diff options
Diffstat (limited to 'src/multimedia/audio')
| -rw-r--r-- | src/multimedia/audio/qaudiobuffer.cpp | 118 | ||||
| -rw-r--r-- | src/multimedia/audio/qaudiobuffer.h | 33 | ||||
| -rw-r--r-- | src/multimedia/audio/qaudiobuffer_p.h | 2 | ||||
| -rw-r--r-- | src/multimedia/audio/qaudioformat.cpp | 112 | ||||
| -rw-r--r-- | src/multimedia/audio/qaudioformat.h | 12 |
5 files changed, 206 insertions, 71 deletions
diff --git a/src/multimedia/audio/qaudiobuffer.cpp b/src/multimedia/audio/qaudiobuffer.cpp index bde04501f..299a610fa 100644 --- a/src/multimedia/audio/qaudiobuffer.cpp +++ b/src/multimedia/audio/qaudiobuffer.cpp @@ -106,18 +106,18 @@ public: // Private class to go in .cpp file class QMemoryAudioBufferProvider : public QAbstractAudioBuffer { public: - QMemoryAudioBufferProvider(const void *data, int sampleCount, const QAudioFormat &format, qint64 startTime) + QMemoryAudioBufferProvider(const void *data, int frameCount, const QAudioFormat &format, qint64 startTime) : mStartTime(startTime) - , mSampleCount(sampleCount) + , mFrameCount(frameCount) , mFormat(format) { - int numBytes = (sampleCount * format.sampleSize()) / 8; + int numBytes = format.bytesForFrames(frameCount); if (numBytes > 0) { mBuffer = malloc(numBytes); if (!mBuffer) { // OOM, if that's likely mStartTime = -1; - mSampleCount = 0; + mFrameCount = 0; mFormat = QAudioFormat(); } else { // Allocated, see if we have data to copy @@ -149,19 +149,19 @@ public: void release() {delete this;} QAudioFormat format() const {return mFormat;} qint64 startTime() const {return mStartTime;} - int sampleCount() const {return mSampleCount;} + int frameCount() const {return mFrameCount;} void *constData() const {return mBuffer;} void *writableData() {return mBuffer;} QAbstractAudioBuffer *clone() const { - return new QMemoryAudioBufferProvider(mBuffer, mSampleCount, mFormat, mStartTime); + return new QMemoryAudioBufferProvider(mBuffer, mFrameCount, mFormat, mStartTime); } void *mBuffer; qint64 mStartTime; - int mSampleCount; + int mFrameCount; QAudioFormat mFormat; }; @@ -176,7 +176,7 @@ QAudioBufferPrivate *QAudioBufferPrivate::clone() QAbstractAudioBuffer *abuf = mProvider->clone(); if (!abuf) { - abuf = new QMemoryAudioBufferProvider(mProvider->constData(), mProvider->sampleCount(), mProvider->format(), mProvider->startTime()); + abuf = new QMemoryAudioBufferProvider(mProvider->constData(), mProvider->frameCount(), mProvider->format(), mProvider->startTime()); } if (abuf) { @@ -236,7 +236,7 @@ QAudioBuffer::QAudioBuffer(const QAudioBuffer &other) and sizes of the samples are interpreted from the \a data. If the supplied \a data is not an integer multiple of the - calculated sample size, the excess data will not be used. + calculated frame size, the excess data will not be used. This audio buffer will copy the contents of \a data. @@ -247,25 +247,25 @@ QAudioBuffer::QAudioBuffer(const QAudioBuffer &other) QAudioBuffer::QAudioBuffer(const QByteArray &data, const QAudioFormat &format, qint64 startTime) { if (format.isValid()) { - int sampleCount = (data.size() * 8) / format.sampleSize(); // truncate - d = new QAudioBufferPrivate(new QMemoryAudioBufferProvider(data.constData(), sampleCount, format, startTime)); + int frameCount = format.framesForBytes(data.size()); + d = new QAudioBufferPrivate(new QMemoryAudioBufferProvider(data.constData(), frameCount, format, startTime)); } else d = 0; } /*! - Creates a new audio buffer with space for \a numSamples samples of - the given \a format. The samples will be initialized to the default - for the format. + Creates a new audio buffer with space for \a numFrames frames of + the given \a format. The individual samples will be initialized + to the default for the format. \a startTime (in microseconds) indicates when this buffer starts in the stream. If this buffer is not part of a stream, set it to -1. */ -QAudioBuffer::QAudioBuffer(int numSamples, const QAudioFormat &format, qint64 startTime) +QAudioBuffer::QAudioBuffer(int numFrames, const QAudioFormat &format, qint64 startTime) { if (format.isValid()) - d = new QAudioBufferPrivate(new QMemoryAudioBufferProvider(0, numSamples, format, startTime)); + d = new QAudioBufferPrivate(new QMemoryAudioBufferProvider(0, numFrames, format, startTime)); else d = 0; } @@ -292,13 +292,13 @@ QAudioBuffer::~QAudioBuffer() /*! Returns true if this is a valid buffer. A valid buffer - has more than zero samples in it and a valid format. + has more than zero frames in it and a valid format. */ bool QAudioBuffer::isValid() const { if (!d || !d->mProvider) return false; - return d->mProvider->format().isValid() && (d->mProvider->sampleCount() > 0); + return d->mProvider->format().isValid() && (d->mProvider->frameCount() > 0); } /*! @@ -306,7 +306,7 @@ bool QAudioBuffer::isValid() const Several properties of this format influence how the \l duration() or \l byteCount() are calculated - from the \l sampleCount(). + from the \l frameCount(). */ QAudioFormat QAudioBuffer::format() const { @@ -316,6 +316,19 @@ QAudioFormat QAudioBuffer::format() const } /*! + Returns the number of complete audio frames in this buffer. + + An audio frame is an interleaved set of one sample per channel + for the same instant in time. +*/ +int QAudioBuffer::frameCount() const +{ + if (!isValid()) + return 0; + return d->mProvider->frameCount(); +} + +/*! Returns the number of samples in this buffer. If the format of this buffer has multiple channels, @@ -323,12 +336,15 @@ QAudioFormat QAudioBuffer::format() const that a stereo buffer with 1000 samples in total will have 500 left samples and 500 right samples (interleaved), and this function will return 1000. - */ + + \sa frameCount() +*/ int QAudioBuffer::sampleCount() const { if (!isValid()) return 0; - return d->mProvider->sampleCount(); + + return frameCount() * format().channelCount(); } /*! @@ -337,21 +353,17 @@ int QAudioBuffer::sampleCount() const int QAudioBuffer::byteCount() const { const QAudioFormat f(format()); - return (f.sampleSize() * sampleCount()) / 8; // sampleSize is in bits + return format().bytesForFrames(frameCount()); } /*! Returns the duration of audio in this buffer, in microseconds. - This depends on the /l format(), and the \l sampleCount(). + This depends on the /l format(), and the \l frameCount(). */ qint64 QAudioBuffer::duration() const { - int divisor = format().sampleRate() * format().channelCount(); - if (divisor > 0) - return (sampleCount() * 1000000LL) / divisor; - else - return 0; + return format().durationForFrames(frameCount()); } /*! @@ -471,7 +483,7 @@ void *QAudioBuffer::data() } // Wasn't writable, so turn it into a memory provider - QAbstractAudioBuffer *memBuffer = new QMemoryAudioBufferProvider(constData(), sampleCount(), format(), startTime()); + QAbstractAudioBuffer *memBuffer = new QMemoryAudioBufferProvider(constData(), frameCount(), format(), startTime()); if (memBuffer) { d->mProvider->release(); @@ -487,35 +499,35 @@ void *QAudioBuffer::data() // Template helper classes worth documenting /*! - \class QAudioBuffer::StereoSampleDefault + \class QAudioBuffer::StereoFrameDefault \internal Just a trait class for the default value. */ /*! - \class QAudioBuffer::StereoSample - \brief The StereoSample class provides a simple wrapper for a stereo audio sample. + \class QAudioBuffer::StereoFrame + \brief The StereoFrame class provides a simple wrapper for a stereo audio frame. \inmodule QtMultimedia \ingroup multimedia \ingroup multimedia_audio This templatized structure lets you treat a block of individual samples as an - interleaved stereo stream. This is most useful when used with the templatized + interleaved stereo stream frame. This is most useful when used with the templatized \l {QAudioBuffer::data()}{data()} functions of QAudioBuffer. Generally the data is accessed as a pointer, so no copying should occur. There are some predefined instantiations of this template for working with common stereo sample depths in a convenient way. - This structure has \e left and \e right members for accessing individual channel data. + This frame structure has \e left and \e right members for accessing individual channel data. For example: \code // Assuming 'buffer' is an unsigned 16 bit stereo buffer.. - QAudioBuffer::S16U *sample = buffer->data<QAudioBuffer::S16U>(); - for (int i=0; i < buffer->sampleCount() / 2; i++) { - qSwap(sample[i].left, sample[i].right); + QAudioBuffer::S16U *frames = buffer->data<QAudioBuffer::S16U>(); + for (int i=0; i < buffer->frameCount(); i++) { + qSwap(frames[i].left, frames[i].right); } \endcode @@ -523,77 +535,77 @@ void *QAudioBuffer::data() */ /*! - \fn QAudioBuffer::StereoSample::StereoSample() + \fn QAudioBuffer::StereoFrame::StereoFrame() - Constructs a new sample with the "silent" value for this + Constructs a new frame with the "silent" value for this sample format (0 for signed formats and floats, 0x8* for unsigned formats). */ /*! - \fn QAudioBuffer::StereoSample::StereoSample(T leftSample, T rightSample) + \fn QAudioBuffer::StereoFrame::StereoFrame(T leftSample, T rightSample) - Constructs a new sample with the supplied \a leftSample and \a rightSample values. + Constructs a new frame with the supplied \a leftSample and \a rightSample values. */ /*! - \fn QAudioBuffer::StereoSample::operator=(const StereoSample &other) + \fn QAudioBuffer::StereoFrame::operator=(const StereoFrame &other) - Assigns \a other to this sample. + Assigns \a other to this frame. */ /*! - \fn QAudioBuffer::StereoSample::average() const + \fn QAudioBuffer::StereoFrame::average() const Returns the arithmetic average of the left and right samples. */ -/*! \fn QAudioBuffer::StereoSample::clear() +/*! \fn QAudioBuffer::StereoFrame::clear() - Sets the values of this sample to the "silent" value. + Sets the values of this frame to the "silent" value. */ /*! - \variable QAudioBuffer::StereoSample::left + \variable QAudioBuffer::StereoFrame::left \brief the left sample */ /*! - \variable QAudioBuffer::StereoSample::right + \variable QAudioBuffer::StereoFrame::right \brief the right sample */ /*! \typedef QAudioBuffer::S8U - \relates QAudioBuffer::StereoSample + \relates QAudioBuffer::StereoFrame This is a predefined specialization for an unsigned stereo 8 bit sample. Each channel is an \e {unsigned char}. */ /*! \typedef QAudioBuffer::S8S - \relates QAudioBuffer::StereoSample + \relates QAudioBuffer::StereoFrame This is a predefined specialization for a signed stereo 8 bit sample. Each channel is a \e {signed char}. */ /*! \typedef QAudioBuffer::S16U - \relates QAudioBuffer::StereoSample + \relates QAudioBuffer::StereoFrame This is a predefined specialization for an unsigned stereo 16 bit sample. Each channel is an \e {unsigned short}. */ /*! \typedef QAudioBuffer::S16S - \relates QAudioBuffer::StereoSample + \relates QAudioBuffer::StereoFrame This is a predefined specialization for a signed stereo 16 bit sample. Each channel is a \e {signed short}. */ /*! \typedef QAudioBuffer::S32F - \relates QAudioBuffer::StereoSample + \relates QAudioBuffer::StereoFrame This is a predefined specialization for an 32 bit float sample. Each channel is a \e float. diff --git a/src/multimedia/audio/qaudiobuffer.h b/src/multimedia/audio/qaudiobuffer.h index 14718cb38..ac16e2182 100644 --- a/src/multimedia/audio/qaudiobuffer.h +++ b/src/multimedia/audio/qaudiobuffer.h @@ -65,7 +65,7 @@ public: QAudioBuffer(QAbstractAudioBuffer *provider); QAudioBuffer(const QAudioBuffer &other); QAudioBuffer(const QByteArray &data, const QAudioFormat &format, qint64 startTime = -1); - QAudioBuffer(int numSamples, const QAudioFormat &format, qint64 startTime = -1); // Initialized to empty + QAudioBuffer(int numFrames, const QAudioFormat &format, qint64 startTime = -1); // Initialized to empty QAudioBuffer& operator=(const QAudioBuffer &other); @@ -75,6 +75,7 @@ public: QAudioFormat format() const; + int frameCount() const; int sampleCount() const; int byteCount() const; @@ -93,23 +94,23 @@ public: void *data(); // detaches // Structures for easier access to stereo data - template <typename T> struct StereoSampleDefault { enum { Default = 0 }; }; + template <typename T> struct StereoFrameDefault { enum { Default = 0 }; }; - template <typename T> struct StereoSample { + template <typename T> struct StereoFrame { - StereoSample() - : left(T(StereoSampleDefault<T>::Default)) - , right(T(StereoSampleDefault<T>::Default)) + StereoFrame() + : left(T(StereoFrameDefault<T>::Default)) + , right(T(StereoFrameDefault<T>::Default)) { } - StereoSample(T leftSample, T rightSample) + StereoFrame(T leftSample, T rightSample) : left(leftSample) , right(rightSample) { } - StereoSample& operator=(const StereoSample &other) + StereoFrame& operator=(const StereoFrame &other) { // Two straight assigns is probably // cheaper than a conditional check on @@ -123,14 +124,14 @@ public: T right; T average() const {return (left + right) / 2;} - void clear() {left = right = T(StereoSampleDefault<T>::Default);} + void clear() {left = right = T(StereoFrameDefault<T>::Default);} }; - typedef StereoSample<unsigned char> S8U; - typedef StereoSample<signed char> S8S; - typedef StereoSample<unsigned short> S16U; - typedef StereoSample<signed short> S16S; - typedef StereoSample<float> S32F; + typedef StereoFrame<unsigned char> S8U; + typedef StereoFrame<signed char> S8S; + typedef StereoFrame<unsigned short> S16U; + typedef StereoFrame<signed short> S16S; + typedef StereoFrame<float> S32F; template <typename T> const T* constData() const { return static_cast<const T*>(constData()); @@ -145,8 +146,8 @@ private: QAudioBufferPrivate *d; }; -template <> struct QAudioBuffer::StereoSampleDefault<unsigned char> { enum { Default = 128 }; }; -template <> struct QAudioBuffer::StereoSampleDefault<unsigned short> { enum { Default = 32768 }; }; +template <> struct QAudioBuffer::StereoFrameDefault<unsigned char> { enum { Default = 128 }; }; +template <> struct QAudioBuffer::StereoFrameDefault<unsigned short> { enum { Default = 32768 }; }; QT_END_NAMESPACE diff --git a/src/multimedia/audio/qaudiobuffer_p.h b/src/multimedia/audio/qaudiobuffer_p.h index 854ca23fc..5f6d3168a 100644 --- a/src/multimedia/audio/qaudiobuffer_p.h +++ b/src/multimedia/audio/qaudiobuffer_p.h @@ -66,7 +66,7 @@ public: // Format related virtual QAudioFormat format() const = 0; virtual qint64 startTime() const = 0; - virtual int sampleCount() const = 0; + virtual int frameCount() const = 0; // R/O Data virtual void *constData() const = 0; diff --git a/src/multimedia/audio/qaudioformat.cpp b/src/multimedia/audio/qaudioformat.cpp index c91620b37..32e17a9f9 100644 --- a/src/multimedia/audio/qaudioformat.cpp +++ b/src/multimedia/audio/qaudioformat.cpp @@ -146,7 +146,8 @@ public: This class is typically used in conjunction with QAudioInput or QAudioOutput to allow you to specify the parameters of the audio - stream being read or written. + stream being read or written, or with QAudioBuffer when dealing with + samples in memory. You can obtain audio formats compatible with the audio device used through functions in QAudioDeviceInfo. This class also lets you @@ -154,6 +155,11 @@ public: the parameters yourself. See the \l QAudioDeviceInfo class description for details. You need to know the format of the audio streams you wish to play or record. + + In the common case of interleaved linear PCM data, the codec will + be "audio/pcm", and the samples for all channels will be interleaved. + One sample for each channel for the same instant in time is referred + to as a frame in QtMultimedia (and other places). */ /*! @@ -282,6 +288,8 @@ void QAudioFormat::setSampleSize(int sampleSize) /*! Returns the current sample size value, in bits. + + \sa bytesPerFrame() */ int QAudioFormat::sampleSize() const { @@ -345,6 +353,108 @@ QAudioFormat::SampleType QAudioFormat::sampleType() const } /*! + Returns the number of bytes required for this audio format for \a duration microseconds. + + Returns 0 if this format is not valid. + + Note that some rounding may occur if \a duration is not an exact fraction of the + sampleRate(). + + \sa durationForBytes() + */ +qint32 QAudioFormat::bytesForDuration(qint64 duration) const +{ + return bytesPerFrame() * framesForDuration(duration); +} + +/*! + Returns the number of microseconds represented by \a bytes in this format. + + Returns 0 if this format is not valid. + + Note that some rounding may occur if \a bytes is not an exact multiple + of the number of bytes per frame. + + \sa bytesForDuration() +*/ +qint64 QAudioFormat::durationForBytes(qint32 bytes) const +{ + if (!isValid() || bytes <= 0) + return 0; + + // We round the byte count to ensure whole frames + return qint64(1000000LL * (bytes / bytesPerFrame())) / sampleRate(); +} + +/*! + Returns the number of bytes required for \a frameCount frames of this format. + + Returns 0 if this format is not valid. + + \sa bytesForDuration() +*/ +qint32 QAudioFormat::bytesForFrames(qint32 frameCount) const +{ + return frameCount * bytesPerFrame(); +} + +/*! + Returns the number of frames represented by \a byteCount in this format. + + Note that some rounding may occur if \a byteCount is not an exact multiple + of the number of bytes per frame. + + Each frame has one sample per channel. + + \sa framesForDuration() +*/ +qint32 QAudioFormat::framesForBytes(qint32 byteCount) const +{ + int size = bytesPerFrame(); + if (size > 0) + return byteCount / size; + return 0; +} + +/*! + Returns the number of frames required to represent \a duration microseconds in this format. + + Note that some rounding may occur if \a duration is not an exact fraction of the + \l sampleRate(). +*/ +qint32 QAudioFormat::framesForDuration(qint64 duration) const +{ + if (!isValid()) + return 0; + + return qint32((duration * sampleRate()) / 1000000LL); +} + +/*! + Return the number of microseconds represented by \a frameCount frames in this format. +*/ +qint64 QAudioFormat::durationForFrames(qint32 frameCount) const +{ + if (!isValid() || frameCount <= 0) + return 0; + + return (frameCount * 1000000LL) / sampleRate(); +} + +/*! + Returns the number of bytes required to represent one frame (a sample in each channel) in this format. + + Returns 0 if this format is invalid. +*/ +int QAudioFormat::bytesPerFrame() const +{ + if (!isValid()) + return 0; + + return (sampleSize() * channelCount()) / 8; +} + +/*! \enum QAudioFormat::SampleType \value Unknown Not Set diff --git a/src/multimedia/audio/qaudioformat.h b/src/multimedia/audio/qaudioformat.h index 3bc5780d6..fccb206eb 100644 --- a/src/multimedia/audio/qaudioformat.h +++ b/src/multimedia/audio/qaudioformat.h @@ -91,6 +91,18 @@ public: void setSampleType(QAudioFormat::SampleType sampleType); QAudioFormat::SampleType sampleType() const; + // Helper functions + qint32 bytesForDuration(qint64 duration) const; + qint64 durationForBytes(qint32 byteCount) const; + + qint32 bytesForFrames(qint32 frameCount) const; + qint32 framesForBytes(qint32 byteCount) const; + + qint32 framesForDuration(qint64 duration) const; + qint64 durationForFrames(qint32 frameCount) const; + + int bytesPerFrame() const; + private: QSharedDataPointer<QAudioFormatPrivate> d; }; |