-/**
- * the init function of the writer
- *
- * It must fill in all other function pointers of the given
- * writer structure.
- *
- */
-void (*init)(struct writer *w);
-/**
- *
- * 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 *);
-/**
- * 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 *);
-};
-
-/**
- * describes a set of writer nodes that all write the same stream.
- */
-struct writer_node_group {
-/** number of nodes belonging to this group */
-unsigned num_writers;
-/** array of pointers to the corresponding writer nodes */
-struct writer_node *writer_nodes;
-/** keeps track of how many bytes have been written by each node */
-int *written;
-/** the maximum of the chunk_bytes values of the writer nodes in this group */
-size_t max_chunk_bytes;
-/** non-zero if end of file was encountered */
-int eof;
+ /**
+ * 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)(const char *options);
+ void (*free_config)(void *conf);
+ /**
+ * Open one instance of this writer.
+ *
+ * This function should perform any work necessary to write the incoming
+ * stream. To this aim, it may allocate its private data structure and store
+ * a pointer to that structure via the given writer_node parameter.
+ */
+ int (*open)(struct writer_node *);
+ /**
+ * Prepare the fd sets for select.
+ *
+ * This is called from scheduler. It may use the sched pointer to add
+ * any file descriptors or to decrease the select timeout.
+ */
+ void (*pre_select)(struct sched *s, struct task *t);
+ /**
+ * Write audio data.
+ *
+ * Called from the post_select function of the writer node's task.
+ */
+ 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 *);
+ struct ggo_help help;
+ btr_command_handler execute;