OpenShot Library | libopenshot-audio  0.2.0
juce_MidiMessageCollector.cpp
1 /*
2  ==============================================================================
3 
4  This file is part of the JUCE library.
5  Copyright (c) 2017 - ROLI Ltd.
6 
7  JUCE is an open source library subject to commercial or open-source
8  licensing.
9 
10  The code included in this file is provided under the terms of the ISC license
11  http://www.isc.org/downloads/software-support-policy/isc-license. Permission
12  To use, copy, modify, and/or distribute this software for any purpose with or
13  without fee is hereby granted provided that the above copyright notice and
14  this permission notice appear in all copies.
15 
16  JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
17  EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
18  DISCLAIMED.
19 
20  ==============================================================================
21 */
22 
23 namespace juce
24 {
25 
27 {
28 }
29 
31 {
32 }
33 
34 //==============================================================================
35 void MidiMessageCollector::reset (const double newSampleRate)
36 {
37  jassert (newSampleRate > 0);
38 
39  const ScopedLock sl (midiCallbackLock);
40  #if JUCE_DEBUG
41  hasCalledReset = true;
42  #endif
43  sampleRate = newSampleRate;
44  incomingMessages.clear();
45  lastCallbackTime = Time::getMillisecondCounterHiRes();
46 }
47 
49 {
50  #if JUCE_DEBUG
51  jassert (hasCalledReset); // you need to call reset() to set the correct sample rate before using this object
52  #endif
53 
54  // the messages that come in here need to be time-stamped correctly - see MidiInput
55  // for details of what the number should be.
56  jassert (message.getTimeStamp() != 0);
57 
58  const ScopedLock sl (midiCallbackLock);
59 
60  auto sampleNumber = (int) ((message.getTimeStamp() - 0.001 * lastCallbackTime) * sampleRate);
61 
62  incomingMessages.addEvent (message, sampleNumber);
63 
64  // if the messages don't get used for over a second, we'd better
65  // get rid of any old ones to avoid the queue getting too big
66  if (sampleNumber > sampleRate)
67  incomingMessages.clear (0, sampleNumber - (int) sampleRate);
68 }
69 
71  const int numSamples)
72 {
73  #if JUCE_DEBUG
74  jassert (hasCalledReset); // you need to call reset() to set the correct sample rate before using this object
75  #endif
76 
77  jassert (numSamples > 0);
78 
79  auto timeNow = Time::getMillisecondCounterHiRes();
80  auto msElapsed = timeNow - lastCallbackTime;
81 
82  const ScopedLock sl (midiCallbackLock);
83  lastCallbackTime = timeNow;
84 
85  if (! incomingMessages.isEmpty())
86  {
87  int numSourceSamples = jmax (1, roundToInt (msElapsed * 0.001 * sampleRate));
88  int startSample = 0;
89  int scale = 1 << 16;
90 
91  const uint8* midiData;
92  int numBytes, samplePosition;
93 
94  MidiBuffer::Iterator iter (incomingMessages);
95 
96  if (numSourceSamples > numSamples)
97  {
98  // if our list of events is longer than the buffer we're being
99  // asked for, scale them down to squeeze them all in..
100  const int maxBlockLengthToUse = numSamples << 5;
101 
102  if (numSourceSamples > maxBlockLengthToUse)
103  {
104  startSample = numSourceSamples - maxBlockLengthToUse;
105  numSourceSamples = maxBlockLengthToUse;
106  iter.setNextSamplePosition (startSample);
107  }
108 
109  scale = (numSamples << 10) / numSourceSamples;
110 
111  while (iter.getNextEvent (midiData, numBytes, samplePosition))
112  {
113  samplePosition = ((samplePosition - startSample) * scale) >> 10;
114 
115  destBuffer.addEvent (midiData, numBytes,
116  jlimit (0, numSamples - 1, samplePosition));
117  }
118  }
119  else
120  {
121  // if our event list is shorter than the number we need, put them
122  // towards the end of the buffer
123  startSample = numSamples - numSourceSamples;
124 
125  while (iter.getNextEvent (midiData, numBytes, samplePosition))
126  {
127  destBuffer.addEvent (midiData, numBytes,
128  jlimit (0, numSamples - 1, samplePosition + startSample));
129  }
130  }
131 
132  incomingMessages.clear();
133  }
134 }
135 
136 //==============================================================================
137 void MidiMessageCollector::handleNoteOn (MidiKeyboardState*, int midiChannel, int midiNoteNumber, float velocity)
138 {
139  MidiMessage m (MidiMessage::noteOn (midiChannel, midiNoteNumber, velocity));
141 
142  addMessageToQueue (m);
143 }
144 
145 void MidiMessageCollector::handleNoteOff (MidiKeyboardState*, int midiChannel, int midiNoteNumber, float velocity)
146 {
147  MidiMessage m (MidiMessage::noteOff (midiChannel, midiNoteNumber, velocity));
149 
150  addMessageToQueue (m);
151 }
152 
154 {
155  addMessageToQueue (message);
156 }
157 
158 } // namespace juce
juce::MidiMessage::setTimeStamp
void setTimeStamp(double newTimestamp) noexcept
Changes the message's associated timestamp.
Definition: juce_MidiMessage.h:173
juce::MidiBuffer::isEmpty
bool isEmpty() const noexcept
Returns true if the buffer is empty.
Definition: juce_MidiBuffer.cpp:108
juce::MidiMessageCollector::handleNoteOff
void handleNoteOff(MidiKeyboardState *, int midiChannel, int midiNoteNumber, float velocity) override
Definition: juce_MidiMessageCollector.cpp:145
juce::MidiBuffer::Iterator
Used to iterate through the events in a MidiBuffer.
Definition: juce_MidiBuffer.h:174
juce::MidiMessageCollector::reset
void reset(double sampleRate)
Clears any messages from the queue.
Definition: juce_MidiMessageCollector.cpp:35
juce::MidiBuffer::clear
void clear() noexcept
Removes all events from the buffer.
Definition: juce_MidiBuffer.cpp:106
juce::MidiBuffer
Holds a sequence of time-stamped midi events.
Definition: juce_MidiBuffer.h:46
juce::MidiInput
Represents a midi input device.
Definition: juce_MidiInput.h:96
juce::MidiBuffer::addEvent
void addEvent(const MidiMessage &midiMessage, int sampleNumber)
Adds an event to the buffer.
Definition: juce_MidiBuffer.cpp:118
juce::MidiMessageCollector::handleIncomingMidiMessage
void handleIncomingMidiMessage(MidiInput *, const MidiMessage &) override
Definition: juce_MidiMessageCollector.cpp:153
juce::MidiBuffer::Iterator::getNextEvent
bool getNextEvent(MidiMessage &result, int &samplePosition) noexcept
Retrieves a copy of the next event from the buffer.
Definition: juce_MidiBuffer.cpp:224
juce::MidiMessage::noteOn
static MidiMessage noteOn(int channel, int noteNumber, float velocity) noexcept
Creates a key-down message (using a floating-point velocity).
Definition: juce_MidiMessage.cpp:584
juce::MidiMessageCollector::removeNextBlockOfMessages
void removeNextBlockOfMessages(MidiBuffer &destBuffer, int numSamples)
Removes all the pending messages from the queue as a buffer.
Definition: juce_MidiMessageCollector.cpp:70
juce::MidiMessage
Encapsulates a MIDI message.
Definition: juce_MidiMessage.h:38
juce::MidiMessageCollector::addMessageToQueue
void addMessageToQueue(const MidiMessage &message)
Takes an incoming real-time message and adds it to the queue.
Definition: juce_MidiMessageCollector.cpp:48
juce::GenericScopedLock
Automatically locks and unlocks a mutex object.
Definition: juce_ScopedLock.h:58
juce::MidiMessageCollector::handleNoteOn
void handleNoteOn(MidiKeyboardState *, int midiChannel, int midiNoteNumber, float velocity) override
Definition: juce_MidiMessageCollector.cpp:137
juce::MidiMessage::getTimeStamp
double getTimeStamp() const noexcept
Returns the timestamp associated with this message.
Definition: juce_MidiMessage.h:167
juce::Time::getMillisecondCounterHiRes
static double getMillisecondCounterHiRes() noexcept
Returns the number of millisecs since a fixed event (usually system startup).
juce::MidiBuffer::Iterator::setNextSamplePosition
void setNextSamplePosition(int samplePosition) noexcept
Repositions the iterator so that the next event retrieved will be the first one whose sample position...
Definition: juce_MidiBuffer.cpp:201
juce::MidiMessageCollector::MidiMessageCollector
MidiMessageCollector()
Creates a MidiMessageCollector.
Definition: juce_MidiMessageCollector.cpp:26
juce::MidiKeyboardState
Represents a piano keyboard, keeping track of which keys are currently pressed.
Definition: juce_MidiKeyboardState.h:90
juce::MidiMessage::noteOff
static MidiMessage noteOff(int channel, int noteNumber, float velocity) noexcept
Creates a key-up message.
Definition: juce_MidiMessage.cpp:598
juce::MidiMessageCollector::~MidiMessageCollector
~MidiMessageCollector() override
Destructor.
Definition: juce_MidiMessageCollector.cpp:30