Converting H264 MKV’s to H265 MKV’s

Is there a way to convert a video file from 264 to 265 without quality loss? I am using the ffmpeg encoder and HEVC MKV profile with the quality slider set to 0. I am getting a file that is about half the size or better but the bitrate goes down to about 25% of the original bitrate and the video looks washed out especially in dark scenes. Are there any settings that will allow close to the same quality when converting from 256 to 265?

Here’s what my HEVC MKV profile looks like. I’m pretty sure i didn’t touch this one, so this is what yours should look like as well.

Description=HEVC in MKV (H.265/AC3) conversion. Creates a smaller file (50% smaller than H.264) with comparable quality but very slow.
ffmpeg-general=-threads 0
ffmpeg-video=-ss 0 -vf yadif=0:-1:1,hqdn3d -vcodec libx265 -preset ultrafast -crf 26 -map 0:v -sn
ffmpeg-audio=-acodec ac3 -ab 160k -map 0:a
ffmpeg-audioac3=-acodec ac3 -ab 256k -map 0:a
handbrake-general=--decomb --loose-anamorphic --verbose=2
handbrake-video=--start-at duration:0 -e x265 --encoder-preset ultrafast -q 26
handbrake-audio=-E ffac3 -R auto -B 160 -D 0 -a 1,2,3,4,5
handbrake-audioac3=-E ffac3 -R auto -B 256 -D 0 -a 1,2,3,4,5

Quality is set to 26, which i personally consider to be a bit low. It’s watchable but… It’s not something i would personally use, especially along with the “ultrafast” preset. So, at least for me, the Hevc MKV preset with it’s default is set towards the lower end of acceptable quality. It should be pretty fast, though. Bump the Q from 26 to 23-20 and change ultrafast to medium, and quality will improve drastically at the expense of speed.

You can adjust the quality from the gui via a slider, but I don’t know if there is a way to adjust conversion speed from the gui. If you want to get a bit more in “in the weeds” you can write your own profile.

Below is the handbrake profile i use for x264-x265 10bit conversions. Q is 20, medium, Eac3 audio at 640. This is my “high quality” profile. Adjust the settings to your preference. My “low/fast” settings are Q23, fast, eac3 224(2channel), etc, etc.

[HEVC MKV - HB x265 10bit Q20med eAC3 640]
Description=HEVC in MKV (H.265/AC3) conversion. Creates a smaller file (50% smaller than H.264) with comparable quality but very slow.
handbrake-general=--loose-anamorphic --verbose=2 --subtitle "1,2,3,4,5" 
handbrake-video=--start-at duration:0 --encoder x265_10bit --encoder-preset medium -q 20 --encoder-profile main10 
handbrake-audio=-E eac3 -R auto -B 640 -D 0 -a 1,2,3,4,5

In the gui i have remuxing turned off. Multichannel audio enabled. If you’re going for quality/size, make sure you don’t enable any hardware acceleration.

You can try it out and see if that works for you, or just play with the slider. Either way, bump up your Q a bit higher and see if that fixes your problem.

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Just like if you tried to make a flac from a mp3, once the data has been removed you are not going to get it back. Sure you CAN make a x265 from a x264 but it’s not going to look ANYTHING like original source made into an x265 because x265 keeps different information than x264. That’s why it’s so improved.