[Question] x264 vs x265 - Quality Difference with same Bitrate?

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Neipas09
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[Question] x264 vs x265 - Quality Difference with same Bitrate?

Post by Neipas09 »

I have a BluRay I want to rip and encode.

If all the settings are EXACTLY the same (with a Bitrate of 3000 kbps), only difference being the codec (x264 vs x265), will I notice any difference in quality with the finished product?

Or, does the quality difference between x264 and x265 only occur if I use CRF instead of Avg Bitrate?
x264 CRF23 vs x265 CRF23
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Rodeo
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Re: [Question] x264 vs x265 - Quality Difference with same Bitrate?

Post by Rodeo »

x264 and x265 are two different encoders producing a different video bitstream format (H.2654 resp. HEVC). There is no way for settings to be exactly the same, each encoder has specific settings not available in the other.
Neipas09
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Re: [Question] x264 vs x265 - Quality Difference with same Bitrate?

Post by Neipas09 »

Rodeo wrote: Fri Sep 11, 2020 11:00 pm x264 and x265 are two different encoders producing a different video bitstream format (H.2654 resp. HEVC). There is no way for settings to be exactly the same, each encoder has specific settings not available in the other.
That's incorrect, but ok...
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Rodeo
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Re: [Question] x264 vs x265 - Quality Difference with same Bitrate?

Post by Rodeo »

So how do you set the CTU size in x264?
Neipas09
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Re: [Question] x264 vs x265 - Quality Difference with same Bitrate?

Post by Neipas09 »

Rodeo wrote: Fri Sep 11, 2020 11:15 pm So how do you set the CTU size in x264?
Did i say ANYTHING about custom settings??? NO!
This is under the assumption that i'm using settings from drop down menus in the application.
If you didn't understand that, then that's your problem.
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Rodeo
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Re: [Question] x264 vs x265 - Quality Difference with same Bitrate?

Post by Rodeo »

Except custom settings are precisely what affects compression efficiency (quality at a given bitrate) the most. Given the same bitrate, you cannot expect x265 ultrafast to compare to x264 placebo and vice-versa.
mduell
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Re: [Question] x264 vs x265 - Quality Difference with same Bitrate?

Post by mduell »

The same video encoder presets for x264 and x265 set different options, since they're different codecs and encoders.
musicvid
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Re: [Question] x264 vs x265 - Quality Difference with same Bitrate?

Post by musicvid »

Be aware that you are challenging a program developer and coder. His patience is stellar, even with an unruly stepchild such as me.
As for your core question, and all else being theoretically equal (which btw is impossible), and assuming that neither the source nor either encode is of suboptimal quality or compression (a huge IF), the x265 encode should maintain a higher compression ratio (smaller file) at the same quality as the x264 encode. I wouldn't know how to design a test to quantify such an outcome, because of literally hundreds of untrapped variables that @Rodeo correctly points out that exist between different encoders. Hope this helps your thought process.
rollin_eng
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Re: [Question] x264 vs x265 - Quality Difference with same Bitrate?

Post by rollin_eng »

Neipas09 wrote: Fri Sep 11, 2020 10:28 pm If all the settings are EXACTLY the same (with a Bitrate of 3000 kbps), only difference being the codec (x264 vs x265), will I notice any difference in quality with the finished product?
Maybe. Try it and find out.
Sigward003
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Re: [Question] x264 vs x265 - Quality Difference with same Bitrate?

Post by Sigward003 »

Theoretically, the H.265 have better bit reduction with 56% compare to H.264 profile.
My dumb question is, If I have a H.264 video and transcode it to H.265 video will it be smaller + without graphic quality dropping?
musicvid
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Re: [Question] x264 vs x265 - Quality Difference with same Bitrate?

Post by musicvid »

If I have a H.264 video and transcode it to H.265 video will it be smaller + without graphic quality dropping?
Answer was given above:
1. IF the original video is not already of suboptimal quality, the x265 encode should be smaller! That's one big "IF."

2. There will always be quality losses from encoding again with a lossy encoder.
Sigward003
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Re: [Question] x264 vs x265 - Quality Difference with same Bitrate?

Post by Sigward003 »

Thank you musicvid, If I am not making this wrong, it means it depends on the video quality & properties the original video file is? (no matter if it was or not encode with H.264 codec) a optimal video encode to H.265 will end up the result of a better compressed file?
musicvid
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Re: [Question] x264 vs x265 - Quality Difference with same Bitrate?

Post by musicvid »

Yes.
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