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The article starts off with talking about "raw" video containing 3 bytes for every pixel. However, most video is YUV, which is typically 1.5 bytes/pixel. http
by the-dude 5y ago
The article starts off with talking about "raw" video containing 3 bytes for every pixel.
However, most video is YUV, which is typically 1.5 bytes/pixel.
https://en.wikipedia.org/wiki/YUV https://en.wikipedia.org/wiki/YUV
- _zywo 5y agoWell, if we're being pedantic here, raw RGB video as would be displayed on a RGB monitor does indeed take 3 bytes per pixel. Technically, YUV is either an optimization or a backwards compatibility measure, and hence the adjective "raw" does not apply to it.
- Closi 5y agoIf you define raw video as RGB with 1 byte for red, 1 byte for green and 1 byte for blue, then yes, it will be 3 bytes per pixel. But there are clearly other ways to store a pixel of colour information in less than 3 bytes, which is OP's point. It's not an optimization really - it's just a different coding format (Just as ASCII isn't an optimization of Unicode).
- sly010 5y agoActually the "raw" data coming from most cameras are often already compressed somehow, otherwise the camera would not be able to write it to storage (or send it over USB) fast enough. In fact since decoding also often happens in hardware, the raw size may never materialize anywhere in the pipeline, other than the framebuffer of the video card. Even HDMI has compression now [0] The author probably choose a screenshot as a benchmark, because otherwise it's hard to get your hands on anything compressible but not already compressed.
- iso1631 5y ago10 bit video 444 with 8294400 or 8847360 samples per picture for 4k (tv vs movie) tops out below 270mbit per frame, or at 60hz 16gbit, so you can fit half a dozen signals down a 100G transceiver, or two down a 40G. Throw in YUV compression and you can shift 120hz 8k with relatively little problem.
- jasongill 5y agoIf you actually read the rest of the article, the author covers this in the section about chroma subsampling.
- phire 5y agoYUV alone is still 3 bytes per pixel and can be converted back to rgb without any loss. But YUV is almost always combined with color subsampling, which gets you to 1.5 or 2 bytes per pixel.
- bumblebritches5 5y ago
- fomine3 5y agoYes, OP might want to say YUV422 or YUV420 that most videos are encoded.
- iso1210 5y agoMost video I deal with is YUV (YCbCr) 422 at 30 bits per 2 pixels