Hi,

I am seeking advice on the DM6446...

Our product requirements
==================
Display a 1024x768 graphic background with a video overlay.

Using the DM6446, there is no problem doing this is in D1 resolution, using
VID0 for video, OSD0 for graphics and OSD1 for transparency.  For
resolutions higher than D1, there seems to be a few limitations...

Methods
======

1) The first method would be to use VID0 for video, OSD0 for
graphics(RGB565) and OSD1 for transparency.

I read in the VPBE document (section 4.3.1 of sprue37) that the combined
bandwith of the OSDs cannot be more than 25MB/sec.  This is exactly a D1
resolution OSD at 30 fps.  So... this method would not work...  Correct?

2) The second method would be to use VID0 for graphics(RGB888) and VID1 for
video (as a picture in picture).

In the VPBE document (again section 4.3.1 of sprue37), it is stated that
when doing HD, VID0 should be used and VID1 disabled.  Also, reading through
the mailing list, it seems that there is a silicon problem on the DM6446
that prevents using VID0 and VID1 at the same time.   So... this method
would not work...  Correct?

3) The third method would be to use VID0 for graphics(RGB888), OSD0 for
video(RGB565) and OSD1 for transparency.

My understanding is that this should be possible if we limit the video to be
a D1 frame within the 1024x768 graphics of VID0.  This would respect the OSD
bandwidth limitation.  However, since OSD0 only takes RGB565 (and bitmap), I
would need to convert the YUV 4:2:2 video to RGB565 on the ARM(or DSP).
Correct?

Is my understanding correct?  Is there any other option on the DM6446 to
meet our requirements?

Thank you!
_______________________________________________
Davinci-linux-open-source mailing list
[email protected]
http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source

Reply via email to