constant quantizer for vp9

[madloggan]

hey

how I can use constant quantizer mode on vp9
I know there is Constant Quantizer (Q) and you can select it by using --end-usage=q and -min-q=10 --max-q=10

so my question is this mode like the mode on x264 and the x265 range is from 0 to 51?

but when i trying to encode file with q = 10 on x264 or x265 i got bitrate range is from 150 mb/s to 200 mb/s but when I'm using vp9 with --end-usage=q and -min-q=10 --max-q=10 i got file with 23 mb/s how can this is possible ?


Codec: WebM Project VP9 Encoder v1.7.0



my command for x264 :

with qp mode :

x264 qp = 10

x264 --frames 100 --profile high --preset medium -o x264_10.264 --input-csp i420 --output-csp i420 --input-depth 8 --output-depth 8 --input-res 1920x1080 --fps 50 --verbose --dump-yuv x264_10.yuv /home/siraj/Desktop/Project/Samples/1080p/ReadySteadyGo_1920x1080_120fps_420_8bit_YUV.yuv --qp=10

the output bitrate = 165813.47 kb/s

x265 qp = 10

x265 -o hevc_3500.265 --output-depth 8 --input ReadySteadyGo_1920x1080_120fps_420_8bit_YUV.yuv --fps 50 --input-res 1920x1080 --input-depth 8 --input-csp 1 -P main -p medium --qp=10 --frames=100 --recon x265_40.yuv --recon-depth 8 --recon x265_50.yuv

the bitrate = 132423.19 kb/s

with crf mode :

x264 crf=20

x264 --frames 100 --profile high --preset medium -o x264_10.264 --input-csp i420 --output-csp i420 --input-depth 8 --output-depth 8 --input-res 1920x1080 --fps 50 --verbose --dump-yuv x264_10.yuv /home/siraj/Desktop/Project/Samples/1080p/ReadySteadyGo_1920x1080_120fps_420_8bit_YUV.yuv --crf=20

bitrate = 8865.74 kb/s


x265 : crf = 20

x265 -o hevc_3500.265 --output-depth 8 --input ReadySteadyGo_1920x1080_120fps_420_8bit_YUV.yuv --fps 50 --input-res 1920x1080 --input-depth 8 --input-csp 1 -P main -p medium --crf=20 --frames=100 --recon x265_40.yuv --recon-depth 8 --recon x265_50.yuv

bitrate = 6388.08 kb/s

--------------------------------------------------------------------------

for vp9

vp9 q mode = 10

./vpxenc --output=ReadySteadyGo_1920x1080_120fps_420_8bitzzz. webm --codec=vp9 --passes=2 --good -v --i420 --width=1920 --height=1080 --profile=0 --fps=50000/1001 --auto-alt-ref=1 --input-bit-depth=8 --tile-columns=4 /home/siraj/Desktop/Project/Samples/1080p/ReadySteadyGo_1920x1080_120fps_420_8bit_YUV.yuv --bit-depth=8 --end-usage=q --limit=100 --min-q=30 --max-q=30 --threads=4 --cpu-used=4 Warning: Bad quantizer values. Quantizer values should not be equal, and should differ by at least 8.
1 encoder configuration warning(s). Continue? (y to continue) y

bitrate: 24089 kb/s





cq mode = 20

./vpxenc --output=RrreadySteadyGo_1920x1080_120fps_420_8bit_. webm --codec=vp9 --passes=2 --good -v --i420 --width=1920 --height=1080 --profile=0 --fps=50000/1001 --input-bit-depth=8 /home/siraj/Desktop/Project/Samples/1080p/ReadySteadyGo_1920x1080_120fps_420_8bit_YUV.yuv --bit-depth=8 --end-usage=q --limit=100 --cq-level=20 --tile-columns=4 --threads=4 --cpu-used=4

bitrate = 15090 kb/s


when change end-usage to cq :

./vpxenc --output=RrreadySteadyGo_1920x1080_120fps_420_8bit_. webm --codec=vp9 --passes=2 --good -v --i420 --width=1920 --height=1080 --profile=0 --fps=50000/1001 --input-bit-depth=8 /home/siraj/Desktop/Project/Samples/1080p/ReadySteadyGo_1920x1080_120fps_420_8bit_YUV.yuv --bit-depth=8 --end-usage=cq --limit=100 --cq-level=20 --tile-columns=4 --threads=4 --cpu-used=4

bitrate = 8865.74 kb/s

and if i set cq=24 bucz CQ(VP9)=((CRF(X264.X265)*63))/51

./vpxenc --output=RrreadySteadyGo_1920x1080_120fps_420_8bit_. webm --codec=vp9 --passes=2 --good -v --i420 --width=1920 --height=1080 --profile=0 --fps=50000/1001 --input-bit-depth=8 /home/siraj/Desktop/Project/Samples/1080p/ReadySteadyGo_1920x1080_120fps_420_8bit_YUV.yuv --bit-depth=8 --end-usage=q --limit=100 --cq-level=24 --tile-columns=4 --threads=4 --cpu-used=4

bitrate = 12804 kb/s