From 8e080c2e6cadada82a6b520e0c23a1cb974822d5 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Sun, 13 Sep 2009 22:16:04 -0300 Subject: V4L/DVB (12761): DocBook: add media API specs The V4L and DVB API's are there for a long time. however, up to now, no efforts were done to merge them to kernel DocBook. This patch adds the current versions of the specs as an unique compendium. Signed-off-by: Mauro Carvalho Chehab --- Documentation/DocBook/v4l/pixfmt-yuv420.xml | 157 ++++++++++++++++++++++++++++ 1 file changed, 157 insertions(+) create mode 100644 Documentation/DocBook/v4l/pixfmt-yuv420.xml (limited to 'Documentation/DocBook/v4l/pixfmt-yuv420.xml') diff --git a/Documentation/DocBook/v4l/pixfmt-yuv420.xml b/Documentation/DocBook/v4l/pixfmt-yuv420.xml new file mode 100644 index 00000000000..42d7de5e456 --- /dev/null +++ b/Documentation/DocBook/v4l/pixfmt-yuv420.xml @@ -0,0 +1,157 @@ + + + V4L2_PIX_FMT_YVU420 ('YV12'), V4L2_PIX_FMT_YUV420 ('YU12') + &manvol; + + + V4L2_PIX_FMT_YVU420 + V4L2_PIX_FMT_YUV420 + Planar formats with ½ horizontal and +vertical chroma resolution, also known as YUV 4:2:0 + + + Description + + These are planar formats, as opposed to a packed format. +The three components are separated into three sub- images or planes. +The Y plane is first. The Y plane has one byte per pixel. For +V4L2_PIX_FMT_YVU420, the Cr plane immediately +follows the Y plane in memory. The Cr plane is half the width and half +the height of the Y plane (and of the image). Each Cr belongs to four +pixels, a two-by-two square of the image. For example, +Cr0 belongs to Y'00, +Y'01, Y'10, and +Y'11. Following the Cr plane is the Cb plane, +just like the Cr plane. V4L2_PIX_FMT_YUV420 is +the same except the Cb plane comes first, then the Cr plane. + + If the Y plane has pad bytes after each row, then the Cr +and Cb planes have half as many pad bytes after their rows. In other +words, two Cx rows (including padding) is exactly as long as one Y row +(including padding). + + + <constant>V4L2_PIX_FMT_YVU420</constant> 4 × 4 +pixel image + + + Byte Order. + Each cell is one byte. + + + + + + start + 0: + Y'00 + Y'01 + Y'02 + Y'03 + + + start + 4: + Y'10 + Y'11 + Y'12 + Y'13 + + + start + 8: + Y'20 + Y'21 + Y'22 + Y'23 + + + start + 12: + Y'30 + Y'31 + Y'32 + Y'33 + + + start + 16: + Cr00 + Cr01 + + + start + 18: + Cr10 + Cr11 + + + start + 20: + Cb00 + Cb01 + + + start + 22: + Cb10 + Cb11 + + + + + + + + + Color Sample Location. + + + + + + + 01 + 23 + + + 0 + YY + YY + + + + C + C + + + 1 + YY + YY + + + + + + 2 + YY + YY + + + + C + C + + + 3 + YY + YY + + + + + + + + + + + -- cgit v1.2.3-70-g09d2