bwh: (Default)
2007-02-21 09:07 pm
Entry tags:

Security bug in CAPI code; please test updates

There is a potential buffer overflow in logging of CAPI messages in libcapi20 (part of isdnutils; bug 408530). The same broken code from libcapi20 is present in the Linux kernel (bug 411294). Also, the affected functions are not thread-safe and are unlikely to be made so without API changes; multithreaded programs calling them must use a mutex to avoid another security flaw; (such as asterisk-chan-capi; bug 411293).

I have prepared updates of asterisk-chan-capi and isdnutils for sarge and sid but I have no ISDN hardware to test them with. I would appreciate it if users of these packages would test the updates and report their results to the associated bugs.

The patches can be found attached to the bug reports. Updated packages are at:

deb distribution/
deb-src distribution/

(the repository is signed with my personal GPG key).

bwh: (Default)
2006-11-21 11:49 am
Entry tags:

Interface checking

Robert Collins writes: "Added to my list of 'things we need'... a version of icheck that requires less configuration to hook into package builds. Ideally one that we can get running automatically on any package build."

There's only so much you can do without having debug information from both versions, which of course we don't keep at present. However, Steve Langasek implemented some basic checks on exported symbols in the unixodbc package which you can find in its debian directory.

I'm slowly starting to work on a more comprehensive ABI checker that would use debug information. This would require someone to keep or rebuild debug information from the previous version (and to delay stripping it from the new version) so I don't think it could be automatic.

bwh: (Default)
2006-10-25 11:18 am
Entry tags:

While Planet Debian is talking about money...

Julien Blache: "You’ll be pleased to learn that a release manager needs $6000 USD to cover for living expenses for a month."

Sounds high, right? But we're talking about contractors, not employees. Contractors have to cover certain expenses that are generally paid for by employers, such as (depending on jurisdiction):

  • Sales tax/VAT on receipts
  • Payroll tax
  • Health insurance
  • Unemployment insurance
  • Pension contributions
  • Vacation time

and in this case, their own equipment. (But they save on transport!)

Besides which, you have little idea how much Steve or Andi might need to pay in mortgage repayments or rent, or how many dependents they have. Nor should we pry into these personal circumstances.

bwh: (Default)
2006-10-21 08:31 pm
Entry tags:

Finally I'm going to shut up about these DVDs

As posted to debian-devel-announce and debconf-announce (and partially written by Holger):

On behalf of the DebConf6 video team I'm proud to announce the DebConf6 DVDs!

They include all formal sessions from Debian Day and DebConf, plus the group photos, the video team BoF, and some documentary videos made by Gabriella Coleman. They are divided into

(there is a small overlap between these).

The DVD images are now available for download along with the source videos, as are the software and menu design used for them. You can also order DVDs to be shipped to you in a nice box.

Many thanks to the sponsors, organisers and other people who made DebConf6 a fun and productive event to be remembered.

See you at DebConf7 in Edinbourgh - or maybe DebConf8 in your town!

Finally, I apologise for the delay in producing these discs. We ran into a number of technical problems along the way but it's primarily a result of discouragement and procrastination on my part. However I believe that the VideoLink software is now sufficiently reliable and that next year's DVDs need not be so dependent on me.

bwh: (Default)
2006-10-04 01:41 am
Entry tags:

DebConf6 DVDs, release candidate 1

Now at There are no images for download because it takes too long for me to upload them, but it should be easy to build a DVD; that page refers to everything you need.

If you ran a session, please check that it's correctly categorised (no need to build; just browse the menus online).

If you can, please build a DVD and check that it works in your players. I'm particularly interested in results from hardware players as I can try software myself. I know that ogle in stable doesn't like the videos but it seems to be the odd one out. Please check that menu navigation is sane and videos play as expected.

Barring compatibility problems that need to be fixed, the only change I intend to make before release is to reinstate the logo in the menus. Then I should upload images and offer discs for sale starting next week.

ETA:There was one other thing to fix: the glitch at the bottom of the group photos is a Mozilla bug which I will try to work around by doing the v1.0 build in sid.
bwh: (Default)
2006-09-28 12:19 pm
Entry tags:

DebConf6 DVDs

They're very nearly done. Menus are available for preview: English disc 1, English disc 2, Spanish disc (you can preview them in a Mozilla-based browser but you need to use VideoLink to see them exactly as they will appear).

To do: add background pictures where missing, adjust some menus that are slightly too long in an "NTSC" frame, add the day trip if we ever find some music for it, test, release. I'm also considering moving or duplicating the Debian Day session that's in English to English disc 1.

I uploaded VideoLink 0.11 this morning and intend to put up the DebConf6 DVD sources (other than video) this evening.

Update: Done. Still lacking the day trip, and I pulled the logo because I forgot to ask permission to use it yet.

bwh: (Default)
2006-08-20 11:48 pm
Entry tags:

Finish the job

I'm currently uploading the last of the final files for DebConf session videos, which should complete in about 5 hours (it's a long one). In the queue behind that are three documentary videos filmed by Biella, two of which I have edited. There's a fourth which is just lacking a caption for one person I don't recognise. I still have to sort out the DVDs but hope this shouldn't take too long.

Updated for DWN readers: The files are on They include Biella's documentary videos. There's a single-page index elsewhere. Note that the lightning talks are all in one recording and don't each have their own links.

bwh: (Default)
2006-08-19 06:19 pm
Entry tags:

Video, video, video

I fixed the known bugs in WebDVD, renamed it to VideoLink and uploaded it to Debian. To get it into Debian, I had to make it work with Mozilla/XULRunner 1.8 (roughly the same code base as Firefox 1.5) since Mozilla 1.7 is no longer supported. In the process of doing that I also fixed a bug in setting the nominal screen resolution - I tell Mozilla it's 40 dpi because I reckon that's the average resolution when the video is played full-screen - which is likely to change existing layouts. The sarge version still seems to ignore the claimed screen resolution which I'll need to investigate and fix as I really don't want layout to depend on which version of Mozilla was used.

I have stopped procrastinating on finishing off the DebConf video files, put all the information I have into a database and used that to work out what's left to do. The answer to that was, not that much really. Based on the database you can see the status of all the recordings and final files which shows that we have all the final files for all the official sessions. About 20 of the final files (mostly Theora unscaled versions) have still to be uploaded, which will take a few days over my 448 kbps uplink. (Due to a deficiency of my schema, the lightning talks are shown as not having final files. Actually they just weren't split up into separate files.)

I'm intending to produce 3 DVDs this time - two for DebConf sessions and one for Debian Day plus any Spanish-language material from DebConf - because these recordings just won't fit on 2 single-layer DVDs. There should be room for some extras such as Biella's recordings and the day trip, which I have still to deal with. I need to sort out menus for the DVDs. Please suggest good background pictures that can be distributed under the DebConf video licence.

bwh: (Default)
2006-05-28 02:51 am
Entry tags:

DebConf video status

Due to this bug and some rather late checking, we're some way off producing finished videos. The video storage/encoding servers are now with gigio who's very kindly helping to fix this.
bwh: (Default)
2006-05-14 09:08 pm
Entry tags:

Notes and slides from my talk at Debconf

Before I forget about it, here are the materials I prepared for my talk "Multithreading: why and how we should use it". I know I didn't present very well, but hopefully the links will give you a bit more explanation.
bwh: (Default)
2006-05-14 11:18 am
Entry tags:

Debconf video streaming: bugs and fixes

Yesterday we found some problems with our streaming set-up that hadn't appeared in the short time we had to test it beforehand. Firstly, due to a misconfiguration, the 10 Mbps link from the Parliamentary Tower to our network became congested with broadcast traffic. This seems to have been fixed, though I don't know the details. Secondly, at times when the picture kept changing, the encoding machine was unable to encode it in real time. We believe we've fixed this by using libtheora-mmx in place of the standard libtheora. Finally, we weren't able to set up both internal and external Icecast servers, and to save bandwidth we had to stop people at Debconf from streaming from the external servers. We have fixed this with the aid of some new NAT and firewall rules.

If you're at Debconf you can use http://video:8000/hacklab.ogg or http://video:8000/tower.ogg.

If you're outside, carry on using One of the servers has gone down due to a disk failure, but should be back later. In the mean time we should be able to add more relay servers.

bwh: (Default)
2006-05-13 01:28 am
Entry tags:

Debconf video streaming: the details

You'll need to refer to the schedules for Debian Day (en español) and the main conference. (Local time is GMT-5.)

Point your media player at or depending on the session venue. We have multiple servers; use or to select one nearer to you.

bwh: (Default)
2006-05-12 09:21 pm
Entry tags:

(no subject)

Today we got access to all the audio equipment and the remaining cables we needed in our main venue, the Parliamentary Tower. We've worked out locations of the various equipment (projectors, screens, speakers, microphones, camera, computers) and wired them all together. We were unable to get a sight-line for a wireless link from the tower to the rest of our network, but the centre finally agreed to let us use their house network for this purpose. We have to go through a 10 Mbps hub, but it should be sufficient. Finally this evening we were able to test streaming video and audio from the camera and mixer in the tower down to the rest of the network. The tower is now closed, but we will test from the hacklab to the outside world tonight. Fingers crossed, Debian Day should go live to the world tomorrow!
bwh: (Default)
2006-05-11 09:02 pm
Entry tags:

Slumming it

The magic switch for the Debconf wireless network is sharing its socket with a TV. When the TV is plugged in or unplugged, sometimes the switch's plug comes loose, and the whole wireless network goes down.

Our Internet connection is dependent on an antenna on the roof of the local Internet café that sometimes comes down in high wind, and which has a flaky power connection.

And now the route from the airport is blocked too. (Maybe not any more.. we don't know.)

On a more personal note, my laptop's power cable is now held together with insulating tape.

bwh: (Default)
2006-05-10 10:12 pm
Entry tags:

Screaming video

At Debconf we'll be having talks in the Parliamentary Tower and some other sessions in a room by the hacklab. In each of these rooms there will be one small quiet computer capturing video from the camera over Firewire, connected by Ethernet to a second computer (preferably outside the room) with more disk space and processor power, which will record, transcode and stream the video to the outside world.

On the first of these we just need to pipe dvgrab into netcat. On the second we need to netcat to a file and simultaneously feed that file into the transcoding and streaming software (ffmpeg2theora and oggfwd). Since our link to the Internet may not be reliable (and certainly isn't now) we expect that streaming may lag behind; that's where dvtail (which I mentioned previously) comes in.

Having identified the various pieces of the video puzzle, last night I actually wrote the scripts to do this. I didn't have a chance to test them properly, so they didn't actually work. Today I packaged them, fixed various silly bugs, and tried them on some of the computers we plan to use. This was stalled for a stupidly long time by the lack of Internet access, since Ganneff had planned to create users on an LDAP server elsewhere and then use a local LDAP cache, rather than create them entirely locally. Eventually we ended up with user accounts created on each machine. Next problem: we attached a camera to a Powerbook G4 and got nothing but errors from the Firewire driver and dvgrab. We tried changing cameras, cables, kernel versions, but with no success. Changing the kernel itself was a problem without access to backports. I was cursing the air blue and banging my head against the wall in frustration.

Finally we tried using different computers, and suddenly everything worked. I had missed one option to ffmpeg2theora, but once I added that we were able to stream across the LAN. Of course, that won't be of much use if we don't get the Internet connection working much better soon.

bwh: (Default)
2006-05-10 09:37 pm
Entry tags:

Useful phrases in Latin American Spanish

Courtesy of my phrasebook:

I'd like to get Internet accessQuisiera usar el Internet

I noticed this morning that the book has a section on romance, going from "asking someone out" through "sex" to "problems". Suddenly this book became more interesting to my breakfast companions.

I can't get it up - sorryLo siento, no puedo levantarla
bwh: (Default)
2006-05-10 12:41 pm
Entry tags:


Nattie ([ profile] tea_cantata) and I arrived safely in Mexico and have been fairly busy since then, while not blocked by lack of network access.

The Debian archive mirror prepared by Steve made it here safely and is now attached to our main server. Yay for USB2.

Video team preparations are a bit behind schedule but we are just about to do a smoke test with cameras and computers (but no audio mixer yet). I have backported Icecast 2.3 and Ffmpeg2Theora to sarge, and written a "dvtail" program to read the DV recordings for streaming, so that problems with our Internet link won't break recording or result in a huge lag in the streams.

I have also had to make and lay out a 100m power extension cable for a switch in the middle of a 200m stretch of network cable. This requiring fixing the crappy extension socket shut with a hammer, jumping^Wclimbing from rooftop to rooftop with cable, and then untangling it under a baking sun.

I'm loving the spicy food here, though I think I can do without jelly as a "vegetarian" dessert (I think this mistake will not be repeated) and may have to ask for refritos sin queso (without cheese). The heat is bearable and my hat and sun cream have so far protected me from sun burn. The insects are horribly noisy, but one eventually tunes them out, like the noise of fans.

bwh: (Default)
2006-03-04 01:20 am
Entry tags:


This is rather belated; I seem to have trouble summarising long events. [ profile] tea_cantata posted about the trip earlier and I'll assume you've already read what she wrote.


Sledge and I settled on leaving Cambridge at 11:30 the next day to catch the ferry departing at 14:45. I had to take the car in for its "MoT" test, having put it off almost to the last minute, and around 18:00 I realised the garage had closed without calling to let me know it was ready.


Thankfully the car was ready early on Friday morning and I was able to collect it and get some fuel by around 11:10. Our additional passenger, tbm, arrived at our house by bus shortly afterwards, and Sledge arrived with passengers shortly after 11:30. The journey was fairly long - about 230 miles by road and 2 hours plus waiting time on the ferry - but uneventful. This was my first time trying to drive "in convoy" and my first time driving on the right, but I coped reasonably well, I think.

Most of the FOSDEM attendees at the youth hostel had a round of drinks there, then left for the Roy d'Espagne in two groups a few minutes apart; I was among the laggards and, lacking a map, I attempted to lead the way to the Grand Place based on what I remembered from my previous weekend trip. This was surprisingly successful; it helped that I had stayed nearby on that trip.

The Roy was terribly crowded; not so much as to make me uncomfortable, but enough to make it difficult to get served. I shortly joined a group going elsewhere for dinner, consisting mostly of Debian-UK people, and we ended up in the Leon restaurant not far off the Grand Place. I dithered over the menu but eventually decided to take a risk and ordered a dish marked with a Belgian flag, Anguille (eel) aux verts. This turned out to be quite tasty; the "verts" consisted of an oil and herb sauce not wholly unlike pesto, and some cress on the side. I'm not sure whether the flag indicated this as a particularly Belgian dish or that it would come with a miniature flag and flagpole stuck in it (which it did).

Back at the Roy, greeted many people that I had met previously at Debconf and other events, talked to some - but fewer than I would have liked - and had a a few beers. All too soon it was 1a.m. and time to walk back to the hostel.


I dragged myself out of bed on Saturday morning, and, finding our wash-bag entirely absent of soap, shower gel or shaving cream, had to make do with a minimal wash in the communal toilets and letting my bristles grow. At breakfast, to the digust of most of those sharing the table, [ profile] tea_cantata got a bowl of cornflakes with what appeared to be mayonnaise, though it was actually yogurt. Shortly after 9, Sledge and I drove over to the FOSDEM venue, the UBL. I think I would rather have taken public transport, but the daily parking charges by the hostel would have been €30.

I found the Debian stand was always well-staffed, so I spent most of the day going to various talks. I'll post the details in a later entry.

bwh: (Default)
2006-01-30 09:50 am
Entry tags:

I pass...and now, I wait

ID CheckPassed on 2006-01-15
Philosophy and Procedures CheckPassed on 2006-01-19
Tasks and Skills CheckPassed on 2006-01-30

Full details

bwh: (Default)
2006-01-16 12:58 am
Entry tags:

Debian stuff

I booked flights for this year's DebConf in Mexico. I'm taking 2 weeks and 2 days off to allow me to go to the whole conference plus the preceding DebCamp and/or some tourism. I've also arranged to drive via ferry to FOSDEM in Brussels at the end of February, which should be fun and a good opportunity to stock up on fine Belgian beer.

I submitted packages of Maypole and several other Perl modules for sponsorship into Debian. They're now waiting in the NEW queue for approval, which should hopefully happen some time this week. If that all goes OK, I should be able to get the very cool Memories application into Debian fairly soon.

Meanwhile my sponsor, [ profile] maulkin_rss, arranged to be the Application Manager for my application for membership of the Debian project. I've now answered his first two sets of questions, which hopefully puts me well on the way there.