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/***************************************************************************
copyright : (C) 2012 by Lukáš Lalinský
email : lalinsky@gmail.com
copyright : (C) 2002 - 2008 by Scott Wheeler
email : wheeler@kde.org
(original Vorbis implementation)
***************************************************************************/
/***************************************************************************
* 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 <taglib/tstring.h>
#include "tdebug.h"
#include <taglib/oggpageheader.h>
#include "opusproperties.h"
#include "opusfile.h"
using namespace TagLib;
using namespace TagLib::Ogg;
class Opus::Properties::PropertiesPrivate
{
public:
PropertiesPrivate(File *f, ReadStyle s) :
file(f),
style(s),
length(0),
inputSampleRate(0),
channels(0),
opusVersion(0) {}
File *file;
ReadStyle style;
int length;
int inputSampleRate;
int channels;
int opusVersion;
};
////////////////////////////////////////////////////////////////////////////////
// public members
////////////////////////////////////////////////////////////////////////////////
Opus::Properties::Properties(File *file, ReadStyle style) : AudioProperties(style)
{
d = new PropertiesPrivate(file, style);
read();
}
Opus::Properties::~Properties()
{
delete d;
}
int Opus::Properties::length() const
{
return d->length;
}
int Opus::Properties::bitrate() const
{
return 0;
}
int Opus::Properties::sampleRate() const
{
// Opus can decode any stream at a sample rate of 8, 12, 16, 24, or 48 kHz,
// so there is no single sample rate. Let's assume it's the highest
// possible.
return 48000;
}
int Opus::Properties::channels() const
{
return d->channels;
}
int Opus::Properties::inputSampleRate() const
{
return d->inputSampleRate;
}
int Opus::Properties::opusVersion() const
{
return d->opusVersion;
}
////////////////////////////////////////////////////////////////////////////////
// private members
////////////////////////////////////////////////////////////////////////////////
void Opus::Properties::read()
{
// Get the identification header from the Ogg implementation.
// http://tools.ietf.org/html/draft-terriberry-oggopus-01#section-5.1
ByteVector data = d->file->packet(0);
// *Magic Signature*
int pos = 8;
// *Version* (8 bits, unsigned)
d->opusVersion = uchar(data.at(pos));
pos += 1;
// *Output Channel Count* 'C' (8 bits, unsigned)
d->channels = uchar(data.at(pos));
pos += 1;
// *Pre-skip* (16 bits, unsigned, little endian)
ushort preSkip = data.mid(pos, 2).toUShort(false);
pos += 2;
// *Input Sample Rate* (32 bits, unsigned, little endian)
d->inputSampleRate = data.mid(pos, 4).toUInt(false);
pos += 4;
// *Output Gain* (16 bits, signed, little endian)
pos += 2;
// *Channel Mapping Family* (8 bits, unsigned)
pos += 1;
const Ogg::PageHeader *first = d->file->firstPageHeader();
const Ogg::PageHeader *last = d->file->lastPageHeader();
if(first && last) {
long long start = first->absoluteGranularPosition();
long long end = last->absoluteGranularPosition();
if(start >= 0 && end >= 0)
d->length = (int) ((end - start - preSkip) / 48000);
else {
debug("Opus::Properties::read() -- The PCM values for the start or "
"end of this file was incorrect.");
}
}
else
debug("Opus::Properties::read() -- Could not find valid first and last Ogg pages.");
}
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