============ README.mysql ============ ---- This file describes how to use the mysql audio file selector which comes with the paraslash package. It assumes you have already installed mysql and paraslash as described in INSTALL, so read README and INSTALL before proceeding. First of all, make sure that - mysqld is running - para_server is running and compiled with mysql support (type "para_client si" to find out) - the user who runs para_client has the paraslash AFS_WRITE and AFS_READ permissions set in server.users - the user who runs para_server has create privileges on the mysql server. Remember: If something doesn't work as expected, look at the server log file and/or increase output verbosity by using the -l switch for server and client. ------------------------------------- Specify mysql data (port, passwd,...) ------------------------------------- Type para_server -h and look at the mysql options. You may either specify these options in ~/.paraslash/server.conf or directly at the command line (not recommended for passwd option). Don't forget to do chmod 600 ~/.paraslash/server.conf as this file contains the mysql passwd. To make these changes take effect you'll need to do para_client hup Or, restart the server. --------------------------------------- Switch to the mysql audio file selector --------------------------------------- The command para_client chs prints the name of the current selector. Try para_client chs mysql to switch to the mysql selector. If this doesn't work, it means that some required config options were not specified (check the log for more info) or that para_server was built without mysql support. Type para_client si to find out. If mysql is not mentioned as a supported selector, you'll have to recompile. If configure does not detect your mysql installation, use the --with-mysql-headers and --with-mysql-libs options to specify the mysql path explicitly . Example: ./configure --with-mysql-headers=/Library/MySQL/include \ --with-mysql-libs=/Library/MySQL/lib/mysql --------------------- Create a new database --------------------- Once the mysql selector is activated, create the database: para_client cdb para_client chs mysql The second command forces para_server to re-init the mysql selector. Check the log. There should not be any warnings or errors. ------------------------------- Fill your database with content ------------------------------- para_client upd Note that the mysql selector assumes that the basenames of your audio files are unique. If this is not the case, duplicates are ignored. If this command fails, it most likely means the audio file directory (given in the server configuration file) does not exist, is empty, or not readable. Fix this problem before proceeding. The command para_client ls prints the list of all files known by the mysql selector. If the list is empty, double check the mysql_audio_file_dir option. --------------------------------------- Create a stream which selects all files --------------------------------------- To keep it simple, let's only define the stream "all_songs". See below for advanced stream usage. para_client stradd all_songs < /dev/null para_client sl 10 all_songs The latter command should show you ten filenames. ------------------------------ Change to the all_songs stream ------------------------------ para_client cs all_songs You should now be able to start streaming with para_client play --------------- Attribute usage --------------- An attribute is simply a bit which can be set for each audio file individually. You may have as many attributes as you like. A new attribute "test" is created by para_client na test and para_client laa lists all available attributes. You can set the "test" attribute for the current audio file by executing para_client sa test+ or for any particular audio file by para_client sa test+ filename Unset the attribute "test" for the current audio file with para_client sa test- and drop the test attribute entirely from the database with para_client da test ------------ Stream usage ------------ A stream is a pair of expressions in terms of attributes and other data contained in the database. The first, boolian, expression determines the set of audio files which are admissible in this stream. The second, integer, expression determines the order in which admissible files are going to be fed to the audio file sender(s). To create a new stream called "my_stream", put arbitrary many (including none) accept or deny lines and one or zero score lines into some temporary file, say tmpfile. An accept/deny/score line consists of an identifier ("accept:", "deny:", or "score:"), followed by an expression. The command para_client stradd my_stream < tmpfile adds the stream "my_stream" to the table of streams. If the stream definition is really short, you may also just pipe it to the client rather than using temporary files. Like this: echo "$MYSTREAMDEF" | para_client stradd my_stream Example: ~~~~~~~~ Assume you already have an attribute "test" and you'd like to to restrict audio streaming to those files having the "test" attribute set. Define a new stream "only_test" by echo 'accept: IS_SET(test)' | para_client stradd only_test Then, after switching to the "only_test" stream with para_client cs only_test only the desired files are going to be streamed. There is no need to keep the temporary files containing the stream definition since you can always use the strq command to get it back: para_client strq only_test The accept/deny expressions are used to find out which songs are permitted. The following four cases are all possible and valid: - Neither accept nor deny lines: This selects all songs. - Only accept lines: Songs that match at least one accept expression are accepted, all others are denied: accept_expr1 or accept_expr2 or ... - Only deny lines: Songs that match at least one deny expression are denied, all others are accepted: not (deny_expr1 or deny_expr2 ...) - Both accept and deny lines: A song is accepted if it matches at least one accept expression, but no deny expression, i.e. (accept_expr1 or accept_expr2 or ..) and not (deny_expr1 or deny_expr2 ..) The command para_client streams lists all available streams and para_client strdel streamname removes the stream "streamname". There are more sophisticated ways to define a stream than just using one IS_SET() macro as in the example above. Of course, IS_SET(foo) is true for a given audio file if and only if it has the attribute "foo" set. Here are some more macros you can use: - IS_N_SET(attr): True if attribute attr is not set - NAME_LIKE(string): True if basename is like (in the sense of mysql) "string" - LASTPLAYED(): Expands to number of minutes that are gone since this audio file has been played (by paraslash). - NUMPLAYED(): Expands to number of times, the file has been played. - PICID(): Expands to the number of the picture which is associated with this song. To give a real-life example, suppose you have already added the attributes "pop", "rock" with the "na" command. Assume also that you have set these attributes for some or all of your songs having the corresponding properties. If you like to be waked up in the morning by poprock songs, but you have some strange feeling telling you that just a few seconds of Madonna's voice will be enough to mess up your whole day, just write the lines accept: IS_SET(pop) and IS_SET(rock) deny: NAME_LIKE(%Madonna%) to some temporary file "tmp" and do para_client stradd wake < tmp You can then switch to the new stream with para_client cs wake or you can let cron do this for you on a daily basis.. Accept/deny lines affect only the set of admissible audio files, but not the order in which these are streamed. That's where the score expression comes into play. ------- Scoring ------- You may put a single score line anywhere in the stream definition. If omitted, the default scoring rule specified in the configuration file applies. If there is no default scoring rule in the config file either, the compiled in default is going to be used (see para_server -h). Simple examples of scoring rules (either specified in a stream definition or as the default scoring rule in the config file) include: LASTPLAYED()/1440 This means that the score of an audio file is just the number of days that went by since it has been played the last time (one day is 1440 minutes). In other words, the mysql selector choses that admissible file which wasn't played for the longest time. However, one disadvantage of this scoring sheme is that new files, once played, are going to be deferred for a possibly very long period depending on the size of your collection of (admissible) files. Hence the following scoring rule comes into mind: score: -NUMPLAYED() since this gives newer files, i.e. files to which you haven't listen to that often, a higher score than older songs you already know by heart. You can also use a combination of these two methods: score: LASTPLAYED()/1440 - 10 * NUMPLAYED() which subtracts 10 score points for each time paraslash has played this file. Another useful feature for scoring is due to the fact that "true" expands to one and "false" to zero. So you can also use the IS_SET/IS_N_SET/NAME_LIKE macros in a score line to give your favorite band "bar" some extra points: score: 40 * IS_SET(foo) + 20 * NAME_LIKE(%bar%) + LASTPLAYED()/1440 ------ Images ------ The mysql selector can also magage images that, when associated with one or more audio files, can be displayed by para_sdl_gui and para_krell. It is also possible to just retrieve the current image via para_client pic > filename in order to feed it to your favorite tool. Try para_client help | grep ^pic and read the online help of the shown commands for more information.