manual/rockbox_interface/tagcache.tex

   1 % $Id$ %
   2 \section{\label{ref:database}Database}
   3
   4 \subsection{Introduction}
   5 This chapter describes the Rockbox music database system. Using the information
   6 contained in the tags (ID3v1, ID3v2%
   7   \opt{swcodec}{, Vorbis Comments, Apev2, etc.}%
   8 ) in your audio files, Rockbox builds and maintains a database of the music
   9 files on your player and allows you to browse them by Artist, Album and Genre.
  10
  11 \subsection{Initializing the database}
  12 The first time you use the database, Rockbox will scan your disk for audio files.
  13 This can take quite a while depending on the number of files on your \dap{}.
  14 This scan happens in the background, so you can choose to return to the
  15 Main Menu and continue to listen to music.
  16 If you shut down your player, the scan will continue next time you turn it on.
  17 After the scan is finished you may be prompted to restart your \dap{} before
  18 you can use the database.
  19
  20 \subsubsection{Ignoring directories during database initialization}
  21
  22 You may have directories on your \dap{} whose contents should not be added
  23 to the database. Placing a file named \fname{database.ignore} in a directory
  24 will exclude the files in that directory and all its subdirectories from
  25 scanning their tags and adding them to the database. This will speed up the
  26 database initialization.
  27
  28 If a subdirectory of an 'ignored' directory should still be scanned, place a
  29 file named \fname{database.unignore} in it. The files in that directory and
  30 its subdirectories will be scanned and added to the database.
  31
  32 \subsection{\label{ref:databasemenu}The Database Menu}
  33
  34 \begin{description}
  35   \opt{swcodec}{
  36   \item[Load To Ram.]
  37     The database can either be kept on disk (to save memory), or
  38     loaded into RAM (for fast browsing). Setting this to \setting{Yes} loads
  39     the database to RAM, allowing faster browsing and searching. Setting this
  40     option to \setting{No} keeps the database on the disk, meaning slower
  41     browsing but it does not use extra RAM and saves some battery on boot up.
  42
  43     \note{If you browse your music frequently using the database, you should
  44       load to RAM, as this will reduce the overall battery consumption because
  45       the disk will not need to spin on each search.}
  46   }
  47
  48 \item[Auto Update.]
  49   If \setting{Auto update} is set to \setting{on}, each time the \dap{}
  50   boots, the database will automatically be updated.
  51   \opt{swcodec}{
  52     \note{The \setting{Auto Update} will only check for deleted files if the
  53       \setting{Directory Cache} (\setting{Settings $\rightarrow$ General
  54       Settings $\rightarrow$ System $\rightarrow$ Disk $\rightarrow$
  55       Directory Cache}) is enabled. \setting{Update now} includes that check
  56       whether dircache has been enabled or not.}
  57   }%
  58   \opt{MASCODEC}{\setting{Auto Update} does not detect deleted files. To remove
  59     deleted files from the database you need to run \setting{Update Now}.}%
  60
  61 \item[Initialize Now.]
  62   You can force Rockbox to rescan your disk for tagged files by
  63   using the \setting{Initialize Now} function in the \setting{Database
  64     Menu}.
  65   \warn{\setting{Initialize Now} removes all database files (removing
  66     runtimedb data also) and rebuilds the database from scratch.}
  67
  68 \item[Update Now.]
  69   \setting{Update now} causes the database to detect new and deleted files
  70   \opt{swcodec}{
  71     \note{Unlike the \setting{Auto Update} function, \setting{Update Now}
  72       will update the database regardless of whether the \setting{Directory Cache}
  73       is enabled. Thus, an update using \setting{Update now} may take a long
  74       time.
  75     }
  76   }
  77   Unlike \setting{Initialize Now}, the \setting{Update Now} function
  78   does not remove runtime database information.
  79
  80 \item[Gather Runtime Data.]
  81   When enabled, rockbox will record how often and how long a track is being played,
  82   when it was last played and its rating. This information can be displayed in
  83   the WPS and is used in the database browser to, for example, show the most played,
  84   unplayed and most recently played tracks.
  85
  86 \item[Export Modifications.]
  87   This allows for the runtime data to be exported to the file \\
  88   \fname{/.rockbox/database\_changelog.txt}, which backs up the runtime data in
  89   ASCII format. This is needed when database structures change, because new
  90   code cannot read old database code. But, all modifications
  91   exported to ASCII format should be readable by all database versions.
  92
  93 \item[Import Modifications.]
  94   Allows the \fname{/.rockbox/database\_changelog.txt} backup to be
  95   conveniently loaded into the database. If \setting{Auto Update} is
  96   enabled this is performed automatically when the database is initialized.
  97
  98 \end{description}
  99
 100 \subsection{Using the database}
 101 Once the database has been initialized, you can browse your music by Artist,
 102 Album, Genre and Song Name. To use the database, go to the \setting{Main Menu}
 103 and select \setting{Database}.\\
 104
 105 \note{You may need to increase the value of the \setting{Max files in dir
 106 browser} setting (\setting{Settings $\rightarrow$ General Settings
 107 $\rightarrow$ System $\rightarrow$ Limits}) in order to view long lists of
 108 tracks in the ID3 database browser.\\
 109
 110 There is no option to turn off database completely. If you do not want
 111 to use it just do not do the initial build of the database and do not load it
 112 to RAM.}
 113 %
 114 \begin{table}
 115 \begin{center}
 116   \begin{tabularx}{.75\textwidth}{XXX}%
 117   \toprule%
 118   \textbf{Tag}   & \textbf{Type}  & \textbf{Origin} \\
 119   \midrule
 120   filename              & string    & system \\
 121   album                 & string    & id tag \\
 122   albumartist           & string    & id tag \\
 123   artist                & string    & id tag \\
 124   comment               & string    & id tag \\
 125   composer              & string    & id tag \\
 126   genre                 & string    & id tag \\
 127   grouping              & string    & id tag \\
 128   title                 & string    & id tag \\
 129   bitrate               & numeric   & id tag \\
 130   discnum               & numeric   & id tag \\
 131   year                  & numeric   & id tag \\
 132   tracknum              & numeric   & id tag/filename \\
 133   autoscore             & numeric   & runtime db \\
 134   lastplayed            & numeric   & runtime db \\
 135   playcount             & numeric   & runtime db \\
 136   Pm (play time - min)  & numeric   & runtime db \\
 137   Ps (play time - sec)  & numeric   & runtime db \\
 138   rating                & numeric   & runtime db \\
 139   commitid              & numeric   & system \\
 140   entryage              & numeric   & system \\
 141   length                & numeric   & system \\
 142   Lm (track len - min)  & numeric   & system \\
 143   Ls (track len - sec)  & numeric   & system \\
 144   \bottomrule
 145   \end{tabularx}
 146 \end{center}
 147 \end{table}