kdatarequest_impl.cpp

    /*
 
    Copyright (C) 2002 Nikolas Zimmermann <wildfox@kde.org>
 
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.
  
    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.
 
    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
 
    */
 
#include <kdebug.h>
#include "flowsystem.h"
#include "convert.h"
#include "kdatarequest_impl.moc"
 
using namespace Arts;
 
KDataRequest_impl::KDataRequest_impl()
{
    m_lastBlockSize = 0;
    m_outBlock = 0;
}
 
KDataRequest_impl::~KDataRequest_impl()
{
    delete []m_outBlock;
}
 
void KDataRequest_impl::streamInit()
{
}
 
void KDataRequest_impl::streamEnd()
{
}
 
void KDataRequest_impl::calculateBlock(unsigned long samples)
{
    long blockSize = samples * 4;
 
    if(m_lastBlockSize != blockSize)
    {
        delete []m_outBlock;
        emit newBlockSize(blockSize);
    
        m_outBlock = new unsigned char[blockSize]; // 2 channels, 16 bit
    
        emit newBlockPointer((long) m_outBlock);
 
        m_lastBlockSize = blockSize;
    }
 
    convert_stereo_2float_i16le(samples, left, right, m_outBlock);
    emit newData();
}
 
/*
 * this is the most tricky part here - since we will run in a context
 * where no audio hardware will play the "give me more data role",
 * we'll have to request things ourselves (requireFlow() tells the
 * flowsystem that more signal flow should happen, so that
 * calculateBlock will get called
 */
void KDataRequest_impl::goOn()
{
    _node()->requireFlow();
}
 
REGISTER_IMPLEMENTATION(KDataRequest_impl);