X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=filter.h;h=94657a738a4ae1b620148d28400c20ed4c27a710;hp=bf99a677b7c0b6e5cab95111834ad031c19c7619;hb=bda95f9508b456dcea89d300f6d4104e30ab9f3e;hpb=fdd1f83d38148ecb76aac90ec02b12a985de8821

diff --git a/filter.h b/filter.h
index bf99a677..94657a73 100644
--- a/filter.h
+++ b/filter.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005-2011 Andre Noll <maan@systemlinux.org>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -15,75 +15,23 @@ 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;
+	/** The task corresponding to this filter node. */
 	struct task task;
+	/** The minimal input queue size, see \ref btr_node_status(). */
 	size_t min_iqs;
 };
 
-/** 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.
-	 *
-	 * Set by the decoding filter.
-	 */
-	unsigned int channels;
-	/**
-	 * Current sample rate in Hz.
-	 *
-	 * Set by the decoding filter.
-	 */
-	unsigned int samplerate;
-	/** The list containing all filter nodes in this filter chain. */
-	struct filter_node *filter_nodes;
-	/**
-	 * The input buffer of the filter chain.
-	 *
-	 * This is set to point to the output buffer of the receiving application (the
-	 * buffer used to read from stdin for para_filter; the output buffer of the
-	 * current receiver for para_audiod).
-	 */
-	char **inbufp;
-	/**
-	 * The output buffer of the filter chain.
-	 *
-	 * Points to the output buffer of the last filter in the filter chain.
-	 */
-	char **outbufp;
-	/** Contains the number of bytes loaded in the input buffer. */
-	size_t *in_loaded;
-	/** Contains the number of bytes loaded in the output buffer. */
-	size_t *out_loaded;
-	/** Pointer to the error variable of the receiving application. */
-	int *input_error;
-	/** Pointer to the error variable of the writing application. */
-	int *output_error;
-	/** The task associated with the filter chain. */
-	struct task task;
-};
-
-#define FOR_EACH_FILTER_NODE(fn, fc, i) for (i = 0; i < (fc)->num_filters \
-	&& (fn = (fc)->filter_nodes + i); i++)
-
 /**
  * The structure associated with a paraslash filter.
  *
@@ -119,7 +67,8 @@ struct filter {
 	 * Close one instance of this filter.
 	 *
 	 * Free all resources of associated with \a fn that were previously allocated
-	 * by the open() function.
+	 * by the open() function. It's OK to leave this alone if the filter does not
+	 * need any cleanups.
 	 */
 	void (*close)(struct filter_node *fn);
 	/**
@@ -135,19 +84,38 @@ 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;
+	/**
+	 * Set scheduler timeout and add file descriptors to fd sets.
+	 *
+	 * This function is used to control the timeout value for select. It
+	 * only allowed to decrease the current value. The second purpose of
+	 * this function is to set file descriptors to be watched by the
+	 * subsequent select call to the two fd sets.
+	 */
 	void (*pre_select)(struct sched *s, struct task *t);
 	/**
 	 * 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 set t->error to a (negative)
+	 * error code.
 	 */
 	void (*post_select)(struct sched *s, struct task *t);
+	/**
+	 * 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.
+	 */
 	btr_command_handler execute;
 };
 
@@ -155,6 +123,8 @@ 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 decoder_execute(const char *cmd, unsigned sample_rate, unsigned channels,
+		char **result);
 
 static inline void write_int16_host_endian(char *buf, int val)
 {
@@ -169,6 +139,7 @@ static inline void write_int16_host_endian(char *buf, int val)
 
 DECLARE_FILTER_INITS
 
+/** Iterate over the array of supported filters. */
 #define FOR_EACH_SUPPORTED_FILTER(j)  for (j = 0; j < NUM_SUPPORTED_FILTERS; j++)
 
 /** The filter array, one structure for each supported filter. */