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Do anyone know how to conconfigure AV1 for low delay applications , i mean like HM (HEVC) low delay configuration where the GOP is IPPP..( just 2 temporal layers ) ,

I tried these , but i am not sure because it's not different from the regular mode (random access) :

aomenc.exe  --profile=0  --auto-alt-ref=0  --lag-in-frames=0   --arnr-maxframes=0 --arnr-strength=5  --static-thresh=0 --passes=2 --pass=1 --end-usage=cq --cq-level=40  --width=352 --height=288  --fpf=aom_QP40.log --cpu-used=4 --threads=8 --limit=10 --fps=25/1 --bit-depth=8  --kf-min-dist=32 --kf-max-dist=32 --psnr  -o output_QP40.webm akiyo_cif.yuv 

aomenc.exe  --profile=0  --auto-alt-ref=0  --lag-in-frames=0   --arnr-maxframes=0 --arnr-strength=5  --static-thresh=0 --passes=2 --pass=2 --end-usage=cq --cq-level=40  --width=352 --height=288  --fpf=aom_QP40.log --cpu-used=4 --threads=8 --limit=10 --fps=25/1 --bit-depth=8  --kf-min-dist=32 --kf-max-dist=32 --psnr  -o output_QP40.webm akiyo_cif.yuv

i am using --kf-min-dist=32 --kf-max-dist=32 because i want an golden frame ( IDR/I-frame like ) to be reproduce each 1 sec for streaming purposes.

Mourad
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  • Do you mean low latency or faster turn-around time ? Low delay could mean several things right ? The kf-min-dist and kf-max-dist I think are for key frame settings. Perhaps you could play with the min-gf-interval and max-gf-interval settings. – hit.at.ro Jun 05 '18 at 20:53
  • Thanks for answering ; yeah i mean low latency, which means in term of encoding , using only backward prediction and no bidirectional inter prediction ( e. g. only P frames and no B frames in hevc ). so i want to disactivate ALTREF2 and BWDREF, to keep only ALTREF2 frames , – Mourad Jun 06 '18 at 13:26
  • playing with this paras could be the answer but i am not sure : `--kf-min-dist= Minimum keyframe interval (frames) --kf-max-dist= Maximum keyframe interval (frames) --arnr-maxframes= AltRef max frames (0..15) --min-gf-interval= min gf/arf frame interval --max-gf-interval= --sframe-dist= S-Frame interval (frames) --sframe-mode= ` so what doest it means gf/arf frames and S frames ? – Mourad Jun 06 '18 at 13:26

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Here is the answer. In x265 we have zero latency mode which has only IPPP frames and in VP9 you have to use this command for libvpx * --arnr-maxframes=0 --arnr-strength=0 --arnr-type=3 --auto-alt-ref=0 --lag-in-frames=0* I have attached the screenshot from the Bitstream analyzer where you can see ALTREF=0

enter image description here

GalactusB
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