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Here's some tips on creating videos to demonstrate J, and some thoughts on the usefulness of using this medium to promote the language.

Some Basic Technical Considerations

Brian's efforts on the video medium over the web gave him some insights on tips for other people who would like to do something similar. Also, other people contributed there ideas and experiences with tools and settings for web video.

Tips on Creating Videos for YouTube

from	Brian Schott
to	General forum <>
date	Fri Mar 20 01:46:50 HKT 2009	
Re: [[Jgeneral] screen cast of downloading J

There were several small issues that I needed to adjust before I could achieve technically good video and audio quality. For me the most annoying problem was the lack of synchronization between video and audio and I am still a little disappointed with the video quality. But the support person told me to export the recorded videos in formats that are not standard because he has found that the nonstandard settings better match YouTube's software.

So, I exported the newer video with jpeg compression and 425x318 size, not the default H.264 compression or 1024x768 "current" size, and for the audio to use mpeg4 at 30fps. I am not quite sure I am using the 30fps because a couple of times when I forced 30fps the upload file ballooned to 150+ mb and it looked liked the upload stalled. So I let the software determine the fps.

I also increased the font size of J to 18 from 12 which I myself use and I think the text in the ijx and ijs windows are more readable. I don't know how to change the font size of native J menus, for example, but that would be an improvement, I think.

As to my low voice, I am not sure I can change that without a lot of practice because a louder voice tends to make me more anxious. But I will try to speak louder. Speaking is very guarded for me, because I often block on words, and my speech is not that clear.

The robot is very minimal, as Devon observed. But the robot matches my implicit philosophy for this demo, and maybe for many J demo's, that they should be teasers and simple to attract new users, because for me the joy of J has been puzzling through the programming and searching for programming solutions, with the help of the forum and the great resources. So for me the screencast demo's would mostly be targeted to showing ways to make the work flow easier and more effective to people new to the J environment.

I am assuming that lots of short screencasts are superior to fewer long ones, especially because YouTube states their preference for limiting videos to 10 minutes. But also, because I think it may be difficult for a viewer to maintain attention for longer times.

Further Thoughts on Screen Resolution and Sound Quality

Oleg had these comments:

from	Oleg Kobchenko <>
date	Mon, Mar 23, 2009 at 4:39 AM
subject	Re: [Jgeneral] screen cast of downloading J

The flicks are really cool.

It is really hard but necessary to choose the correct video resolution for best trade-off between quality and file size. Also iPhone support is nice to have, which probably means not more than 640x480. (YouTube recently offers HD support--such as your 1024-- which cool, but nice to find an HD format compatible with iPhone.)

One possibility is to record at 1/75% the target and then reduce to 75%, which is typically very readable. Would be good to make it wide-screen ratio with intent for slightly narrower viewable area.

Regarding "voice" is really volume of the sound, which should be controlled not by loudness or pitch, but only by recording or audio-editing controls. You should speak in your natural comfortable voice level.

Bill Lam had this suggestion:

YouTube allows different picture quality by appending an "&fmt=xx" to the URL, where the number xx is 18 or 22.

This discussion about video resolution proceeds at some length here.

Suggestions on Media Tools

This is taken from a note from Jeff Heon

There is, of course, a wealth of information about J through the labs, papers, books.

Most of it is available through PDFs, which are perfect to view on a computer or to print.

All these are great of course, but I think the availability of new mediums could be exploited to boost J understanding.

To make a parallel, I've been following Clojure, a recent Lisp dialog, for the last year. Its popularity is growing and I think one of the reasons is the availability of presentation recording, like the 2007 LispNYC presentation here ( ), and screencasts like here ( ) and there ( )

All this to say, If you're already making a tele-conference, you might consider making a recording of it.

Services like vimeo ( ) and BlipTv ( ) let you upload a certain amount of video for free so you can get exposure for J without added cost. Of course, there is still the hassle of making and editing the videos ;)

I would also add epub as an interesting media with the popularity of mobile devices. A lot of developer, myself included, commute to work everyday by bus or train and it's great to use that time to read up on interesting technologies. Unfortunately for that, PDF aren't practical, but epubs are. The availability of the first Clojure book in epub ( ) was really practical for me.

Mac Tools for Video Creation

Rob had this suggestion

from	Rob Hodgkinson <>
date	Sun, Mar 15, 2009 at 9:56 PM
subject	Re: [Jgeneral] screen cast of downloading J

... there is a really nice tool on Mac OSX 10.5 you can use called Screenflow. I have used this to create similar videos (incredibly easy to use/mix) and you can export using other tools (eg Quicktime Pro) to create Windows or other standard formats for replay.

Other Video Tools

David Mitchell recommends CamStudio on Windows XP. It seems to work fine. I used it to record a product demo with voice annotation for work. See .