an honest (p)review of x265

[deadrats]

before i get started allow me to thank a few people without whom this "review" would not be possible. we have Selur, who was nice enough to supply me with a preview version of Hybrid that supports x265 encoding. there is also El Heggunte who started the x265 thread as well as the couple of people who have unofficial x265 builds. of course a big pat on the back goes to me because aside from the fact that i am the one writing this "review" the existence of a version of x265 that features std::in support is entirely attributable to my contributions in the x265 thread. call it flaming, trolling, harassing or as i see it putting forward sound advice and criticism, i don't think too many people will argue that if it weren't for me repeatedly beating the "you need to add std::in support now", this version of x265 wouldn't exist, Tom had made it clear that they had no intention of including said support anytime soon.

anyone that has read any of my posts about x264 knows that among other things i consider x264 to be way over-engineered, with way too many options that can appear contradictory and in all honesty leads to numerous "what are the best settings for encodes of this type" posts.

as i expected, basing x265 on x264 is leading to the exact same situation and even though x265 is still in its infancy in a state that could be considered somewhere between alpha and beta quality there are still numerous configurable encoding parameters that in all frankness the average person will have no idea what they do nor what to choose. by the time x265 is at a state where the developers feel it's complete the number of options will have skyrocketed and forums such as this will be saturated with questions concerning which combination of options is "best".

making matters worse is that in its current state, x265 is buggy as hell, with various combinations of settings causing a crash of the encoder. the speed is also abysmal, with 8mb/s 1080p encoding on an i7 3770k at just over 2fps. this i can't really complain about that though because h264 encoders ran slowly on the hardware of the day when they were first coming to market and in all honesty within 2 years intel will be releasing 512bit simd instruction capabilities. on top of that x265 does seem to be very well threaded, so we may actually see an arms race of sorts with cpu companies releasing high core count processors.

the most important thing with regards to x265 right now is the quality and when i could get it to work, the quality of the encode was impressive to say the least. even with x265 configured with all the major options turned down for maximum speed, x265 encodes routinely beat x264 encodes and divx h265 encodes and quite easily at that.

i ran numerous tests with dvd and blu-ray sourced content and bit rate for bit rate neither of the two above reference encoders could hold a candle to what i could get out of x265.

unfortunately this is technology still in its infancy, as playback could be spotty at best, using LAV filters and mpc/mpc-hd and pot player not to mention that many combinations of x265 parameters resulted in an instantaneous crash.

making matters worse are the bugs in the preview version of Hybrid i was supplied with but the version i was supplied was not meant for public consumption and i intend to PM Selur and share with him a few things i discovered for him to look into.

all in all the past few days i spent with Hybrid+x265 have left me excited about a time in the near future when they are both working flawlessly and i think we'll see x265 adopted into most, if not all the major open source projects probably within the next 6 months.

unfortunately i don't see x265 being included in any commercial projects anytime soon, even if all the bugs could be worked out, primarily because of the speed issue. while 2fps for 1080p may be acceptable for a free open source pre-beta preview there is no way that someone paying hundreds of dollars for a commercial product is going to put up with that kind of performance.

making matters worse is that the development of x265 seems to be behind where rovi's hevc sdk is, elecard is almost ready to release their sdk and encoder and cyberlink is also slated to release an hevc encoder in the first quarter of 2014.

if i were running the x265 team i would stop any development aimed at adding more parameters/features and instead focus on getting what was already there to run without any crashes and also on making massive speed gains. the quality of x265 is good enough right now that people would flock to it in a heart beat if the x265 team could get 20fps performance at 1080p with an intel hexa core processor if said encoding speed was with settings in the mid range.

i wish the x265 people good luck, i'm not entirely convinced that they will be the dominant player in the hevc encoding segment they hope to be when all the dust settles but there is no question that their product currently offers the best encoding quality.

when it works.

[Mephesto]

There's no stable implementation of H265 yet and you're doing a review? Are you serious?

Most of what you wrote is misguided and sophomoric and what wasn't wrong was obvious, readily available information.

First off, there are many handheld devices, HANDHELD, and more to come with hardware support for HEVC which already plays back at a satisfactory rate, H264 was not met with early hardware adoption. The game will be different this decade. The 2 fps for 1080p is pretty good, that's how fast it takes me to encode with x264 with the unmatchable quality settings I use.

the quality of x265 is good enough right now that people would flock to it in a heart beat if the x265 team could get 20fps performance at 1080p with an intel hexa core processor if said encoding speed was with settings in the mid range.

Don't make assumptions. The public consist of morons who can barely add and subtract, this includes morons who put enough effort to install ripping and encoding software who to this day are convinced that Xvid is "warmer quality" than H264. I came across people like this a dozen times on this very website a few years back. As of 2013 when x264 is nearing its end, idiots are finally adopting H264 by the masses. This took what, 10 years?

People take forever to catch up, they are always behind the technology. x264 in its early days was faster than Xvid with a minimal settings configuration and was still better quality. Nobody used it. Too much novophobia and the obsessive, confrontational doom9 losers would accept no compromise with supporting H264 in the AVI container to ease up problems with users who had no free software to edit MP4/MKV containers, certainly not helping its popularity.

There's no reason not to add support for advanced features just because x265 is new. Newbs can use presets or RTFM like I did when I first used x264 and learned what does what. In the end, I chose what I wanted to fit a reasonable encoding speed on the equipment I had at the time.

x265 is a hobbyist encoder right now and there's no good reason to use it for anything serious period. It's in alpha mode and what you encode with it now you probably won't be able to decode a year from now. So what's your rush? Let them focus on implementing all the advanced features they want.

[johns0]

The only reason to use x265 is for 4k and higher and most people don't have any such videos and uber sized hdtv so it will only be of interest to a very few who can afford it so it will a long time till it becomes primary to users.

Heck,even dvd players are what a lot of people still use.

[Mephesto]

The only reason to use x264 is for 720p and higher and most people don't have any such videos and uber sized TVs so it will only be of interest to a very few who can afford it so it will a long time till it becomes primary to users.

Do you dullards ever vanish? Why not use x264 for 4K since it will encode faster and playback faster not to mention be more compatible? x265 offers better efficiency at any not just 4k resolution.

[johns0]

The only reason to use x264 is for 720p and higher and most people don't have any such videos and uber sized TVs so it will only be of interest to a very few who can afford it so it will a long time till it becomes primary to users.

Do you dullards ever vanish? Why not use x264 for 4K since it will encode faster and playback faster not to mention be more compatible? x265 offers better efficiency at any not just 4k resolution.

Please don't misquote me,you are the dullard for changing my statement.

[Mephesto]

You are echoing the exact same newb misconceptions that were common about H264 when it was new (H264 iz 4 HD!) when you say H265 is only good for 4K and nothing else.

[johns0]

That's just your opinion,i said 4k and higher and that's my opinion.

[Baldrick]

Please try and behave in this thread. We are ONLY discussing VIDEO and not real world politics problems. .



I have no comments because I wont test x265 until 2015...

[hello_hello]

anyone that has read any of my posts about x264 knows that among other things i consider x264 to be way over-engineered, with way too many options that can appear contradictory and in all honesty leads to numerous "what are the best settings for encodes of this type" posts.

as i expected, basing x265 on x264 is leading to the exact same situation and even though x265 is still in its infancy in a state that could be considered somewhere between alpha and beta quality there are still numerous configurable encoding parameters that in all frankness the average person will have no idea what they do nor what to choose. by the time x265 is at a state where the developers feel it's complete the number of options will have skyrocketed and forums such as this will be saturated with questions concerning which combination of options is "best".

Where's the evidence this forum was "saturated" with questions concerning the best combination of x264 options to use?

Sure, there's plenty of options to choose from, but the majority of people would use an encoder GUI, and most of them are designed to encourage the use of x264's speed presets and tunings etc, in preference to fiddling with advanced options individually.
Maybe that wasn't always the case, but it is now, and I'd assume GUIs aren't going to take a step backwards when they implement x265 encoding. With any luck, by the time x265 is mainstream most users will be trained to use the built in presets and won't give x265's advanced options any more thought than they currently give to x264's.