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

[Henrik Antonsson]

Thanks very much for your answer Colin, just the answer I hoped for.

I have tried to use the MMF to solve my problem but it does not work with
streaming, it can only download the whole file before it can start playback.
Maybe it would work if I wrote some sink/source plugins and a controller to
use the built-in H.263 codec, but I don't have very much information about
that so I thought porting the H.263 codec from libavcodec and display it
with direct screen access would be a better idea. Unless I could get my
hands on a Symbian DevKit which would give me tighter access to the decoder
and encoder. I guess I am thinking of writing my own independent player so I
would be very glad to know about the pitfalls with doing this.

I don't need the complete libavcodec so hopefully the executable size could
be kept relatively small and about the speed issue I only need to encode or
decode the video. So maybe this would work..

thanks again for your answer

/Henrik

On 8/15/06, Colin Ward <lists at codehq.org> wrote:
>
> 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!
>
> --
> /-------------------------------------------------------------------\
> [Hitman/Code HQ - 6502/z80/68000/604e/80x86/ARM coder - Amiga rulez!]
> [VZ-200/VIC-20/MZ-700/c16/c64*10/c128*8/Plus-4/CPC464/CD32/500*2    ]
> [600/1000/1200*2/A4000/SNES/N64/Dreamcast/Athlon 1100/AmigaOne      ]
> [Assembly Language: The most fun you can have with your clothes on! ]
> \-------------------------------------------------------------------/
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at mplayerhq.hu
> http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel
>