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Conference preservation howto

As I made I took notes of what I've done, so I can make a nice conference preservation howto out of them. This is the first part, a second one, which will show how to use the software, will follow soon.

Basically you'll need a digital camera (mini-dv with firewire output (this is the most important part)) with a reasonable good microphone (external microphones might produce better sounds, but are more difficult to handle - in Darmstadt we used a camera with an internal microphone with good results.

Don't forget a firewire cable :) There are two kinds of plugs: small ones with 4pins and bigger ones with 6 pins. Cameras usually have the ones with 4 pins, thinkpads have the small ones as well, whileibooks and powerbooks have a big, 6pin connector.

Then you'll need a big, stable tripod for the camera. Having a good, heavy tripod is essential!

Plus enough mini-dv tapes - I would recommend as many tapes as there are talks planned. Normal tapes have 60min. capacity and mostly 90min. long playing capacity (SP=short playing and LP=long playing), forget about LP. (So if a talk is planned for 90min. get two tapes for that talk.) Get two more tapes than you'll need so you have two extra for testing + backup.

The software side is more easy to get: dvgrab to grab the raw dv-files from the camera (dvgrab is in sarge), cinelerra-cvs to edit the movies (avoid editing at all cost!!!! the darmstadt videos are unedited except for one: this is unedited and unreleased still. cinelerra-cvs is not in debian,

but .debs are available), and (more recent than the sarge version) ffmpeg and ffmpeg2theora.

Finally, dvgrab and ffmpeg(2theora) need some options to be called with. More on this soon.

So much for the technical side. Other important stuff:

  • the speakers shall talk loud and slowly
  • there needs to be proper light in the room (esp. in the front where the speaker is)
  • the camera person should be responsible only for the camera and do this job for a complete talk. Basically it's start and stop the recording at the right times (again: avoid editing) and point the camera to the right spot while avoiding to many (and to fast) movements and zoomings.
  • there should be someone else taking care of the video projector and time limits for a talk. It's handy to have clearly visible signs for the speaker to announce 15, 10 and 5 minutes left til the end. (even 30 might be a good idea.)
  • have a schedule ready. Adjust it if needed :)
  • place the camera and the tripod with care and in a good relation to the speaker and the slides/projector - test this setup before the first talk
  • buy more tapes then you'll need
  • avoid editing. Have I mentioned that ? Really, avoid editing. For example, if something is to be said, which should not become public, stop the recording for this moment. Tell this to the speaker and the audience in advance!

After all the talks are done, the tapes can be grabbed. (Unless you can manage to get two cameras, one for recording, and the other for grabbing. Then the grabbing can be done in parallel.)

One hour of raw dv video takes one hour and needs about 10 gigabyte of harddrive storage. Compressed (in real good quality and in lesser good quality, in mpeg and in ogg theora) it will still take 2gb, maybe a bit more. Multiple this by the number of talks :)

The only tool to create ogg theora files I found is

Also compressing takes time, therefore I doubt this will be done during the conference, unless you'll have heavy number crunchers available at your hands. So someone will need to take the tapes or the raw files home. So for taking those files home you'll need a big harddisc as well.

Once the compressed files are made, I can upload them to$your_debian_conference/ :-)

If something in this "instructions" is unclear, don't hesitate to ask.

Last, but definitly not least: these are my personal experiences based largely on two events, though I watched video efforts at other occasions. I'm prepared & happy to learn more and new things and to give different advice next time :)