Greeting,
Now 16 BPP is used at FB driver and surface flinger, but blue color
has more weight on the display, I don't know why?
The 16 BPP format is: RRRRRGGGGGGBBBBB (RGB565) in the fb driver, is
the surface flinger different data format with driver?Thanks!
Mark

On Dec 4, 12:47 pm, Mathias Agopian <[EMAIL PROTECTED]> wrote:
> On Wed, Dec 3, 2008 at 8:37 PM, FlyCry <[EMAIL PROTECTED]> wrote:
>
> > In my opinion, RGB means red in the high byte and blue in the low
> > byte. But it seems that andriod use red in the low byte and blue in
> > the high byte. I modified the code of load_store.cpp to exchange red
> > and green. Now the display is Ok.
> > Thank you very much.
>
> The notion of "high" byte and "low" byte in a 24-bits frame buffer is
> a little odd. Since these are not 32 bits or 16 bits numbers, I'm not
> sure what you mean.
>
> I stand by what I said, android supports RGB, in that order. One byte
> of red, one byte of green, followed by one byte of blue. R,G,B... btw,
> this order happens to be OpenGL's GL_RGB internal format for textures.
>
> You *cannot* change  load_store.cpp like that, you have now broken
> OpenGL's glTexImage2D() :-(
>
> Mathias
>
>
>
>
>
> > On 12月3日, 下午5时20分, Mathias Agopian <[EMAIL PROTECTED]> wrote:
> >> As far as I can tell from a quick inspection of the code, pixelflinger
> >> reads and outputs RGB24 formats as R,G,B as it should.
>
> >> Are you sure your framebuffer takes RGB and not BGR? Also are you
> >> using "PIXEL_FORMAT_RGB_888" when initializing the frame-buffer
> >> surface?
>
> >> you can see the routines in pixelflinger/codeflinger/load_store.cpp
>
> >> mathias
>
> >> On Wed, Dec 3, 2008 at 12:39 AM, FlyCry <[EMAIL PROTECTED]> wrote:
>
> >> > Yes, red and blue.
> >> > Thanks!
>
> >> > On 12月3日, 下午4时20分, Mathias Agopian <[EMAIL PROTECTED]> wrote:
> >> >> On Tue, Dec 2, 2008 at 11:45 PM, FlyCry <[EMAIL PROTECTED]> wrote:
>
> >> >> > Thanks for your helpful replies.
> >> >> > Acctually, my lcdc support 24-bits packed framebuffer to 18-bits
> >> >> > output to suit the 18bpp lcd. The framebuffer format is
> >> >> > rrrrrr00gggggg00bbbbbb00, packed.
> >> >> > I configed pixelflinger as RGB888. That could compatible to the 24-
> >> >> > bits packed framebuffer. But I found the red and the green exchanged
> >> >> > their place. Is android's default color space BGR but not RGB? The
> >> >> > hardware can't swap red and green. Is there anything I can do to make
> >> >> > android swap red and green.
>
> >> >> you mean red and blue, right?
>
> >> >> SurfaceFlinger should be using RGB (a byte of red followed by a byte
> >> >> of green, followed by a byte of blue). Unless there is a bug in
> >> >> pixelflinger, that's what it should do. I will check tomorrow if this
> >> >> is working properly (I don't think 24-bits mode have ever been used
> >> >> before).
>
> >> >> Mathias
>
> >> >> > Thanks a lot.
>
> >> >> > On 12月2日, 下午6时39分, Phil HUXLEY <[EMAIL PROTECTED]> wrote:
> >> >> >> Perhaps I wasn't being clear enough. Some LCD panels do have 18 bits 
> >> >> >> per
> >> >> >> pixel, but use some (2 or 3) of those bits for other things (can't 
> >> >> >> remember
> >> >> >> what), so the actual colour resolution is 16 bits or less.
>
> >> >> >> All I was suggesting was stay in a traditional 565 domain until the 
> >> >> >> final
> >> >> >> buffer swap to the screen (i.e. don't change any of the rendering 
> >> >> >> side -
> >> >> >> not even the configs), but do as efficient a conversion as possible 
> >> >> >> on the
> >> >> >> final swap - potentially easy to do if that final swap can be 
> >> >> >> singled out.
>
> >> >> >>              Mathias Agopian
> >> >> >>              <[EMAIL PROTECTED]
> >> >> >>              gle.com>                                                
> >> >> >>    To
> >> >> >>              Sent by:                  
> >> >> >> [email protected]
> >> >> >>              [EMAIL PROTECTED]                                       
> >> >> >>    cc
> >> >> >>              ooglegroups.com
> >> >> >>                                                                    
> >> >> >> Subject
> >> >> >>                                        [android-porting] Re: Android
> >> >> >>              02/12/2008 10:09          porting problem - LCD BPP
>
> >> >> >>              Please respond to
> >> >> >>              [EMAIL PROTECTED]
> >> >> >>               ooglegroups.com
>
> >> >> >> On Tue, Dec 2, 2008 at 1:52 AM, Phil HUXLEY <[EMAIL PROTECTED]> 
> >> >> >> wrote:
> >> >> >> > I was thinking that the system would work in 16 bit more - 565 and 
> >> >> >> > just
> >> >> >> > convert to 18 bit. i.e. the composition happens at 16 bit, not 32. 
> >> >> >> >  It's
>
> >> >> >> What's the point of using a 18-bits framebuffer if most graphics are
> >> >> >> done in 16-bits? I assumed, the goal would be to take advantage of 
> >> >> >> the
> >> >> >> extra 2 bits
>
> >> >> >> > definitely an overhead though. Is the screen update done via an
> >> >> >> > eglSwapBuffers call on a single composited surface representing the
>
> >> >> >> screen?
>
> >> >> >> yes
>
> >> >> >> > It might not take very long to try it? and could be faster than the
> >> >> >> > overheads bought about by dealing in 18 bit or 32 bit land when 
> >> >> >> > rendering
> >> >> >> > (more bandwidth needed - particularly if pixels are touched 
> >> >> >> > multiple
> >> >> >> > times). No obvious winner - it just might be quick to try.
>
> >> >> >> > Presumably the rendering routines in the software GL library would 
> >> >> >> > also
> >> >> >> > have to be modified (unless the platform is using hardware).
>
> >> >> >> No, in this scenario, they would be rendering into a 565 buffer as
> >> >> >> usual, which would be composited in 565, and eventually converted to
> >> >> >> 666 during eglSwapBuffers(). GL doesn't need to be changed, just the
> >> >> >> implementation of the EGLNativeWindowType.
>
> >> >> >> Unless the panel cannot be configured to 565 (that would be crazy), I
> >> >> >> wouldn't go down that road, if it's not going to improve visual
> >> >> >> quality.
>
> >> >> >> >             Mathias Agopian
> >> >> >> >             <[EMAIL PROTECTED]
> >> >> >> >             gle.com>                                               
> >> >> >> >     To
> >> >> >> >             Sent by:                  
> >> >> >> > [email protected]
> >> >> >> >             [EMAIL PROTECTED]                                      
> >> >> >> >     cc
> >> >> >> >             ooglegroups.com
> >> >> >> >                                                                   
> >> >> >> > Subject
> >> >> >> >                                       [android-porting] Re: Android
> >> >> >> >             02/12/2008 09:43          porting problem - LCD BPP
>
> >> >> >> >             Please respond to
> >> >> >> >             [EMAIL PROTECTED]
> >> >> >> >              ooglegroups.com
>
> >> >> >> > On Tue, Dec 2, 2008 at 1:25 AM, Phil HUXLEY <[EMAIL PROTECTED]>
> >> >> >> wrote:
> >> >> >> >> Alternatively, couldn't a blit be inserted somewhere such that a
> >> >> >> > conversion
> >> >> >> >> is done at the point of updating the display (and would this 
> >> >> >> >> include a
> >> >> >> >> regionlist of areas that have changed to optimise it?). Is there 
> >> >> >> >> such an
> >> >> >> >> 'update point'?
>
> >> >> >> > I think this would be slower generally. You'd end up doing all the
> >> >> >> > composition in 32-bits, and then doing another copy/conversion by
> >> >> >> > hand. I don't think it buys you anything. Also this would not match
> >> >> >> > the EGL model very well, which SurfaceFlinger (very purposedly) 
> >> >> >> > relies
> >> >> >> > on.
>
> >> >> >> > In my experience update regions don't buy you much because the case
> >> >> >> > you care about is when you're "flinging" a list and that tends to
> >> >> >> > update the whole screen; surfaceflinger uses them though.
>
> >> >> >> > I should have mentioned in the email before that pixelflinger has 
> >> >> >> > some
> >> >> >> > logic to be able to replace the generated code by hand-written
> >> >> >> > routines (see scanline.cpp). You'd want to do this for a few common
> >> >> >> > operations like: RGBA32 -> RGB18 with and without blending. I think
> >> >> >> > the code it'll generate won't be bad at all, but you'll be able to 
> >> >> >> > use
> >> >> >> > pld() and/or process several pixels at a time.
>
> >> >> >> > One of the annoying part will be to chose a new constant for the 
> >> >> >> > new
> >> >> >> > format. The namespace for those is limited and global to the 
> >> >> >> > platform
> >> >> >> > (there are no way -yet- to create pixel formats dynamically at 
> >> >> >> > runtime
> >> >> >> > -- which the codegen should be able to handle). We just need to be
> >> >> >> > absolutely sure that whichever value we pick won't conflict with
> >> >> >> > future version of the platform (I already added a few formats post
> >> >> >> > 1.0).
>
> >> >> >> > Mathias
>
> >> >> >> >>             Mathias Agopian
> >> >> >> >>             <[EMAIL PROTECTED]
> >> >> >> >>             gle.com>
> >> >> >> To
> >> >> >> >>             Sent by:                  
> >> >> >> >> [email protected]
> >> >> >> >>             [EMAIL PROTECTED]
> >> >> >> cc
> >> >> >> >>             ooglegroups.com
>
> >> >> >> Subject
> >> >> >> >>                                       [android-porting] Re: 
> >> >> >> >> Android
> >> >> >> >>             02/12/2008 09:14          porting problem - LCD BPP
>
> >> >> >> >>             Please respond to
> >> >> >> >>             [EMAIL PROTECTED]
> >> >> >> >>              ooglegroups.com
>
> >> >> >> >> On Mon, Dec 1, 2008 at 11:03 PM, FlyCry <[EMAIL PROTECTED]> wrote:
>
> >> >> >> >>> My lcdc support 2 format of 18bpp framebuffer. One is 18bpp 
> >> >> >> >>> packed.
> >> >> >> >>> Another is a format of 3 byte:
> >> >> >> >>> Red[5:0] 0 0 Green[5:0] 0 0 Blue[5:0] 0 0
> >> >> >> >>> could the second format be configed in android display?
>
> >> >> >> >> So there are no mode where it has the color components in the 
> >> >> >> >> higher 6
> >> >> >> >> bits?!
>
> >> >> >> >> There is a way to configure pixelflinger to be able to render into
> >> >> >> >> arbitrary bit-patterns, however, the format you're describing has
> >> >> >> >> never been tested (obviously). It would also be a huge 
> >> >> >> >> performance hit
> >> >> >> >> because:
> >> >> >> >> 1) we would have to make sure all windows are created in 32-bits 
> >> >> >> >> (only
> >> >> >> >> mode > 16 bits supported by the software render), which also 
> >> >> >> >> implies
> >> >> >> >> much higher memory usage and bus pressure
> >> >> >> >> 2) the 32-bits surface will have to be converted at runtime and in
> >> >> >> >> software to 18 bits.
>
> ...
>
> read more >>- Hide quoted text -
>
> - Show quoted text -
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