One of the things that sets Breeze apart from other presentation platforms is it's audio management. And in terms of the "experience", the audio really makes or breaks a presentation. What follows is an "unofficial" FAQ on common Breeze audio misconceptions and wonderments, originally compiled by members of the Breeze team and annotated by yours truly.
Q: Where does the audio get stored when I record? In the PowerPoint file?
A: No, the audio is stored in a separate PPC file that is automatically created in the same directory as the PowerPoint file that you are using. The PPC “shadows” the PowerPoint file, using the same name and directory. The PPC file contains the audio and other related Breeze information such as slide timing.
[GB] It's worth pointing out that the Breeze plugin does a much better job of handling the audio recording altogether. Microsoft's built-in audio for PowerPoint is flaky at best.
Q: What happens to the audio when I publish my presentation?
A: When you publish the audio is converted to MP3 by the Breeze server. By default audio is conveted at 24kpbs.
Q: What audio rate does Breeze use for encoding? Where is this set, and can it be changed for each presentation?
A: By default, every Breeze account is set to 24kbs audio encoding. However accounts can be configured to use one of three preset audio encoding rates – 16kbs, 24kbs (standard), and 64kbs. In addition, we can enable selectable audio for your account – this will allow authors to choose from the three encoding rates for each presentation published.
Q: How big is the audio file for a 15-minute presentation?
A: You can calculate your audio file size based on 24kbs. For every minute of audio, you add approx 180k. Therefore a 15-minute presentation will be 2,700k, or approx 2.6 MB.
Q: Can you import more than one audio file to a slide?
A: Though you select multiple audio files to import, only one file can be associated per slide. If you need to combine imported audio files on one slide, you could create blank placeholder slides and import one WAV per slide. Once the audio has been imported you can open the Breeze ”Edit Audio” dialog and use standard cut and paste to move any part of the imported waveform to any slide.
Q: Can breeze import audio that has been encoded using other encoders, such as MP3, Ogg Vorbis, Real, Window Media, etc.
A: At this time, Breeze can only work with audio that has been either recorded directly by Breeze or with PCM encoded WAV files that have been imported using the Breeze “Import Audio” menu. Once audio is imported it is converted to the Breeze compressed format - this is much more efficient than the WAV format.
Q: How can I use audio that is already in my PowerPoint file?
A: The ”Import Audio” menu can import some types of audio files that have already been placed in the PowerPoint file using PowerPoints’ ”Insert>Movies and Sounds>Sound from File. If you have inserted audio using PowerPoint then the following two things must be true for Breeze to import it –
- The file you imported must have been a WAV file. Even though PowerPoint will let you insert other audio formats such as MP3, Breeze will only recognize PCM encoded WAV files.
- When inserted the audio you must have set the audio to ”play automatically” - ”clickable” audio will not import.
To convert PowerPoint inserted audio to Breeze format, just open the ”Import Audio” dialog in Breeze and click on the ”Import from Presentation” button that will be there. Once you have imported the audio, Breeze will ask you if you would like to throw away the original audio, as it is no longer needed.
[GB] If you're having trouble importing audio, here is a quick Breeze presentation from Kim Roelands that goes through the basics:
Importing Audio: A Short Review
Add existing audio to your PowerPoint presentations.
Q: Will Breeze add imported audio to the audio already on the slide?
A: No, the Import Audio menu does not keep a reference to the original audio file, and will replace any audio that may already exists for a slide.
Q: Does the Breeze player download all of my audio at once?
A: No the audio is converted to a series of smaller audio files – one per slide, and played along with the contents of the slide.
[GB] The fact that everything, the controls, slide, audio and other assets are all separate SWFs gives the presentation a very responsive feel -- even if it's not all appearing at once you get the sense that something is happening.
Q: Is the audio “streamed” to the Breeze player from a streaming server?
A: No, the audio is sent to the Breeze player as an HTTP “progressive download”, just like any other Flash content. This eliminates many of the firewall issues associated with many streaming formats.
[GB] This has the added benefit of letting you deliver Breeze presentations from other mediums like CDROM, or completely separate servers -- handy if you're integrating your presentation as courseware into another learning management system.
Q: How much audio is buffered before playback starts on any slide?
A: 2 seconds
Macromedia Breeze Audio Technotes (as at 17-June-2003)
| 16806 | Microphone recording level cannot be set when recording audio | |
| 16808 | Audio not playing back after recording | |
| 16809 | Audio recorded in Breeze presentation is poor quality | |
| 16810 | Breeze presentation is not able to load recordings for all slides | |
| 16812 | Audio inserted using PowerPoint is missing in published presentation | |
| 16811 | Using inserted audio in a presentation | |
| 16815 | Breeze encounters error while recoding audio | |
| 16814 | Audio is cut off at the beginning or end of a slide |
Posted by modius at 11:21 AM | Permalink
Trackback: http://blog.daemon.com.au/cgi-bin/dmblog/mt-tb.cgi/130
Excellent info! Can you provide some more details about changing the audio rate, and enabling selectable audio?
Posted by: Andrew on February 14, 2004 12:20 AM