JUCE/examples/Demo/Source/Demos/AudioRecordingDemo.cpp

/*
  ==============================================================================

   This file is part of the JUCE library.
   Copyright (c) 2017 - ROLI Ltd.

   JUCE is an open source library subject to commercial or open-source
   licensing.

   By using JUCE, you agree to the terms of both the JUCE 5 End-User License
   Agreement and JUCE 5 Privacy Policy (both updated and effective as of the
   27th April 2017).

   End User License Agreement: www.juce.com/juce-5-licence
   Privacy Policy: www.juce.com/juce-5-privacy-policy

   Or: You may also use this code under the terms of the GPL v3 (see
   www.gnu.org/licenses).

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

  ==============================================================================
*/

#include "../JuceDemoHeader.h"
#include "AudioLiveScrollingDisplay.h"

//==============================================================================
/** A simple class that acts as an AudioIODeviceCallback and writes the
    incoming audio data to a WAV file.
*/
class AudioRecorder  : public AudioIODeviceCallback
{
public:
    AudioRecorder (AudioThumbnail& thumbnailToUpdate)
        : thumbnail (thumbnailToUpdate),
          backgroundThread ("Audio Recorder Thread"),
          sampleRate (0), nextSampleNum (0), activeWriter (nullptr)
    {
        backgroundThread.startThread();
    }

    ~AudioRecorder()
    {
        stop();
    }

    //==============================================================================
    void startRecording (const File& file)
    {
        stop();

        if (sampleRate > 0)
        {
            // Create an OutputStream to write to our destination file...
            file.deleteFile();
            ScopedPointer<FileOutputStream> fileStream (file.createOutputStream());

            if (fileStream != nullptr)
            {
                // Now create a WAV writer object that writes to our output stream...
                WavAudioFormat wavFormat;
                AudioFormatWriter* writer = wavFormat.createWriterFor (fileStream, sampleRate, 1, 16, StringPairArray(), 0);

                if (writer != nullptr)
                {
                    fileStream.release(); // (passes responsibility for deleting the stream to the writer object that is now using it)

                    // Now we'll create one of these helper objects which will act as a FIFO buffer, and will
                    // write the data to disk on our background thread.
                    threadedWriter = new AudioFormatWriter::ThreadedWriter (writer, backgroundThread, 32768);

                    // Reset our recording thumbnail
                    thumbnail.reset (writer->getNumChannels(), writer->getSampleRate());
                    nextSampleNum = 0;

                    // And now, swap over our active writer pointer so that the audio callback will start using it..
                    const ScopedLock sl (writerLock);
                    activeWriter = threadedWriter;
                }
            }
        }
    }

    void stop()
    {
        // First, clear this pointer to stop the audio callback from using our writer object..
        {
            const ScopedLock sl (writerLock);
            activeWriter = nullptr;
        }

        // Now we can delete the writer object. It's done in this order because the deletion could
        // take a little time while remaining data gets flushed to disk, so it's best to avoid blocking
        // the audio callback while this happens.
        threadedWriter = nullptr;
    }

    bool isRecording() const
    {
        return activeWriter != nullptr;
    }

    //==============================================================================
    void audioDeviceAboutToStart (AudioIODevice* device) override
    {
        sampleRate = device->getCurrentSampleRate();
    }

    void audioDeviceStopped() override
    {
        sampleRate = 0;
    }

    void audioDeviceIOCallback (const float** inputChannelData, int /*numInputChannels*/,
                                float** outputChannelData, int numOutputChannels,
                                int numSamples) override
    {
        const ScopedLock sl (writerLock);

        if (activeWriter != nullptr)
        {
            activeWriter->write (inputChannelData, numSamples);

            // Create an AudioSampleBuffer to wrap our incoming data, note that this does no allocations or copies, it simply references our input data
            const AudioSampleBuffer buffer (const_cast<float**> (inputChannelData), thumbnail.getNumChannels(), numSamples);
            thumbnail.addBlock (nextSampleNum, buffer, 0, numSamples);
            nextSampleNum += numSamples;
        }

        // We need to clear the output buffers, in case they're full of junk..
        for (int i = 0; i < numOutputChannels; ++i)
            if (outputChannelData[i] != nullptr)
                FloatVectorOperations::clear (outputChannelData[i], numSamples);
    }

private:
    AudioThumbnail& thumbnail;
    TimeSliceThread backgroundThread; // the thread that will write our audio data to disk
    ScopedPointer<AudioFormatWriter::ThreadedWriter> threadedWriter; // the FIFO used to buffer the incoming data
    double sampleRate;
    int64 nextSampleNum;

    CriticalSection writerLock;
    AudioFormatWriter::ThreadedWriter* volatile activeWriter;
};

//==============================================================================
class RecordingThumbnail  : public Component,
                            private ChangeListener
{
public:
    RecordingThumbnail()
        : thumbnailCache (10),
          thumbnail (512, formatManager, thumbnailCache),
          displayFullThumb (false)
    {
        formatManager.registerBasicFormats();
        thumbnail.addChangeListener (this);
    }

    ~RecordingThumbnail()
    {
        thumbnail.removeChangeListener (this);
    }

    AudioThumbnail& getAudioThumbnail()     { return thumbnail; }

    void setDisplayFullThumbnail (bool displayFull)
    {
        displayFullThumb = displayFull;
        repaint();
    }

    void paint (Graphics& g) override
    {
        g.fillAll (Colours::darkgrey);
        g.setColour (Colours::lightgrey);

        if (thumbnail.getTotalLength() > 0.0)
        {
            const double endTime = displayFullThumb ? thumbnail.getTotalLength()
                                                    : jmax (30.0, thumbnail.getTotalLength());

            Rectangle<int> thumbArea (getLocalBounds());
            thumbnail.drawChannels (g, thumbArea.reduced (2), 0.0, endTime, 1.0f);
        }
        else
        {
            g.setFont (14.0f);
            g.drawFittedText ("(No file recorded)", getLocalBounds(), Justification::centred, 2);
        }
    }

private:
    AudioFormatManager formatManager;
    AudioThumbnailCache thumbnailCache;
    AudioThumbnail thumbnail;
    bool displayFullThumb;

    void changeListenerCallback (ChangeBroadcaster* source) override
    {
        if (source == &thumbnail)
            repaint();
    }

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (RecordingThumbnail)
};

//==============================================================================
class AudioRecordingDemo  : public Component,
                            private Button::Listener
{
public:
    AudioRecordingDemo()
        : deviceManager (MainAppWindow::getSharedAudioDeviceManager()),
          recorder (recordingThumbnail.getAudioThumbnail())
    {
        setOpaque (true);
        addAndMakeVisible (liveAudioScroller);

        addAndMakeVisible (explanationLabel);
        explanationLabel.setText ("This page demonstrates how to record a wave file from the live audio input..\n\nPressing record will start recording a file in your \"Documents\" folder.", dontSendNotification);
        explanationLabel.setFont (Font (15.00f, Font::plain));
        explanationLabel.setJustificationType (Justification::topLeft);
        explanationLabel.setEditable (false, false, false);
        explanationLabel.setColour (TextEditor::textColourId, Colours::black);
        explanationLabel.setColour (TextEditor::backgroundColourId, Colour (0x00000000));

        addAndMakeVisible (recordButton);
        recordButton.setButtonText ("Record");
        recordButton.addListener (this);
        recordButton.setColour (TextButton::buttonColourId, Colour (0xffff5c5c));
        recordButton.setColour (TextButton::textColourOnId, Colours::black);

        addAndMakeVisible (recordingThumbnail);

        deviceManager.addAudioCallback (&liveAudioScroller);
        deviceManager.addAudioCallback (&recorder);
    }

    ~AudioRecordingDemo()
    {
        deviceManager.removeAudioCallback (&recorder);
        deviceManager.removeAudioCallback (&liveAudioScroller);
    }

    void paint (Graphics& g) override
    {
        g.fillAll (getUIColourIfAvailable (LookAndFeel_V4::ColourScheme::UIColour::windowBackground));
    }

    void resized() override
    {
        Rectangle<int> area (getLocalBounds());
        liveAudioScroller.setBounds (area.removeFromTop (80).reduced (8));
        recordingThumbnail.setBounds (area.removeFromTop (80).reduced (8));
        recordButton.setBounds (area.removeFromTop (36).removeFromLeft (140).reduced (8));
        explanationLabel.setBounds (area.reduced (8));
    }

private:
    AudioDeviceManager& deviceManager;
    LiveScrollingAudioDisplay liveAudioScroller;
    RecordingThumbnail recordingThumbnail;
    AudioRecorder recorder;
    Label explanationLabel;
    TextButton recordButton;

    void startRecording()
    {
        const File file (File::getSpecialLocation (File::userDocumentsDirectory)
                            .getNonexistentChildFile ("Juce Demo Audio Recording", ".wav"));
        recorder.startRecording (file);

        recordButton.setButtonText ("Stop");
        recordingThumbnail.setDisplayFullThumbnail (false);
    }

    void stopRecording()
    {
        recorder.stop();
        recordButton.setButtonText ("Record");
        recordingThumbnail.setDisplayFullThumbnail (true);
    }

    void buttonClicked (Button* button) override
    {
        if (button == &recordButton)
        {
            if (recorder.isRecording())
                stopRecording();
            else
                startRecording();
        }
    }

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (AudioRecordingDemo)
};


// This static object will register this demo type in a global list of demos..
static JuceDemoType<AudioRecordingDemo> demo ("31 Audio: Recording");