Update audio terminology
Change-Id: I5d37d75ee64968c932bdbc0d65ca704052baa375
diff --git a/src/devices/audio/latency.jd b/src/devices/audio/latency.jd
index a779157..9063895 100644
--- a/src/devices/audio/latency.jd
+++ b/src/devices/audio/latency.jd
@@ -166,7 +166,8 @@
is a broad term that encompasses efforts to monitor
and reduce power consumption while optimizing performance.
<a href="http://en.wikipedia.org/wiki/Thermal_management_of_electronic_devices_and_systems">Thermal management</a>
- is similar, but seeks to measure and control heat to avoid damage due to excess heat.
+ and <a href="http://en.wikipedia.org/wiki/Computer_cooling">computer cooling</a>
+ are similar, but seek to measure and control heat to avoid damage due to excess heat.
In the Linux kernel, the CPU
<a href="http://en.wikipedia.org/wiki/Governor_%28device%29">governor</a>
is responsible for low-level policy, while user mode configures high-level policy.
diff --git a/src/devices/audio/latency_measure.jd b/src/devices/audio/latency_measure.jd
index 14574fb..0b1724a 100644
--- a/src/devices/audio/latency_measure.jd
+++ b/src/devices/audio/latency_measure.jd
@@ -91,7 +91,8 @@
<h2 id="measuringRoundTrip">Measuring Round-Trip Latency</h2>
<p>
- Round-trip latency is the sum of output latency and input latency.
+ <a href="http://en.wikipedia.org/wiki/Round-trip_delay_time">Round-trip latency</a>
+ is the sum of output latency and input latency.
</p>
<h3 id="larsenTest">Larsen test</h3>
diff --git a/src/devices/audio/terminology.jd b/src/devices/audio/terminology.jd
index ba2eb19..53c719c 100644
--- a/src/devices/audio/terminology.jd
+++ b/src/devices/audio/terminology.jd
@@ -81,6 +81,15 @@
Compare to "mute."
</dd>
+<dt>FIFO</dt>
+<dd>
+A hardware module or software data structure that implements
+<a href="http://en.wikipedia.org/wiki/FIFO">First In, First Out</a>
+queueing of data. In the context of audio, the data stored in the queue
+are typically audio frames. A FIFO can be implemented by a
+<a href="http://en.wikipedia.org/wiki/Circular_buffer">circular buffer</a>.
+</dd>
+
<dt>frame</dt>
<dd>
A set of samples, one per channel, at a point in time.
@@ -109,6 +118,32 @@
Time delay as a signal passes through a system.
</dd>
+<dt>lossless</dt>
+<dd>
+A <a href="http://en.wikipedia.org/wiki/Lossless_compression">lossless data compression</a>
+algorithm preserves bit accuracy across encoding and decoding.
+The result of decoding any previously encoded data is equivalent to the original data.
+Examples of lossless audio content distribution formats include
+<a href="http://en.wikipedia.org/wiki/Compact_disc">CDs</a>, PCM within
+<a href="http://en.wikipedia.org/wiki/WAV">WAV</a>, and
+<a href="http://en.wikipedia.org/wiki/FLAC">FLAC</a>.
+Note that the authoring process may reduce the bit depth or sample rate from that of the
+<a href="http://en.wikipedia.org/wiki/Audio_mastering">masters</a>.
+Distribution formats that preserve the resolution and bit accuracy of masters
+are the subject of "high-resolution audio".
+</dd>
+
+<dt>lossy</dt>
+<dd>
+A <a href="http://en.wikipedia.org/wiki/Lossy_compression">lossy data compression</a>
+algorithm attempts to preserve the most important features of media across
+encoding and decoding. The result of decoding any previously encoded
+data is perceptually similar to the original data, but is not identical.
+Examples of lossy audio compression algorithms include MP3 and AAC.
+As analog values are from a continuous domain, whereas digital values are discrete,
+ADC and DAC are lossy conversions with respect to amplitude. See also "transparency."
+</dd>
+
<dt>mono</dt>
<dd>
One channel.
@@ -190,6 +225,14 @@
sound position beyond stereo left and right.
</dd>
+<dt>transparency</dt>
+<dd>
+The ideal result of lossy data compression, as stated in the
+<a href="http://en.wikipedia.org/wiki/Transparency_%28data_compression%29">Transparency Wikipedia article</a>.
+A lossy data conversion is said to be transparent if it is perceptually indistinguishable from the
+original by a human subject.
+</dd>
+
<dt>underrun</dt>
<dd>
An audible <a href="http://en.wikipedia.org/wiki/Glitch">glitch</a> caused by failure
@@ -271,6 +314,13 @@
audio and video data. For mobile devices, either a micro-HDMI (type D) or MHL connector is used.
</dd>
+<dt>Intel HDA</dt>
+<dd>
+<a href="http://en.wikipedia.org/wiki/Intel_High_Definition_Audio">Intel High Definition Audio</a>
+(commonly shortened to HDA) is a specification for, among other things, a front-panel connector.
+Not to be confused with generic "high-definition audio" or "high-resolution audio."
+</dd>
+
<dt>MHL</dt>
<dd>
Mobile High-Definition Link is a mobile audio/video interface, often
@@ -294,6 +344,12 @@
See Wikipedia article <a href="http://en.wikipedia.org/wiki/S/PDIF">S/PDIF</a>.
</dd>
+<dt>Thunderbolt</dt>
+<dd>
+<a href="http://en.wikipedia.org/wiki/Thunderbolt_%28interface%29">Thunderbolt</a>
+is a multimedia interface that competes with USB and HDMI for connecting to high-end peripherals.
+</dd>
+
<dt>USB</dt>
<dd>
Universal Serial Bus.
@@ -310,7 +366,9 @@
implementor may need to be aware of these, but not the end user.
</p>
+<p>
See these Wikipedia articles:
+</p>
<ul>
<li><a href="http://en.wikipedia.org/wiki/General-purpose_input/output">GPIO</a></li>
<li><a href="http://en.wikipedia.org/wiki/I%C2%B2C">I²C</a>, for control channel</li>
@@ -469,6 +527,11 @@
tinyalsa.
</dd>
+<dt>audio device</dt>
+<dd>
+Any audio I/O end-point which is backed by a HAL implementation.
+</dd>
+
<dt>AudioEffect</dt>
<dd>
An API and implementation framework for output (post-processing) effects
@@ -525,6 +588,13 @@
<a href="src.html">sample rate conversion</a>.
</dd>
+<dt>audio source</dt>
+<dd>
+An <a href="http://developer.android.com/reference/android/media/MediaRecorder.AudioSource.html">audio source</a>
+is an enumeration of constants that indicates the desired use case for capturing audio input.
+As of API level 21 and above, <a href="attributes.html">audio attributes</a> are preferred.
+</dd>
+
<dt>AudioTrack</dt>
<dd>
The primary low-level client API for sending data to an audio output