X-Git-Url: https://git.decadent.org.uk/gitweb/?p=lca-dvswitch.git;a=blobdiff_plain;f=index.html;h=880e691f7b23b5ac508faf7fdd9424123dae1a72;hp=5f8ad5872ba017cfb33f06bafc46aa2e93d49ae7;hb=b9bdbeaace6942eb89fa3c5400fe91f8e7bbb771;hpb=289841024a8d070931fe3aab2b4b422cfa8bb3a3

diff --git a/index.html b/index.html
index 5f8ad58..880e691 100644
--- a/index.html
+++ b/index.html
@@ -4,7 +4,7 @@
 <html xmlns="http://www.w3.org/1999/xhtml">
 
 <head>
-<title>DVswitch - Ben Hutchings - LCA2011</title>
+<title>Making great conference videos on a budget - Ben Hutchings - LCA2011</title>
 <!-- metadata -->
 <meta name="generator" content="S5" />
 <meta name="version" content="S5 1.1" />
@@ -36,7 +36,7 @@
 </div>
 <div id="footer">
 <h1>LCA2011</h1>
-<h2>DVswitch</h2>
+<h2>Making great conference videos on a budget</h2>
 </div>
 
 </div>
@@ -45,7 +45,7 @@
 <div class="presentation">
 
 <div class="slide">
-<h1>DVswitch</h1>
+<h1>Making great conference videos on a budget</h1>
 <h3>Ben Hutchings</h3>
 </div>
 
@@ -96,12 +96,12 @@
       Now used more widely, often without streaming
     </li>
     <li>
-      Mixing is <em>live</em> - a requirement for streaming, and a way to
-      avoid the need for extensive editing after the event
+      Mixing is <em>live</em> - required for streaming, and avoids the
+      need for extensive editing after the event
     </li>
     <li>
-      Mixing is <em>interactive</em> - a requirement for good coverage of
-      presenters, audience and slides, but very limited in other
+      Mixing is <em>interactive</em> - required for good coverage of
+      presenters, audience and slides; very limited in other
       streaming software
     </li>
   </ul>
@@ -118,7 +118,8 @@
       A general video editor
     </li>
     <li>
-      An audio mixer (but it does implement audio dubbing and level monitoring)
+      An audio mixer - audio functionality is limited to dubbing and
+      level monitoring
     </li>
     <li>
       A complete recording and publishing system
@@ -133,7 +134,7 @@
 <div class="slide">
   <h1>The 'DV' in DVswitch</h1>
   <p>
-    The name refers to the DV formats used by many video cameras:
+    The name refers to the DV format used by many video cameras:
   </p>
   <table>
     <tr>
@@ -179,10 +180,13 @@
 
 <div class="slide">
   <h1>Overview of the system</h1>
-  <p>
-    A simplified view of the typical components:
-  </p>
-  <object data="dvswitch-simple.svg" width="60%" height="60%"></object>
+  <object data="dvswitch-simple.dia.svg" width="75%"></object>
+  <div class="handout">
+    <p>
+      This is a simplified view of the typical components.  The system
+      is completely flexible as to which sinks and sources are used.
+    </p>
+  </div>
 </div>
 
 <div class="slide">
@@ -218,6 +222,12 @@
       </ul>
     </li>
   </ul>
+  <div class="handout">
+    <p>
+      DIF is the DV Interchange Format, sometimes referred to as 'raw
+      DV' although it is a container format in its own right.
+    </p>
+  </div>
 </div>
 
 <div class="slide">
@@ -246,13 +256,35 @@
 </div>
 
 <div class="slide">
-  <h1>Mixer</h1>
+  <h1>Mixer UI</h1>
   <object data="screenshot-1.png" width="50%"></object>
 </div>
 
 <div class="slide">
-  <h1>Mixer</h1>
-  <object data="screenshot-1-annotated.png" width="50%"></object>
+  <h1>Mixer UI, annotated</h1>
+  <object data="screenshot-1-annotated.xcf.png" width="50%"></object>
+</div>
+
+<div class="slide">
+  <h1>Mixer internals</h1>
+  <object data="dvswitch-internal.dia.svg" width="90%" height="90%"></object>
+  <div class="handout">
+    <p>
+      To simplify the diagram, I omitted connection setup, tally light
+      and recording control, and the internal sinks that haven't been
+      implemented yet.
+    </p>
+    <p>
+      All these interfaces have limited-length queues.  If a queue
+      fills up, frames have to be dropped - we must not block or use
+      unlimited memory!
+    </p>
+    <p>
+      The mixer clock thread maintains a frame clock at about 25 or
+      30&nbsp;Hz depending on the video system, constantly adjusted to
+      follow the audio source.
+    </p>
+  </div>
 </div>
 
 </body>
