--- a/reqs/Overview.html Fri Jul 13 12:12:54 2012 +0100
+++ b/reqs/Overview.html Fri Jul 13 13:29:18 2012 +0100
@@ -168,46 +168,38 @@
<section>
- <h3>UC 3: Online music production tool</h3>
+ <h3>Scenario 3: Online music production tool</h3>
<p>(online audio workstation tool?)
</p>
- <p>A user arranges a musical composition using a non-linear timeline-based DAW (digital audio workstation) application.
- Audio "clips" are arranged on a timeline representing multiple tracks of audio. Each track's volume, panning, and effects
+ <p>A user arranges a musical composition using a web-based Digital Audio Workstation (DAW) application.</p>
+
+ <p>Audio "clips" are arranged on a timeline representing multiple tracks of audio. Each track's volume, panning, and effects
may be controlled separately. Individual tracks may be muted or soloed to preview various combination of tracks at a given moment.
Audio effects may be applied per-track as inline (insert) effects. Additionally, each track can send its signal to one or
- more global send effects which are shared across tracks. Submixes of various combinations of tracks can be made, and a final
- mix bus controls the overall volume of the mix, and may have additional insert effects.
- </p>
-
- <p>Insert and send effects include dynamics compressors (including multi-band), extremely high-quality reverberation, filters such as parametric, low-shelf, high-shelf, graphic EQ, etc. Also included are various kinds of delay effects such as ping-pong delays, and BPM-synchronized delays with feedback. Various kinds of time-modulated effects are available such as chorus, phasor, resonant filter sweeps, and BPM-synchronized panners. Distortion effects include subtle tube simulators, and aggressive bit decimators. Each effect has its own UI for adjusting its parameters. Real-time changes to the parameters can be made (e.g. with a mouse) and the audible results heard with no perceptible lag.
- </p>
-
- <p>Audio clips may be arranged on the timeline with a high-degree of precision (with sample accurate playback). Certain clips may be repeated loops containing beat-based musical material, and are synchronized with other such looped clips according to a certain musical tempo. These, in turn, can be synchronized with sequences controlling real-time synthesized playback. The values of volume, panning, send levels, and each parameter of each effect can be changed over time, displayed and controlled through a powerful UI dealing with automation curves. These curves may be arbitrary and can be used, for example, to control volume fade-ins, filter sweeps, and may be synchronized in time with the music (beat synchronized).
- </p>
-
- <p>Visualizers may be applied for technical analysis of the signal. These visualizers can be as simple as displaying the signal level in a VU meter, or more complex such as real-time frequency analysis, or L/R phase displays.
- </p>
-
- <p>The actual audio clips to be arranged on the timeline are managed in a library of available clips. These can be searched and sorted in a variety of ways and with high-efficiency. Although the clips can be cloud-based, local caching offers nearly instantaneous access and glitch-free playback.
- </p>
+ more global send effects which are shared across tracks. Sub-mixes of various combinations of tracks can be made, and a final
+ mix bus controls the overall volume of the mix, and may have additional insert effects.</p>
- <p>The final mix may be rendered at faster than real-time and then uploaded and shared with others. The session representing the clips, timeline, effects, automation, etc. may also be shared with others for shared-mixing collaboration.
- </p>
-
- <pre>-- Moved from UC7: The webpage provides the user with the ability to control the buffer size of the underlying Audio API: <br /> this allows users with slower machines to pick a larger buffer setting that does not cause clicks and pops in the audio stream. --
- </pre>
+ <p>Insert and send effects include dynamics compressors (including multi-band), extremely high-quality reverberation, filters such as parametric, low-shelf, high-shelf, graphic EQ, etc. Also included are various kinds of delay effects such as ping-pong delays, and BPM-synchronized delays with feedback. Various kinds of time-modulated effects are available such as chorus, phasor, resonant filter sweeps, and BPM-synchronized panners. Distortion effects include subtle tube simulators, and aggressive bit decimators. Each effect has its own UI for adjusting its parameters. Real-time changes to the parameters can be made (e.g. with a mouse) and the audible results heard with no perceptible lag.</p>
- <h4>UC3 — Priority</h4>
- <pre> <i>Priority: <b>LOW</b></i>
- </pre>
- <p>… consensus reached during the teleconference on <a href="http://www.w3.org/2012/02/13-audio-minutes" title="http://www.w3.org/2012/02/13-audio-minutes">13 Feb 2012</a>.
- </p><p>General consensus that while this is an interesting use case, there is no clamor to facilitate it entirely and urgently.</p>
+ <p>Audio clips may be arranged on the timeline with a high-degree of precision (with sample accurate playback). Certain clips may be repeated loops containing beat-based musical material, and are synchronized with other such looped clips according to a certain musical tempo. These, in turn, can be synchronized with sequences controlling real-time synthesized playback. The values of volume, panning, send levels, and each parameter of each effect can be changed over time, displayed and controlled through a powerful UI dealing with automation curves. These curves may be arbitrary and can be used, for example, to control volume fade-ins, filter sweeps, and may be synchronized in time with the music (beat synchronized).</p>
+ <p>Visualizers may be applied for technical analysis of the signal. These visualizers can be as simple as displaying the signal level in a VU meter, or more complex such as real-time frequency analysis, or L/R phase displays.</p>
+
+ <p>The actual audio clips to be arranged on the timeline are managed in a library of available clips. These can be searched and sorted in a variety of ways and with high-efficiency. Although the clips can be cloud-based, local caching offers nearly instantaneous access and glitch-free playback.</p>
+
+ <p>The final mix may be rendered at faster than real-time and then uploaded and shared with others. The session representing the clips, timeline, effects, automation, etc. may also be shared with others for shared-mixing collaboration.</p>
+
+
+ <h4>Notes and Implementation Considerations</h4>
+ <ol>
+ <li><p>This scenario details the large number of feature requirements typically expected of professional audio software or hardware. It encompasses many advanced audio control capabilities such as filtering, effects, dynamics compression and control of various audio parameters.</p></li>
+
+ <li><p>Building such an application may only be reasonably possible if the technology enables the control of audio with acceptable performance, in particular for <em>real-time processing</em> and control of audio parameters and <em>sample accurate scheduling of sound playback</em>. Because performance is such a key aspect of this scenario, it should probably be possible to control the buffer size of the underlying Audio API: this would allow users with slower machines to pick a larger buffer setting that does not cause clicks and pops in the audio stream.</p></li>
+
+ <li><p>The ability to visualise the samples and their processing would highly benefit from <em>real-time time-domain and frequency analysis</em>.</p></li>
+ </ol>
- <h4>UC3 related demos </h4>
- <p><a href="http://vimeo.com/37250605" title="http://vimeo.com/37250605">Video of online multi-track sequencer using the Web Audio API</a>.
- </p>
</section>