Use our Powerful now! Read below to see the quality comparisons!HEVC or H.265 is the latest and greatest video encoder. The open source implementation of this is provided by x265. H.265 is fantastic at providing great quality video at lower bitrates, which means smaller file sizes. H.265 can be very CPU intensive to both encode (create) and decode (play back).Single Pass vs Dual PassThis page is a quick analysis of the x265 encoder's settings and show some differences of encodes using some various settings. Encodes can be single pass, dual pass, or N pass. The benefits of multipass are seen more when attempting to achieve very specific file sizes.
In this case, you would want to run at least 2 passes so that you can tell where in the video you have fast action scenes that require more bitrate vs where you might have still or dark scenes that require less bitrate. In this way, the bitrate can be pre-allocated to where it needs to go to produce the best quality file at a specific required size.Getting Decent Encodes with CRFIn the event that you don't need a very specific file size (more common), you really do not need to run dual pass encodes. You can instead run a constant rate factor. This is what we do here at ConvertThisFile.com. Constant Rate Factor (CRF) ranges from 0-51, but reasonable ranges are 18 - 28 where 18 is considered highest quality and 28 is considered lowest quality. The smaller the CRF, the longer it takes to encode the file and also the larger the file will be. (There are other factors here, this is a simplification).Speed PresetsIn addition to CRF, there are some encoding speed presets available.
For x265, the preset options are: ultrafast, veryfast, faster, fast, medium (default), slow, slower, veryslow, and placebo. The general concensus is to stick with encoding presets between fast and slow. The slower you go, the longer the encode times. Doing some encode testing on a 1280x720 source using the various settings, we see a vast range of frame rates. If medium runs around 20 FPS, ultrafast can be as fast as 100 FPS and veryslow as low as 2FPS.
X264 Vs X265 File Size 1
One of the main benefits of dropping from normal to slower is it enables me=star over me=hex which improves motion artifacting.Other Interesting ParametersIn addition, there are some other settings that can impact the quality of the encode. Among there are the deblock filter.
HEVC vs H.264: File Size. The great compression ratio also has a great relationship with the digital storage requirement of video streams and transmission. The reduced bandwidth leads to smaller file size. Test shows a video encoded with H.264 is 1-3X larger than H.265.
This filter runs from -6 (lightest deblock) to +6 (strongest deblock). The default is 0. Compared to x264, the deblock filter seems to provide more of an overall blur and it is our experience that lessening the deblock greatly sharpens the entire image. While we used a deblock of -2,0 on x264, we use a deblock of -4,0 or even -5,0 for x265 to achieve similar sharpness (at much lower bitrate). The me value defaults to hex, which is a decent fast motion search algorithm. Star is a better motion estimate search algorithm but significantly slower.Encoding ComparisonsLet's do some encoding comparisons using an episode of The Big Bang Theory. Here is our first comparison showing an encode using our.
The two encodes show our 'low' quality setting compared to our 'high' quality setting.The image on the left uses -preset ultrafast and -crf 18. The resultant file 252mb for 21 minutes. This encoded at 60fps The image on the right used -crf 18 and normal preset, which encoded at 15fps.
The resultant file was 630mb. There is very little difference in noticeable quality on the still shots.Click to view the image comparison full screen.Same encode settings just a different frame.Click to view the image comparison full screen.This comparison shows a poor quality noisy source using our encoder on its high quality profile.Click to view the image comparison full screen.This comparison shows a poor quality noisy source using our encoder on its low quality profile.Click to view the image comparison full screen.
To convert from one codec to another always involves re-encoding. Whether it reduces quality or not, depends on the settings used during the process. The main benefit to re-encode to x265 is to save space, but generally you're not going to save heaps of space, unless you also lose some quality. I think you could estimate that x265 is 50% of the size of x264 for similar quality.There's also a downside to converting to x265 - you need more powerful hardware for playback, and there are fewer devices out there that can even play it at all. And if you're streaming from an Emby server to something like an iOS device, Emby server will need to use more CPU power whilst transcoding an x265 file compared to an x264 file.Some of my downloaded TV episodes I consider to be far too large for their length (3.5GB for a 50 minute show seems too big to me) - so I re-encode those to x265 just to save space on my NAS. To convert from one codec to another always involves re-encoding. Whether it reduces quality or not, depends on the settings used during the process.
The main benefit to re-encode to x265 is to save space, but generally you're not going to save heaps of space, unless you also lose some quality. I think you could estimate that x265 is 50% of the size of x264 for similar quality.There's also a downside to converting to x265 - you need more powerful hardware for playback, and there are fewer devices out there that can even play it at all. Well, I have done a fair bit of playing around and looking into it myself, even done some encodes from full blue-ray which do take time a bit of extra time.
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Would their be any substantial loss from RE-ENCODING to x265 that would be considered a huge drawback in terms of quality in comparison to say encoding to x265 straight from the source?If you're already happy with the x264 encodes and you're not worried about file size - then just leave them as x264. No one will be removing x264 support at any time in the future, so converting to x265 is not going to 'future-proof' anything.But, to answer your question - no you're not going to lose quality, as long as you use appropriate settings when encoding to x265. There's lots of ridiculously small x265 stuff out there - and the quality is atrocious, but they've just used far too aggressive compression.
I think the default quality setting for x265 is 26 which is great for significantly reducing size but terrible for retaining quality.I'd suggest you try a conversion or two - and then compare before and after on a quality screen. When I encode to x265 I use a quality setting of 19 which gives very good results. There are many, many different encoder settings that can be adjusted - but I leave them alone. Other users spend ages fiddling with them to get the best quality the can (read some of the replies in ).(I use MeGUI for my encoding, but I'm sure Handbrake will also do what you want).
I'm new to Emby, but I've been testing the crap outta x265 over the past couple weeks. I even let a 48hr x265 supa slow encode complete to see the result.
Don't do that!As for your original question: Generally it's a bad idea to re-encode your x264 into x265. The quality loss might be fairly small, but there will be some loss. Of course, if you have 4,000kbps+ x264 1080p video files, go for it. Just stay between Constant Quality 24 and 18.
You might have to try a few times to find the sweet spot for your encodes. And download the Handbrake Nightly, it has an up to date x265 encoder that beats the last stable release by a mile (losta improvements between v1.5 and v1.8).StaxRip lets you update x265 encoder on the fly, btw, but it's got a bit of a learning curve.
I tested both, Stax would be preferable if you want to tweak the hell outta your x265 encodes. Handbrake allows command line passthrough, which is currently undocumented, but it's otherwise very limited.You didn't say what kinda quality your original files were. More info gets ya better answers. I could give you a good idea of what Bitrate to shoot for with x265.Personally, I'm okay with sub 4,000kbps x264 archive video, so I rip BR-2-x265 at Constant Quality 25-22 Medium Main, with 5.1 HE-AAC. I get between 15-23FPS for the encode on my i5 6600k, that's less than 4 hours (as long as I don't use any filters). Sorry for the late reply, Busy leading up to Christmas and been avoiding using my PC while encoding.The quality is source material apart from the encodes I have done.
Anything New I do I am going to go with x265, I feel as if at the level I want to encode at in terms of file size and quality seems to make sense to me.So I have taken your advice and gone with CQ22. I don't have a surround sound system yet but have been re-encoding them to AC3. Only reason for AC3 has been due to compatibility etc from what I have read up.
Can I still get true surround using HE-AAC? I just dunno where receivers are at these days with all these new codecs coming out etc.