Re: Next stable Rygel release

["Zeeshan Ali (Khattak)" <zeenix gmail com>]

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.

-- 
Regards,

Zeeshan Ali (Khattak)
FSF member#5124