What's your comment about this test?

[Drahnreb]

Hi,

I hope the cause is not in hardware only in software!

Read here the whole test about the videoframerate of the N800:

http://maemo.org/pipermail/maemo-developers/2007-March/009133.html

What do the other experts thinking about that fact?

Bernhard

[Serge]

Hi,

I hope the cause is not in hardware only in software!

Read here the whole test about the videoframerate of the N800:

http://maemo.org/pipermail/maemo-developers/2007-March/009133.html

What do the other experts thinking about that fact?

Bernhard
Hi Bernhard, that was a post to the developers mailing list and for developers who are supposed to be ably to interpret them properly. All these numbers are the results of some low level tests with some rough estimates of the effects that they may have on video performance. Also these tests were done with the first revision of N800 firmware and have shown some strange things that are obviously software related (the same long screen update time for any resolution of video frames, btw. this problem is apparently fixed now) and explained why video support was so bad in the first version of firmware.

Graphics bus performance is just one of the system characteristics which affects overall performance, and its influence is complicated and definitely nonlinear (just because the graphics bus of the device A is N times faster than that of the device B, you can't say that the device A would be N times better for some practical task). You can consider that Nokia 770 just had a hugely excessive graphics bus performance (which does not harm it though) and N800 graphics bus performance is barely enough to keep high framerate when it has to handle fullscreen (800x480 resolution) screen updates.

Now for example, the latest version of MPlayer running on N800 with the latest firmware can easily play 30 fps 320x240 video very smoothly and without dropping any frames. That's simple - 320x240 data does not require a very fast graphics bus. But if we took 800x480 video, it might have to skip some frames (we can't test it as decoding 800x480 video at high framerate would be a heavy task for CPU and it would become a bottleneck, but not the graphics bus). A set of resolutions that you will most likely encounter in video and watch on the device are 512x288, 640x360 and probably a bit higher, they are also not a problem for the graphics bus :) In this sense graphics bus performance is balanced with the video decoding capabilities of CPU.

You can also check my followup post in the mailing list (posted a few days before the new firmware got released) as a reaction to the worries just like yours: http://maemo.org/pipermail/maemo-developers/2007-March/009202.html

[Drahnreb]

@Serge: Thank you for your detailed answer!

I hope in the next few days my new N800 will arrive to me. And than i can make my own tests ...

thx

Bernhard

[TA-t3]

I also read that thread. But then the upgraded N800 software arrived, and I for one am happy with the new video performance. If videos can be played the way the Nokia pre-installed demo video now plays, it's good enough for me (actually there's now a second N800-specific demo video there). It looks completely smooth, at least to my eyes.

(Now if they could just add some codecs so that the media player can actually be _used_ for something more than just demo videos, then I would be even happier.. ;))