Re: Next stable Rygel release

[Alper Guler <aguler ubicom com>]

Hi Zeeshan,

On 09/22/2010 02:29 PM, Zeeshan Ali (Khattak) wrote:
> Hi,
>
> On Wed, Sep 22, 2010 at 2:10 PM, Alper Guler<aguler ubicom com>  wrote:
>    
> > On 09/22/2010 01:20 PM, Zeeshan Ali (Khattak) wrote:
> >      
> > > > Now we want to use it as a DMS. The porting we have done is
> > > > mostly about writing the makefiles for Rygel and the required libraries
> > > > on
> > > > OpenWrt, which is the router platform we are using.
> > > >
> > > >          
> > >     Hm.. Interesting. Doesn't autotools support that platform or aren't
> > > there any modified version of autotools that supports OpenWrt? I would
> > > really love to have rygel be buildable/working out of the box on as
> > > many platforms as possible so if you could contribute patches to rygel
> > > for that, it'll be very much appreciated.
> > >
> > >        
> > This is not about Rygel. The thing is OpenWrt has a different structure. It
> > is based on buildroot and it does not contain any source code. When you
> > build OpenWrt, it reads makefiles of packages and firstly downloads the
> > package (app or lib) source from a server in the web. So, you have to write
> > an Openwrt makefile to add a new package to OpenWrt. This makefile contains
> > the URL of the package source and tells Openwrt how to build the package.
> > This is what we have done. We wrote makefiles for rygel and some other
> > libraries, for which OpenWrt does not have support yet. Some of the
> > dependencies were already supported by Openwrt, like gstreamer,
> > gst-plugins-base,good,ugly and we used them with some modifications.
> >
> > An Openwrt package also consists of  a "files" folder to put script and
> > config files, etc. in and "patches" folder for your patches to be applied to
> > the original package after it is  downloaded from its URL.
> >
> > We can add Rygel and other new packages we have added in our local distro to
> > OpenWrt upstream later. Actually, we have a plan for uploading all our
> > modifications on OpenWrt to OpenWrt upstream, and we had even started
> > discussions with the OpenWrt team, but the fact that we are the first
> > OpenWrt target with no MMU has made things very difficult to integrate and
> > we have postponed this effort for now.
> >      
>    Thanks for the detailed explanation. :)
>
>    
> > >    Hm.. that makes me a bit more curious, We are not using fork in
> > > rygel so why you need that?
> > >
> > >        
> > Rygel does not use fork, but some dependencies do, for example glib and
> > dbus.
> >      
>    Ah ok but you don't actually need D-Bus but only libdbus. Regarding
> glib, read below.
>
>    
> > >    Rygel itself takes less than an MB (~ 5K) both on the disk and when
> > > running and plugins don't take much of memory at all so I assume you
> > > are talking about all its dependencies. The thing is Rygel is designed
> > > for GNOME Mobile and hence it makes maximum use of core GNOME
> > > libraries. Having said that, you might want to strip all the binaries
> > > (if you haven't done that already).
> > >
> > >        
> > Yes, I am talking about Rygel together with all its dependencies and when
> > they are stripped.
> > Below is what I get when I build Rygel with media-export plugin for ubicom
> > IP7K processor.
> >      
>     Have you looked into the '--gc-sections' option of gcc? If you
> could make use of that, that'll greatly help you reduce the memory
> footprint.
>
> http://blog.flameeyes.eu/2008/03/14/how-to-avoid-unused-functions-to-creep-into-final-binaries
> http://blog.flameeyes.eu/2009/11/21/garbage-collecting-sections-is-not-for-production
>
>    
> > BTW, I want to ask a question. Does Rygel use the codec plugins
> > (gst-plugins-good, etc) for metadata parsing or just for transcoding?
> >      
>     Yes, media-export plugin (gupnp-dlna actually) uses gstreamer for
> metadata extraction.
>
>    
> > If I
> > don`t want to do any transcoding, do I still have to use gst-plugins-good,
> > bad, ugly to serve many different types of media or is it enough to use only
> > gst-plugins-base?
> >      
>    These packages are not so indivisible and you can easily
> build/install only the plugins that you actually need. Rygel core only
> needs a few plugins and for metadata extraction, it all depends on
> which codecs you want to support.
>
>    
> > Total size of Rygel without any plugins: 4518 KB
> >
> > size of gst-plugins-base library, which is a must: ~1400 KB
> >
> > So, total minimum size of Rygel is: 5918 KB
> >      
>     I really don't think its fair to include the size of dependencies
> when specifying the size of Rygel. You might as well include the size
> of Linux kernel then.
>
>    
No offense :-) My point of view is how much flash space do I need to run 
Rygel on my board and this adds the dependency sizes as well, because I 
don`t need those libraries for any other application. I will add them to 
my system just for Rygel, so I have to count them in.
But thanks for you suggestions. I will try to optimize the size as much 
as possible by removing anything which is not really needed.

Regards,
Alper