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/***************************************************************************
copyright : (C) 2002 - 2008 by Scott Wheeler
email : wheeler@kde.org
***************************************************************************/
/***************************************************************************
* This library is free software; you can redistribute it and/or modify *
* it under the terms of the GNU Lesser General Public License version *
* 2.1 as published by the Free Software Foundation. *
* *
* 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 *
* Lesser General Public License for more details. *
* *
* You should have received a copy of the GNU Lesser General Public *
* License along with this library; if not, write to the Free Software *
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA *
* 02110-1301 USA *
* *
* Alternatively, this file is available under the Mozilla Public *
* License Version 1.1. You may obtain a copy of the License at *
* http://www.mozilla.org/MPL/ *
***************************************************************************/
#include <tdebug.h>
#include <tstring.h>
#include "mpegproperties.h"
#include "mpegfile.h"
#include "xingheader.h"
#include "apetag.h"
#include "apefooter.h"
using namespace TagLib;
class MPEG::Properties::PropertiesPrivate
{
public:
PropertiesPrivate() :
xingHeader(0),
length(0),
bitrate(0),
sampleRate(0),
channels(0),
layer(0),
version(Header::Version1),
channelMode(Header::Stereo),
protectionEnabled(false),
isCopyrighted(false),
isOriginal(false) {}
~PropertiesPrivate()
{
delete xingHeader;
}
XingHeader *xingHeader;
int length;
int bitrate;
int sampleRate;
int channels;
int layer;
Header::Version version;
Header::ChannelMode channelMode;
bool protectionEnabled;
bool isCopyrighted;
bool isOriginal;
};
////////////////////////////////////////////////////////////////////////////////
// public members
////////////////////////////////////////////////////////////////////////////////
MPEG::Properties::Properties(File *file, ReadStyle style) :
AudioProperties(style),
d(new PropertiesPrivate())
{
read(file);
}
MPEG::Properties::~Properties()
{
delete d;
}
int MPEG::Properties::length() const
{
return lengthInSeconds();
}
int MPEG::Properties::lengthInSeconds() const
{
return d->length / 1000;
}
int MPEG::Properties::lengthInMilliseconds() const
{
return d->length;
}
int MPEG::Properties::bitrate() const
{
return d->bitrate;
}
int MPEG::Properties::sampleRate() const
{
return d->sampleRate;
}
int MPEG::Properties::channels() const
{
return d->channels;
}
const MPEG::XingHeader *MPEG::Properties::xingHeader() const
{
return d->xingHeader;
}
MPEG::Header::Version MPEG::Properties::version() const
{
return d->version;
}
int MPEG::Properties::layer() const
{
return d->layer;
}
bool MPEG::Properties::protectionEnabled() const
{
return d->protectionEnabled;
}
MPEG::Header::ChannelMode MPEG::Properties::channelMode() const
{
return d->channelMode;
}
bool MPEG::Properties::isCopyrighted() const
{
return d->isCopyrighted;
}
bool MPEG::Properties::isOriginal() const
{
return d->isOriginal;
}
////////////////////////////////////////////////////////////////////////////////
// private members
////////////////////////////////////////////////////////////////////////////////
void MPEG::Properties::read(File *file)
{
// Only the first valid frame is required if we have a VBR header.
const long firstFrameOffset = file->firstFrameOffset();
if(firstFrameOffset < 0) {
debug("MPEG::Properties::read() -- Could not find an MPEG frame in the stream.");
return;
}
const Header firstHeader(file, firstFrameOffset, false);
// Check for a VBR header that will help us in gathering information about a
// VBR stream.
file->seek(firstFrameOffset);
d->xingHeader = new XingHeader(file->readBlock(firstHeader.frameLength()));
if(!d->xingHeader->isValid()) {
delete d->xingHeader;
d->xingHeader = 0;
}
if(d->xingHeader && firstHeader.samplesPerFrame() > 0 && firstHeader.sampleRate() > 0) {
// Read the length and the bitrate from the VBR header.
const double timePerFrame = firstHeader.samplesPerFrame() * 1000.0 / firstHeader.sampleRate();
const double length = timePerFrame * d->xingHeader->totalFrames();
d->length = static_cast<int>(length + 0.5);
d->bitrate = static_cast<int>(d->xingHeader->totalSize() * 8.0 / length + 0.5);
}
else if(firstHeader.bitrate() > 0) {
// Since there was no valid VBR header found, we hope that we're in a constant
// bitrate file.
// TODO: Make this more robust with audio property detection for VBR without a
// Xing header.
d->bitrate = firstHeader.bitrate();
// Look for the last MPEG audio frame to calculate the stream length.
const long lastFrameOffset = file->lastFrameOffset();
if(lastFrameOffset < 0) {
debug("MPEG::Properties::read() -- Could not find an MPEG frame in the stream.");
return;
}
const Header lastHeader(file, lastFrameOffset, false);
const long streamLength = lastFrameOffset - firstFrameOffset + lastHeader.frameLength();
if(streamLength > 0)
d->length = static_cast<int>(streamLength * 8.0 / d->bitrate + 0.5);
}
d->sampleRate = firstHeader.sampleRate();
d->channels = firstHeader.channelMode() == Header::SingleChannel ? 1 : 2;
d->version = firstHeader.version();
d->layer = firstHeader.layer();
d->protectionEnabled = firstHeader.protectionEnabled();
d->channelMode = firstHeader.channelMode();
d->isCopyrighted = firstHeader.isCopyrighted();
d->isOriginal = firstHeader.isOriginal();
}
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