Acceleration in our pockets

Carsten Haitzler (The Rasterman) raster at openmoko.org
Fri Jun 13 11:04:13 CEST 2008 

On Fri, 13 Jun 2008 07:37:39 +0000 (GMT) David Samblas Martinez
<dsamblas at yahoo.es> babbled:

> 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

no problems. what i don't want is people to get their hopes up. this was in the
context of people asking if they can play vga video and me going "good luck!".
there is reality - and you can sit and hack away spend lots of time and get 1
case to work, and work well. as i said - it will depend on codec, bitrate,
quality etc. mpeg4 decode in hw is great - but remember it is also limiting to
just mp4 - all your mpeg1, ogg, etc. videos will not work. also as long as
mplayer is accessing glamo hardware it must run as root. admittedly we run
everything as root - but come the day when we don't... this is trouble.

as i said - it is possible within limits. the limits of using a software codec
in mplayer (for example) in the example mp4 video i used @ 320x240 was 21fps
from flash, 19fps from sd card. :) in reality most phones don't really play any
or much video beyond qvga anyway - so it's within ballpark. some do do better,
but most don't.

i just don't want people to be more optimisitc than they should be - i want you
to be pleasantly surprised rather than bitterly disappointed. which do you
prefer - use to tell you all sorts of things and then find they aren't
possible, or us tell you it's unlikely/not so great, you buy anyway, and find
it's better than we said? i suspect the 2nd case is one where you will keep
coming back and be a loyal customer as we are (brutally) honest with you. i
would have serious moral issues in telling you anything i didn't sincerely
believe is the truth :)

> [...]> > > 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.
> > > > > 
> > > > >
> > _______________________________________________
> > > > > Openmoko community mailing list
> > > > > 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>
> 
> 
>       ______________________________________________ 
> Enviado desde Correo Yahoo! La bandeja de entrada más inteligente.


-- 
Carsten Haitzler (The Rasterman) <raster at openmoko.org>

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