GUAC-1354: Refactor Guacamole.AudioChannel to Guacamole.AudioPlayer.

This commit is contained in:
Michael Jumper
2015-09-28 12:37:09 -07:00
parent c54001476d
commit ff5687c01e
3 changed files with 465 additions and 332 deletions

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@@ -1,291 +0,0 @@
/*
* Copyright (C) 2015 Glyptodon LLC
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
var Guacamole = Guacamole || {};
/**
* Abstract audio channel which queues and plays arbitrary audio data.
*
* @constructor
*/
Guacamole.AudioChannel = function AudioChannel() {
/**
* Reference to this AudioChannel.
*
* @private
* @type Guacamole.AudioChannel
*/
var channel = this;
/**
* The earliest possible time that the next packet could play without
* overlapping an already-playing packet, in milliseconds.
*
* @private
* @type Number
*/
var nextPacketTime = Guacamole.AudioChannel.getTimestamp();
/**
* The last time that sync() was called, in milliseconds. If sync() has
* never been called, this will be the time the Guacamole.AudioChannel
* was created.
*
* @type Number
*/
var lastSync = nextPacketTime;
/**
* Notifies this Guacamole.AudioChannel that all audio up to the current
* point in time has been given via play(), and that any difference in time
* between queued audio packets and the current time can be considered
* latency.
*/
this.sync = function sync() {
// Calculate elapsed time since last sync
var now = Guacamole.AudioChannel.getTimestamp();
var elapsed = now - lastSync;
// Reschedule future playback time such that playback latency is
// bounded within the duration of the last audio frame
nextPacketTime = Math.min(nextPacketTime, now + elapsed);
// Record sync time
lastSync = now;
};
/**
* Queues up the given data for playing by this channel once all previously
* queued data has been played. If no data has been queued, the data will
* play immediately.
*
* @param {String} mimetype
* The mimetype of the audio data provided.
*
* @param {Number} duration
* The duration of the data provided, in milliseconds.
*
* @param {Blob} data
* The blob of audio data to play.
*/
this.play = function play(mimetype, duration, data) {
var packet = new Guacamole.AudioChannel.Packet(mimetype, data);
// Determine exactly when packet CAN play
var packetTime = Guacamole.AudioChannel.getTimestamp();
if (nextPacketTime < packetTime)
nextPacketTime = packetTime;
// Schedule packet
packet.play(nextPacketTime);
// Update timeline
nextPacketTime += duration;
};
};
// Define context if available
if (window.AudioContext) {
try {Guacamole.AudioChannel.context = new AudioContext();}
catch (e){}
}
// Fallback to Webkit-specific AudioContext implementation
else if (window.webkitAudioContext) {
try {Guacamole.AudioChannel.context = new webkitAudioContext();}
catch (e){}
}
/**
* Returns a base timestamp which can be used for scheduling future audio
* playback. Scheduling playback for the value returned by this function plus
* N will cause the associated audio to be played back N milliseconds after
* the function is called.
*
* @return {Number} An arbitrary channel-relative timestamp, in milliseconds.
*/
Guacamole.AudioChannel.getTimestamp = function() {
// If we have an audio context, use its timestamp
if (Guacamole.AudioChannel.context)
return Guacamole.AudioChannel.context.currentTime * 1000;
// If we have high-resolution timers, use those
if (window.performance) {
if (window.performance.now)
return window.performance.now();
if (window.performance.webkitNow)
return window.performance.webkitNow();
}
// Fallback to millisecond-resolution system time
return new Date().getTime();
};
/**
* Abstract representation of an audio packet.
*
* @constructor
*
* @param {String} mimetype The mimetype of the data contained by this packet.
* @param {Blob} data The blob of sound data contained by this packet.
*/
Guacamole.AudioChannel.Packet = function(mimetype, data) {
/**
* Schedules this packet for playback at the given time.
*
* @function
* @param {Number} when The time this packet should be played, in
* milliseconds.
*/
this.play = function(when) { /* NOP */ }; // Defined conditionally depending on support
// If audio API available, use it.
if (Guacamole.AudioChannel.context) {
var readyBuffer = null;
// By default, when decoding finishes, store buffer for future
// playback
var handleReady = function(buffer) {
readyBuffer = buffer;
};
// Read data and start decoding
var reader = new FileReader();
reader.onload = function() {
Guacamole.AudioChannel.context.decodeAudioData(
reader.result,
function(buffer) { handleReady(buffer); }
);
};
reader.readAsArrayBuffer(data);
// Set up buffer source
var source = Guacamole.AudioChannel.context.createBufferSource();
source.connect(Guacamole.AudioChannel.context.destination);
// Use noteOn() instead of start() if necessary
if (!source.start)
source.start = source.noteOn;
var play_when;
function playDelayed(buffer) {
source.buffer = buffer;
source.start(play_when / 1000);
}
/** @ignore */
this.play = function(when) {
play_when = when;
// If buffer available, play it NOW
if (readyBuffer)
playDelayed(readyBuffer);
// Otherwise, play when decoded
else
handleReady = playDelayed;
};
}
else {
var play_on_load = false;
// Create audio element to house and play the data
var audio = null;
try { audio = new Audio(); }
catch (e) {}
if (audio) {
// Read data and start decoding
var reader = new FileReader();
reader.onload = function() {
var binary = "";
var bytes = new Uint8Array(reader.result);
// Produce binary string from bytes in buffer
for (var i=0; i<bytes.byteLength; i++)
binary += String.fromCharCode(bytes[i]);
// Convert to data URI
audio.src = "data:" + mimetype + ";base64," + window.btoa(binary);
// Play if play was attempted but packet wasn't loaded yet
if (play_on_load)
audio.play();
};
reader.readAsArrayBuffer(data);
function play() {
// If audio data is ready, play now
if (audio.src)
audio.play();
// Otherwise, play when loaded
else
play_on_load = true;
}
/** @ignore */
this.play = function(when) {
// Calculate time until play
var now = Guacamole.AudioChannel.getTimestamp();
var delay = when - now;
// Play now if too late
if (delay < 0)
play();
// Otherwise, schedule later playback
else
window.setTimeout(play, delay);
};
}
}
};

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@@ -0,0 +1,418 @@
/*
* Copyright (C) 2015 Glyptodon LLC
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
var Guacamole = Guacamole || {};
/**
* Abstract audio player which accepts, queues and plays back arbitrary audio
* data. It is up to implementations of this class to provide some means of
* handling a provided Guacamole.InputStream. Data received along the provided
* stream is to be played back immediately.
*
* @constructor
*/
Guacamole.AudioPlayer = function AudioPlayer() {
/**
* Notifies this Guacamole.AudioPlayer that all audio up to the current
* point in time has been given via the underlying stream, and that any
* difference in time between queued audio data and the current time can be
* considered latency.
*/
this.sync = function sync() {
// Default implementation - do nothing
};
};
/**
* Returns a base timestamp which can be used for scheduling future audio
* playback. Scheduling playback for the value returned by this function plus
* N will cause the associated audio to be played back N milliseconds after
* the function is called.
*
* @return {Number}
* An arbitrary relative timestamp, in milliseconds.
*/
Guacamole.AudioPlayer.getTimestamp = function() {
// If we have high-resolution timers, use those
if (window.performance) {
var now = performance.now || performance.webkitNow();
return now();
}
// Fallback to millisecond-resolution system time
return Date.now();
};
/**
* Implementation of Guacamole.AudioPlayer providing support for raw PCM format
* audio. This player relies only on the Web Audio API and does not require any
* browser-level support for its audio formats.
*
* @constructor
* @augments Guacamole.AudioPlayer
* @param {Guacamole.InputStream} stream
* The Guacamole.InputStream to read audio data from.
*
* @param {String} mimetype
* The mimetype of the audio data in the provided stream, which must be a
* "audio/L8" or "audio/L16" mimetype with necessary parameters, such as:
* "audio/L16;rate=44100,channels=2".
*/
Guacamole.RawAudioPlayer = function RawAudioPlayer(stream, mimetype) {
/**
* The format of audio this player will decode.
*
* @type Guacamole.RawAudioPlayer._Format
*/
var format = Guacamole.RawAudioPlayer._Format.parse(mimetype);
/**
* An instance of a Web Audio API AudioContext object, or null if the
* Web Audio API is not supported.
*
* @type AudioContext
*/
var context = (function getAudioContext() {
// Fallback to Webkit-specific AudioContext implementation
var AudioContext = window.AudioContext || window.webkitAudioContext;
// Get new AudioContext instance if Web Audio API is supported
if (AudioContext) {
try {
return new AudioContext();
}
catch (e) {
// Do not use Web Audio API if not allowed by browser
}
}
// Web Audio API not supported
return null;
})();
/**
* Returns a base timestamp which can be used for scheduling future audio
* playback. Scheduling playback for the value returned by this function plus
* N will cause the associated audio to be played back N milliseconds after
* the function is called.
*
* @return {Number}
* An arbitrary relative timestamp, in milliseconds.
*/
var getTimestamp = function getTimestamp() {
// If we have an audio context, use its timestamp
if (context)
return context.currentTime * 1000;
// Otherwise, use the internal timestamp implementation
return Guacamole.AudioPlayer.getTimestamp();
};
/**
* The earliest possible time that the next packet could play without
* overlapping an already-playing packet, in milliseconds.
*
* @private
* @type Number
*/
var nextPacketTime = getTimestamp();
/**
* The last time that sync() was called, in milliseconds. If sync() has
* never been called, this will be the time the Guacamole.AudioPlayer
* was created.
*
* @type Number
*/
var lastSync = nextPacketTime;
/**
* Guacamole.ArrayBufferReader wrapped around the audio input stream
* provided with this Guacamole.RawAudioPlayer was created.
*
* @type Guacamole.ArrayBufferReader
*/
var reader = new Guacamole.ArrayBufferReader(stream);
// Play each received raw packet of audio immediately
reader.ondata = function playReceivedAudio(data) {
// Calculate total number of samples
var samples = data.byteLength / format.channels / format.bytesPerSample;
// Calculate overall duration (in milliseconds)
var duration = samples * 1000 / format.rate;
// Determine exactly when packet CAN play
var packetTime = getTimestamp();
if (nextPacketTime < packetTime)
nextPacketTime = packetTime;
// Obtain typed array view based on defined bytes per sample
var maxValue;
var source;
if (format.bytesPerSample === 1) {
source = new Int8Array(data);
maxValue = 128;
}
else {
source = new Int16Array(data);
maxValue = 32768;
}
// Get audio buffer for specified format
var audioBuffer = context.createBuffer(format.channels, samples, format.rate);
// Convert each channel
for (var channel = 0; channel < format.channels; channel++) {
var audioData = audioBuffer.getChannelData(channel);
// Fill audio buffer with data for channel
var offset = channel;
for (var i = 0; i < samples; i++) {
audioData[i] = source[offset] / maxValue;
offset += format.channels;
}
}
// Set up buffer source
var source = context.createBufferSource();
source.connect(context.destination);
// Use noteOn() instead of start() if necessary
if (!source.start)
source.start = source.noteOn;
// Schedule packet
source.buffer = audioBuffer;
source.start(nextPacketTime / 1000);
// Update timeline
nextPacketTime += duration;
};
/** @override */
this.sync = function sync() {
// Calculate elapsed time since last sync
var now = getTimestamp();
var elapsed = now - lastSync;
// Reschedule future playback time such that playback latency is
// bounded within the duration of the last audio frame
nextPacketTime = Math.min(nextPacketTime, now + elapsed);
// Record sync time
lastSync = now;
};
};
Guacamole.RawAudioPlayer.prototype = new Guacamole.AudioPlayer();
/**
* A description of the format of raw PCM audio received by a
* Guacamole.RawAudioPlayer. This object describes the number of bytes per
* sample, the number of channels, and the overall sample rate.
*
* @private
* @constructor
* @param {Guacamole.RawAudioPlayer._Format|Object} template
* The object whose properties should be copied into the corresponding
* properties of the new Guacamole.RawAudioPlayer._Format.
*/
Guacamole.RawAudioPlayer._Format = function _Format(template) {
/**
* The number of bytes in each sample of audio data. This value is
* independent of the number of channels.
*
* @type Number
*/
this.bytesPerSample = template.bytesPerSample;
/**
* The number of audio channels (ie: 1 for mono, 2 for stereo).
*
* @type Number
*/
this.channels = template.channels;
/**
* The number of samples per second, per channel.
*
* @type Number
*/
this.rate = template.rate;
};
/**
* Parses the given mimetype, returning a new Guacamole.RawAudioPlayer._Format
* which describes the type of raw audio data represented by that mimetype. If
* the mimetype is not supported by Guacamole.RawAudioPlayer, null is returned.
*
* @private
* @param {String} mimetype
* The audio mimetype to parse.
*
* @returns {Guacamole.RawAudioPlayer._Format}
* A new Guacamole.RawAudioPlayer._Format which describes the type of raw
* audio data represented by the given mimetype, or null if the given
* mimetype is not supported.
*/
Guacamole.RawAudioPlayer._Format.parse = function parseFormat(mimetype) {
var bytesPerSample;
// Rate is absolutely required - if null is still present later, the
// mimetype must not be supported
var rate = null;
// Default for both "audio/L8" and "audio/L16" is one channel
var channels = 1;
// "audio/L8" has one byte per sample
if (mimetype.substring(0, 9) === 'audio/L8;') {
mimetype = mimetype.substring(9);
bytesPerSample = 1;
}
// "audio/L16" has two bytes per sample
else if (mimetype.substring(0, 10) === 'audio/L16;') {
mimetype = mimetype.substring(10);
bytesPerSample = 2;
}
// All other types are unsupported
else
return null;
// Parse all parameters
var parameters = mimetype.split(',');
for (var i = 0; i < parameters.length; i++) {
var parameter = parameters[i];
// All parameters must have an equals sign separating name from value
var equals = parameter.indexOf('=');
if (equals === -1)
return null;
// Parse name and value from parameter string
var name = parameter.substring(0, equals);
var value = parameter.substring(equals+1);
// Handle each supported parameter
switch (name) {
// Number of audio channels
case 'channels':
channels = parseInt(value);
break;
// Sample rate
case 'rate':
rate = parseInt(value);
break;
// All other parameters are unsupported
default:
return null;
}
};
// The rate parameter is required
if (rate === null)
return null;
// Return parsed format details
return new Guacamole.RawAudioPlayer._Format({
bytesPerSample : bytesPerSample,
channels : channels,
rate : rate
});
};
/**
* Determines whether the given mimetype is supported by
* Guacamole.RawAudioPlayer.
*
* @param {String} mimetype
* The mimetype to check.
*
* @returns {Boolean}
* true if the given mimetype is supported by Guacamole.RawAudioPlayer,
* false otherwise.
*/
Guacamole.RawAudioPlayer.isSupportedType = function isSupportedType(mimetype) {
// No supported types if no Web Audio API
if (!window.AudioContext && !window.webkitAudioContext)
return false;
return Guacamole.RawAudioPlayer._Format.parse(mimetype) !== null;
};
/**
* Returns a list of all mimetypes supported by Guacamole.RawAudioPlayer. Only
* the core mimetypes themselves will be listed. Any mimetype parameters, even
* required ones, will not be included in the list. For example, "audio/L8" is
* a raw audio mimetype that may be supported, but it is invalid without
* additional parameters. Something like "audio/L8;rate=44100" would be valid,
* however (see https://tools.ietf.org/html/rfc4856).
*
* @returns {String[]}
* A list of all mimetypes supported by Guacamole.RawAudioPlayer, excluding
* any parameters. If the necessary JavaScript APIs for playing raw audio
* are absent, this list will be empty.
*/
Guacamole.RawAudioPlayer.getSupportedTypes = function getSupportedTypes() {
// No supported types if no Web Audio API
if (!window.AudioContext && !window.webkitAudioContext)
return [];
// We support 8-bit and 16-bit raw PCM
return [
'audio/L8',
'audio/L16'
];
};

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@@ -78,12 +78,12 @@ Guacamole.Client = function(tunnel) {
var layers = {};
/**
* All audio channels currentl in use by the client. Initially, this will
* be empty, but channels may be allocated by the server upon request.
* All audio players currently in use by the client. Initially, this will
* be empty, but audio players may be allocated by the server upon request.
*
* @type Object.<Number, Guacamole.AudioChannel>
* @type Object.<Number, Guacamole.AudioPlayer>
*/
var audioChannels = {};
var audioPlayers = {};
// No initial parsers
var parsers = [];
@@ -440,6 +440,25 @@ Guacamole.Client = function(tunnel) {
*/
this.onerror = null;
/**
* Fired when a audio stream is created. The stream provided to this event
* handler will contain its own event handlers for received data.
*
* @event
* @param {Guacamole.InputStream} stream
* The stream that will receive audio data from the server.
*
* @param {String} mimetype
* The mimetype of the audio data which will be received.
*
* @return {Guacamole.AudioPlayer}
* An object which implements the Guacamole.AudioPlayer interface and
* has been initialied to play the data in the provided stream, or null
* if the built-in audio players of the Guacamole client should be
* used.
*/
this.onaudio = null;
/**
* Fired when the clipboard of the remote client is changing.
*
@@ -499,27 +518,6 @@ Guacamole.Client = function(tunnel) {
*/
this.onsync = null;
/**
* Returns the audio channel having the given index, creating a new channel
* if necessary.
*
* @param {Number} index
* The index of the audio channel to retrieve.
*
* @returns {Guacamole.AudioChannel}
* The audio channel having the given index.
*/
var getAudioChannel = function getAudioChannel(index) {
// Get audio channel, creating it first if necessary
var audio_channel = audioChannels[index];
if (!audio_channel)
audio_channel = audioChannels[index] = new Guacamole.AudioChannel();
return audio_channel;
};
/**
* Returns the layer with the given index, creating it if necessary.
* Positive indices refer to visible layers, an index of zero refers to
@@ -626,24 +624,32 @@ Guacamole.Client = function(tunnel) {
"audio": function(parameters) {
var stream_index = parseInt(parameters[0]);
var channel = getAudioChannel(parseInt(parameters[1]));
var mimetype = parameters[2];
var duration = parseFloat(parameters[3]);
var mimetype = parameters[1];
// Create stream
var stream = streams[stream_index] =
new Guacamole.InputStream(guac_client, stream_index);
// Assemble entire stream as a blob
var blob_reader = new Guacamole.BlobReader(stream, mimetype);
// Get player instance via callback
var audioPlayer = null;
if (guac_client.onaudio)
audioPlayer = guac_client.onaudio(stream, mimetype);
// Play blob as audio
blob_reader.onend = function() {
channel.play(mimetype, duration, blob_reader.getBlob());
};
// If unsuccessful, use a default implementation
if (!audioPlayer) {
if (Guacamole.RawAudioPlayer.isSupportedType(mimetype))
audioPlayer = new Guacamole.RawAudioPlayer(stream, mimetype);
}
// Send success response
guac_client.sendAck(stream_index, "OK", 0x0000);
// If player somehow successfully retrieved, send success response
if (audioPlayer) {
audioPlayers[stream_index] = audioPlayer;
guac_client.sendAck(stream_index, "OK", 0x0000);
}
// Otherwise, mimetype must be unsupported
else
guac_client.sendAck(stream_index, "BAD TYPE", 0x030F);
},
@@ -1113,11 +1119,11 @@ Guacamole.Client = function(tunnel) {
// Flush display, send sync when done
display.flush(function displaySyncComplete() {
// Synchronize all audio channels
for (var index in audioChannels) {
var audioChannel = audioChannels[index];
if (audioChannel)
audioChannel.sync();
// Synchronize all audio players
for (var index in audioPlayers) {
var audioPlayer = audioPlayers[index];
if (audioPlayer)
audioPlayer.sync();
}
// Send sync response to server