nanogui: Thread: jpeg drawing

I've been playing some with the new jpeg functions and have a couple of
questions.  

1) Do I need to define a palette? I'm running 16 bpp fb and the color of
the image is not even close. What am I missing?

2) Drawing is very slooowww. I'm running on top of a vesa fb. It takes a
couple of seconds to draw a 800x600 image. Should it be this slow???

I'm currently using Nano-X (with app and server linked together). I'm
guessing that Microwindows may have better support for drawings. Is this
true? I really prefer the Nano-X API and may have a need for
client/server on down the road.

Thanks for any advice, Kyle.

Kyle,

Don't know if that could help ...

Kyle Harris wrote:

> I've been playing some with the new jpeg functions and have a couple of
> questions.
>
> 1) Do I need to define a palette? I'm running 16 bpp fb and the color of
> the image is not even close. What am I missing?
>

I ported libjpeg to nano-X. You do not need to set a palette. Make sure the
SCREEN_PIXTYPE is set to the right value.

>
> 2) Drawing is very slooowww. I'm running on top of a vesa fb. It takes a
> couple of seconds to draw a 800x600 image. Should it be this slow???
>

Yeah, it's slow a bit. Blitting is not used ... maybe it should. Some
tweaking could be done in the libjpeg configuration parameters to speed up
things.
Clipping is used if the picture is larger than the window ... (might slow
things)

>
> I'm currently using Nano-X (with app and server linked together). I'm
> guessing that Microwindows may have better support for drawings. Is this
> true? I really prefer the Nano-X API and may have a need for
> client/server on down the road.
>

I don't know if Greg made a Microwindows api for jpeg support ...


>
> Thanks for any advice, Kyle.
>
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On Monday, January 31, 2000 12:34 PM, Kyle Harris  wrote:
: I've been playing some with the new jpeg functions and have a couple of
: questions.  
: 
: 1) Do I need to define a palette? I'm running 16 bpp fb and the color of
: the image is not even close. What am I missing?
: 

No.  However there are considerations with 5 bits per color.  
Can you display the image well with another application?  Are you
running X, or pure framebuffer?


: 2) Drawing is very slooowww. I'm running on top of a vesa fb. It takes a
: couple of seconds to draw a 800x600 image. Should it be this slow???
: 

That's pretty bad.  I suspect that the GrArea code needs heavy
optimization.  I'll take a look at this.


: I'm currently using Nano-X (with app and server linked together). I'm
: guessing that Microwindows may have better support for drawings. Is this
: true? I really prefer the Nano-X API and may have a need for
: client/server on down the road.

Microwindows is currently superior when a palette is used, since
it uses the GdImage routine which has it's own image format, and
will add entries to the system palette when required.  In a typical
"X" way, there's not much agreement on how images should be
displayed, and everyone want's to do it differently, so I haven't
built a standard into Nano-X yet.  For non-palettized
systems, it shouldn't be a big issue.


Greg



: Thanks for any advice, Kyle.
: 
: ---------------------------------------------------------------------
: To unsubscribe, e-mail: ####@####.####
: For additional commands, e-mail: ####@####.####
: 

: Yeah, it's slow a bit. Blitting is not used ... maybe it should. Some
: tweaking could be done in the libjpeg configuration parameters to speed up
: things.
: Clipping is used if the picture is larger than the window ... (might slow
: things)

Morten and I have been having some conversation regarding
GdArea and GdBlit.  We will soon find that nothing will be fast
enough until blitting is used.  Period.  In fact, I've stated on this
list before, that even inside blit, a cpu machine instruction must
be used for memset(), *dst++ = *src++ is even too slow...
So you can only imagine what happens if pixels have to be
converted.

I'm going to get 0.87 stable and release it, and then I think we've
got to pull together the GdArea/conversion/GdBlit stuff, and have
everything go through (at least for one fast case) a set of fast
blitting routines.  (I say a set because there will be one blitter
for each of the bits per pixel formats, another for alpha blending,
another for srccopy, etc)




: 
: >
: > I'm currently using Nano-X (with app and server linked together). I'm
: > guessing that Microwindows may have better support for drawings. Is this
: > true? I really prefer the Nano-X API and may have a need for
: > client/server on down the road.
: >
: 
: I don't know if Greg made a Microwindows api for jpeg support ...

I haven't yet.

Greg

Greg Haerr wrote:
> 
> On Monday, January 31, 2000 12:34 PM, Kyle Harris  wrote:
> : I've been playing some with the new jpeg functions and have a couple of
> : questions.
> :
> : 1) Do I need to define a palette? I'm running 16 bpp fb and the color of
> : the image is not even close. What am I missing?
> :
> 
> No.  However there are considerations with 5 bits per color.
> Can you display the image well with another application?  Are you
> running X, or pure framebuffer?

I've ran it on pure fb and X (2 different machines), both with same
results. I'll take a closer look at it within the next day. Just wanted
to be reasonably sure I was doing things correctly.

Thanks for all your help, Kyle.

: > : 1) Do I need to define a palette? I'm running 16 bpp fb and the color
of
: > : the image is not even close. What am I missing?
: > :
: > 
: > No.  However there are considerations with 5 bits per color.
: > Can you display the image well with another application?  Are you
: > running X, or pure framebuffer?
: 
: I've ran it on pure fb and X (2 different machines), both with same
: results. I'll take a closer look at it within the next day. Just wanted
: to be reasonably sure I was doing things correctly.

As Martin mentioned, it's very important to have the SCREEN_PIXTYPE
value set properly for X11.

I still don't know what mode you're running the FB driver in.

You're welcome to send me your jpeg, and I'll take a look at it.
Unfortunately, I'm only running 8bpp, since I can't get my fb
to run in truecolor.  So I haven't tested the truecolor stuff.

Regards,

Greg