TI 81xx: frame buffer fb2 to be used for 720p graphics

Geo Varghese

Hi all,

Iam working on Ti 8107 based DVR , using DVR RDK 3.0. Iam using the 4 channel usecase with HDMI and SD using the different SWMS unit for live display.

I want to get QT graphics + Video in my HDMI and SD display. QT display window is maintained in 1280x720 resolution.

VRAM size 24M and frame buffer allocation to insmod ./kermod/ti81xxfb.ko vram=8M:8M:8M

We start the qt application by the command

./dvrmain -qws hdmi0 hdmi1 -display \"Multi: LinuxFb:/dev/fb0 LinuxFb:/dev/fb2\

In case of SD, the output QT window is cropped. The video is fine in this case, only the graphics get affected.

Is the cropping due to a higher resolution application buffer, used with fb2, which is only 720x480? When I tried with QT window 72x480, The output was fine. So is there a way to increase the fb2 size?

Following a previous thread in e2e, I tried to increase fb2 size using fbset utility , then it was ending up in an error ' out of frame'.

Regards,

Geo

over 13 years ago

0 Brijesh Jadav over 13 years ago

TI__Guru**** 504445 points

Hi Geo,

Could you check the vram size from /proc/cmdline? the sum of frame buffer size for all Fb devices should be less or equal to vram size in bootargs.

Rgds,

Brijesh

0 Geo Varghese over 13 years ago in reply to Brijesh Jadav

Prodigy 205 points

Hi Brijesh,

Thanks for your response.

I have verified the vram size. Its 24M, equal to the sum of fb sizes 8:8:8.

Regards,

Geo

0 Brijesh Jadav over 13 years ago in reply to Geo Varghese

TI__Guru**** 504445 points

Hi Geo,

So does it fail for the 8MB allocation? if yes, Can you check the messages printed on console to know why it is failing? You could write dmesg command and get kernel messages.

Rgds,

Brijesh

0 Geo Varghese over 13 years ago in reply to Brijesh Jadav

Prodigy 205 points

Hi Brijesh,

8 Mb allocation seems fine. Iam getting fb2 size as 8 MB.

/sys/class/graphics/fb2/size 8388608

But the virtual size still remains be that of SD.

/sys/class/graphics/fb2/virtual_size is 720,480

Regards,

Geo

0 Geo Varghese over 13 years ago in reply to Geo Varghese

Prodigy 205 points

Hi Brijesh,

Iam able to sort out the issue. Now Iam able to get the graphics without any cropping. I have increased the fb2 size using fbset utility to 1280x720. Then from the application, i could scale down the resolution to 720x480.

My graphics quality is a bit low now. I guess its due to the scaling.

Thanks for your attention,

Regards,

Geo

0 Mark Leonhardt over 13 years ago in reply to Geo Varghese

Prodigy 90 points

Geo,

Could you comment on how you were able to change the size of fb2 using fbset?

Thanks,

- Mark

0 Geo Varghese over 13 years ago in reply to Mark Leonhardt

Prodigy 205 points

Hi Mark,

Please refer to the link

http://linux.about.com/library/cmd/blcmdl8_fbset.htm for fbset utility.

With sufficient vram size, I used the command fbset -fb /dev/fb2 -vxres 1280 -vyres 720 -xres 1280 -yres 720 before loading my Qt application the frame buffer.

Regards,

Geo

0 Mark Leonhardt over 13 years ago in reply to Geo Varghese

Prodigy 90 points

Thanks Geo!

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TI 81xx: frame buffer fb2 to be used for 720p graphics