For the sake of consistency and correctness, I'd like to propose a couple of changes for the YUV packed modes, and would like to hear if anyone has any objections. V4L2 ---- Currently has two packed YUV modes: V4L2_PIX_FMT_YUYV "YUY2" V4L2_PIX_FMT_UYVY "UYVY" These are documnented as being 4:2:2 modes, with UYVY only differing from YUYV in terms of the component ordering. These are therefore well defined, and correspond to the AVI "FourCC" names I have indicated. I would like to suggest that V4L2 adds an additional mode: V4L2_PIX_FMT_Y41P "Y41P" Which is the 4:1:1 "Y41P" AVI format, otherwise known as the BtYUV format that the Bt848 can generate (macro pixel component order UYVYUYVYYYYY). Additionally, to be explicit (although there can be no confusion about this), the V4L2 documentation should add that V4L2_PIX_FMT_YUYV corresponds to the "YUY2" AVI format. V4L --- Currently has five packed YUV modes: VIDEO_PALETTE_YUV422 -> bttv.c YUY2 VIDEO_PALETTE_YUYV -> bttv.c Y41P VIDEO_PALETTE_UYVY VIDEO_PALETTE_YUV420 VIDEO_PALETTE_YUV411 There is no documentation as to what these modes are meant to be, other than that implied by the names themselves. The bttv.c driver maps two of these names onto it's YUY2, Y41P capabilities as indicated (I've tested these - they work), and doesn't implement the other threee. The YUV422 = YUY2 mapping is reasonable, although it would be less ambiguous (there are many 4:2:2 modes) if it was YUYV = YUY2. The YUYV = Y41P (aka BtYUV) mapping is simply wrong! I'd therefore like to suggest that we change/document the meaning of the V4L packed YUV formats as follows: VIDEO_PALETTE_YUV422 "YUY2" (deprecated) VIDEO_PALETTE_YUYV "YUY2" (4:2:2) VIDEO_PALETTE_UYVY "UYVY" (4:2:2) - not supported by bttv.c VIDEO_PALETTE_YUV420 ???? VIDEO_PALETTE_YUV411 "Y41P" (4:1:1) If noone has a problem with this, I'll submit the required table change for bttv.c. The only potential problem I see would be if any other drivers have chosen to interpret the ambiguous "YUV411" differently. Ben P.S. The definitive format reference is: http://www.webartz.com/fourcc/
