is it possible to chnage fb0 width and height for dual display.

[Puneet B]

Hi All,

I have anddroid 4.2 in my A20 board with dual display support(HDMI and Tv).
But HDMI is not full screen and some portion is missing in TV.
Once i changed fb0_width=1280 fb0_height=720 , HDMI become full screen but TV output is going out of home screen and has some jitter.
i need to change fb0 width and height to TV as 720*480 .
Is it possible, without disturbing HDMI?

Regards
Punith  

[Puneet B]

 Hi All,

Is it possible to scale the width and height of tv display without enabling scaler(By usig a10disp tool)?.
can you tell how can i get full screen on both display?.

Regards
Punith

[Toroshin Dmitry]

Hello. It is possible to change framebuffer size using fbset. Use fbset -a -x -xres 720 -yres 480 to reduce framebuffer resolution.

Set 480p mode on hdmi to make same resolution and use scaler of you HDMI TV/monitor. Try different size modes on TV to get whole screen visible. You also can use bigger output resolution on hdmi and move output to center (for example, 720x480 image in the middle of 720p hdmi screen.

Use "a10disp enablescaler n x100y100" to move image from center. It will not enable scaler as "n" specified. 

[Puneet B]

 Hi Dmitry,

Thanks for your replay.

I need HDMI and TV both full screen display.

"a10disp enablescaler n x100y100"
this is not affecting anything ..

"a10disp --screen 1enablescaler n x100y100w720h480"
then getting black screen overlapped on  home screen for screen 1(TV) .

fbset -a -x -xres 720 -yres 480

this will change fb width and height for both display then i will not get full screen on HDMI.

if i am enabled scaler . then video output is not coming. so i need to do without enabling scaler.

Regards
Punith

[Toroshin Dmitry]

Try separate screen configuration, it is more stable. try last version of a10disp. It has instruction to enable dual screen after boot. Disable scaler before readfbinfo command.
If you only need vdpau support, try to fix OSD mode in patch, https://github.com/linux-sunxi/libvdpau-sunxi/issues/32
I have not tested a10disp on android.

[Puneet B]

Hi Dmitry,

You are making confused, i tested a10disp in both android and ubuntu.

Can you tell the a10disp command to increase the width and height without enabling scaler?.

send the link a10disp which has instruction to enable dual screen after boot.

Regards
Punith

[Toroshin Dmitry]

Hi Punith.
I have not tested hdmi and dual-screen on android, i only tested scaler and it worked. Also i tried to change framebuffer size by fbset. I used

fbset -xres 1600 -yres 900 -vxres 1600 -vyres 900 -depth 16 -rgba 5,6,5,0 -a -x

in fbcon and started Xorg after that. a10disp already uses fbset. Note that scaler does not work in 16 bit mode.
https://github.com/mittorn/a10disp/blob/testing/a10disp.c
See usage of printfbinfo/readfbinfo commands. It has some bugs, which has to be fixed, but i have no time to fix it now. Sometimes it writes wrong values to onhandled fileds such as 3d_mode. It often breaks scaler until reboot.
a10disp also has --noscaler option.
if scaler does not work after some actions or video not showing, just try to reboot.
Regards
Dmitry

[Puneet B]

 Hi Dmitry,

Thanks for your reply, Here my update in ubuntu.
My HDMI is full screen with 1280x720p mode with normal layer (scaler not enabled).
My TV output is full screen with 720x480 mode with scaler enable.

but problem is i am not getting video output on TV because scaler enabled.
so i disable the scaler for TV by fallowing command
a10disp --screen 1 disablescaler.
then i am getting video on both display(i did some changes in VDAPU code also).

but home screen on TV going out of monitor.
i need to reduce fb width and height for only TV without affecting HDMI. this i need to do without enabling scaler for TV.

Could you have any idea to fix this , kindly let me know.

Regards
Punith

[Toroshin Dmitry]

Hi Punith,

Try run

fbset -xres 720 -yres 480 -x -a

 before starting Xorg, it works for me with LCD+HDMI configuretion.

Why didn't you try  480p HDMI mode?

Regards

Dmitry