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Old 8th July 2016, 09:54   #1032  |  Link
r0lZ
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Well, I don't encode in x265 myself, because my TV doesn't understand that format yet. I have simply encoded the default settings in BD3D2MK3D. (For example, the default CRF value is 28 instead of 23 for x264.) Many peoples consider the default CRF values too high, and they prefer to encode with a lower CRF, between 17 and 20 for x264. Personally, I use often the CRF 20, but with a slower preset (slow or slower instead of medium, again for x264), but take in mind that x265 is by nature much slower than x264, and selecting a slow preset can result in extremely long encoding times.

Personally, I don't like to change individual settings precisely, because usually that give worse results than a good preset, that has been fine-tuned by specialists to give excellent results. But again, some peoples want to try different settings, perhaps (and IMO too often) because they have read somewhere on the net that incredible compression with low quality loss can be archived with specific settings. It's usually not true, and often, that settings were conceived when there was no "Preset" setting in x264. It was therefore necessary to give all settings explicitly anyway. But now, things are much more simple, and I see no good reason to overwrite the selected preset with specific settings. If you are not happy with an encoding, try to lower the CRF or use another preset first, and specify manually additional settings only if you know what you are doing.

Also, don't forget that x265 is still under constant development, and it may have some bugs or weakness that will be fixed over time. Therefore, it might be difficult to say today what are the best parameters for that encoder. And, of course, there is no "best" method. The quality of the encoding depends greatly of the source video, and even with the same source, some peoples may prefer an encoding that others don't like. So, there is no precise answer to your question.

Here in the BD3D2MKL3D thread, youli has posted recently a message explaining that he is not happy with the x265 default settings, and he suggests to add manually a lot of additional settings. Maybe he is right. You can try his settings if you wish. But don't ask me if that will certainly give better results than the default parameters. Honestly, I don't know.

You may also use the SSIM or PSNR tunes to have a relatively precise and objective measure of the quality of the encodings. You should encode the same short clip several times with different settings, and compare the final SSIM or PSNR values to determine the "best" method. However, remember that it's not because one settings gives excellent results with your test clip that it's the best setting for any video source. See the articles on Wikipedia for more info (SSIM, PSNR).

[EDIT] tebasuna51 has posted his reply when I was writing mine. And he has explained essentially the same thing than me.

@tebasuna51: Perhaps you can move these new posts in the BD3D2MK3D thread?
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Last edited by r0lZ; 8th July 2016 at 09:57.
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