Centralization of graphical awesomeness

Eric Olson eric at ericanddebbie.com
Mon Oct 26 17:37:06 CET 2009

Vasco Névoa wrote:
> Downgrading to QVGA is something that should have been done a long time ago.
> There's no point in trying to force a badly designed system.
> How do we do it? Which files must be changed?
> Citando Carsten Haitzler <raster at rasterman.com>:
>> On Mon, 26 Oct 2009 13:57:27 +0300 Evgeniy Karyakin  
>> <anthropophagite at gmail.com>
>> said:
>>> 2009/10/26 Carsten Haitzler <raster at rasterman.com>:
>>>> you want speed? you will need to give up something. if you still  
>>> want it to
>>>> look nice, then drop pixels. its the simplest and easiest  
>>> solution. its the
>>>> right resolution for that cpu anyway. the glamo will still hurt you, but
>>>> not as much.
>>>    I'm sure everybody who has any professional connections with
>>> Freerunner+Glamo development already took all possible measures to
>>> solve this problem. But what concrete steps were taken to ease Glamo
>>> bottleneck? If its throughput is so narrow, can we lower amount of
>> none. it's a hardware issue. you simply cant read or write to video  
>> ram faster
>> than that. andy tried timing stuff all that happened was instability from
>> memory. glamo is most likely also the cause for the cpu runnig at 400 not
>> 500mhz. the extra load on the memory bus (because glamo is hooked there
>> externally providing another addressable chip) probably caused the  
>> instability.
>> remove it and there is a big change the cpu could run at 500mhz  
>> instead of 400.
>> it's rated to do 500. (yes power consumption would go up - but it'd  
>> only be up
>> while its on. when suspended it wont matter).
>>> data flowing through it? There's one neighbor unanswered thread with a
>> render on the device - and this will then limit what you can render.  
>> evas can't
>> be fully accelerated by the glamo. it has too many opretations. a bit like
>> asking why quake4 is slow on a a voodoo2. it does much mroe than the old gfx
>> chip ever was designed to do and you will hit software fallbacks. evas has
>> multiple engnines. software (which is what is used - the 16bit renderer as
>> opposed to the full 32bit one). it has xrender - if xrender were fully
>> accelerated this should be better, but glamo cannot fully accelerate all the
>> ops evas uses, so... it will rely on software fallbacks. thus slow  
>> down. my bet
>> is you'll end up same speed as the pure software engine, or worse. aftera
>> bunch of hard work you'll have gone nowhere. evas also has a gl and gles2
>> engine - but thats no use on glamo. it's gles1.1 and very limited  
>> (from memory
>> texture size is 256x256 which is pretty useless for 2d as most data you deal
>> with breaks these bounds).
>>> question on how to start the kernel with qvga resolution. Aside of
>> no need to do that - just configure x for qgva. :)
>>> this, what can be reduced, for example amount of available colours
>>> (256 or even 16)? And if this [too] low throughput only of video
>>> memory channel?
>> 256 won't help. it increases complexity and really reduces display quality
>> through the floor. the best best is qvga 16bpp. its simple. it  
>> doesn't require
>> any hard work. it is actually the most common resolution for most phones and
>> devices out there so the software is more portable if you work on that (and
>> then higher). but... in the past everyone has moaned and complained  
>> and refused
>> to use it, and insisted on their vga resolution... and then complained about
>> speed.
>> if people don't believe me that the gta02 is just plain a "bad bit of
>> hardware and you have few choices" here's some examples. here'es an ooold efl
>> demo app i did:
>> http://www.rasterman.com/files/eem.avi
>> and here it is on a 206mhz ipaq 3660 with 64m ram and 16m flash,  
>> qvga(240x320).
>> it's from like 2001/2002 (from memory). its ancient. and watch it run evas:
>> http://www.rasterman.com/files/eem-live.avi
>> here is something i videoed today. it's an samsung s3c6410 at 667 mhz, 128m
>> ram, and 800x480 (higher res than gta02):
>> http://www.rasterman.com/files/ello-elementary-smartq5.mp4
>> everywhere i look... theres much better hardware. if you look at  
>> performance vs
>> age of hardware (when it was released) gta02 is almost at the bottom of the
>> pile. :( you simply have a bad piece of hardware if you want graphics
>> performance. as soon as you acknowledge that and either downgrade the device
>> resolution for example to bring it in line with its performance, or just use
>> different hardware, the better life will be :)

I agree with you Vasco, (about switching to QVGA) for the most part, but 
a long time ago when Carsten asked this question, much of the community 
responded that they wanted to keep the high res screen.  Things like 
viewing webpages at 640x480 instead of qvga, viewing maps, etc. were 
cited as useful and important.

Anyway, I agree we should make QVGA work well, and I would use it for 
most apps.  We should also keep in mind ways to allow use of the high 
res screen -- maybe picking certain apps (like browsers) that could 
switch to VGA automatically, and making sure the transition between 
resolutions is a smooth, fast, and automatic (where desired).

I don't have a lot of free coding time at the moment, but I can at least 
test (with a neo1973, not a freerunner).

Anyway, the more immediate issues: when I switch to qvga, I get the same 
lighter screen with horizontal bands that Marcel described, and I'm 
using a neo1973 (no glamo).  Also my xrandr only lists 480x640 as 
possible resolution which is not a problem for freerunners.

The graphics artifacts in QVGA are the most immediate problem if anyone 
has any ideas.


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