230 lines
9.5 KiB
C++
230 lines
9.5 KiB
C++
/*
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==============================================================================
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This file is part of the JUCE library.
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Copyright (c) 2017 - ROLI Ltd.
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JUCE is an open source library subject to commercial or open-source
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licensing.
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By using JUCE, you agree to the terms of both the JUCE 5 End-User License
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Agreement and JUCE 5 Privacy Policy (both updated and effective as of the
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27th April 2017).
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End User License Agreement: www.juce.com/juce-5-licence
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Privacy Policy: www.juce.com/juce-5-privacy-policy
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Or: You may also use this code under the terms of the GPL v3 (see
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www.gnu.org/licenses).
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JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
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EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
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DISCLAIMED.
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==============================================================================
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*/
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namespace juce
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{
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//==============================================================================
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/**
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Makes it easy to quickly draw scaled views of the waveform shape of an
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audio file.
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To use this class, just create an AudioThumbNail class for the file you want
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to draw, call setSource to tell it which file or resource to use, then call
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drawChannel() to draw it.
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The class will asynchronously scan the wavefile to create its scaled-down view,
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so you should make your UI repaint itself as this data comes in. To do this, the
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AudioThumbnail is a ChangeBroadcaster, and will broadcast a message when its
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listeners should repaint themselves.
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The thumbnail stores an internal low-res version of the wave data, and this can
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be loaded and saved to avoid having to scan the file again.
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@see AudioThumbnailCache, AudioThumbnailBase
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@tags{Audio}
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*/
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class JUCE_API AudioThumbnail : public AudioThumbnailBase
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{
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public:
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//==============================================================================
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/** Creates an audio thumbnail.
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@param sourceSamplesPerThumbnailSample when creating a stored, low-res version
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of the audio data, this is the scale at which it should be done. (This
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number is the number of original samples that will be averaged for each
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low-res sample)
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@param formatManagerToUse the audio format manager that is used to open the file
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@param cacheToUse an instance of an AudioThumbnailCache - this provides a background
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thread and storage that is used to by the thumbnail, and the cache
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object can be shared between multiple thumbnails
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*/
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AudioThumbnail (int sourceSamplesPerThumbnailSample,
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AudioFormatManager& formatManagerToUse,
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AudioThumbnailCache& cacheToUse);
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/** Destructor. */
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~AudioThumbnail();
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//==============================================================================
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/** Clears and resets the thumbnail. */
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void clear() override;
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/** Specifies the file or stream that contains the audio file.
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For a file, just call
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@code
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setSource (new FileInputSource (file))
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@endcode
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You can pass a nullptr in here to clear the thumbnail.
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The source that is passed in will be deleted by this object when it is no longer needed.
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@returns true if the source could be opened as a valid audio file, false if this failed for
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some reason.
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*/
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bool setSource (InputSource* newSource) override;
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/** Gives the thumbnail an AudioFormatReader to use directly.
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This will start parsing the audio in a background thread (unless the hash code
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can be looked-up successfully in the thumbnail cache). Note that the reader
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object will be held by the thumbnail and deleted later when no longer needed.
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The thumbnail will actually keep hold of this reader until you clear the thumbnail
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or change the input source, so the file will be held open for all this time. If
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you don't want the thumbnail to keep a file handle open continuously, you
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should use the setSource() method instead, which will only open the file when
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it needs to.
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*/
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void setReader (AudioFormatReader* newReader, int64 hashCode) override;
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/** Resets the thumbnail, ready for adding data with the specified format.
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If you're going to generate a thumbnail yourself, call this before using addBlock()
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to add the data.
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*/
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void reset (int numChannels, double sampleRate, int64 totalSamplesInSource = 0) override;
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/** Adds a block of level data to the thumbnail.
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Call reset() before using this, to tell the thumbnail about the data format.
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*/
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void addBlock (int64 sampleNumberInSource, const AudioBuffer<float>& newData,
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int startOffsetInBuffer, int numSamples) override;
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//==============================================================================
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/** Reloads the low res thumbnail data from an input stream.
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This is not an audio file stream! It takes a stream of thumbnail data that would
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previously have been created by the saveTo() method.
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@see saveTo
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*/
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bool loadFrom (InputStream& input) override;
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/** Saves the low res thumbnail data to an output stream.
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The data that is written can later be reloaded using loadFrom().
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@see loadFrom
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*/
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void saveTo (OutputStream& output) const override;
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//==============================================================================
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/** Returns the number of channels in the file. */
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int getNumChannels() const noexcept override;
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/** Returns the length of the audio file, in seconds. */
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double getTotalLength() const noexcept override;
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/** Draws the waveform for a channel.
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The waveform will be drawn within the specified rectangle, where startTime
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and endTime specify the times within the audio file that should be positioned
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at the left and right edges of the rectangle.
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The waveform will be scaled vertically so that a full-volume sample will fill
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the rectangle vertically, but you can also specify an extra vertical scale factor
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with the verticalZoomFactor parameter.
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*/
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void drawChannel (Graphics& g,
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const Rectangle<int>& area,
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double startTimeSeconds,
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double endTimeSeconds,
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int channelNum,
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float verticalZoomFactor) override;
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/** Draws the waveforms for all channels in the thumbnail.
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This will call drawChannel() to render each of the thumbnail's channels, stacked
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above each other within the specified area.
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@see drawChannel
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*/
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void drawChannels (Graphics& g,
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const Rectangle<int>& area,
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double startTimeSeconds,
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double endTimeSeconds,
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float verticalZoomFactor) override;
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/** Returns true if the low res preview is fully generated. */
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bool isFullyLoaded() const noexcept override;
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/** Returns a value between 0 and 1 to indicate the progress towards loading the entire file. */
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double getProportionComplete() const noexcept;
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/** Returns the number of samples that have been set in the thumbnail. */
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int64 getNumSamplesFinished() const noexcept override;
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/** Returns the highest level in the thumbnail.
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Note that because the thumb only stores low-resolution data, this isn't
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an accurate representation of the highest value, it's only a rough approximation.
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*/
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float getApproximatePeak() const override;
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/** Reads the approximate min and max levels from a section of the thumbnail.
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The lowest and highest samples are returned in minValue and maxValue, but obviously
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because the thumb only stores low-resolution data, these numbers will only be a rough
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approximation of the true values.
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*/
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void getApproximateMinMax (double startTime, double endTime, int channelIndex,
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float& minValue, float& maxValue) const noexcept override;
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/** Returns the hash code that was set by setSource() or setReader(). */
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int64 getHashCode() const override;
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private:
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//==============================================================================
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AudioFormatManager& formatManagerToUse;
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AudioThumbnailCache& cache;
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class LevelDataSource;
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struct MinMaxValue;
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class ThumbData;
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class CachedWindow;
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friend class LevelDataSource;
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friend class ThumbData;
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friend class CachedWindow;
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friend struct ContainerDeletePolicy<LevelDataSource>;
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friend struct ContainerDeletePolicy<ThumbData>;
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friend struct ContainerDeletePolicy<CachedWindow>;
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std::unique_ptr<LevelDataSource> source;
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std::unique_ptr<CachedWindow> window;
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OwnedArray<ThumbData> channels;
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int32 samplesPerThumbSample = 0;
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int64 totalSamples = 0, numSamplesFinished = 0;
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int32 numChannels = 0;
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double sampleRate = 0;
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CriticalSection lock;
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void clearChannelData();
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bool setDataSource (LevelDataSource* newSource);
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void setLevels (const MinMaxValue* const* values, int thumbIndex, int numChans, int numValues);
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void createChannels (int length);
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JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (AudioThumbnail)
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};
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} // namespace juce
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