[Ffmpeg-devel] Porting to symbian, possible ??

[Colin Ward]

Henrik Antonsson wrote:
> 
> I'm about to write my own support for H.263 on Symbian and I thought that
> maybe I could port libavcodecs H.263 support to achieve this. I'm not very
> familiar to ffmpeg and libavcodec so I don't know if this idea is somewhat
> crazy or not.
> 
> Anyone having som idea or arguments whether this is possible or not?

   As someone who has worked extensively with both Symbian OS and 
FFMPEG, I think that I can offer the (unfortunately) vague answer of 
"maybe."

   Yes, you should be able to get it compiling and linking relatively 
easily, although you will have to make up your own makefiles rather than 
use configure (that's easy, I did it with my Amiga port of FFMPEG).

   However, actually using the resulting binary might be problematic, 
for two reasons:

   1) Executable size.  Given the structure of FFMPEG and the fact that 
GCC doesn't do function level linking, even if you disable all but a few 
required codecs you end up with a 2+ MB executable.  Pull in a table or 
a function from one module and you pull in everything else, even if its 
not used.  This might not be a problem if you are targeting the more 
modern phones such as Series 60 DP3 though, as these do have large 
heaps.  But for the older Symbian OS phones, which often only have a 
couple of MB heap, forget it.

   2) Speed.  I have never really looked into this too much, but running 
a heavyweight audio/video decoder such as FFMPEG on a 200 Mhz ARM CPU 
might be pushing it.  I suppose someone else here could comment on the 
amount of CPU power that is required for H.263 video.  I once ported the 
xiph.org implementation of Vorbis and Theora to Symbian and for full 
screen video on a UIQ phone (Sony Ericsson P900 - 208 x 255 pixels) I 
could only get around 10 FPS.  And that was for local playback - for 
streaming I could only get about 6 FPS.

   But I suppose the only way to know is to try.  Maybe there is a stand 
along version of H.263 that you can use?  I would have thought that 
H.263 is supported by the Multi Media Frame work already, but I might be 
wrong.  Or alternatively you might be wanting to write a stand alone 
player that isn't dependent upon the MMF.  In that case chat to me 
first, because Symbian has such latencies involved in just about 
everything that it took me months to get the playback timing just right! 
  So I could let you know the pitfalls to look out for (damn active 
objects).

   Anyway, I hoped that this E-Mail proves helpful!

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