X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=filter.h;h=0bd546903927d412fccef946cf8f43783ed8bc70;hp=e7dc1ca632684b928236aa9d6a7e86317c626cdf;hb=fc8dfbb416ff07cca08fbf4e13efcaa25e17cc54;hpb=7571dbdb6da9e5a9154390b899968eb44f632dec

diff --git a/filter.h b/filter.h
index e7dc1ca6..0bd54690 100644
--- a/filter.h
+++ b/filter.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -15,25 +15,20 @@ enum filter_enum {FILTER_ENUM};
 struct filter_node {
 	/** The number in the array of available filters. */
 	unsigned filter_num;
-	/** The filter chain this filter node belongs to. */
-	struct filter_chain *fc;
 	/**
 	 * Each filter may store any filter-specific information about the particular
 	 * instance of the filter here.
 	 */
 	void *private_data;
-	/** The output buffer. */
-	char *buf;
-	/** The size of the output buffer. */
-	size_t bufsize;
-	/** The number of bytes currently loaded in \a buf. */
-	size_t loaded;
 	/** The list of registered callbacks. */
 	struct list_head callbacks;
 	/** A pointer to the configuration of this instance. */
 	void *conf;
+	/** The buffer tree node. */
 	struct btr_node *btrn;
-	struct task task;
+	/** The task corresponding to this filter node. */
+	struct task *task;
+	/** The minimal input queue size, see \ref btr_node_status(). */
 	size_t min_iqs;
 };
 
@@ -63,16 +58,18 @@ struct filter {
 	/**
 	 * Open one instance of this filter.
 	 *
-	 * This should allocate the output buffer of the given filter node and do any
-	 * other filter-specific preparations like initializing the private_data member
-	 * of \a fn suitably. The open function is assumed to succeed.
+	 * This should allocate the output buffer of the given filter node and
+	 * do any other filter-specific preparations like initializing the
+	 * private_data member of \a fn suitably. The open function is
+	 * optional, If it is provided, it is assumed to succeed.
 	 */
 	void (*open)(struct filter_node *fn);
 	/**
 	 * Close one instance of this filter.
 	 *
-	 * Free all resources of associated with \a fn that were previously allocated
-	 * by the open() function.
+	 * Free all resources associated with \a fn that were previously
+	 * allocated by the open() function. It's OK to set this to NULL if the
+	 * filter does not need to perform any cleanup operation.
 	 */
 	void (*close)(struct filter_node *fn);
 	/**
@@ -88,26 +85,48 @@ struct filter {
 	 * argv. On failure, a negative paraslash error code must be returned.
 	 */
 	int (*parse_config)(int argc, char **argv, void **config);
+	/**
+	 * Deallocate the memory for the configuration.
+	 *
+	 * This is called to free whatever ->parse_config() has allocated.
+	 */
 	void (*free_config)(void *conf);
 
 	/** The help texts for this filter. */
 	struct ggo_help help;
-	void (*pre_select)(struct sched *s, struct task *t);
+	/**
+	 * Set scheduler timeout and add file descriptors to fd sets.
+	 *
+	 * This function controls the timeout value for the next call to
+	 * select(2). It may decrease the current timeout but shall never
+	 * increase it. The second purpose of this function is to add file
+	 * descriptors to the two fd sets of the sched structure. The
+	 * descriptors in these sets will be watched by the subsequent
+	 * select(2) call.
+	 */
+	void (*pre_select)(struct sched *s, void *context);
 	/**
 	 * Convert (filter) the given data.
 	 *
-	 * Pointer to the converting function of the filter. It should convert as
-	 * input data as possible. On errors, the post_select function is supposed
-	 * to set t->error to a (negative) error code.
+	 * Pointer to the converting function of the filter. On errors, the
+	 * post_select function is supposed to return a negative error code.
+	 */
+	int (*post_select)(struct sched *s, void *context);
+	/**
+	 * Answer a buffer tree query.
+	 *
+	 * This optional function pointer is used for inter node communications
+	 * of the buffer tree nodes. See \ref btr_command_handler for details.
 	 */
-	void (*post_select)(struct sched *s, struct task *t);
 	btr_command_handler execute;
 };
 
 void filter_init(void);
-int check_filter_arg(char *filter_arg, void **conf);
-void print_filter_helps(int detailed);
-void generic_filter_pre_select(struct sched *s, struct task *t);
+int check_filter_arg(const char *fa, void **conf);
+void print_filter_helps(unsigned flags);
+void generic_filter_pre_select(struct sched *s, void *context);
+int decoder_execute(const char *cmd, unsigned sample_rate, unsigned channels,
+		char **result);
 
 static inline void write_int16_host_endian(char *buf, int val)
 {
@@ -122,7 +141,4 @@ static inline void write_int16_host_endian(char *buf, int val)
 
 DECLARE_FILTER_INITS
 
-#define FOR_EACH_SUPPORTED_FILTER(j)  for (j = 0; j < NUM_SUPPORTED_FILTERS; j++)
-
-/** The filter array, one structure for each supported filter. */
-extern struct filter filters[NUM_SUPPORTED_FILTERS];
+const struct filter *filter_get(int filter_num);