Sunday, 30 June 2013

Node.js for Nokia N900

Node.js for Nokia N900 is available from the maemo extras-devel repository. The package name is nodejs. It gets installed to /opt. After installation add /opt/node/bin to the path (/etc/profile).

Sunday, 23 June 2013

ARM Port of Lua 5.2.2 for Maemo

Thanks to great programming by the Lua team, porting Lua 5.2.2 to ARM is just a matter of recompiling for the target CPU. This is my first port for Maemo running on Nokia N900 which has an OMAP 3430 ARM Cortex A8 SoC. The armel debian package can be downloaded from Maemo Garage. I have yet to explore on submitting to maemo-devel. It's compiled to run on any POSIX compliant OS running on ARM.
The install paths are as follows: lua, luac goes to /usr/local/bin/ and liblua.a goes to /usr/local/lib.

wget and Proxy

wget can channel it's connections via a proxy. It can be used along with Tor to download files.
wget "http://example.com" -e use_proxy=yes -e http_proxy=127.0.0.1:8118

Extract Audio from a Video File

ffmpeg can be used to extract audio from a video file. Install ffmpeg for the host OS (add it to the path if using Windows) and use the command as below.
ffmpeg -i video.mp4 -ac 2 -ar 44100 -vn audio.mp3
-i specify input file
-ac audio channels
-ar audio rate which is the sampling rate per second
-vn video none to not output video data
-ab audio bitrate for constant bitrate. -ab 320k means a bit rate of 320 kBit/sec.
Specifying a bit rate using -ab will produce audio file with constant bit rate (CBR). Leaving it out will give audio with variable bit rate (VBR). I recommend using VBR for better quality to size ratio.

Friday, 7 June 2013

Install Lua in Nokia N900

Lua v5.1 is available from the maemo extras-devel repository.
1. Activate extras-devel.
2. Open terminal and enter the following commands.
root #needs to be root
apt-get install lua5.1