8 bit vs 10 bit Color: What's the Difference? And does it matter for YouTube?
248 bit video vs 10 bit video - Does it matter for YouTube - With downloadable video test files.
In this video I'm explaining the basic difference between 8 bit video and 10 bit video.
The video also shows that there is no advantage to uploading YouTube videos in 10 bit video compared to 8 bit video as far as the amount of colours are concerned in the final YouTube video streams. This is because YouTube uses 8 bit for its SDR standard dynamic range rec.709 video outputs.
In this instance, YouTube basically truncates the 10 bit video file to 8 bit video during the transcode and encode process, which will reduce the amount of colours to what it would have been with an 8 bit video upload.
There are certain advantages with 10 bit in post but this video is about delivery and not post. There are also certain efficiency advantages to using 10 bit over 8 bit for delivery. However, these advantages do not change the result of the reduced colour range or make the 10 bit video upload look any better. Using a high bitrate with the 8 bit output will also further mitigate any differences anyway and that's only if there was an advantage with the 10 bit output in the first place with regard bit rate.
If using 10 bit video sources and media, then it makes sense to export as 10 bit as this will be beneficial if those 10 bit outputs are played back within a 10 bit pipeline. Plus, you may want to reuse a 10 bit video output file again in another edit, which means that 10 bit will once again be better. However, none of these advantages will make any difference for a YouTube upload compared to an 8 bit upload with regard colour range and banding etc.
The output files that I've made available for download will help you see the differences much easier, as YouTube will have converted everything to 8 bit video in this video.
The playback of this video on YouTube will also suffer from the low bandwidth data rate that YouTube uses for its video streams. This actually gets much worse with static images and especially static colour, which is essentially what most of this video is. Again, the downloadable video test files will not suffer with that problem.
Another issue with the YouTube playback is the compounding issue or concatenation. For some of these examples YouTube will be re-encoding 8 bit to 8 bit and this will have certain issues of the banding potentially compounding and looking worse than it actually is. Plus there's also the issues of the codec being used by YouTube, which will also have another negative impact on perceived colour resolution and the banding. Re-encoding any destructive inter-frame codec to another destructive inter-frame codec will keep compounding problems and make things look worse.
So basically, while the 10 bit sources may appear to not look as bad as the 8 bit sources after YouTube had done its thing. Both 10 bit and 8 bit sources will have definite banding, it's just that the 8 bit sources will be taking a worse hit due the compounding issues I've just mentioned. Testing the download files will give you a better idea of all this and if you put all the files in a timeline and export to 8 bit uncompressed, you will see the banding being more evened out.
YouTube really is very good, however, it can introduce some serious issues during its re-encoding and transcoding.
Also, this video was recorded with an Atomos Ninja V in 4K UHD 60FPS using ProRes 422 HQ, which was recoding the HDMI output from my MacBook Pro M1 Max. So the capture was in 10 bit with 4:2:2 chroma subsampling using an intra-frame codec that isn't heavily compressed as far as its bit rate is concerned.
The edit for the video was done in DaVinci Resolve and also exported from DaVinci Resolve to H.265 at 10 bit with 4:2:0 chroma subsampling at 100Mb/s as 4K UHD 60FPS. Due to the static nature of the capture file and it being mostly block colours, the H.265 export for the YouTube upload was essentially visually indistinguishable from the ProRes capture. However, as mentioned before, YouTube will likely have used a very low bit rate because of the simple and solid colours and will likely have introduced low bit rate artefacts on top of the 8 bit colour banding.
Here's link to the 8 bit video and 10 bit video downloadable test files. Their names are descriptive of what they are:
https://www.mediafire.com/folder/rnu3qeha0eljp/8_BIT_VS_10_BIT_VIDEO_FILES
Video chapters:
00:00 Intro and explanation of the video
02:42 What is a bit
05:49 Explaining the master video assets
10:24 Explaining how the downloadable video files were created
14:50 Explaining the differences between the downloadable video files
15:59 Playing through the downloadable video files
17:17 Explaining the playback of the downloadable video files
18:12 What you can use the downloadable video files for
19:32 End summary
I’m David Harry. Thank you very much for watching this video, take care and goodbye now.
Cheers,
Dave.
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