Cheap Android 7' tablet (800x480): wrong aspect ratio, circles look like ellipsis

Question

I need a lot of Android tablets for resale with my app. I bought some from internet (cheap chinese products) but all 7' 800x480 tablets shows circles as ellipsis (squares as rectangles), everything is stretched...

Some are Android 2.3.3, others are Android 4.0 but all of them show stretched UI.

Did someone have encountered the same problem?

Answer 1

After some flashing some new builds with changes in the sysconfig1.lhs, I've come to the conclusion that I don't believe there's a solution. The tests I did were on a Allwinner A10 tablet, specifically the M703 model running Android 4.0.4. Note that there are many devices with the same (or similar) hardware configuration but different names.

I dived into the sysconfig1.lhs that's included in the system image, which contains these lines:

lcd_x = 800
lcd_y = 480

And the corresponding touch screen values:

ctp_screen_max_x = 800
ctp_screen_max_y = 480

I measured the screen, which appears to be identical to Seraphim's measurement: 155×86mm. Working with that, I experimented with changing those values to either 864×480, or 800×444.

Unfortunately, neither option solved the issue.

864×480 simply clipped 64 pixels part of the display.

800×444 crashed SystemUI (as it no longer qualifies as sw480dp and therefore expected the device to be phone) and left a 36 pixel gap.

Perhaps the screen resolution needs to be set somewhere else, but I believe that it's the hardware that's somehow misconfigured.

There are many other lines in sysconfig1.lhs that are meaningless to me, such as:

lcd_dclk_freq            = 33
lcd_if                   = 0
lcd_hbp                  = 46
lcd_ht                   = 1055
lcd_vbp                  = 23
lcd_vt                   = 1050

Perhaps there's some way of changing the pixel ratio, but I haven't experimented.

Answer 2

They are probably either:

1. not matching the screen physical size with the resolution aspect ratio. What is the physical size (width and height) of the screen?
2. having non-square physical pixels

If either of that is the case there is not much you can do unless you can do some serious hacking and change the resolution. You get what you pay for I'm afraid.