h.265 vs h 265 10 bit

[jamespoo]

so guys i have a 32gb usb flash stick there is a site that does legal streams of movies and tv shows for free movies are 1080p most being like 4gb + and some older movies in 480p most being 1gb +

what i wanted to know is i have a tv that supports h.265 and h 265 10 bit its only 1280x720 18.5inch tv the downloaded 1080p videos lag a bit on this tv so i want to re-encode them

my computer can encode 1080p to 720p h.265 using my gpu and handbreak really fast depending on the length of the movie it takes around 3-5mins and movies get down to a size like 800mb-1.4gb and still look amazing on tv especially animated or cartoon movies

my question is should i encode to h.265 or h 265 10 bit

[krykmoon]

It depends only on the source video: if it's 10bit or not. You don't gain anything in encoding a 8bit video to 10 bit, quality wise. May be the opposite.

Anyway.. even if I don't think that is so relevant in your case: GPU encoding may be very FAST but the result it's usually worse in quality than with CPU encoding.

[jamespoo]

It depends only on the source video: if it's 10bit or not. You don't gain anything in encoding a 8bit video to 10 bit, quality wise. May be the opposite.

Anyway.. even if I don't think that is so relevant in your case: GPU encoding may be very FAST but the result it's usually worse in quality than with CPU encoding.

thanks i will stick with h.265 encoding
cpu encoding gives me smaller size but take like 2hrs to encode movie to 720p im happy having a bigger file size if it means that i can encode the video really fast

[jagabo]

10 bit h.265 encoding can deliver better visual quality than 8 bit, even with 8 bit sources and viewing on 8 bit displays. This is because the deblocking stage of h.265 decoding can be done while the YUV video is 10 bit, before conversion to RGB for display. That gives much smoother RGB gradients. Not all devices decode this way so your results may vary. Attached are 8 and 10 bit h.265 encodings of a difficult source. And an 8 bit encoding at a very high bitrate as a reference (it looks very much like the 8 bit source). Watch the shallow gradients in the background in a dark room. On my computer (8 bit display) the 10 bit h.265 shows almost no posterization of the gradients. The 8 bit h.265 encoding shows very obvious posterization. The 8x bigger 8 bit x264 encoding looks best because of the much higher (8x) bitrate.

ffmpeg -y -loglevel error -benchmark -v verbose ^
    -i "%~dpnx1" -pix_fmt nv12 ^
    -c:v hevc_nvenc -cq:v 23 ^
    -colorspace bt709 -color_range tv ^
    -acodec copy "%~dpn1.hevc08.nvenc.mkv"

ffmpeg -y -loglevel error -benchmark -v verbose ^
    -i "%~dpnx1" -pix_fmt p010le ^
    -c:v hevc_nvenc -cq:v 23 ^
    -colorspace bt709 -color_range tv ^
    -acodec copy "%~dpn1.hevc10.nvenc.mkv"

"g:\program files\x264\x264-64bit.exe" --preset=slow --crf 10 --sar=1:1 --keyint 50 --colormatrix %COLORS% --colorprim=%COLORS% --transfer=%COLORS%  --range=tv --stitchable --output "%~1.mkv" "%~1"