-/**
- * 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 *);
-};
-
-/**
- * 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 *input_eof;
- int eof;
- char *buf;
- size_t *loaded;
- struct task task;
+ /**
+ * 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 and return a pointer to the writer-specific configuration
+ * data determined by \a options. This function must either succeed or
+ * call exit(). Note that parse_config_or_die() might be called more
+ * than once with different values of \a options. \sa \ref
+ * free_config().
+ */
+ void *(*parse_config_or_die)(const char *options);
+ /**
+ * Dellocate all configuration resources.
+ *
+ * This should free whatever was allocated by \ref parse_config_or_die().
+ */
+ void (*free_config)(void *config);
+ /**
+ * 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 *);
+ /** The short and the log help text of this writer. */
+ struct ggo_help help;
+ /**
+ * The callback handler.
+ *
+ * Each writer may provide an ->execute callback which can be used for
+ * inter-node communication.
+ */
+ btr_command_handler execute;