The video track of the 8-bit encode has 275 MiB, while the 10-bit encode has no more than 152 MiB and doesn’t look worse at all - in fact, it even looks better than the much larger 8-bit encode. I used the exact same input and settings for both encodes. Want an example? One of my first tests was encoding episode 13 of Shakugan no Shana from a DVD source, with dithering added to prevent banding. Losing one bit of information in an 8-bit color space is equivalent to losing three bits in a 10-bit color space, and thus the same quality can be achieved with less bitrate. That’s right: Not only do we no longer need to hardcode any dithering, but higher bit depth also means higher error tolerance. This brings us to the real advantage of higher bit depths: We can save bandwidth even if the source only uses 8 bits per channel. But this also has a big drawback: The bitrate required to keep the dithering intact is disproportionately high. The exact same trick can be used to display high-bit-depth encodes.īut by that logic, couldn’t we just encode with 8 bits and hardcode that dithering? Of course that’s possible, and in fact we’re already doing this to prevent so-called banding ( ). When done correctly, this creates the illusion of a higher color accuracy than what the panel is actually capable of displaying. In simplified terms, this means that the panel’s controller quickly alternates between the nearest colors in a dynamic pattern. This would look pretty awful under normal circumstances, so these displays use a little trick called “dithering” to simulate a bit depth of 8 bits per channel. This makes higher bit depth sound pretty pointless, so why are we doing this? Here’s a bit of side info: Most LCD displays (TN panels to be precise) can only represent a bit depth of 6 bits per channel (a mere 64 levels). But: Most graphics cards and display devices don’t allow more than 24 bits per pixel. Now, you can use a higher bit depth for video encoding, and x264 currently allows up to 10 bits per channel (1024 levels and 30 bits per pixel), and of course that allows for much higher precision. There are usually three color channels, so that makes a bit depth of 24 bits per pixel, which is also the most commonly used bit depth of modern desktop PCs.
The encodes you’re used to have a precision of 8 bits (256 levels) per color channel. So, why another format, and what makes this stuff different from what you know already?įirst off: What is bit depth? In short, bit depth is the level of precision that’s available for storing color information. For all those who haven’t heard of it already, here’s a quick rundown about the newest trend in making our encodes unplayable on even more systems: So-called high-bit-depth H.264.
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