Chris Bore wrote:
The issue of video decoding is to some extent a niche within DirectFB.
For video decoding, DirectFB uses VideoProviders (and ImageProviders
for still images). These are interfaces that read data from a source,
decode it, and render it (usually to a hardware layer). The
VideoProvider is a black box to DirectFB - and for any given new
platform, or new media format, you have to write one. From the
DirectFB viewpoint this is straightforward: all you have to do is
implement the required VideoProvider interface to your own code - and
the VideoProvider interface is quite simple. From the hardware
viewpoint of course you must implement the actual video decoding, and
you may use the hardware acceleration or not according to your own choice.
So you have to invest in writing the implementation of the
VideoProvider (or wrapping an existing decoder in the required
DirectFB interface), but then you benefit from the main features of
DirectFB (provided those are supported on your platform..).
Chris
==================================
Chris Bore
Training Director
BORES Signal Processing
ch...@bores.com
www.bores.com <http://www.bores.com>
+44 (0)1483 740138
------------------------------------------------------------------------
*From:* David Henderson <dhender...@digital-pipe.com>
*To:* Georgios Tsalikis <aliver...@tsalikis.net>
*Cc:* directfb-users@directfb.org
*Sent:* Tue, 21 December, 2010 22:05:34
*Subject:* Re: [directfb-users] DirectFB Questions
Georgios Tsalikis wrote:
>
>
> On 12/21/2010 07:24 PM, David Henderson wrote:
>> Hi everyone,
>>
>> I'm working on a lightweight project that might end up using
DirectFB, but I have a couple of questions that need answering by the
pro's here first. :) Also, I'm in the process of learning some aspects
so forgive any illogical or newbie questions.
> I am not a pro but i am interested in using DFB in a custom distro,
too. (i guess that's what you have in mind.
>>
>> 1) I can see DirectFB is used to replace X11. In doing so, are the
drivers for graphics cards still needed or are they avoided by writing
directly to the frame buffer? If drivers are still required, is there
a database somewhere that has them for download?
> Devs avoid, so far, to claim that DFB is a replacement for X, but i
agree with you. Graphics drivers are needed for writing to the FB in
an accelerated way. Here is a database for the little range of drivers
for desktop systems:
> http://www.directfb.org/index.php?path=Support/Graphics
>> 2) The project's hardware will be working with an Intel motherboard
using Intel's GMA X4500HD video chipset. It's supposed to have all
kinds of goodies for hardware decoding of videos. Are there any
compile options, patches, or additional software that can work with
DirectFB to utilize all that this chipset has to offer?
> AFAIK no...
>> 3) I see that DirectFB has the option of adding OpenGL which is
supposed to offload graphics processing to the GPU correct? What about
vdpau or is that just for mplayer (or other media playing programs)?
> DirectFBGL is practically a concept project that works with Matrox
cards, only. It needs Mesa embedded drivers of a branch that doesn't
exist anymore.
>>
>> 4) What are my options for a Window Manager with DirectFB? I looked
over the website, but I can't really tell. Apparently SaWMaN is one,
but the associated pictures don't show any "windows", title bars, etc.
Is it possible to use XDirectFB with an existing embedded WM?
Following the XDirectFB link on the website shows a picture of a Gnome
Desktop. Is this Gnome running on DirectFB or am I mistaken? Also, why
do some of the Windows in that graphic look like they're using two
different WM's?
> As far as i understand, SawMan is intented for embedded systems.
Yes, that picture shows Gnome running over XDirectFB. The different
window style is because some windows are in X driven WM while others
are using DirectFB's simple WM with the LiTE toolkit engine.
>>
>> 5) Do I need to enable anything in the Kernel to make DirectFB work?
> A Linux Fusion patch is a way of letting DirectFB applications talk
to each other, or allow multiple DFB apps work simultaneously under
something that could be defined as a single desktop.
>
>> Looks like that's all for now. Thanks for any help you guys can
provide.
>>
>> Dave
>
> Wait for news about DirectFB 2.0. I sense it will solve lots of
problems for people like us.
>
> George
>
> _______________________________________________
Thanks for the reply George. The requirements I have for the OS are to
use as much hardware as possible to free the CPU for other tasks and
to be able to play media via OpenGL, vdpau, and/or other accelerators.
Seems that DirectFB can't currently satisfy either of those tasks.
Does anyone know of any plans to make a driver for Intel's GMA X4500HD
video chipset? Looking at the website for version 2 of DFB seems to
show that it's still in the design stage which means I'd have to wait
for a while before moving forward with the project. I might have to go
with TinyX instead. Can anyone else add anything that would make it
worth using DirectFB instead of TinyX?
Thanks,
Dave
_______________________________________________
Doesn't that mean that the decoding is still being performed by the CPU
and not GPU?
Dave
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