Docs: Add figure captions to images

Bug: 18334770
Change-Id: I4ed95bb638b6502129d59c099de9a0cd8b16ccb4
diff --git a/src/devices/audio/debugging.jd b/src/devices/audio/debugging.jd
index 8cee394..4dacb5c 100644
--- a/src/devices/audio/debugging.jd
+++ b/src/devices/audio/debugging.jd
@@ -260,7 +260,11 @@
 The diagram below shows the relationship of the <code>mediaserver</code> process
 and the <code>init</code> process, before <code>media.log</code> is introduced:
 </p>
-<img src="images/medialog_before.png" alt="Architecture before media.log" />
+<img src="images/medialog_before.png" alt="Architecture before media.log" id="figure1" />
+<p class="img-caption">
+  <strong>Figure 1.</strong> Architecture before media.log
+</p>
+
 <p>
 Notable points:
 </p>
@@ -274,7 +278,11 @@
 The diagram below shows the new relationship of the components,
 after <code>media.log</code> is added to the architecture:
 </p>
-<img src="images/medialog_after.png" alt="Architecture after media.log" />
+<img src="images/medialog_after.png" alt="Architecture after media.log" id="figure2" />
+<p class="img-caption">
+  <strong>Figure 2.</strong> Architecture after media.log
+</p>
+
 <p>
 Important changes:
 </p>
diff --git a/src/devices/audio/funplug.jd b/src/devices/audio/funplug.jd
index 9200556..fb4b527 100644
--- a/src/devices/audio/funplug.jd
+++ b/src/devices/audio/funplug.jd
@@ -38,7 +38,10 @@
 
 <h2 id="funplugCircuit">FunPlug circuit</h2>
 
-<img src="images/funplug_circuit.png" alt="FunPlug circuit" />
+<img src="images/funplug_circuit.png" alt="FunPlug circuit" id="figure1" />
+<p class="img-caption">
+  <strong>Figure 1.</strong> FunPlug circuit diagram
+</p>
 
 <p>
 To ensure that the output signal will not overload the microphone input,
@@ -49,5 +52,7 @@
 
 <h2 id="funplugAssembled">FunPlug assembled</h2>
 
-<img src="images/funplug_assembled.jpg" alt="FunPlug fully assembled" />
-
+<img src="images/funplug_assembled.jpg" alt="FunPlug fully assembled" id="figure2" />
+<p class="img-caption">
+  <strong>Figure 2.</strong> Assembled FunPlug
+</p>
diff --git a/src/devices/audio/index.jd b/src/devices/audio/index.jd
index dd3109b..c42bca7 100644
--- a/src/devices/audio/index.jd
+++ b/src/devices/audio/index.jd
@@ -2,7 +2,7 @@
 @jd:body
 
 <!--
-    Copyright 2013 The Android Open Source Project
+    Copyright 2014 The Android Open Source Project
 
     Licensed under the Apache License, Version 2.0 (the "License");
     you may not use this file except in compliance with the License.
@@ -26,8 +26,9 @@
   The following figure and list describe how audio functionality is implemented and the relevant
   source code that is involved in the implementation:
 </p>
-<p>
-  <img src="images/audio_hal.png" alt="Audio architecture" />
+  <img src="images/audio_hal.png" alt="Audio architecture" id="figure1" />
+<p class="img-caption">
+  <strong>Figure 1.</strong> Android audio architecture
 </p>
 <dl>
   <dt>
diff --git a/src/devices/audio/latency_measure.jd b/src/devices/audio/latency_measure.jd
index cd9df27..ae644df 100644
--- a/src/devices/audio/latency_measure.jd
+++ b/src/devices/audio/latency_measure.jd
@@ -132,7 +132,10 @@
   should not be extrapolated.
 </p>
 
-<img src="images/round_trip.png" alt="round-trip measurement" />
+<img src="images/round_trip.png" alt="round-trip measurement" id="figure1" />
+<p class="img-caption">
+  <strong>Figure 1.</strong> Round-trip measurement
+</p>
 
 <h2 id="measuringInput">Measuring Input Latency</h2>
 
diff --git a/src/devices/audio/testing_circuit.jd b/src/devices/audio/testing_circuit.jd
index 040755d..995062d 100644
--- a/src/devices/audio/testing_circuit.jd
+++ b/src/devices/audio/testing_circuit.jd
@@ -2,7 +2,7 @@
 @jd:body
 
 <!--
-    Copyright 2013 The Android Open Source Project
+    Copyright 2014 The Android Open Source Project
 
     Licensed under the Apache License, Version 2.0 (the "License");
     you may not use this file except in compliance with the License.
@@ -64,17 +64,21 @@
 These photos show the circuit in action.
 </p>
 
-<img style="margin:1.5em auto" src="images/breadboard.jpg" alt="breadboard prototype" />
-<br />
-<center>Breadboard prototype</center>
+<img style="margin:1.5em auto" src="images/breadboard.jpg" alt="breadboard prototype" id="figure1" />
+<p class="img-caption">
+  <strong>Figure 1.</strong> Breadboard prototype
+</p>
 
-<img style="margin:1.5em auto" src="images/pcb.jpg" alt="an early run of the PCB" />
-<br />
-<center>An early run of the PCB</center>
+<img style="margin:1.5em auto" src="images/pcb.jpg" alt="an early run of the PCB" id="figure2" />
+<p class="img-caption">
+  <strong>Figure 2.</strong> An early run of the PCB
+</p>
 
-<img style="margin:1.5em auto" src="images/display.jpg" alt="example display">
-<br />
-<center>Example display</center>
+<img style="margin:1.5em auto" src="images/display.jpg" alt="example display" id="figure3" />
+<p class="img-caption">
+  <strong>Figure 3.</strong> Example display
+</p>
+
 <p>
 This image
 shows the scope display for an unspecified device, software release, and test conditions;
diff --git a/src/devices/audio/usb.jd b/src/devices/audio/usb.jd
index c01105f..a033d1b 100644
--- a/src/devices/audio/usb.jd
+++ b/src/devices/audio/usb.jd
@@ -151,7 +151,11 @@
 such as this is usually required:
 </p>
 
-<img src="images/otg.jpg" style="image-orientation: 90deg;" height="50%" width="50%" alt="OTG">
+<img src="images/otg.jpg" style="image-orientation: 90deg;" height="50%" width="50%" alt="OTG" id="figure1" />
+<p class="img-caption">
+  <strong>Figure 1.</strong> On-the-go (OTG) adapter
+</p>
+
 
 <p>
 An Android device might not provide sufficient power to operate a
@@ -162,7 +166,10 @@
 <a href="http://en.wikipedia.org/wiki/USB_hub">hub</a> such as this:
 </p>
 
-<img src="images/hub.jpg" alt="Powered hub">
+<img src="images/hub.jpg" alt="Powered hub" id="figure2" />
+<p class="img-caption">
+  <strong>Figure 2.</strong> Powered hub
+</p>
 
 <h3 id="accessoryMode">Accessory mode</h3>
 
@@ -434,7 +441,10 @@
 also with headphones.
 </p>
 
-<img src="images/dac.png" alt="DAC comparison">
+<img src="images/dac.png" alt="DAC comparison" id="figure3" />
+<p class="img-caption">
+  <strong>Figure 3.</strong> Comparison of two DACs
+</p>
 
 <p>
 Which design is better?  The answer depends on your needs.