X264 Vs X265 File Size
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.
X264 Vs X265 File Size Comparison
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. 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.
H265 (HEVC) Comparison - H265 vs H264 vs Original File Vitor Sandrini. Unsubscribe from Vitor Sandrini? Cancel Unsubscribe. Subscribe Subscribed Unsubscribe 500. X265 and x264 are two different video compression standards that are used to compress video in size but still maintain the quality of the video. X264 is an earlier codec and is used in a lot of videos nowdays and x265 is a newer standard.
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.