Kwave::Writer Class Reference

#include <Writer.h>

Inheritance diagram for Kwave::Writer:

Collaboration diagram for Kwave::Writer:

Public Slots
void	input (Kwave::SampleArray data)

Signals
void	sigSamplesWritten (sample_index_t)
void	proceeded ()
Signals inherited from Kwave::StreamObject
void	attributeChanged (const QVariant value)

Public Member Functions
	Writer ()
	Writer (Kwave::InsertMode mode, sample_index_t left=0, sample_index_t right=0)
virtual	~Writer () Q_DECL_OVERRIDE
virtual Writer &	operator<< (const Kwave::SampleArray &samples)
virtual Writer &	operator<< (const sample_t &sample)
Writer &	operator<< (Writer &(*modifier)(Writer &))
Writer &	operator<< (Kwave::SampleReader &reader)
virtual bool	write (const Kwave::SampleArray &buffer, unsigned int &count)=0
bool	flush ()
virtual bool	eof () const
virtual bool	done () const Q_DECL_OVERRIDE
sample_index_t	first () const
sample_index_t	last () const
sample_index_t	position () const
Kwave::InsertMode	mode () const
Public Member Functions inherited from Kwave::SampleSink
	SampleSink (QObject *parent=Q_NULLPTR)
virtual	~SampleSink ()
Public Member Functions inherited from Kwave::StreamObject
	StreamObject (QObject *parent=Q_NULLPTR)
virtual	~StreamObject ()
virtual unsigned int	tracks () const
virtual Kwave::StreamObject *	operator[] (unsigned int track)
virtual unsigned int	tracksOfPort (const char *port) const
virtual Kwave::StreamObject *	port (const char *port, unsigned int track)
virtual unsigned int	blockSize () const
void	setAttribute (const char *attribute, const QVariant &value)

Protected Attributes
sample_index_t	m_first
sample_index_t	m_last
Kwave::InsertMode	m_mode
sample_index_t	m_position
Kwave::SampleArray	m_buffer
unsigned int	m_buffer_size
unsigned int	m_buffer_used

Additional Inherited Members
Static Public Member Functions inherited from Kwave::StreamObject
static void	setInteractive (bool interactive)

Detailed Description

Definition at line 35 of file Writer.h.

Constructor & Destructor Documentation

Writer() [1/2]

Kwave::Writer::Writer

(

)

default constructor

Definition at line 35 of file Writer.cpp.

    :Kwave::SampleSink(Q_NULLPTR),
     m_first(0), m_last(0), m_mode(Kwave::Insert), m_position(0),
     m_buffer(BUFFER_SIZE), m_buffer_size(BUFFER_SIZE), m_buffer_used(0)
{
}

Writer() [2/2]

Kwave::Writer::Writer ( Kwave::InsertMode  mode, sample_index_t  left = 0, sample_index_t  right = 0  )

explicit

Constructor. Creates an input stream for writing.

Parameters

mode	specifies where and how to insert
left	start of the input (only useful in insert and overwrite mode)
right	end of the input (only useful with overwrite mode)

See also

InsertMode

Definition at line 43 of file Writer.cpp.

    :Kwave::SampleSink(Q_NULLPTR),
     m_first(left), m_last(right), m_mode(mode), m_position(left),
     m_buffer(BUFFER_SIZE), m_buffer_size(BUFFER_SIZE), m_buffer_used(0)
{
}

~Writer()

Kwave::Writer::~Writer ( )

virtual

Destructor

Definition at line 52 of file Writer.cpp.

References m_buffer_used, m_first, m_last, m_mode, m_position, Kwave::Overwrite, and sigSamplesWritten().

{
    // If this assert gets hit, you deleted a writer without calling
    // flush() before. Flushing in the destructor is problematic and
    // might be too late when the derived classes' destructor was
    // already done and signal/slot connections were already released!
    Q_ASSERT(!m_buffer_used);
    if (m_buffer_used) qWarning("Writer was not flushed!?");

    Q_ASSERT((m_mode != Kwave::Overwrite) || (m_position <= m_last + 1));

    // inform others that we proceeded
    emit sigSamplesWritten(m_position - m_first);
}

Member Function Documentation

done()

virtual bool Kwave::Writer::done ( ) const

inlinevirtual

the same as eof(), needed for the Kwave::SampleSink interface

Reimplemented from Kwave::SampleSink.

Definition at line 105 of file Writer.h.

{ return eof(); }

eof()

bool Kwave::Writer::eof ( ) const

virtual

Returns true if the end of the writeable area has been reached if the writer has been opened in "overwrite" mode. Note that this does not make sense in append or insert mode, so in these cases the return value will always be false.

Definition at line 139 of file Writer.cpp.

References m_last, m_mode, m_position, and Kwave::Overwrite.

Referenced by operator<<().

{
    return (m_mode == Kwave::Overwrite) ? (m_position > m_last) : false;
}

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first()

sample_index_t Kwave::Writer::first ( ) const

inline

Returns the index of the first sample of the range.

Definition at line 108 of file Writer.h.

Referenced by Kwave::MultiTrackWriter::init(), and Kwave::MultiWriter::proceeded().

{ return m_first; }

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flush()

bool Kwave::Writer::flush ( )

inline

Shortcut for flush(m_buffer, m_buffer_used)

Definition at line 94 of file Writer.h.

Referenced by Kwave::MultiWriter::flush(), flush(), operator<<(), Kwave::ReversePlugin::reverseSlice(), and Kwave::TrackWriter::~TrackWriter().

{ return write(m_buffer, m_buffer_used); }

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input

void Kwave::Writer::input ( Kwave::SampleArray  data )

slot

Interface for the signal/slot based streaming API.

Parameters

data	sample data to write

Definition at line 152 of file Writer.cpp.

References Kwave::SampleArray::size().

{
    if (data.size()) (*this) << data;
}

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last()

sample_index_t Kwave::Writer::last ( ) const

inline

Returns the current index of the last sample in range or the index of the last written sample when in insert/append mode.

Definition at line 114 of file Writer.h.

References Kwave::Append.

Referenced by Kwave::MultiTrackWriter::init(), Kwave::MultiWriter::last(), and Kwave::MultiWriter::proceeded().

                                           {
            return ((m_mode == Kwave::Append) ?
                (m_last + m_buffer_used) : m_last);
        }

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mode()

Kwave::InsertMode Kwave::Writer::mode ( ) const

inline

Returns the insert mode

Definition at line 125 of file Writer.h.

Referenced by Kwave::MultiWriter::proceeded().

{ return m_mode; }

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operator<<() [1/4]

Kwave::Writer & Kwave::Writer::operator<< ( const Kwave::SampleArray &  samples )

virtual

operator for inserting an array of samples

Definition at line 68 of file Writer.cpp.

References flush(), m_buffer, m_buffer_size, m_buffer_used, MEMCPY, MIN_DIRECT_IO_BLOCK_SIZE, Kwave::SampleArray::size(), and write().

{
    unsigned int count = samples.size();

    if ( (m_buffer_used || (count < MIN_DIRECT_IO_BLOCK_SIZE)) &&
         (m_buffer_used + count <= m_buffer_size) )
    {
        // append to the internal buffer if it is already in use
        // and if there is still some room,
        // or if the buffer so small that it would make too much overhead
        // to process it by block operation
        MEMCPY(&(m_buffer[m_buffer_used]), &(samples[0]),
               count * sizeof(sample_t));
        m_buffer_used += count;
        if (m_buffer_used >= m_buffer_size) flush();
    } else {
        // first flush the single-sample buffer before doing block operation
        if (m_buffer_used) flush();

        // now flush the block that we received as parameter (pass-through)
        write(samples, count);
        Q_ASSERT(!count);
    }

    return *this;
}

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operator<<() [2/4]

Kwave::Writer & Kwave::Writer::operator<< ( const sample_t &  sample )

virtual

operator for inserting a single sample

Definition at line 96 of file Writer.cpp.

References flush(), m_buffer, m_buffer_size, and m_buffer_used.

{
    m_buffer[m_buffer_used++] = sample;
    if (m_buffer_used >= m_buffer_size) flush();
    return *this;
}

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operator<<() [3/4]

Writer& Kwave::Writer::operator<< ( Writer &(*)(Writer &)  modifier )

inline

operator for simple modifiers like flush()

Definition at line 65 of file Writer.h.

        {
            return modifier(*this);
        }

operator<<() [4/4]

Kwave::Writer & Kwave::Writer::operator<<

(

Kwave::SampleReader &

reader

)

Fill the Writer with data from a SampleReader. If the reader reaches EOF the writer will be filled up with zeroes.

Definition at line 104 of file Writer.cpp.

References Kwave::SampleReader::eof(), eof(), flush(), m_buffer, m_buffer_size, m_buffer_used, m_last, m_mode, m_position, Kwave::Overwrite, Kwave::SampleReader::read(), and Kwave::toUint().

{
    if (m_buffer_used) flush();

    // transfer data, using our internal buffer
    unsigned int buflen = m_buffer_size;
    while (!reader.eof() && !eof()) {

        // overwrite mode -> clip at right border
        if (m_mode == Kwave::Overwrite) {
            if (m_position + buflen - 1 > m_last)
                buflen = Kwave::toUint(m_last - m_position + 1);
        }

        m_buffer_used = reader.read(m_buffer, 0, buflen);
        Q_ASSERT(m_buffer_used);
        if (!m_buffer_used) break;

        if (!flush()) return *this; // out of memory
    }

    // pad the rest with zeroes
    if (m_mode == Kwave::Overwrite) {
        Q_ASSERT(m_position <= m_last + 1);
        while (m_buffer_used + m_position <= m_last) {
            *this << static_cast<sample_t>(0);
            m_position++;
        }
        Q_ASSERT(m_position <= m_last + 1);
    }

    return *this;
}

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position()

sample_index_t Kwave::Writer::position ( ) const

inline

Returns the current position

Definition at line 122 of file Writer.h.

Referenced by Kwave::MultiWriter::proceeded().

{ return m_position; }

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proceeded

void Kwave::Writer::proceeded ( )

signal

Emitted when the internal buffer is flushed or the writer is closed

Referenced by Kwave::TrackWriter::write().

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sigSamplesWritten

void Kwave::Writer::sigSamplesWritten ( sample_index_t  )

signal

Is emitted once immediately before the writer gets closed and tells the receiver the total number of written samples.

Referenced by ~Writer().

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write()

virtual bool Kwave::Writer::write ( const Kwave::SampleArray &  buffer, unsigned int &  count  )

pure virtual

Flush the content of a buffer. Normally the buffer is the internal intermediate buffer used for single-sample writes. When using block transfers, the internal buffer is bypassed and the written block is passed instead.

Parameters

buffer	reference to the buffer to be flushed
count	number of samples in the buffer to be flushed, will be internally set to zero if successful

Returns

true if successful, false if failed (e.g. out of memory)

Implemented in Kwave::TrackWriter, and Kwave::StreamWriter.

Referenced by Kwave::RecordPlugin::flushPrerecordingQueue(), and operator<<().

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Member Data Documentation

m_buffer

Kwave::SampleArray Kwave::Writer::m_buffer

protected

intermediate buffer for the input data

Definition at line 161 of file Writer.h.

Referenced by operator<<().

m_buffer_size

unsigned int Kwave::Writer::m_buffer_size

protected

for speedup: cached buffer size

Definition at line 164 of file Writer.h.

Referenced by operator<<().

m_buffer_used

unsigned int Kwave::Writer::m_buffer_used

protected

number of used elements in the buffer

Definition at line 167 of file Writer.h.

Referenced by operator<<(), Kwave::StreamWriter::~StreamWriter(), and ~Writer().

m_first

sample_index_t Kwave::Writer::m_first

protected

first sample

Definition at line 149 of file Writer.h.

Referenced by ~Writer().

m_last

sample_index_t Kwave::Writer::m_last

protected

last sample

Definition at line 152 of file Writer.h.

Referenced by eof(), operator<<(), Kwave::TrackWriter::write(), and ~Writer().

m_mode

Kwave::InsertMode Kwave::Writer::m_mode

protected

mode for input (insert, overwrite, ...)

Definition at line 155 of file Writer.h.

Referenced by eof(), operator<<(), Kwave::TrackWriter::write(), and ~Writer().

m_position

sample_index_t Kwave::Writer::m_position

protected

current position within the track

Definition at line 158 of file Writer.h.

Referenced by eof(), operator<<(), Kwave::TrackWriter::write(), and ~Writer().

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The documentation for this class was generated from the following files:

• libkwave/Writer.h
• libkwave/Writer.cpp