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