Hi, I’ve posted this to my site in order to find people looking for a central coast linux user group (Central Coast, NSW, Australia that is.) Basically, I’ve sort-of found one at http://cclug.com, but it seems to be a bit dead with hardly any info. If you are interested in a central coast LUG, please leave a comment with your email address and I’ll get in touch. Perhaps you can help me find the mysterious CCLUG, or help me establish a new one? Who knows! Either way, it’d be nice to have a LUG that’s not all the way down in Sydney.
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Why laconi.ca and identi.ca should be your choice for microblogging
Explaining microblogging is slightly difficult, but I’ll give it a go:
You sign up for a microblogging service like twitter. You ‘follow’ your friends that are already on there, and perhaps some people that aren’t your friends but people who say interesting things. Once you’ve started following your friends, you might download a program for your computer to alert you when they post (or in the case of twitter ‘tweet’), and to allow you to post your own ‘tweets’ without having to visit the twitter website at all. This is great because it allows you to know what your friends are up to, or tell the world what you’re up to, or that you’ve just discovered an amazing new pizza at dominos.
When you post an update on a service like twitter, it’s totally public. You are broadcasting, and people who are following you will be automatically alterted to what you say. It gets really cool when you consider all of it can be done from your mobile/laptop/pc etc..
What’s wrong with twitter?
Now that’s cool, and I’ve used twitter and it’s good. However, there’s one (or two, perhaps three?) major flaws with twitter. The first being that it’s a closed service. Imagine if email was a closed service, eg people on hotmail could only send and recieve email from other people on hotmail and people on gmail could only send and recieve mail to @gmail addresses. This is effectively the problem with twitter, jaiku and all the 100’s of other closed microblogging services – it’s cool, but it’s silly. Oh yeah, the other things wrong with twitter are it breaks often is all closed up.
Enter laconi.ca. Laconi.ca is an open source microblogging server program. This means that anyone can start their own microblogging website. Please don’t stop reading here! This is where it gets good. You can easily link your microblogging website to any other laconi.ca microblogging website – adding to a big mesh of microblogging servers.. just like email servers. laconi.ca uses an open standard for communication also meaning that you’re not limited to using laconi.ca as your server.
Why is it better for me though?
laconi.ca does lots of cool things that twitter doesn’t! Firstly, you can use an instant messeging client with it, and post to your feed just by sending the laconi.ca contact a message. Secondly, you can ‘track’ certain words. Say you’re interested in cake, you can type into your IM client: track cake and every time someone posts something with the word ‘cake’ in it (not just your friends!) you’ll get their post. There’s other neat things I haven’t tried yet such as posting attachments and things, but it’s got some killer features that no other microblogging services have.. the best being it’s open.
Find me on identi.ca
You probably don’t want to have to set up your own laconi.ca server, so why not just use the ‘main’ one! Check out identi.ca and subscribe to me: johnhunt
Move to Australia
Just a quick upadte, john-hunt.com is now hosted in Australia rather than the UK. This is good because it means I don’t have to wait ages for pages to load on my own sites etc..
I’m going to set up a more personal blog, probably at blog.john-hunt.com with posts about life in Aus, photos etc…what I should have sorted out ages ago really.
revalidation failed (errorno =-5)
If you find your system isn’t booting sometimes and you get this funny error message, edit your kernel boot line in /boot/grub/menu.lst:
kernel /boot/vmlinuz-2.6.24-19-generic root=UUID=75a92494-bdae-4715-92d9-f06d1887008e ro all_generic_ide
e.g – Add the all_generic_ide parameter. All should be fine once again. I believe this is a strange Ubuntu kernel bug, although I’m not sure.
MKV (h.264) playback on XBOX360
While it’s not possible to play mkv files directly on the xbox360, you only need to do a few things to remux the video and audio streams into the mp4 format. This means that no re-encoding is done with the video, therefore there is no loss in video quality.
At the time of writing, the xbox360 doesn’t support anything other than 2 channel AAC audio for mp4 streams, so you’ll have to put up with that. It does work well though.
1. Gather video information
mkvinfo movie.mkv
Look for things like the following:
|+ Segment tracks
| + A track
| + Track number: 1
| + Track UID: 1
| + Track type: video
- snip -
| + Default duration: 41.708ms (23.976 fps for a video track)
This shows us track 1 is the video stream. Remember that, it’ll come in handy later. Also, make a note of the fps, if you get the FPS wrong later you’ll have a/v sync issues. Generally track 1 is always the video stream and track 2 is always the main audio stream:
| + A track
| + Track number: 2
| + Track UID: 445320639
| + Track type: audio
- snip -
| + Name: Main audio DTS 1536
| + Audio track
| + Sampling frequency: 48000.000000
| + Channels: 6
Make a note of whether you’re dealing with a DTS stream (as in my example) or an AC3 stream. There is a newer format ACC3 or something..I don’t know much about that.
2. Extract the video and audio streams from the mkv
Remember, mkv and mp4 are just like avi (in some ways.) They are all container formats, not the actual video itself. Now we extract the audio and video streams we want. If you like you could choose different audio and video streams you discovered using mkvinfo.
Extract the video:
mkvextract tracks movie.mkv 1:video.h264
Next we have to do something quite strange in order to make our h.264 file compatible with the xbox360. Run hexedit video.h264 and change the sequence: “67 64 00 33” to “67 64 00 29”.
Now we have our video file ready for muxing, we need to deal with the audio stream:
mplayer movie.mkv -novideo -ao pcm:fast:file=audiodump.wav -channels 2
This gets the audio from the mkv file and saves it as audiodump.wav ready for re encoding using nero’s AACenc program (http://www.nero.com/eng/down-ndaudio.php):
3. Encode the audio dump to AAC format
Now we encode the wav file to AAC:
neroAacEnc -lc -ignorelength -q 0.50 -if audiodump.wav -of audio.m4a
Both the audio and video streams are now ready to be muxed (put together) by MP4Box:
4. Mux the files
Remember to use the correct FPS value we obtained using mkvinfo from earlier!
MP4Box -new output.mp4 -add video.h264 -add audio.m4a -fps 23.976
output.mp4 is now ready to watch!!
Footnotes:
1. I didn’t have any luck getting windows media player 11 to stream the mp4’s to my xbox, I got the all to common ‘format not supported’ thing on the xbox even though they played just fine on WMP11.
2. You’ll want to split your original MKV into just under 4GB chunks if you’re putting the files on anything other than DVD5/DVD9. Do this:
mkvmerge -o output_part.mkv --split 3900M movie.mkv
*note – we leave it just under 4000M for two reasons, firstly fat32 can’t store eactly 4GB, secondly I’m not sure if it’s GiB or GB…!
3. Special thanks to Mike from Linux Love. For some tips that actually worked!
4. I’m not sure if there’s an artificial limit on the file size of mp4s that can be played back, but I will know by this afternoon!
Update:
It appears as though the xbox360 doesn’t like any media files > 4GB, a bit of a shame really. Hopefully the next dashboard update will fix these issues. Until then, looks like we’ll have to put up with split files.
Banshee 1.0
Once in a while, a fantastic piece of open source software comes along. Just the other day, banshee 1.0 was released. I must say, I’m *very* impressed. It’s like a much better, really great iTunes. With the addition of video it now covers pretty much everything I wanted in a media player thingi for Linux.
Check it out: Banshee 1.0!
Ubuntu UK Podcast
The Ubuntu UK Podcast show was recently established, someone I met from HantsLUG hosts it and it’s pretty interesting for those of you who are Ubuntu users. Check it out!
PHP-Clearsilver installation guide for Ubuntu/Debian
I updated my php-clearsilver installation guide today after discovering it’s wrong in a few places. Fortunately, I don’t think anyone’s ever used it (apart from me today.)
If you know what clearsilver is and you use php, you might find it interesting.
Installing PHP Clearsilver module for apache on Ubuntu and Debian
Creating a bridge for VirtualBox / wireless bridging on Ubuntu
Following several guides on setting up a bridge on my laptop between the wireless network interface and VirtualBox for direct networking was simply not working for me. Today after lots of head scratching I finally discovered why.
Turns out that the standard bridge utils are no good for most wireless cards, but there is a workaround.
Check out this guide, and read under the wireless section:
Bridged Networking with VirtualBox on Linux Hosts
What you can do is add those various commands to a little script file in /etc/network/if-up.d/ which will set up the ‘bridge’ upon starting networking.
Woohoo!
Ripping copy protected DVDs on linux (ripguard, puppetlock, arccos etc)
Unfortunately, you can’t!!! Well, not as far as I can tell, I’ve asked around and scoured the web but it seems there’s no use, there simply isn’t a way to do it on linux. The next best thing is to use DVDFab for windows via Wine (it kind of semi-officially works with Wine).
As I found nothing really solid on google, I thought I’d write this post as it’s annoying when you can’t find anything.
How infuriating! What a great way to encourage people to illegally download things instead of buying them. I wonder when (or if) these movie studios will ever learn that it’s a really dumb idea to stop people having total control over things they buy.