N810
From Theory of Measurements Wiki
Contents |
Nokia n810
This device is lot of fun: a handheld Linux box with a nice development environment with all GNU tools easily available. I already ported the GNU R for the Maemo 3.2 OS; 4.0 port will soon follow.
This page contains some random minor notes regarding how to set up stuff on the device.
SIP and NAT
The n810 comes with a SIP client. I found some odd details while setting it up to work on Saunalahti's ADSL network. My setup is such that the n810 sits behind a NATed private network. I'm using an OpenBSD box with the PF firewall.
Basically, if the "Discover public address" box is checked (Accounts -> SIP -> Advanced), the n810 sends voice data out but doesn't receive any. But if the option is unchecked, calling via SIP works just fine.
Why? It seems that when initating a call and when the "Discover public address" box is checked, the n810 constructs the SIP INVITE packet so that the Contact: header is of the form <phone number>@<public-IP>:<port>. And when the option is unchecked, the header is <phone number>@<private-IP>:<port>. There might be other differences as well. Anyway, when the "Discover public address" option is checked, no incoming RTP traffic arrives at my firewall at all.
Watching movies on the n810
First: install mplayer on the device, as the built-in media player doesn't seem to support too many codecs.
The mplayer that is available for the n810 apparently cannot play divx movies, at least not with the codecs I found, anyway.
I created the following script to convert divx AVI files to ffmpeg-mpeg4 encoded mpg files. The script scales the movies to 400x240 as well, which causes nice pixel doubling, and also reduces the bit rate somewhat.
#!/bin/sh basename=`echo "$1" | sed -e 's/\.avi$//' -e 's/\.AVI$//'` mencoder "$1" -oac copy -ovc lavc -lavcopts vbitrate=200 -vf scale=320:240 -o "$basename.mpg"
IMAP mail client
It's wise to keep the Inbox quite small. If there are really many messages on the Inbox, the mail client on the n810 works quite slowly...
