Video lectures from the iCS group @ IIT Madras

Recording the lectures on a tablet PC

These lectures are recorded on a tablet PC using Camtasia Studio. Some tips about using the tablet PC and recording:

Lectures and recording

  • Binding the tablet key to F9 makes it very convenient to pause/resume recording on Camtasia.
  • I find medium chisel tip pens to be best for visibility on the projected screen.
  • For web distribution, the best format(with Camtasia 5 or earlier) is flash .swf. Without automatic zoom, a 50 min. lecture at 5 frames/sec. occupies 12MB or so. My production preset is here. .swf is limited to 16000 frames which limits the duration to 53.3 minutes. .flv file at the same resolution settings is 5-6 times larger.
  • Watermarking: If you are using windows journal as a whiteboard, using a background image on journal produces cleaner visibility in the recorded file rather than adding it in as a watermark later during production.
  • I disable automatic zoom in produced videos. This feature seems not all that useful, and sometimes even irritating when viewing produced videos. (This is for technical lectures. It may be useful for something else).
  • With Camtasia 6, .mp4 is very good and is not limited in duration.
  • When Camtasia studio 5 is installed, the default audio recording format seems to be some PCM … This results in very large .camrec files(~180MB/hr). Change the recording format to Techsmith LAME MP3 with resolution that results in about 10kb/sec. This results .camrec files with about 60MB/hr. In the default format, what is even more annoying than the file size is the skew between audio that you hear and audio waveform that is displayed in Camtasia while editing. This makes it very hard to edit. If you end up with such a case, extract the contents into an folder file from Camtasia Studio, reimport the .avi stream into a new .camproj file and edit it. Techsmith website has detailed information on fixing the skew.

Tablet PC care

  • While opening or closing the tablet, hold the screen directly above the hinge in the middle. Laptops are hinged at two places, but tablets have a swivel hinge only in the middle. Lateral forces will likely damage this. (I haven't yet broken a tablet like this, but the possibility looks likely). For the same reason, never lift up the tablet holding the screen-this is a bad idea with any laptop, but particularly so with a swivel hinge.
  • To save on battery life, remove the battery while plugged in. Battery life is shortest when it is fully charged, and at a high temperature, both of which happen if you have the battery in the laptop when plugged in. Keep the battery at about 60% charge.