X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=filter.h;h=2d1c150afdda6add9bb498c625889fdcbdda5ea3;hp=500a85379bd42b0dabdea4383d875a4f2180b640;hb=b779fcfc62bca2e728348c70bab3c50df3fe63b8;hpb=2b8ac364a9ad11f67bfc1cdd01c113bde30baaf7

diff --git a/filter.h b/filter.h
index 500a8537..2d1c150a 100644
--- a/filter.h
+++ b/filter.h
@@ -34,6 +34,7 @@ struct filter_node {
 
 /** Describes one running instance of a chain of filters */
 struct filter_chain {
+	/** The length of the filter chain. */
 	unsigned int num_filters;
 	/**
 	 * The number of channels of the current stream.
@@ -190,14 +191,16 @@ struct filter {
 	/**
 	 * A pointer to the filter's command line parser.
 	 *
-	 * If this optional function pointer is not NULL, any filter options are passed
-	 * from the main program to this command line parser once at application
-	 * startup. The command line parser should check its command line options given
-	 * by \a argc and \a argv and abort on errors. On success, it should return a
-	 * pointer to the filter-specific configuration data determined by \a argc and
-	 * \a argv.
+	 * If this optional function pointer is not NULL, any filter options
+	 * are passed from the main program to this command line parser once at
+	 * application startup. The command line parser should check its
+	 * command line options given by \a argc and \a argv and abort on
+	 * errors. Success must be indicated by a non-negative return value. In
+	 * this case the function should return a pointer to the
+	 * filter-specific configuration data determined by \a argc and \a
+	 * argv. On failure, a negative paraslash error code must be returned.
 	 */
-	void *(*parse_config)(int argc, char **argv);
+	int (*parse_config)(int argc, char **argv, void **config);
 };
 
 void close_filters(struct filter_chain *fc);