juce/source/src/audio/audio_file_formats/juce_AudioCDReader.h

   1 /*
   2   ==============================================================================
   3
   4    This file is part of the JUCE library - "Jules' Utility Class Extensions"
   5    Copyright 2004-11 by Raw Material Software Ltd.
   6
   7   ------------------------------------------------------------------------------
   8
   9    JUCE can be redistributed and/or modified under the terms of the GNU General
  10    Public License (Version 2), as published by the Free Software Foundation.
  11    A copy of the license is included in the JUCE distribution, or can be found
  12    online at www.gnu.org/licenses.
  13
  14    JUCE is distributed in the hope that it will be useful, but WITHOUT ANY
  15    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  16    A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
  17
  18   ------------------------------------------------------------------------------
  19
  20    To release a closed-source product which uses JUCE, commercial licenses are
  21    available: visit www.rawmaterialsoftware.com/juce for more information.
  22
  23   ==============================================================================
  24 */
  25
  26 #ifndef __JUCE_AUDIOCDREADER_JUCEHEADER__
  27 #define __JUCE_AUDIOCDREADER_JUCEHEADER__
  28
  29 #if JUCE_USE_CDREADER || DOXYGEN
  30
  31 #include "juce_AudioFormatReader.h"
  32 #include "../../containers/juce_Array.h"
  33 #include "../../memory/juce_ScopedPointer.h"
  34 #include "../../text/juce_StringArray.h"
  35 #include "../../memory/juce_MemoryBlock.h"
  36 #if JUCE_MAC
  37  #include "../../io/files/juce_File.h"
  38 #endif
  39
  40 //==============================================================================
  41 /**
  42     A type of AudioFormatReader that reads from an audio CD.
  43
  44     One of these can be used to read a CD as if it's one big audio stream. Use the
  45     getPositionOfTrackStart() method to find where the individual tracks are
  46     within the stream.
  47
  48     @see AudioFormatReader
  49 */
  50 class JUCE_API  AudioCDReader  : public AudioFormatReader
  51 {
  52 public:
  53     //==============================================================================
  54     /** Returns a list of names of Audio CDs currently available for reading.
  55
  56         If there's a CD drive but no CD in it, this might return an empty list, or
  57         possibly a device that can be opened but which has no tracks, depending
  58         on the platform.
  59
  60         @see createReaderForCD
  61     */
  62     static StringArray getAvailableCDNames();
  63
  64     /** Tries to create an AudioFormatReader that can read from an Audio CD.
  65
  66         @param index    the index of one of the available CDs - use getAvailableCDNames()
  67                         to find out how many there are.
  68         @returns        a new AudioCDReader object, or 0 if it couldn't be created. The
  69                         caller will be responsible for deleting the object returned.
  70     */
  71     static AudioCDReader* createReaderForCD (const int index);
  72
  73     //==============================================================================
  74     /** Destructor. */
  75     ~AudioCDReader();
  76
  77     /** Implementation of the AudioFormatReader method. */
  78     bool readSamples (int** destSamples, int numDestChannels, int startOffsetInDestBuffer,
  79                       int64 startSampleInFile, int numSamples);
  80
  81     /** Checks whether the CD has been removed from the drive.
  82     */
  83     bool isCDStillPresent() const;
  84
  85     /** Returns the total number of tracks (audio + data).
  86     */
  87     int getNumTracks() const;
  88
  89     /** Finds the sample offset of the start of a track.
  90
  91         @param trackNum     the track number, where trackNum = 0 is the first track
  92                             and trackNum = getNumTracks() means the end of the CD.
  93     */
  94     int getPositionOfTrackStart (int trackNum) const;
  95
  96     /** Returns true if a given track is an audio track.
  97
  98         @param trackNum     the track number, where 0 is the first track.
  99     */
 100     bool isTrackAudio (int trackNum) const;
 101
 102     /** Returns an array of sample offsets for the start of each track, followed by
 103         the sample position of the end of the CD.
 104     */
 105     const Array<int>& getTrackOffsets() const;
 106
 107     /** Refreshes the object's table of contents.
 108
 109         If the disc has been ejected and a different one put in since this
 110         object was created, this will cause it to update its idea of how many tracks
 111         there are, etc.
 112     */
 113     void refreshTrackLengths();
 114
 115     /** Enables scanning for indexes within tracks.
 116
 117         @see getLastIndex
 118     */
 119     void enableIndexScanning (bool enabled);
 120
 121     /** Returns the index number found during the last read() call.
 122
 123         Index scanning is turned off by default - turn it on with enableIndexScanning().
 124
 125         Then when the read() method is called, if it comes across an index within that
 126         block, the index number is stored and returned by this method.
 127
 128         Some devices might not support indexes, of course.
 129
 130         (If you don't know what CD indexes are, it's unlikely you'll ever need them).
 131
 132         @see enableIndexScanning
 133     */
 134     int getLastIndex() const;
 135
 136     /** Scans a track to find the position of any indexes within it.
 137
 138         @param trackNumber  the track to look in, where 0 is the first track on the disc
 139         @returns    an array of sample positions of any index points found (not including
 140                     the index that marks the start of the track)
 141     */
 142     const Array <int> findIndexesInTrack (const int trackNumber);
 143
 144     /** Returns the CDDB id number for the CD.
 145
 146         It's not a great way of identifying a disc, but it's traditional.
 147     */
 148     int getCDDBId();
 149
 150     /** Tries to eject the disk.
 151
 152         Of course this might not be possible, if some other process is using it.
 153     */
 154     void ejectDisk();
 155
 156     //==============================================================================
 157     enum
 158     {
 159         framesPerSecond = 75,
 160         samplesPerFrame = 44100 / framesPerSecond
 161     };
 162
 163 private:
 164     //==============================================================================
 165     Array<int> trackStartSamples;
 166
 167    #if JUCE_MAC
 168     File volumeDir;
 169     Array<File> tracks;
 170     int currentReaderTrack;
 171     ScopedPointer <AudioFormatReader> reader;
 172     AudioCDReader (const File& volume);
 173
 174    #elif JUCE_WINDOWS
 175     bool audioTracks [100];
 176     void* handle;
 177     MemoryBlock buffer;
 178     bool indexingEnabled;
 179     int lastIndex, firstFrameInBuffer, samplesInBuffer;
 180     AudioCDReader (void* handle);
 181     int getIndexAt (int samplePos);
 182
 183    #elif JUCE_LINUX
 184     AudioCDReader();
 185    #endif
 186
 187     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (AudioCDReader);
 188 };
 189
 190 #endif
 191 #endif   // __JUCE_AUDIOCDREADER_JUCEHEADER__