Question: What would be the preferred x265 preset when recoding a x264 file?

[Addict]

I'm not familiar enough with recoding video files in general so I'm not sure what would be the preferred x265 preset to get the same quality when recoding a x264 file and no original source file exists.

I assume that the slowest preset, or perhaps even placebo, would give the same quality without further quality reduction (assuming that recoding with a different encoding reduces quality similar to how recoding an MP3/JPG causes further quality reduction.)

[rollin_eng]

You will always lose quality unless you do a lossless encode.

x265 has a lossless option but I'm not sure if HB supports it or if you actually want it.

[Addict]

I understand I'll always lose some quality, I just want to know which will give the least amount of acceptable loss without the encoding time going up to half a day for a single 40 minute episode.

I've already tried various presets to compare them to the x264 version but to my untrained eye I only can see obvious differences when using fast and up. For as far as I can see Medium stays comparatively close to the source x264 but it's hard to compare because I cannot find a player that will take two files and plays them spliced down the middle side by side in the same window. So that the left half of the screen plays left part of one file and the right half of the player screen plays the right half of the other file so I can drag a separation slider to compare instead of having to switch back and forth between two separate players

[rollin_eng]

Speed, Size, Quality.

Pick 2.

[Addict]

That's an impossible choice. Quality and speed will never ever go hand in hand together. If I want speed than I am forced to forego on quality and the other way around I will have to accept a hefty reduction of speed. Size doesn't even come into the equation when comparing x265 to x264 I suspect, because the first method will almost always produce smaller files if I understand correctly.

Also I think that these choices are only valid when you have an original unencoded source file at your disposal and cannot apply to recoding given the mentioned encodings

[rollin_eng]

It's really not impossible, just pick 2 of them

[s55]

It's the general rule for all lossy video encoders and applies here. If you want speed and quality, you need to use a lowerRF (higher quality) but with faster settings, thus leading to higher file sizes.

You also have to take into account your audience. If these are for you, and you get good results at Fast@RF20, great, use that. SOmeone else may be able to tell a difference from that and Medium@RF20. We all have different eyesight.

Basically, find the trade off that works for you and go with that.

[mduell]

That's an impossible choice. Quality and speed will never ever go hand in hand together. If I want speed than I am forced to forego on quality and the other way around I will have to accept a hefty reduction of speed. Size doesn't even come into the equation when comparing x265 to x264 I suspect, because the first method will almost always produce smaller files if I understand correctly.

None of what you're claiming is true.

[Trypt]

I know it's physically impossible to improve on quality while encoding, but to my eyes, that is exactly what HEVC does. I have downloaded numerous sources, 1080p in the 5-10GB range, so 720p in the 1GB range, when I really want quality for something that I've been waiting for a long time to watch. But then I find a HEVC encode online (before I found I can do it myself) by some good encoder or other, and even though the source stated is one of the above, and their file is 3-4x smaller, the HEVC video looks much much better to my eyes, Potplayer and MadVR and Lav filters. I cannot understand it, but even the 10GB 1080p source when I watched it (in this case it was a remastered 60s classic like Zhivago or maybe Fistful of Dollars, don't remember) and compared it to the HEVC 1-2GB encode from the same source, I preferred the HEVC in every way. Crisper, no artifacts, way less noise, all kinds of improvement, I can't explain it.