20 --target-bitrate=15000 --profile=0 --cpu-used=8 --min-q=1 --max-q=63 --undershoot-pct=0 --overshoot-pct=0 --buf-sz=6 --buf-initial-sz=4 --buf-optimal-sz=5 --drop-frame=0 --kf-min-dist=0 --kf-max-dist=250 --auto-alt-ref=0 --sharpness=0 --static-thresh=0 --noise-sensitivity=0 --denoise-noise-level=0 --tune-content=default --tile-columns=0 --tile-rows=0 --mtu-size=0 --frame-boost=0 --aq-mode=1 --min-gf-interval=0 --max-gf-interval=2 --gf-min-pyr-height=0 --gf-max-pyr-height=5 --threads=64 --width=640 --height=352 --input-bit-depth=8 --bit-depth=8 --denoise-noise-level=0 --min-partition-size=4 --max-partition-size=128 --fp-mt=1 --sb-size=dynamic --max-reference-frames=7 --disable-trellis-quant=0 --enable-tpl-model=1 --enable-keyframe-filtering=0 --force-video-mode=1 --reduced-tx-type-set=1 --use-intra-dct-only=0 --use-inter-dct-only=0 --use-intra-default-tx-only=0 --quant-b-adapt=1 --coeff-cost-upd-freq=0 --mode-cost-upd-freq=0 --mv-cost-upd-freq=0 -o "G:\Output\crf_without.ivf" -

where I use '-end-usage=cq --cq-level=20 --target-bitrate=15000'

=> Would need some example calls in which one can see the difference altrefs are used in 1pass, or some documentation that shows that alternative references are not only used in 2pass, since I can't show that they are used using 1pass even with --auto-alt-ref=1.

Cu Selur