Acceleration in our pockets

David Samblas Martinez dsamblas at yahoo.es
Fri Jun 13 09:37:39 CEST 2008 

Hi Raster,

Your are not wrong at all about resolutions maths and bus bottlenecks, I have learned a lot from your posts , and I'm very thankful for you effort to communicate this to us.

Nevertheless I think you were wrong about the pessimistic approach, "no decent video from sd" .
You have never said this explicit but some post destilate such idea(at the end of this message I have extract some of them) balrog have said it has pass over the 21 fps in 320x240 barrier  (not clear if he had tried from sd yet) so maybe wrong is a strong word (I don't thing so, but you may find it offensive) but don't confuse it with lie that is really a strong word and I have never pretend to insinuate this.

And again I was thinking loud, and I was think I have erase this sentence that have irritating you, again and again and again please accept my apologizes


[...]> > > with the glamo you need to be careful what you do
> > and how you do it. if you can
> > > keep something entirely within the glamo - it
> > should be ok. so things like
> > > uploaded pixmaps and then blitting them around is
> > ok. video decode is another
> > > matter entirely. the glamo has an mpeg4 decoder on
> > it - but we don't have any
> > > api to access that directly/sanely and just feed
> > it an mpeg4 stream. any other
> > > codec has to be done on the cpu anyway and
> > uploaded across the bus as yuv data.[...]

[...]that is quite possible. 320x240 video would be sane possibly if the source is
internal flash instead of SD or maybe 802.11.[...]

[...]but the problem here
is that xv does not provide a way to do this sanely (stream just mpeg4 data to
x so it decodes in hardware). the graphics chip (glamo) can decode mpeg4
itself, but we dont have the time or resources to do this properly ourselves.
you are free to do it yourself as we provide all the code, but you would need to
reverse-engineer the graphics chip or hope that graphics documentation can be
made public. right now you need an NDA to see the docs.[...]

[...]what freerunner *IS* good at is nice high resolution still images. it is NOT
good at motion (animation). that's possibly the simplest way i know to describe
its graphics :) great for ebook and text reading. great for your high-res
photos. don't expect a media-center out of it with swooshy bits and fanciness
and video at wonderful quality and resolutions and framerates.[...]

[...]see my other mail. 320x240 at 30fps is not possible. off sd card about 19fps is
the limit @ 320x240. 21fps if from internal flash. i did actual tests. mpeg4
video.[...]


--- El vie, 13/6/08, Carsten Haitzler <raster at openmoko.org> escribió:

> De: Carsten Haitzler <raster at openmoko.org>
> Asunto: Re: Acceleration in our pockets
> Para: dsamblas at yahoo.es, "List for Openmoko community discussion" <community at lists.openmoko.org>
> CC: "David Samblas Martinez" <dsamblas at yahoo.es>
> Fecha: viernes, 13 junio, 2008 2:47
> On Thu, 12 Jun 2008 19:22:30 +0000 (GMT) David Samblas
> Martinez
> <dsamblas at yahoo.es> babbled:
> 
> > Hehehe definitively you have something to say :) 
> > oops I thought that I have erased this final this so
> unfortunate sentence  so
> > please accept my apologizes lets joy the fact that the
> glamo will not be a
> > wasted chip 
> 
> it never was wasted, but it's not the ultimate solution
> to everything either.
> i'm still wondering where i was so "wrong"? 
> 
> > --- El jue, 12/6/08, Carsten Haitzler
> <raster at openmoko.org> escribió:
> > 
> > > De: Carsten Haitzler <raster at openmoko.org>
> > > Asunto: Re: Acceleration in our pockets
> > > Para: dsamblas at yahoo.es, "List for Openmoko
> community discussion"
> > > <community at lists.openmoko.org> CC:
> "David Samblas Martinez"
> > > <dsamblas at yahoo.es> Fecha: jueves, 12
> junio, 2008 6:58
> > > On Thu, 12 Jun 2008 14:52:07 +0000 (GMT) David
> Samblas
> > > Martinez
> > > <dsamblas at yahoo.es> babbled:
> > > 
> > > nb - i codec only - and i also used mplayer at
> the time.
> > > mpeg1, mpeg2, not to
> > > mention a myriad of other codecs won't work
> there, and
> > > it still only producing
> > > qvga video.
> > > 
> > > if you do follow prior threads on this, you will
> notice
> > > that i never covered
> > > the mp3 decode of the glamo. that's always
> possible,
> > > but as such to do well
> > > would need a generic codec-level api supporting
> it - like
> > > openmax.
> > > 
> > > > I copy & paste an very interesting
> comment from
> > > balrog ,seems that I have
> > > > become his(totally voluntary) mail list
> assistant ;)
> > > > 
> > > > Rasterman..... 352x288 25 fps..... something
> to say?
> > > > 
> > > > --------------Begin of
> comment-----------------------
> > > > #  balrog Says:
> > > > June 11, 2008 at 4:20 am
> > > > 
> > > > Mikko: I hope we’ll eventually see more
> than just
> > > MPEG support on the Glamo
> > > > (3D stuff etc). Regarding QVGA at this
> moment it’s a
> > > conjecture… and at this
> > > > moment it’s confirmed. I’ve just tried
> QVGA and
> > > while the colours became a
> > > > bit undersaturated and gamma seems to be too
> high, I
> > > got full 25fps playback
> > > > both straight and with rotation, hw-scalled
> from
> > > 352×288 to 240×320 or
> > > > 320×240. Unfortunately tslib seems to not
> have
> > > noticed the change and still
> > > > reports touch coords in 0…640 range.
> > > > 
> > > > i_m_bison: Darude_-_Feel_the_beat.mp4 (the
> video is
> > > ok, the music not so
> > > > much:))
> > > > 
> > > > tuXXX: I was wondering about that too, but
> rather MPEG
> > > decoding on the CPU
> > > > and scaling/rotation on Glamo - this would
> allow us to
> > > do more stuff
> > > > concurrently. The other way, as Mikko notes
> you
> > > transfer the video to the
> > > > VRAM, then back to the RAM and then back to
> the VRAM
> > > and the bus becomes a
> > > > bottleneck. In the current setup and normal
> usage I
> > > don’t agree with Raster
> > > > that 7M/s is a bottleneck, it’s rather
> hard to
> > > saturate with normal X usage
> > > > even coupled with SD card traffic etc.
> > > > ----------End of
> comment------------------------------
> > > > Raster, I'm really happy that you where
> so wrong
> > > at this topic
> > > > 
> > > > --- El jue, 12/6/08, Joerg Reisenweber
> > > <joerg at openmoko.org> escribió:
> > > > 
> > > > > De: Joerg Reisenweber
> <joerg at openmoko.org>
> > > > > Asunto: Re: Acceleration in our pockets
> > > > > Para: community at lists.openmoko.org
> > > > > CC: "Peter Nijs"
> > > <peter at familienijs.be>
> > > > > Fecha: jueves, 12 junio, 2008 2:37
> > > > > Am Do  12. Juni 2008 schrieb Peter
> Nijs:
> > > > > > Isn't the shared bus an
> advantage
> > > because now it
> > > > > can use DMA? Maybe that's 
> > > > > > why  
> > > > > > it is possible to hook up an
> sd-card to the
> > > glamo
> > > > > anyway. I see no other 
> > > > > > explanation why one would put an
> sd
> > > cardreader in a
> > > > > graphics ship. Please 
> > > > > > tell me if and why I'm wrong.
> > > > > > 
> > > > > > Peter
> > > > > > 
> > > > > Good point. Would make perfect sense...
> > > > >
> /j_______________________________________________
> > > > > Openmoko community mailing list
> > > > > community at lists.openmoko.org
> > > > >
> > >
> http://lists.openmoko.org/mailman/listinfo/community
> > > > 
> > > > 
> > > >      
> ______________________________________________ 
> > > > Enviado desde Correo Yahoo! La bandeja de
> entrada más
> > > inteligente.
> > > > 
> > > >
> _______________________________________________
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> > > > community at lists.openmoko.org
> > > >
> http://lists.openmoko.org/mailman/listinfo/community
> > > 
> > > 
> > > -- 
> > > Carsten Haitzler (The Rasterman)
> > > <raster at openmoko.org>
> > 
> > 
> >       ______________________________________________ 
> > Enviado desde Correo Yahoo! La bandeja de entrada más
> inteligente.
> > 
> > _______________________________________________
> > Openmoko community mailing list
> > community at lists.openmoko.org
> > http://lists.openmoko.org/mailman/listinfo/community
> 
> 
> -- 
> Carsten Haitzler (The Rasterman)
> <raster at openmoko.org>


      ______________________________________________ 
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