1 /*************************************************************************** 2 copyright : (C) 2002 - 2008 by Scott Wheeler 3 email : wheeler@kde.org 4 ***************************************************************************/ 5 6 /*************************************************************************** 7 * This library is free software; you can redistribute it and/or modify * 8 * it under the terms of the GNU Lesser General Public License version * 9 * 2.1 as published by the Free Software Foundation. * 10 * * 11 * This library is distributed in the hope that it will be useful, but * 12 * WITHOUT ANY WARRANTY; without even the implied warranty of * 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * 14 * Lesser General Public License for more details. * 15 * * 16 * You should have received a copy of the GNU Lesser General Public * 17 * License along with this library; if not, write to the Free Software * 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA * 19 * 02110-1301 USA * 20 * * 21 * Alternatively, this file is available under the Mozilla Public * 22 * License Version 1.1. You may obtain a copy of the License at * 23 * http://www.mozilla.org/MPL/ * 24 ***************************************************************************/ 25 26 #ifndef TAGLIB_AUDIOPROPERTIES_H 27 #define TAGLIB_AUDIOPROPERTIES_H 28 29 #include "taglib_export.h" 30 31 namespace TagLib { 32 33 //! A simple, abstract interface to common audio properties 34 35 /*! 36 * The values here are common to most audio formats. For more specific, codec 37 * dependent values, please see see the subclasses APIs. This is meant to 38 * compliment the TagLib::File and TagLib::Tag APIs in providing a simple 39 * interface that is sufficient for most applications. 40 */ 41 42 class TAGLIB_EXPORT AudioProperties 43 { 44 public: 45 46 /*! 47 * Reading audio properties from a file can sometimes be very time consuming 48 * and for the most accurate results can often involve reading the entire 49 * file. Because in many situations speed is critical or the accuracy of the 50 * values is not particularly important this allows the level of desired 51 * accuracy to be set. 52 */ 53 enum ReadStyle { 54 //! Read as little of the file as possible 55 Fast, 56 //! Read more of the file and make better values guesses 57 Average, 58 //! Read as much of the file as needed to report accurate values 59 Accurate 60 }; 61 62 /*! 63 * Destroys this AudioProperties instance. 64 */ 65 virtual ~AudioProperties(); 66 67 /*! 68 * Returns the length of the file in seconds. 69 */ 70 virtual int length() const = 0; 71 72 /*! 73 * Returns the length of the file in seconds. The length is rounded down to 74 * the nearest whole second. 75 * 76 * \see lengthInMilliseconds() 77 */ 78 // BIC: make virtual 79 int lengthInSeconds() const; 80 81 /*! 82 * Returns the length of the file in milliseconds. 83 * 84 * \see lengthInSeconds() 85 */ 86 // BIC: make virtual 87 int lengthInMilliseconds() const; 88 89 /*! 90 * Returns the most appropriate bit rate for the file in kb/s. For constant 91 * bitrate formats this is simply the bitrate of the file. For variable 92 * bitrate formats this is either the average or nominal bitrate. 93 */ 94 virtual int bitrate() const = 0; 95 96 /*! 97 * Returns the sample rate in Hz. 98 */ 99 virtual int sampleRate() const = 0; 100 101 /*! 102 * Returns the number of audio channels. 103 */ 104 virtual int channels() const = 0; 105 106 protected: 107 108 /*! 109 * Construct an audio properties instance. This is protected as this class 110 * should not be instantiated directly, but should be instantiated via its 111 * subclasses and can be fetched from the FileRef or File APIs. 112 * 113 * \see ReadStyle 114 */ 115 AudioProperties(ReadStyle style); 116 117 private: 118 AudioProperties(const AudioProperties &); 119 AudioProperties &operator=(const AudioProperties &); 120 121 class AudioPropertiesPrivate; 122 AudioPropertiesPrivate *d; 123 }; 124 125 } 126 127 #endif 128