(Web) LectureScribe
LectureScribe is a simple web-based application
(available here)
that allows you to record handwritten "whiteboard lectures" along with
audio to produce light-weight instructional videos that can be easily
viewed on any web or mobile platform. Here is a
short example
video explaining some of its features.
The program was written
by Brian C. Dean, an
associate professor of computer science at Clemson Univeristy, to
develop supplemental instructional content for his courses and for an
upcoming algorithms book.
Please feel welcome to make use of the program for your own
instructional needs. The web version of the program is fairly new
so please let me know if you encounter any issues with it. I'm
always interested in hearing about use of the program by others,
so if you use LectureScribe in your own classes, please feel
welcome to let me know or to send me an example video!
Some quick notes:
- The application should be easy to figure out -- mostly just click
record and start writing and speaking, clicking stop when done.
Clicking ? or pressing ? will give you a list of keystrokes; the
program is most efficiently used if you know these keystroke
shortcuts. For example, if you mis-speak, then press B to back up 3
seconds, P to play up to the point of the error, S to stop, K to kill
from that point on, and R to start recording again. You can also
switch between pen and pointer modes and change colors using
convenient keyboard shortcuts.
- Lectures are stored as a pair of files: a .wav file for audio
and a .lsv file for video. When you save, you will be prompted
to save both these files. When you load, you will need to select
both of these files (hold down CTRL while clicking on them in the
file open dialog box). Please feel welcome to transcode your
audio into a more efficient format (e.g., .mp3) to supply to
the viewer, although you still need the original .wav file
for editing.
- The authoring tool seems to run properly in Firefox and
Chrome. It doesn't work in Internet Explorer (although videos
produced by the platform are viewable in Internet Explorer).
- The lecture canvas keeps expanding vertically as needed.
Expansion only happens while stopped though, so if you are recording
and run out of room, just stop temporarily to allow the document to
expand and resume recording. Many editing features (e.g., select and
delete/move, import image, add eyeball or reference) only work while
stopped (by design).
- I'd recommend recording short "mini-lectures", not super-long
lectures, as these may stress your browser / system (if the browser
runs out of memory, it can crash and you can lose your work!).
Anything up to an hour or so is _probably_ fine; please let me know if
you have issues recording longer lectures. There is a "reference"
facility for creating multi-part hierarchical lectures.
- When importing images, please only import relatively small image
files, since these get bundled up with your video and can cause
very slow downloads during viewing otherwise.
- Due to the "same origin" policy in JavaScript, you need to host
your files on the same website that hosts the viewer program
wlsviewer.html (otherwise, the viewer will be prohibited by the
browser from downloading your lecture from a different website). For
example, to host a video named V.lsv with accompanying audio file
A.wav, simply put these two files and the wlsviewer.html web page
(which you can download in zipped form
here)
in the same web directory and use the URL wlsviewer.html?video=V.lsv&audio=A.wav
- I've tested viewing on a few mobile platforms and it seems to
work ok; mobile devices tend not to "auto-play" audio content though,
so the user usually needs to click "play" to start the video. Any
mobile issues: please let me know, although bear in mind that getting
perfectly consistent playback across every known device can be quite a
challenge!
- Closed captioning is available by loading a transcipt in
SubViewer format, much like with YouTube (see the YouTube instructions
here
for an example. You can also export the caption data from a lecture
if needed (e.g., if you want to pipe it through a translator to
make subtitles in other languages).
- I'd recommend saving fairly often, as any glitch that causes
your web browser to crash or re-load the page will lose un-saved work.
- The original version of Lecturescribe, written nearly 15 years
ago, was a Windows app that exported videos in Adobe Flash (.swf)
format, which becoming less-widely supported. I've kept the old
version available here for those who
need it, although I encourage you to move to the new version instead
(n.b., files from the old version are not compatible with the new
version).
Current issues / bugs:
- Currently the hierarchical playback is broken -- specifically the
functionality that goes back to the parent video. I'm working on fixing
this soon...