[MPlayer-dev-eng] Colorspace conversion and image buffer format
rtogni at bresciaonline.it
Mon Mar 4 13:45:42 CET 2002
I'm writing a native decoder for HuffYUV (fourcc HFYU).
Image format can be RGB, RGBA (RGB plus alpha channel) and YUY2 (it
will use new output format selection when it will be available).
I have some question about colorspaces:
- what about RGBA? Should I store it as RGB32, using the 4th byte as A,
or shoud I ignore alpha channel?
- what's the best way to output YV12 using YUY2 as source? should I
convert it "on the fly" averaging U (and V) every 2 rows or it's better
to store the image into a temporary buffer and use yuy2toyv12()
function from rgb2rgb.c? What's the best way to do it if input is
Another question about buffer format:
image buffer will be MP_TEMP (every frame is independent from others).
Do I have to use MP_IMGFLAG_READABLE if I need to read from buffer
during decompression (I need to access previous pixel and top pixel
from previous row)?
Other flags used are MP_IMGFLAG_YUV for YUY2 case and also
MP_IMGFLAG_PLANAR for YV12 case.
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