taglib/taglib/audioproperties.h
Urs Fleisch c9486731d9 Fix MSVC warning needs to have dll-interface (#1185)
Unfortunately, MSVC exports everything (not only public members) when
__declspec(dllexport) is set at the class level via TAGLIB_EXPORT, which
leads to many "needs to have dll-interface to be used by clients" 4251
warnings issued by MSVC, because the std::unique_ptr pimpls are
exported too. As it is not possible to "unexport" private members,
such a warning has to be explicitly suppressed for these cases or
all public and protected class member now have to be exported
for classes derived from a template (StringList, ByteVectorList,
PropertyMap).
2023-12-11 06:35:08 +01:00

136 lines
4.7 KiB
C++

/***************************************************************************
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/ *
***************************************************************************/
#ifndef TAGLIB_AUDIOPROPERTIES_H
#define TAGLIB_AUDIOPROPERTIES_H
#include <memory>
#include "taglib.h"
#include "taglib_export.h"
namespace TagLib {
//! A simple, abstract interface to common audio properties
/*!
* The values here are common to most audio formats. For more specific, codec
* dependent values, please see see the subclasses APIs. This is meant to
* compliment the TagLib::File and TagLib::Tag APIs in providing a simple
* interface that is sufficient for most applications.
*/
class TAGLIB_EXPORT AudioProperties
{
public:
/*!
* Reading audio properties from a file can sometimes be very time consuming
* and for the most accurate results can often involve reading the entire
* file. Because in many situations speed is critical or the accuracy of the
* values is not particularly important this allows the level of desired
* accuracy to be set.
*/
enum ReadStyle {
//! Read as little of the file as possible
Fast,
//! Read more of the file and make better values guesses
Average,
//! Read as much of the file as needed to report accurate values
Accurate
};
/*!
* Destroys this AudioProperties instance.
*/
virtual ~AudioProperties();
AudioProperties(const AudioProperties &) = delete;
AudioProperties &operator=(const AudioProperties &) = delete;
/*!
* Returns the length of the file in seconds. The length is rounded down to
* the nearest whole second.
*
* \note This method is just an alias of lengthInSeconds().
*
* \deprecated Use lengthInSeconds().
*/
TAGLIB_DEPRECATED
virtual int length() const;
/*!
* Returns the length of the file in seconds. The length is rounded down to
* the nearest whole second.
*
* \see lengthInMilliseconds()
*/
virtual int lengthInSeconds() const;
/*!
* Returns the length of the file in milliseconds.
*
* \see lengthInSeconds()
*/
virtual int lengthInMilliseconds() const;
/*!
* Returns the most appropriate bit rate for the file in kb/s. For constant
* bitrate formats this is simply the bitrate of the file. For variable
* bitrate formats this is either the average or nominal bitrate.
*/
virtual int bitrate() const;
/*!
* Returns the sample rate in Hz.
*/
virtual int sampleRate() const;
/*!
* Returns the number of audio channels.
*/
virtual int channels() const = 0;
protected:
/*!
* Construct an audio properties instance. This is protected as this class
* should not be instantiated directly, but should be instantiated via its
* subclasses and can be fetched from the FileRef or File APIs.
*
* \see ReadStyle
*/
AudioProperties(ReadStyle style);
private:
class AudioPropertiesPrivate;
TAGLIB_MSVC_SUPPRESS_WARNING_NEEDS_TO_HAVE_DLL_INTERFACE
std::unique_ptr<AudioPropertiesPrivate> d;
};
} // namespace TagLib
#endif