On Sat, 5 Sep 2009, Marek Vasut wrote: > Dne So 5. záÅ?à 2009 22:19:42 Guennadi Liakhovetski napsal(a): > > On Sat, 5 Sep 2009, Marek Vasut wrote: > > > Dne So 5. záÅ?à 2009 10:55:55 Guennadi Liakhovetski napsal(a): > > > > > > > > Marek, please, look in PXA270 datasheet. To support a specific pixel > > > > format means, e.g., to be able to process it further, according to this > > > > format's particular colour component ordering. Process further can mean > > > > convert to another format, extract various information from the data > > > > (statistics, etc.)... Now RGB555 looks like (from wikipedia) > > > > > > > > 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00 > > > > R4 R3 R2 R1 R0 G4 G3 G2 G1 G1 B4 B3 B2 B1 B1 -- > > > > > > > > (Actually, I thought bit 15 was unused, but it doesn't matter for this > > > > discussion.) Now, imagine what happens if you swap the two bytes. I > > > > don't think the PXA will still be able to meaningfully process that > > > > format. > > > > > > Not on the pxa side, but on the camera side -- Bs and Rs swapped in the > > > diagram above. > > > > And then? Are you trying to tell me, that the PXA then swaps them back?... > > No, the software has to do it then, I'm trying to tell you that it has nothing > to do with PXA (as PXA really doesnt care if the channel is actually blue or > red). Of course it does. I asked you to swap the above two bytes, you would get this: 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00 G1 G0 B4 B3 B2 B1 B0 -- R4 R3 R2 R1 R0 G4 G3 G2 and PXA would still inerpret this as R4 R3 R2 R1 R0 G4 G3 G2 G1 G0 B4 B3 B2 B1 B0 -- i.e., it would take bits R2 R1 R0 G4 G3 for blue, bits B1 B0 -- R4 R3 for green, and bits G1 G0 B4 B3 B2 as red. Which, as you see, makes no sense. That's why I'm saying, that it doesn't support this format, and we can only pass it through as raw data. Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/ -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
