kdatarequest_impl.cpp

00001     /*
00002 
00003     Copyright (C) 2002 Nikolas Zimmermann <wildfox@kde.org>
00004 
00005     This library is free software; you can redistribute it and/or
00006     modify it under the terms of the GNU Library General Public
00007     License as published by the Free Software Foundation; either
00008     version 2 of the License, or (at your option) any later version.
00009   
00010     This library is distributed in the hope that it will be useful,
00011     but WITHOUT ANY WARRANTY; without even the implied warranty of
00012     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013     Library General Public License for more details.
00014 
00015     You should have received a copy of the GNU Library General Public License
00016     along with this library; see the file COPYING.LIB.  If not, write to
00017     the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
00018     Boston, MA 02110-1301, USA.
00019 
00020     */
00021 
00022 #include <kdebug.h>
00023 #include "flowsystem.h"
00024 #include "convert.h"
00025 #include "kdatarequest_impl.moc"
00026 
00027 using namespace Arts;
00028 
00029 KDataRequest_impl::KDataRequest_impl()
00030 {
00031     m_lastBlockSize = 0;
00032     m_outBlock = 0;
00033 }
00034 
00035 KDataRequest_impl::~KDataRequest_impl()
00036 {
00037     delete []m_outBlock;
00038 }
00039 
00040 void KDataRequest_impl::streamInit()
00041 {
00042 }
00043 
00044 void KDataRequest_impl::streamEnd()
00045 {
00046 }
00047 
00048 void KDataRequest_impl::calculateBlock(unsigned long samples)
00049 {
00050     long blockSize = samples * 4;
00051 
00052     if(m_lastBlockSize != blockSize)
00053     {
00054         delete []m_outBlock;
00055         emit newBlockSize(blockSize);
00056     
00057         m_outBlock = new unsigned char[blockSize]; // 2 channels, 16 bit
00058     
00059         emit newBlockPointer((long) m_outBlock);
00060 
00061         m_lastBlockSize = blockSize;
00062     }
00063 
00064     convert_stereo_2float_i16le(samples, left, right, m_outBlock);
00065     emit newData();
00066 }
00067 
00068 /*
00069  * this is the most tricky part here - since we will run in a context
00070  * where no audio hardware will play the "give me more data role",
00071  * we'll have to request things ourselves (requireFlow() tells the
00072  * flowsystem that more signal flow should happen, so that
00073  * calculateBlock will get called
00074  */
00075 void KDataRequest_impl::goOn()
00076 {
00077     _node()->requireFlow();
00078 }
00079 
00080 REGISTER_IMPLEMENTATION(KDataRequest_impl);
KDE Home | KDE Accessibility Home | Description of Access Keys