Engagement/Gnome3In30Seconds/HOWTO

Things you need

HD camera (many "consumer" SLR's and point-and-shoot cameras record in 720P video which is more than sufficient); I used a mid-range Sony a55 SLT
tripod (rent $25 per day)
green (or blue) screen big enough (~ 2 meters x 2 meters?)
correct lighting to film with a green screen or just buy some high-wattage work lights from a hardware store (point them at white ceiling or use a reflector so the light is not directly on the speaker).
- Some basic references
  - http://www.youtube.com/watch?v=AcMX1RcNRYA (maybe too commercial)
  - http://www.youtube.com/watch?v=f7uWuLntyo8
  - Google: green screen chromakey lighting
a professional mic; I used a Sony PCM-D50 and recorded the audio separately from the video and merged the files during post-production
very calm, quiet place to film (something similar to a closed room or studio). You can muffle room noise by bringing in pillows, towels, and mattresses.
laptop or desktop with wide-screen display with relatively recent graphics card; if using Intel, nothing older than GM45/G45 (due to bus bandwidth issues with glReadPixels() the frame rate may be too low)

We were able to find many items from local people, so ask around before renting.

Do not record the default, customized desktop of a particular distribution. For example, Ubuntu and OpenSUSE use custom look and feels in their default installs. In each case, you must use a jhbuild of the next GNOME release (highly visible features like symbolic icons will appear there, for example). You may need to use the following directions to make your distro. close to upstream. On OpenSUSE, you can just install the gconf2-config-upstream package to get the upstream themeing (log out afterword). Fedora and Debian are close to upstream already. On Debian, you only need to do "sudo update-alternatives --config start-here.svg" and choose the gnome-foot.svg option. On all distributions you should make sure that you use Adwaita theme, the Adwaita cursors, and set the background to the Blue Stripes.
GNOME Shell built from jhbuild (DO NOT USE A PPA OR BUILD CREATED BY THE DISTRIBUTION OR A COMMUNITY MEMBER.)
recent, full-featured ffmpeg with libx264 from the distribution's multimedia repositories (ie. RPMFusion, PacMan, Debian Multimedia).
video editor (Kdenlive or Cinelerra, for example)
- Chromakey effect support is required for the green screen background replacement
- Pan & zoom effect support is required to zoom in and show the mouse cursor interacting with some UI elements
- Video settings:
  - Aspect ratio 16:9
  - Resolution 720p
  - Framerate 29.97 fps

3 people: videographer, boom operator, and speaker
GNOME 3 in 30 seconds scripts
- Memorize them in chunks...
You NEED stage make-up or a LOT of powder for the face of the person on-camera. Apply evenly all over face. It must be caked on to the point that no blemishes or redness shows through to the camera. Remember, it's even harder to do this in HD because the camera "sees" so much more than SD cameras saw. (THIS IS NOT OPTIONAL! If you don't do this, the final recorded person will look "sickly" to the casual viewer.)
- Different ethnicities and skin colors need different stage make-up and haircare. Look at guides online...

Prepare the stage with enough time. Hurrying just brings problems. Prepare all the equipment and repeat as many takes as you need. It might take half an hour to record a one-minute speech. That's okay.
Sentences have been written as short and direct as possible. Memorize them, reading them from cue cards at a "reading cadence" doesn't sound good. You need to sound like you are having a conversation with the viewer and don't talk too fast. Use the Google Navigation videos as an example to emulate.
Remember to smile when you speak at appropriate points. This invites the viewer to appreciate your excitement for the topic. You do not have to be enthusiastic in your voice; a smile is enough.
Record small segments at a time but don't take too long of a break between takes so that tone and pitch are the same between segments.

Do not wear any cloth with a color similar to the screen (no blue jeans with a blue screen, no green t-shirt with a green screen); feel free to represent your own personal dress and style, but don't go barechested. A GNOME shirt is not required but would be nice.
The person should be centered in the frame with the "lower clip" at the waist and the center of the neck in the direct XY center of the frame. That is, the head is above center.
Avoid creases on the green screen. If the screen has creases, the chromakey will not work and you will have to do the recording all over again.
Do not cast shadows on the green screen (check how to set-up the lights correctly above).
Clap in front of the camera at the beginning of the recording so that you can make it easy to synchronize audio and video later.

Use a 16:9 aspect ratio resolution even if it is not the resolution of your personal monitor. 1280x720 would be ideal but not all cards (including mine) offer that resolution. In order to force your desktop to this size, regardless of your hardware, use the xrandr "scale" option. Take your native panel resolution and divide by 1280x720. For example, my native panel resolution is 1440x900. The scale factor is 1280 / 1440 = 0.888889 horizontally and 720 / 900 = 0.8 vertically. So, to set my laptop display to the right size I issue this command: "xrandr --output LVDS1 --scale 0.888889x0.8"
Please don't record at a higher resolution. You won't be able to make out the UI elements anyway, and recording at this lower resolution guarantees a higher recording frame rate.
Optional: set the PulseAudio source to the audio coming from the Pulse "monitor" source so that you may record the alert sounds made by the GNOME applications you are showing (ie. IM). Open pavucontrol, go to Input Devices -> Show: All Input Devices -> Monitor of Foo Bar Stereo -> Click the green Green "Set as fallback" and unset all the rest of the input devices
Use the following command to record the screen cast, modifying appropriately for your resolution: "ffmpeg -f alsa -i pulse -f x11grab -r 30 -s 1280x720 -i :0.0 -acodec pcm_s16le -vcodec libx264 -vpre lossless_ultrafast -threads 0 output.mkv". You can remove the audio capture if you don't want to record desktop sounds.