ICTP Workshop 2007/Content Sessions

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{{#titlehere:}} Please note that the present pages on the ICTP workshop were obtained from a mediawiki used during the workshop. There may be a number of links that go to missing pages, and other inconsistencies. Much of it is also very informal, and should be seen as workshop notes!

These sessions, conducted by Björn Hassler, stretched across 8 hours or so.

1 Creating Audio and Podcasts[edit]

1.1 The mechanics: Audio and Audacity[edit]

Introduction to Audacity - cross platforms, open source, free audio editing. (ICTP recordings: EyA)

People were working in pairs (two headsets plugged into one computer, with headphone splitters, as well as microphone stereo to two mono converter). (Note: Stereo recording from the microphone only worked on some computers, as it depends on whether the sound card has got a stereo microphone input.)

Download the 'Audacity Pack' from a local directory. The pack contained the

  • Audacity Application (1.3.4, with local settings file)
  • Documentation (a pdf file, explaining basics of audacity)
  • Example project

Your task:

  • Learn audacity.
  • Record audio from your headset into the sample project.
  • Edit it all together.

Additional documentation: http://www.audacityteam.org/manual/index.php?title=Main_Page

Tips for recording audio:

  • Use the best equipment you have available.
  • Record in a quiet environment, that only has appropriate sounds in it.

Get some Creative Commons Music: http://creativecommons.org/audio

Overall, the following problems were encountered:

  • Instability of the application
  • Performance issues for longer recordings
  • Insufficient monitoring of distortion in the audio mix
  • Lack of adequate audio range compressor

Topics that were covered in a later session:

1.2 The gear: More about kit[edit]

  • Audio equipment available

1.3 What you can and what you can't use[edit]

Copyright, licensing, creative commons, ...

1.4 The creativity: The shapes and forms of media ('literary forms')[edit]

  • online lecture
  • educational CD
  • (non-public) interview
  • drama

2 Sharing your podcast with the world[edit]

2.1 Encoding[edit]

2.2 Licensing[edit]

2.3 Hosting[edit]

Bandwidth requirements

2.4 Bandwidth requirements[edit]

Bandwidth requirements for multimedia

You need to be able to explain bandwidth requirements for multimedia.

How do you compute the total bandwidth of a 'multimedia object', e.g. an audio file, and some slides.

2.5 Audio encoding[edit]

How do you use lame? What are the correct settings?

2.6 Video encoding[edit]

For reference, http://www.sciencemedianetwork.org/Encoding_Timebased_Media

What formats should encode to? For online streaming, Flash 7 or 8, and in the future Flash 9. For downloading, use mp4, ideally with H.264/AAC codec. In the future, you will be able to use mp4 for streaming in Flash 9, but the file needs be encoded with H.264/AAC and to have fast start.

What tools are available for video encoding?


Flash: flv/mp4

Flowplayer vs. swf

  • Find a H.264 open source implementation or free encoder. Compare with H.263 and mpeg4-p2 and flv.
  • Find a H.264 free encoder. Can it do fast start?
  • What flv encoders? (Riva flash in On2VP6?)
  • Batch image conversion for linux.

2.7 Media hosting for low bandwidth[edit]


Recommendations are to use podcast feeds. What software exists to make podcast feeds?

2.8 Putting Flash video online[edit]

FlowPlayer - http://flowplayer.org/. How do you configure flowplayer to play video or audio within websites?

  • How do you play a piece of video?
  • How do you stop the media loading automatically?
  • How do you play a single audio file (with an image)?
  • How do you play a slideshow in flowplayer? (Many separate audio files, with one image each, held together by a playlist)

The following needs checking, but it should be roughly correct:

<object type="application/x-shockwave-flash" data="flowplayer.swf" width="320" height="240" id="FlowPlayer">
  <param name="allowScriptAccess" value="sameDomain" />
  <param name="movie" value="flowplayer.swf" />
  <param name="quality" value="high" />
  <param name="scale" value="noScale" />
  <param name="wmode" value="transparent" />
  <param name="flashvars" value="config={ 
    showPlayListButtons: true, 
    playList:[ { url: 'http://.../A.mp3', overlay: 'http://.../A.jpg' }, 
               { url: 'http://.../B.mp3', overlay: 'http://.../B.jpg' }],
    autoPlay: false, 
    autoBuffering: false,
    splashImageFile: 'http://.../splash.jpg',
    showMenu: false, 
    loop: false,  
    showLoopButton: false,  
    showFullScreenButton: false}"

Working example: http://users.ictp.it/~bhassler/repository/ (Full screen doesn't seem to work for slide shows...)

3 How to get a podcast[edit]

3.1 How to open a podcast in iTunes[edit]


3.2 Now open this podcast[edit]