Rework Podcast on a Flight scenario.
authorJoe Berkovitz <joe@noteflight.com>
Fri, 10 Aug 2012 13:29:01 -0400
changeset 110 b445251bf142
parent 109 1e84896a21ef
child 111 b5e6a31b0b75
Rework Podcast on a Flight scenario.
reqs/Overview.html
--- a/reqs/Overview.html	Fri Aug 10 13:05:12 2012 -0400
+++ b/reqs/Overview.html	Fri Aug 10 13:29:01 2012 -0400
@@ -301,36 +301,31 @@
     </section>
     
     <section>
-
-
       <h3>Podcast on a flight</h3>
-      <p>A user is  subscribed to a podcast, and has downloaded an audio book on 
-      his device.
-      The audio files are stored locally on the user's computer or other 
-      device ready for off line use, giving simple and convenient access to 
-      episodic content, through a web browser.
-      </p><p>The user is sitting in an airplane, for a 2 hours flight. The user opens 
-      his audio book in his HTML browser a sees that the episode he has 
-      selected lasts 3 hours.
-      The user would like to be able to accelerate the speed of the audio 
-      book, without pitch distortion (i.e., voices not sounding like 
-      “chipmunks” when accelerated). He would like to set the audition time to 
-      2 hours in order to finish the audio book before landing.
-      </p><p>The web-page presents a graphic visualization of the speed, the total 
-      duration of the audio on a time line at the corresponding speed.
-      The web-page also associates an audio speed changer interface provided 
-      by the web-page developer allowing the user  to change the tempo of the 
-      speech and speed up audio files without changing the pitch. This lets 
-      the user drastically speed up speech speed without a "chipmunk" effect.
-      </p><p>Another interface allows the user to set the duration of the audio, 
-      regarding its initial duration at normal speed, therefore changing its 
-      speed with pitch lock.
-      The user may also tweak other settings like the tone and timbre to his 
-      taste.
-      </p><p>This would be valuable features for book listeners who want to save time 
-      by accelerating audio books as well as podcasts.
-      </p>
 
+      <p>A user is subscribed to a podcast, and has previously
+      downloaded an audio book on his device using the podcast's
+      web-based application.  The audio files are stored locally on
+      the device, giving simple and convenient access to episodic
+      content whenever the user wishes to listen.</p>
+
+      <p>The user is sitting in an airplane for a 2-hour flight. The user opens 
+      the podcast application in his HTML browser and sees that the episode he has 
+      selected lasts 3 hours. The application offers a speed-up feature that allows
+      the speech to be delivered at a faster than normal speed without pitch distortion
+      ("chipmunk voices"). He sets the audition time to 
+      2 hours in order to finish the audio book before landing. He also sets the sound
+      control in the application to "Noisy Environment", causing the sound to be equalized
+        for greatest intelligibility in a noisy setting such as an airplane.</p>
+
+      <h4>Notes and Implementation Considerations</h4>
+      <ol>
+        <li><p>Local audio can be downloaded, stored and retrieved using the <a href="http://www.w3.org/TR/FileAPI/">HTML File API</a>.</p></li>
+        <li><p>This scenario requires a special audio transformation that can compress the duration of speech
+            without affecting overall timbre and intelligibility. In the Web Audio API this could be accomplished through
+            attaching custom processing code to a <code>JavaScriptAudioNode</code>.</p></li>
+        <li><p>The "Noisy Environment" setting could be accomplished through equalization features in the Web Audio API such as <code>BiquadFilterNode</code> or <code>ConvolverNode</code>.</p></li>
+      </ol>
     </section>
     
     <section>