Tuesday, December 11, 2007

Monitor calibration (epilogue)

So far, so good :

  • argyllcms 0.70 beta7 is now packaged on Mandriva contrib. I had to fight with Jam (because argyllcms insists on shipping a copy of libtiff and libusb and I didn't want those in our package) and with FORTIFY_SOURCE (causing buffer overflow in most tools, because of strange usage of printf, so I disabled FORTIFY_SOURCE).
  • I've updated lprof package in Mandriva contrib to CVS snapshot and I got it to work nicely with Huey colorimeter. There are still some build issues to workaround (calreports.html is missing from CVS, preventing build, embedded copy of argyllcms has the same FORTIFY_SOURCE issue, build being not lib64 aware) and application bugs, such as not disabling screensaver when running calibration (unlike argyllcms), calibration windows badly interacting with Ia Ora QT theme, causing misrendering) but nothing not really serious.
  • Until kernel is fixed to ignore Huey device for HID, you can unbind it from usbhid module, using echo -n "usb_id" > /sys/bus/drivers/usbhid/unbin. I'v created udev rule to handle this workaround until fix is merged in our kernel and put it in both argyllcms and lprof packages.

Sunday, December 9, 2007

PulseAudio, calibration (end of story), Ogg support on Maemo


I guess most people already know about it but after two weeks of tests, we (Mandriva engineering team) have decided to switch next Mandriva Linux release (2008 Spring, scheduled in April 2008) to PulseAudio. We are hoping it will help to fill the gap and fixes the issues our users have sometime, some may be caused by the cross desktop nature of our distribution (we don't want to favor one desktop environment over another). Switch has started on cooker, we will still need to fix some issues, but things are progressing nicely, thanks to Colin Guthrie hard work.
Display calibration
Thanks to everybody who commented on my post about choosing a display calibration device. Unfortunately, nobody reported test for Huey Pantone calibrator. So I decided to go ahead and buy one (in a shop where I could return it for any reason, I'm not completely crazy).

First, a funny fact : there was a sticker translating in french product description and you could read "For Windows 2000 and XP, Mac OS X 10.3 or OS more efficient (in English, real text is "or higher operating system". I guess we can say Linux is more efficient ;)

Second, I tried to build lprof from CVS but I could get it to recognize the device (since Lprof maintainers commented on my previous post, it would be nice to do a new development snapshot, guys ;) but I didn't spend too much time on it (I'll investigate later this week). So, I switched to Argyllcms 0.70 beta 7 (no Mandriva package yet, I'll create one soon). It recognized the device (nice) but couldn't talk with it.. After a little debugging, Huey device is a "false" HID device so kernel decided to handle it with usbhid module. Unloading usbhid module fixed this issue and Argyllcms was able to communicate with calibrator and I was able to tune my monitor !!

I'll have to ask Pascal to add Huey to HID ignore list, just like the fix he did two weeks ago to fix Wacom tablets (this fix was originally done by Frederic Lepied, XFree86 wacom initial driver author and who used to be Mandriva CTO sometime ago) years ago in kernel 2.4 and it was forgotten in Linux usb 2.6 stack and nobody noticed until today :(

So, if you are looking for a cheap display calibration device which doesn't require any additional firmware, I suggest Pantone Huey.
Ogg on Maemo
Hub, check Tuomas work, he has reported good progress on Ogg support in built-in media player on IT2008. Still some issues but it is really encouraging.

Monday, December 3, 2007

Choosing a monitor color calibration device

Christmas is coming, so I'm looking into buying a monitor calibration device. Requirements are simple :

  • must be supported under Linux by Free Software ie must be supported by Argyllcms
  • must be cheap (since it appears most of the features are implemented in software and not in hardware).
Version 0.70beta7 have added support for two cheap calibrators, Spyder2 Express and Huey. I know Ross has been successful with Spyder2 Express but I'm not a big fan of requiring firmware extraction from Windows driver and moreover ColorVision (maker of Spyder2) don't plan to support Free Software in future version of their product.

Huey doesn't seem to need firmware to work, but it is hacking around USB HID protocol, which requires some udev hackery to prevent kernel usbhid driver to handle the device, just like Wacom tablets (well, thanks to Pascal, this Wacom problem will be fixed in future kernel driver). So it would be better to "support" this device, over Spyder2, if possible.
I'm looking for reports of success use of Huey with Argyllcms on Linux (but if I don't get some, I'll probably buy a Spyder2 Express).