H264, H265 And H265 10bit - A Quick Word - Linus Tech Tips

Hello everyone. 

 

Today, I will tackle a topic that seems to elude common forums such that if one needs all the information in one place, there usually isn't one.

So - here is the 3 codecs explained in laymen's terms, and a few HandBrake settings that might be useful. 

 

H264: Released in 2003, replaced MPEG2, H263 and MPEG4 part 10.

Pros: Really easy to run, has decent enough compression for use cases up to 1080p and was (at the time of release) more than twice as efficient as the older MPEG2 standard. It is also very quick to compress.

Cons: Needs quite a bit of bitrate by today's standards to produce watchable content. Gets really blocky in lower bitrates, does not do well with color banding. For a 2 hour 1080p movie, a good H264 encode needs at least 10GB to produce good results. You'll usually see sizes upwards of 15GB though. 

 

H265 (8bit): Released in 2013, also known as High Efficiency Video Codec, or HEVC for short. It is a successor to all previously mentioned codecs.

Pros: Much higher compression capability than H264, upwards of 2.5x smaller file sizes for equal quality compared to H264. Because of smaller size, it is suitable for use cases like 4K media and above.

Cons: Needs dedicated hardware to run (all chips that came out in the last few years support it) and is quite a bit more expensive to compress resource wise. Compared to H264, same files with same settings will take upwards of 3 times longer to compress with single pass compression, and upwards of 5 times longer with dual pass compression. It still has some of that H264 color banding issues well.

 

H265 (10bit): A version of H265. It's also known as H265 Main10, and it's known for its higher fidelity.

Pros: Even better compression than H265 8bit without loosing quality, usually 5-7%. Does away with pretty much all color banding issues and masks video artifacts better in general. It is a clear step up from H265 8bit.

Cons: 20-30% longer compression times compared to H265 8bit, Needs dedicated hardware to run. Anything from Kabylake (2016) onwards will run it natively.

 

Rule of thumb: When compressing H264 video in HandBrake, you need 50% average bitrate for your H265 10bit encode to not loose any quality when compressing with a Medium preset and 2-pass encode. Arguably, videos will look even better since there will be no color banding artifacts (if original file had any). You can go as low as 35% original bitrate, but you will need a slower encoding preset, Slow-Slower. That will significantly elongate your compression times, more than 10 times longer than an equivalent H264 encode. In my experience, it's better to allow for a bit higher average bitrate.

 

All that said, here's my preferred method. H265 10bit needs around 3000kbps avg. bitrate for a 1080p video at medium preset and 2-pass encode. That is 3mbps. I've done 2mbps runs and gotten excellent results as well. That means - if you have an H264 1080p video with 15mbps of data rate, you can get 90% of the quality with just 3mbps and H265 10bit. That said, a 15mbps 1080p H264 video is very high quality (in consumer terms), so I'd probably run the H265 10bit encoder at least at 5-7mbps to maintain it properly. 

 

If you have any questions, I'm here to answer them. For more in-depth info, click here: VP9 vs HEVC (h265) » Quantitative Quality Analysis | Bitmovin

 

Something to look forward to in the future: Versatile Video Coding - Wikipedia 

A general comparison between h264 and H265 at different bitrates: H.264 vs H.265 comparison (1080p) - YouTube