nanogui: patch for microwindows in wdtv live
Subject:
Re: [nanogui] patch for microwindows in wdtv live
From:
"Greg Haerr" ####@####.####
Date:
21 Feb 2010 19:30:08 -0000
Message-Id: <0b3f01cab32c$39c78370$6464a8c0@winXP>
> WDTV live is a HD media player, which is mass production.
Actually, I am familiar with the player. I didn't
know it's running microwindows! Very nice. I recently
evaluated the device.
Are you involved with the programming team? If so,
I would like to have an off-list discussion with
you regarding my evaluation and comments of this
very interesting device. Also, are you trying/planning
on moving to the (v0.92) git version of microwindows?
> WDTV_Live_GPL_Code_package.1.01.24.zip (ZIP 219 MB)
I have downloaded and looked at the source.
My comments follow. It would be interesting
to know all of the areas you have changed.
I will diff with v0.90, are there other areas
than below that need changing in order to
move to the v0.92 git version?
> 1. devdraw better performance
in include\device.h , it defines several macros:
MACRO_DRAWPIXEL, BPP32_DRAWPIXEL etc.
in engine\devdraw.c, GdDrawImage, it has performance issue.
I have looked at this and agree, I will add
the optimization into the git source tree.
> 2. JPEG EOI
in engine\devimage.c, LoadJPEG , it checks the EOI (end of image) of jpeg,
which will make system hang in jpeg lib for certain platform, (which is
happened in network image transport), but in x86 it will not hang.
The newer v0.92 handles incoming data streams a bit
differently. I would like to know more information
to correctly handle this modification. Is the
problem that the jpeg library starts decoding before
the whole file is received? I think I can add
code that checks that last two characters of the
buffer before allowing the image to be decoded.
Some changes will have to be made to the current
buffer mechanism to handle seek to end of file, but
not many.
> 3. png alpha blending
in engine\devimage.c, it adds
#if defined(ALPHA_BLENDING_FOR_PNG)
and it will check "pnginfo->num_trans > 0" which is used for
PNG_EXPAND_tRNS.
===================
/* set load image pixel format 'BGRA' */
if ((colourtype == PNG_COLOR_TYPE_RGB && pnginfo->num_trans > 0) ||
colourtype == PNG_COLOR_TYPE_RGB_ALPHA)
png_set_bgr(state);
This modification looks like no problem. I will likely
leave out the ALPHA_BLENDING_FOR_PNG define, and
set always on, since the v0.92 always supports alpha
channel blending in images. Thus, if the png has
alpha channel, it will always work.
> Glad to see the web site is updated in 2010.
Yes, it has been too long! I am very close to releasing
a 0.92 from the git repository. There have been
several important patches that have come in lately,
and yours is the latest. I will notify you when
these changes are incorporated, and if you could
let me know whether v0.92 could be used for production
WDTV use, I would appreciate it!
Regards,
Greg
