DVswitch/ conference

About this document

Written June 2009 for DVswitch Version 0.8.2

This document is an overview of what is involved in doing video at a large event. It is meant for people who are experienced DVswitch users. Trying to video a large event without being familiar with the tool chain will likely be a waste of your time and cause disruption to the event. If you are helping with an event and want to be familiar with the ecosystem, be sure to read the other docs too.


Recording and or streaming the content live over the Internet is very doable with COTS (Commodity Off The Shelf) technology. It does require some preparation, but given a conference is generally a high concentration of content, economy of scale kicks in and the effort is well worth it.

Pre Conference

Weeks or months in advance you should do the following:


There are legal and politeness issues concerning pointing a camera at someone. You also may want to make use of the venue's equipment, like sound system, VGA projector, lights and network. Where “make use of” is as simple as “touch.” Use your good judgment.

Here are what some events have done:

Sponsors, Advertisers

There is marketing value in the videos. Letting it go to waste is a shame.

Event Schedule

To title the videos, it is best to have the same titles as published in the event materials (website, printed.) For one or 2 talks, this can be done by hand, but much more and it makes sense to have a formal database.



If you are desperate, you can setup the equipment and let it run all day, but there is a high probability that the results will be worthless, so get a team of people to help out. Ideally you want the same people for the whole event, and ideally people only somewhat interested in attending the event. Some interest results in a good attitude, but if they are too interested they are more likely to ignore the video process. You want to fill the following positions:

There can be some overlap, but if you have one person dedicated to each of these tasks, the results will probably be better. There is benefit to the same person doing what they are best at, but it is good if everyone has a little cross training too. This helps when someone can't make it and people need to be redeployed, and it also gives people an idea of what helps the other people. A CamOp probably won't realize how annoying it is to be zooming and panning all the time as they tweak things to make it “just right” but if they get a turn trying to work with that feed, they will appreciate calmness.


For each Event room:

Camcorder needs to be comparable with dvswitch.
Not using a tripod will result in terrible video. Even the cheapest static tripod will make a huge difference. Adding tilt and pan makes another huge difference. After that, better tripods (like fluid head) will result in better video. How much better is a matter of opinion.

TwinPact100 – so far the only device I would consider using for a conference. It is transparent to the presenter, and it works 100%.

Sound should be more than just a feed from the main PA. You want to be able to capture noises that are not fead though the house sound system, like laughter and applause. Ideally audience questions get asked into a mic, but there are times when someone will shout something out, and often it is something worth hearing. The levels coming from the main may not be desirable, so being able to adjust them on the fly can make a big difference. Too high a level will cause clipping, and that's very bad.

Production Room

Backup – If the value of the video is worth all this trouble, then it is worth having a backup. There is a lot of data to back up, and not a lot of time for it to happen, so make sure you have sufficient bandwith. Currently esata drives are a good choice, or a 2nd file server.

File Server – Central place for the files. It should have enough bandwidth to handle the demands of the nodes. It can ealily be the bottle neck if a few rooms of files start getting moved to it at the same time. 1 room will produce abut 100gig for 8 hours of recording (note that it is likely that breaks and such get recorded too) 1 gigabit eathernet connection will be saturated for hours.

Transcoding nodes – trancoding will take a while, the more CPUs that can work on it, the sooner it will be done. Events generally do not run 24 hours a day, so when the dvswich computers are not running dvswitch, they can be used for transcoding.

System Config

You may not have access to the computers unill eveyone avies at the event, hopefully one or 2 days before the event starts. It is good to automate much of the setup. Once they are in use, you want things to be easy and fault tollerent. If things go bad, you want to be able to recover quickly.

For configing the PyCon 09 recording machines:


The last 2 steps are slated to be rolled into a new and improved app. Some of the scripts have hard coded login credentials, so they need to be at least sterilized before they can be made public. Hopefully the new app will just take their place.

Recording Sheets

As recording is taking place, it is wise to have note paper handy that is pre-printed with Date, Room, Talk Names and times. Things will happen like “AC came on next to mic” or “presenter was 10 min late” This helps answer questions later like “why does this sould like a wind tunnle?” or “why is this 30 min talk only 20 min long?”


It really helps for the crew to be very noticeable. It helps the project manager quickly find them which helps things like "is everything ok?" It also is a back stage pass and a "If I say I can here an odd noise, it needs to be fixed."

Conference Setup

Equipment Setup

Ideally the mic stands, cables, tables, chairs, tripods, etc will be setup the day before the event starts. Sometimes this is not possible, like there is some other event taking place in that venue. At a minimum, you should plan to spend an hour setting up a room, and you should be done setting up before the first attendee comes into the room. During the setup will be safety hazards (un secured wires) and you can work much faster when no one is in the way.

Also ideal is if the people running the equipment do the setup. This helps them be familiar with exactly how things are setup, and will be able to react to problems much quicker. It also helps paralize the setup process. 8 rooms at 1 hour each = not enough time it the morning for one person to do it.

Tear down is much less critical, but if the crew can take care of it, the Production Manager will be very appreciative.



About an hour before the first talk starts, the team should gather and figure out who didn't show up and adjust assignments accordingly.


Data Processing

At least once a day:

Post Conference


Once you are done uploading and confident no more work will be done, create a high bitrate version of the files and save to an external HD. Currently that is 'better' than blue-ray disk, but as prices fall and more people have them, that could change.


It is a lot of work, but hopefully you see it isn't rocket science. If you are familiar with DVSwitch and understand this document, you are well on your way. If you can then recruit a good crew and take possession of the equipment well in advance, you are over the hump and the rest is down hill.