Ubuntu Opportunistic Developers Week

I’ve been following along with the latest community program from Ubuntu this week – Ubuntu Opportunistic Developers Week. There are a number of talks, each one hour long, which aim to stir up some action in the minds of would-be developers.

The talks are carried out through a tool called Lernid from community manager Jono Bacon. I feel this has been very successful in bringing down the perceived barriers between the well known developers and those of us who wish to get an application going.

Listeners were encouraged at the beginning of the week to think of an app and, hopefully by the end of the week, make it happen. Almost all levels of programmer could benefit from the talks and the leaders were very willing to answer in depth questioning throughout.

The format has worked really well in that you can choose which parts to listen in on and somehow feel less intimidated to ask questions than in a real-life conference.

The week has definitely inspired me so far to start putting some of the ideas I’ve had in to practise. A few of the projects I had tried before such as Quickly and Ground Control, but I was good to hear from the humans behind them. Talks that engaged me especially were CouchDB/DesktopCouch with Stuart Langridge, GStreamer with Laszlo Pandy and GooCanvas with Rick Spencer.

I look forward to the rest of the week and hope it inspires many more developers like me to create some really cool open-source apps. Thanks to everyone who has taken the time to make it possible.

PC to HDTV HDMI Woes

I’ve connected my PC to my HD TV via HDMI. There were some problems with the picture quality that I came across, so I thought I’d explain how I’ve managed to fix them.

The TV is a 22″ 1680x1050px LG M2294D and is labelled as a ‘Digital TV Monitor’. The PC is an Acer Aspire Revo 3600 which has a dual core Intel Atom 330 processor with Nvidia Ion graphics.

Auto-adjusting backlight

Firstly was the problem with auto-contrast/auto-brightness. If this is enabled, the TV’s processor will look at the picture signal–If it is mainly dark (black) the back-light turns down and if the signal is light (white) the back-light gets brighter. This could be a good feature when watching films or TV (though I’m not convinced) but it is very distracting when using your computer.

With this TV, you configure the picture by first selecting from some pre-defined modes (such as ‘Standard’, ‘Vivid’, ‘Cinema’) and then adjusting brightness contrast etc. to your taste. Apparently, some of these modes have the auto-contrast enabled and some to not. You can try different modes and also the picture reset function if you have this problem. I’m sure it varies from set to set but I set mine to ‘Standard’, then did a ‘picture reset’ which did the job.

Signal post-processing

Secondly the TV was trying to do some sort of processing to the video signal which made it quite blurred. I should clarify that I had the PC set to the exact same resolution as the TV’s native resolution (1680×1050). It is very important to set this as you will never get a good picture otherwise.

The kind of problem I had was that the bright colours appeared to bleed horizontally for maybe 3-4 pixels. I didn’t notice this in text, but did when I saw the Firefox icon against the light grey of my task bar panel. This is also supposed to be something desirable when watching TV or Films as I guess it blurs over the artifacts in video compression. If I had a high-def player I would probably still want to turn this off as I’d want to see the real signal. It was quite hard to turn this off actually on my TV. I had to go into the general settings and then ‘Label inputs’. I had seen this feature before but never thought it would make a difference to the picture quality. There were a pre-defined list of labels for HDMI1, (such as ‘Set-top box, Games console and PC) I chose PC. I then changed to a different input, then back to my newly labeled HDMI1-PC and it was good.

Nvidia drivers

Finally I found the Proprietary Nvidia graphics card drivers were trying to be clever. There is a protocol called EDID which allows the TV to tell the graphics cards about itself. This is useful as the graphics card can then set the correct resolution among other things. Another thing the TV says is that it is a TV and not a monitor. The problem is how the proprietary Nvidia drivers for Linux use this. A kind of unsharp mask is applied to this signal from then on which has the effect of showing small halo type marks around high contrast shapes such as text. This is a bug in my opinion as I don’t see why a high definition television should require extra sharpening. Someone has thankfully come up with a work-around, which involves taking the description data from the TV, saving it, removing the part about the device being a TV, then telling the driver to use this customised EDID file. You can get a further description of how to do this from the project website along with tiny programs that capture and modify the data. After you have your modified EDID file, you need to add a reference to it in your /etc/X11/xorg.conf configuration file as an override.

Final result

The picture still has minor imperfections where it appears to be slightly sharpened. This is apparrent sometimes if you look closely at the edges of text. However, the picture is very much improved from what it was. I reconnected the PC through the TV’s DVI socket and the picture has the same slight sharpening. If I find out any further improvements, I’ll post them here.

All change

OK, so I’ve neglected the blog a bit recently but hopefully I can be excused. I had three weeks of exams for my final year at University of Essex and dissertation presentation before that. The exams were over almost two weeks ago now and since then I have catching up with other work and starting a few of my own projects I have been thinking about lately.

I have been gennerally been working on the way I integrate websites for customers in future, and making my source code for web applications more structured and re-usable. There are several useful segments of code I have written over the years and I feel it would be beneficial to make them more generic so they can be added to new projects more easily and extended.

The management system I developed a few years ago for the family business website http://courchevel-1650.com has proven to be successfull and new features have been developed regularly. The system handles all the areas associated with renting out property to holiday makers, such as storing customer details, managing availability, updating the website and printing letters. With a proven system like this that does so much, I’m sure other businesses could make use of it so am making it more generic.

Aside from these I have several other ideas in the pipeline inspired from courses I took in ‘Image Processing’ and ‘Further Concepts in Databases’ but you’ll have to wait for further details at a later date. I also feel the urge to contribute source code to a few open source projects so expect to see developments in this area in future.

Sony Ericsson phones reading ID3 tags

I’ve been having trouble transferring/playing music on the SE W610i and K800i phones. Copying the MP3 files to the phone is easy–when you plug it in with the USB cable you can select ‘File Transfer’ on the phone and it will reboot as a mass storage device so Linux can mount it. However, after transferring albums and safely unmounting the disks, they appeared to have strange names in the music player. When viewing by artist, album and track in the Walkman and standard music player sometimes the ends of names would be cut off even if they weren’t particularly long. For example, after transferring Mark Ronson’s album ‘Version’ and viewing by artist, the album would be split apparently between three artists:

   Mark Ro
   Mark Ron
   Mark Ronso

Initially I assumed the files were becoming corrupt somehow, even though I made sure I was unmounting properly from Ubuntu and even tried the same files from a Windows machine. After a bit of searching I found a forum thread about the same problem. The problem is due to ID3 tags–specifically version 2.4. The way the Sony Ericssons (at least these phones) display artist and track names has nothing to do with directories or file names but ID3 tag embedded in your MP3 files. Many of my albums had information stored in v2.4 of ID3 (Amarok uses 2.4 by default), but the phones can’t handle this properly and much prefer the 2.3 version. Problem identified! Now for a solution.

Warning: There is a possibility you will loose some ID3 data when converting from v2.4 back to v2.3, However the stuff that does get removed can’t be that great as I haven’t noticed anything missing. V2.4 is supposedly a bit controversial anyway, so v2.3 should make your files more widely supported.

There are two open source tools I can see as being helpful–id3v2 (command line) and Kid3 (graphical GUI KDE application). id3v2 has the argument -c (–convert) which is supposed to convert from id3v1 to id3v2. This will allow you to convert all MP3s in a directory with one command as follows:

id3v2 -C Music/MarkRonson/*

Kid3 has a reasonable user interface and may in fact do a better job at conversion as it has a specific v2.4 to v2.3 conversion tool. You select the files you wish to convert by opening them, Ctrl-A then from the main menu select ‘Tools’ -> ‘Convert ID3v2.4 to ID3v2.3′.

Hope this has helped someone out. This fix works but hopefully a more elegant solution will come at a later date (e.g. ID3 tags get converted automatically when being copied or SE release a firmware update to support v2.4)

Packard Bell Syntek webcam success

Approximately 18 months ago, my girlfriend was looking for a small and light laptop to replace her broken iBook. The replacement laptop is a Packard Bell Easynote BU45-U-045 (I think that’s the model number–product details). Most of the hardware is well supported by Ubuntu Linux–Intel graphics chip runs Compiz-Fusion well, SD card reader, and wireless–although with ‘Restricted Drivers Manager’. There is also a webcam integrated above the screen, but I didn’t get this working until today. The camera chip comes from Syntek Semiconductor Ltd but is usually assembled under the name D-Max.

The command ‘lsusb‘ was an obvious starting point, but no manufacturer/device name is given so you have to look carefully at the ID numbers. This is the output I have (174f:a821) but apparently there are other devices by Syntek that are supported (174f:6a31, 174f:6a33, 174f:6a51, 174f:6a54 and 174f:a311).

jayne@jayne-laptop:~$ lsusb
Bus 004 Device 001: ID 0000:0000
Bus 005 Device 001: ID 0000:0000
Bus 003 Device 001: ID 0000:0000
Bus 003 Device 002: ID 08ff:1600 AuthenTec, Inc.
Bus 002 Device 001: ID 0000:0000
Bus 001 Device 002: ID 174f:a821
Bus 001 Device 001: ID 0000:0000

I found the Syntek DC-1125 Camera Driver Project hosted on SourceForge, still in development (in face the latest version was released today!) but it worked OK for me. These instructions are how I managed to get it to work on Ubuntu. If you decide to carry out these yourself, you do so at you own risk and I accept no responsibility.

Download the drivers from the project page–you want the file stk11xx-*.tar.gz–and extract them. From the extracted directory, make the Loadable Kernel Module with the command sudo make -f Makefile.standalone. I got the following error about ctags, but this didn’t matter as the module had been compiled by this point (.ko file).

make: ctags: Command not found
make: *** [driver] Error 127

If compilation goes OK you should see a file called ‘stk11xx.ko’ in the directory which you should copy to your kernel’s module directory, sudo cp stk11xx.ko /lib/modules/`uname -r`/kernel/drivers.

Run the following commands to load you camera’s kernel module. The light next to it flashes if you have one.

sudo depmod -a
sudo modprobe stk11xx

If all has gone well up to this point, test it with an application like Camorama or Ekiga. Install Camorama through Synaptic or by typing the following command.

sudo apt-get install camorama

For me the image shown was upside down, which was annoying at first. However there is an argument you can pass when you load the module which counteracts this. If you need the image flipped, use these commands to unload the module and re-load it with the argument ‘vflip=1′.

sudo rmmod stk11xx
sudo modprobe stk11xx vflip=1

Open Camorama again and you will hopefully now be the right way up. Now we have to make sure that this argument gets added automatically or you will be the wrong way up next time you start the computer. You want to create a new file in the directory ‘/etc/modprobe.d’ for the module with the line ‘options stk11xx vflip=1′ in it.

sudo touch /etc/modprobe.d/stk11xx
sudo gedit /etc/modprobe.d/stk11xx

If you have a similar webcam, I hope this post is useful to you. If you have tried this for yourself, please leave a comment.