[Haskell-cafe] Making videos of your project

Claus Reinke claus.reinke at talk21.com
Mon Apr 6 13:37:37 EDT 2009

Btw, there seem to be many Haskells on YouTube - should we have
some way of marking clips related to our Haskell? I've used haskell.org
as a tag, but noone else has, yet - also, perhaps there should be a Haskell 
channel or something?

And just in case there are others on the same Windows adventure:-)

>> Is there anyone here with experience in screencasting of text-based
>> applications, who could offer advice on how to produce screencasts
>> on windows/xp? The basic screencasting (capture+annotation/editing)
>> is not the problem, eg, CamStudio seems ok, and Wink gives me
>> more control for mostly input-driven sessions (where I want
>> screenshots whenever something useful happens, not long videos of
>> my mousepointer wavering about the screen;-). Both can generate .swf.
> I think making .swf is a mistake, but I'm not sure.

I should have believed you there!-) I did actually check that Youtube
listed .swf among its supported file types before making my screencast,
but when I had actually joined and uploaded, I discovered that it would
fail on conversion.. More detailed search in the user forums indicated
that this is a common problem, with no solution other than to convert
to another, video- rather than animation-based, format.

Problem is, .swf is very suited to this particular input-driven kind of
screencast (and renders just fine in my browser), eg, Wink has a 
non-video capture mode that only adds frames when something happens
(the only negative: while one can extend the time frames are shown, I've
not yet found a way to reduce the minimum time, so typing looks rather
unnaturally ssllooww). 

Any attempt to convert my just over 1Mb .swf files (one screencast, 
split and edited into 3 sections of 4 minutes or less) to something 
listed as supported (such as .avi, .mpeg2) resulted in huge files sizes 
(60Mb and upwards) that would be impractical to upload with my 
old narrowband connection (might just be that I don't have the right
compressing codecs for these formats?).

Fortunately, while trying to find some way of contacting YT staff, I
stumbled on other help pages that mentioned .wmv in their version
of supported file types. For that, one of the codecs on my machine
produces files that are only 10x the size of the original .swf, so I'm
slowly uploading them to YT, and the first two parts have now been
published without conversion failure.

I was sorely tempted just to upload the small .swfs to haskell.org, 
instead of the .wnk->.swf(1Mb)->.avi(60Mb)->.wmf(10Mb) plus
tedious upload route I had to follow with the free or preinstalled tools 
available to me. But community.haskell.org seems to be having
enough trouble right now, without hosting clips there..

> I rendered it in 2 or 3 formats (at 640x480 etc, following the you tube
> / google video recommendations), and uploaded the one that looked best.
> You-tube immediately(ish) makes a low quality version available
> (320x240?), and a high quality version(480x360?), with more readable
> text etc, is available a little later.

Testing with multiple formats/codecs/uploads is recommended,
though the conversion can be somewhat nightmarish (too many options
and tools, many of which look less than trustworthy, too complex, too
expensive, or all of the above; and too few roads to something that 
works). For 640x400 uploads, the near immediately available version 
seems readable enough (search for tag haskell.org or wait for the 

> I would recommend working in a 640x480 screen area. If you can't show
> anything in that area, then people won't be able to see anything in your
> video (at the size/quality youtube shows it, at least).

Sound advice, which I followed in the end. Just took some more
preparation to find a setup that would fit the screencast, rather than
my usual working habits. I also noticed that I had somehow managed 
to switch off my ClearType support, which explained the initially low
quality font rendering.


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