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27th November 2018, 13:54 | #1 | Link | ||||||||
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Join Date: Aug 2018
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constant quantizer for vp9
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 Quote:
x265 qp = 10 Quote:
with crf mode : x264 crf=20 Quote:
x265 : crf = 20 Quote:
-------------------------------------------------------------------------- for vp9 vp9 q mode = 10 Quote:
cq mode = 20 Quote:
when change end-usage to cq : Quote:
and if i set cq=24 bucz CQ(VP9)=((CRF(X264.X265)*63))/51 Quote:
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27th November 2018, 19:54 | #2 | Link | |
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Join Date: Oct 2001
Location: Germany
Posts: 7,259
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What makes you thing there should be a formula that you can find a relation between quantization mappings between different formats.
Seems to me like assuming that there should be a correlation to between the length of a translated of a text into different languages (which use the same symbols when written down). For x264 and x265 (different languages) which share lots of code (grammar&co) and are quite similar a loose correlation might exist, but looking at different formats this seems to have no logical base. Looking at what quantization is, I see no reason that there should be a a relation like you are looking for,... Also as a side note: Why use '--passes=2' when using constant quantizer with VP9 ? iirc constrained quality is a 1pass encoding mode,.... What makes you thing there should be a formula that you can find a relation between quantization mappings between different formats. Seems to me like assuming that there should be a correlation to between the length of a translated of a text into different languages (which use the same symbols when written down). For x264 and x265 (different languages) which share lots of code (grammar&co) and are quite similar a loose correlation might exist, but looking at different formats this seems to have no logical base. Looking at what quantization is, I see no reason that there should be a a relation like you are looking for,... Also as a side note: Why use '--passes=2' when using constant quantizer with VP9 ? iirc constrained quality is a 1pass encoding mode,.... Quote:
-> wish you the best of luck Last edited by Selur; 27th November 2018 at 19:59. |
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28th November 2018, 12:49 | #4 | Link | ||
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Join Date: Aug 2018
Posts: 5
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Re: constant quantizer for vp9
Quote:
Quote:
with 1-pass, the output bitrate = bitrate: 59061 kb/s why it is different? if the CQ is 1 pass encoding mod.. |
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