- void (*init)(struct writer *w);
- int (*open)(struct writer_node *);
- int (*write)(char *data, size_t nbytes, struct writer_node *);
- void (*close)(struct writer_node *);
- void (*shutdown)(struct writer_node *);
+/**
+ * the init function of the writer
+ *
+ * It must fill in all other function pointers of the given
+ * writer structure.
+ *
+ */
+void (*init)(struct writer *w);
+/**
+ *
+ *
+ * the command line parser of the writer
+ *
+ * It should check whether the command line options given by \a options are
+ * valid. On success, it should return a pointer to the writer-specific
+ * configuration data determined by \a options. Note that this might be called
+ * more than once with different values of \a options.
+ *
+ */
+ void * (*parse_config)(char *options);
+/**
+ *
+ * open one instance of this writer
+ *
+ * This function should perform any work necessary to write the incoming
+ * stream. If To this aim, it may allocate its private data structure and store
+ * a pointer to that structure via the given writer_node paramenter.
+ */
+int (*open)(struct writer_node *);
+/**
+ *
+ * write a chunk of audio data
+ *
+ * This is called from the driving application whenever a data block of \a
+ * chunk_bytes is available. It must return the number of bytes consumed from
+ * \a data on success, and negative on errors.
+ *
+ */
+int (*write)(char *data, size_t nbytes, struct writer_node *);
+void (*pre_select)(struct sched *s, struct task *t);
+void (*post_select)(struct sched *s, struct task *t);
+/**
+ * close one instance of the writer
+ *
+ * This function is assumed to succeed.
+ */
+void (*close)(struct writer_node *);
+/**
+ * shutdown the writer
+ *
+ * This is a optional function pointer used for cleaning
+ * up.
+ */
+void (*shutdown)(struct writer_node *);