add scan_type directive for doing brute-force scans

contrib/mt-daapd.conf

@@ -2,6 +2,14 @@
 #
 # This is the mt-daapd config file.
 #
+# If you have problems or questions with the format of this file,
+# direct your questions to rpedde@users.sourceforge.net.
+#
+# You can also check the website at http://mt-daapd.sourceforge.net,
+# as there is a growing documentation library there, peer-supported
+# forums and possibly more.
+#
+
 
 #
 # web_root (required)
@@ -39,7 +47,9 @@ db_dir		/var/cache/mt-daapd
 #
 # mp3_dir (required)
 #
-# Location of the mp3 files to share
+# Location of the mp3 files to share.  Note that because the
+# files are stored in the database by inode, these must be
+# in the same physical filesystem.
 #
 
 mp3_dir		/mnt/mp3
@@ -49,7 +59,7 @@ mp3_dir		/mnt/mp3
 #
 # This is both the name of the server as advertised
 # via rendezvous, and the name of the database
-# exported via DAAP
+# exported via DAAP.  Also know as "What shows up in iTunes".
 #
 
 servername	mt-daapd
@@ -74,9 +84,9 @@ runas	nobody
 # See the mt-daapd.playlist file in the 
 # contrib directory for syntax and examples
 #
-# Note that static playlists will still
-# show up, even if this directive is not
-# specified
+# This doesn't control static playlists... these
+# are controlled with the "process_m3u" directive
+# below.
 #
 
 playlist	/etc/mt-daapd.playlist
@@ -101,6 +111,7 @@ playlist	/etc/mt-daapd.playlist
 # play them.  Perhaps this would be useful on Linux with
 # Rhythmbox, once it understands daap.  (hurry up!)
 #
+#
 
 extensions .mp3,.m4a,.m4p
 
@@ -145,28 +156,66 @@ extensions .mp3,.m4a,.m4p
 # If background rescanning is disabled, a scan can still be forced from the 
 # "status" page of the administrative web interface
 #
-# Note that right now this is considered EXPERIMENTAL!
-#
 # Setting a rescan_interval lower than the time it takes to rescan
 # won't hurt anything, it will just waste CPU, and make connect times
 # to the daap server longer.
 #
-# There may be memory leaks here.  If you see evidence of leaks, please
-# let me (rpedde@users.sourceforge.net) know.
 #
 
 #rescan_interval 300
 
+# always_scan 
 #
-# always_scan
-#
-# The default behavior is not not do background rescans of the filesystem
-# unless there are clients connected.  The thought is to allow the drives
-# to spin down unless they are in use.  This might be of more importance
-# in IDE drives that aren't designed to be run 24x7.
-#
-# Forcing a scan will always work though, even if no users are connected.
-#
-#
+# The default behavior is not not do background rescans of the
+# filesystem unless there are clients connected.  The thought is to
+# allow the drives to spin down unless they are in use.  This might be
+# of more importance in IDE drives that aren't designed to be run
+# 24x7.  Forcing a scan through the web interface will always work
+# though, even if no users are connected.
+
 # always_scan 0
 
+# 
+# process_m3u
+#
+# By default m3u processing is turned off, since most m3u files
+# sitting around in peoples mp3 directories have bad paths, and
+# I hear about it.  :)
+#
+# If you are sure your m3u files have good paths (i.e. unixly pathed,
+# with relative paths relative to the directory the m3u is in), then
+# you can turn on m3u processing by setting this directive to 1.
+#
+# I'm not sure "unixly" is a word, but you get the idea.
+#
+
+# process_m3u 0
+
+#
+# scan_type
+# 
+#
+# This sets how aggressively mp3 files should be scanned to determine
+# file length.  There are three values:
+#
+# 0 (Normal) 
+#   Just scan the first mp3 frame to try and calculate size.  This will
+#   be accurate for most files, but VBR files without an Xing tag will
+#   probably have wildly inaccurate file times
+#
+# 1 (Aggressive)
+#   This checks the bitrates of 10 frames in the middle of the song.  
+#   This will still be inaccurate for VBR files without an Xing tag,
+#   but they probably won't be quite as inaccurate as 0.  This takes
+#   more time, obviously, although the time hit will only happen the
+#   first time you scan a particular file.
+#
+# 2 (Painfully aggressive)
+#   This walks through the entire song, counting the number of frames.
+#   This should result in accurate song times, but will take the most
+#   time.  Again, this will only have to be incurred the first time
+#   the file is indexed.
+# 
+
+# scan_type  0
+