x264 vs x265 at high bitrates, 1080p bluray, my results
Posted: Tue Jun 09, 2020 12:28 pm
I wanted to compress my bluray rips, but didnt know what codec to use, or what settings to use in general. So i ran a few tests. Im in no way a scientist, and the opposite of an expert when it comes to video encoding, but i think some people may benefit from my tests.
The cpu i am using is a ryzen 5 2600 running at stock speeds, and i have 16gb cl16 3200mhz ddr4 ram. This is so you can adjust some of the results for your own system, to get a better idea of how it may perform. Just a guideline, it wont scale perfectly.
My goals when encoding were to save some space, while producing a video that was (practically) indistinguishable to the source, with some quality buffer, just in case my viewing conditions change (larger tv, closer seating etc). If your goals are different, these results may not apply to you.
I tested the files by doing the following. I chose some movies or episodes at random, and then used mkvtoolnix to split them up, into many different 100mb chunks, removing audio tracks to remove that as a variable. I selected 5 clips per movie/show at random, and encoded them with 2 different configurations in handbrake, and then compared them.
X264 settings were high profile, level 4.1, rf 18, veryslow, and ssim tune (just for testing, would use film for an actual encode), and x265 was main profile, auto level, same rf of 18 and ssim tune, with the slow speed.
I measured 3 variables, size relative to source, speed of encode in fps, and quality with ssim (more on quality later) and then averaged them for each config.
Results:
X264
34.37% of source
SSIM value of 0.982
Speed of 17.83 fps
X265
29.06% of source
SSIM value of 0.980
Speed of 7.55 fps
So as you can see, at high bitrates, aiming for a transparent encode, x265 saves only about 15% space, while taking more than twice as long to encode, which may or may not be worth it depending on your processor, but for me it isnt.
X264 also (acording to a computer) produces ever so slightly higher quality files, but in practice, both were essentialy identical, not only to each other, but to the source as well. At these kinds of bitrates, the smoothing/blurring x265 tend to cause at lower bitrates goes away, and the artifacting of x264 also isnt present. This is obviously expected at high bitrates.
Any other points? I dont intend to do anymore tests, as i said, im not a scientist, and this testing was done purely for my own needs. Just thought i would share my results, on the off chance someone would benefit, or had any input or questions.
The cpu i am using is a ryzen 5 2600 running at stock speeds, and i have 16gb cl16 3200mhz ddr4 ram. This is so you can adjust some of the results for your own system, to get a better idea of how it may perform. Just a guideline, it wont scale perfectly.
My goals when encoding were to save some space, while producing a video that was (practically) indistinguishable to the source, with some quality buffer, just in case my viewing conditions change (larger tv, closer seating etc). If your goals are different, these results may not apply to you.
I tested the files by doing the following. I chose some movies or episodes at random, and then used mkvtoolnix to split them up, into many different 100mb chunks, removing audio tracks to remove that as a variable. I selected 5 clips per movie/show at random, and encoded them with 2 different configurations in handbrake, and then compared them.
X264 settings were high profile, level 4.1, rf 18, veryslow, and ssim tune (just for testing, would use film for an actual encode), and x265 was main profile, auto level, same rf of 18 and ssim tune, with the slow speed.
I measured 3 variables, size relative to source, speed of encode in fps, and quality with ssim (more on quality later) and then averaged them for each config.
Results:
X264
34.37% of source
SSIM value of 0.982
Speed of 17.83 fps
X265
29.06% of source
SSIM value of 0.980
Speed of 7.55 fps
So as you can see, at high bitrates, aiming for a transparent encode, x265 saves only about 15% space, while taking more than twice as long to encode, which may or may not be worth it depending on your processor, but for me it isnt.
X264 also (acording to a computer) produces ever so slightly higher quality files, but in practice, both were essentialy identical, not only to each other, but to the source as well. At these kinds of bitrates, the smoothing/blurring x265 tend to cause at lower bitrates goes away, and the artifacting of x264 also isnt present. This is obviously expected at high bitrates.
Any other points? I dont intend to do anymore tests, as i said, im not a scientist, and this testing was done purely for my own needs. Just thought i would share my results, on the off chance someone would benefit, or had any input or questions.