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jpsdr · 30th July 2018, 16:30

After a long fight (HLG is realy a pain in the ass if you want to optimize things), i'm near the end. But i have two choices, for a specific point. For speed-up i've implemented lookup. 8 bit is 3D lookup, so it's fine, but for 10 and 12 bit i've tried 2D lookup. It's faster than 16 bits, but... there is a noticeable resolution loss on low values (visible on some colors of ColorBars when testing YUVtoRGB followed by RGBtoYUV).
Choice 1 : Keep actual status, with 2D lookup for 10/12 bits.
As most of source filters produce 16bits ouput, if you don't want speed, you keep 16 bits, it you want speed-up, you add ConvertBits to reduce the bitdepth to the actual true bitdepth of the source. With this option, you keep the possibility to choose.
Choice 2 : No 2D lookup, 10 to 16 bit, same speed.
For now, i'm more on "Choice 1", allowing users to keep the possibility to choose, but i want to know what others users thinks what would be better.

BTW :I personnaly have nothing to display HDR video, no reader, no screen, nothing. The only tests i can do is checking ouput is not obvious garbage, no crash or things like this, that an operation followed by its reverse produce output indentical to input, but i have no way to check if output is realy proper.

30th July 2018, 16:30	#42 \| Link
jpsdr Registered User Join Date: Oct 2002 Location: France Posts: 2,316	After a long fight (HLG is realy a pain in the ass if you want to optimize things), i'm near the end. But i have two choices, for a specific point. For speed-up i've implemented lookup. 8 bit is 3D lookup, so it's fine, but for 10 and 12 bit i've tried 2D lookup. It's faster than 16 bits, but... there is a noticeable resolution loss on low values (visible on some colors of ColorBars when testing YUVtoRGB followed by RGBtoYUV). Choice 1 : Keep actual status, with 2D lookup for 10/12 bits. As most of source filters produce 16bits ouput, if you don't want speed, you keep 16 bits, it you want speed-up, you add ConvertBits to reduce the bitdepth to the actual true bitdepth of the source. With this option, you keep the possibility to choose. Choice 2 : No 2D lookup, 10 to 16 bit, same speed. For now, i'm more on "Choice 1", allowing users to keep the possibility to choose, but i want to know what others users thinks what would be better. BTW :I personnaly have nothing to display HDR video, no reader, no screen, nothing. The only tests i can do is checking ouput is not obvious garbage, no crash or things like this, that an operation followed by its reverse produce output indentical to input, but i have no way to check if output is realy proper. __________________ My github. Last edited by jpsdr; 30th July 2018 at 16:35.