write.h File Reference

Writer-related structures. More...

Data Structures
struct	writer_node
	Describes one running instance of a writer. More...
struct	writer
	Describes a data sink for audio streams. More...

Macros
#define	WRITE_CMD(_num)   (lls_cmd(_num, write_cmd_suite))
#define	WRITE_CMD_OPT_RESULT(_cmd, _opt, _lpr)    (lls_opt_result(LSG_WRITE_CMD_ ## _cmd ## _OPT_ ## _opt, _lpr))
#define	WRITE_CMD_OPT_GIVEN(_cmd, _opt, _lpr)    (lls_opt_given(WRITE_CMD_OPT_RESULT(_cmd, _opt, _lpr)))
#define	WRITE_CMD_OPT_UINT32_VAL(_cmd, _opt, _lpr)    (lls_uint32_val(0, WRITE_CMD_OPT_RESULT(_cmd, _opt, (_lpr))))
#define	WRITE_CMD_OPT_STRING_VAL(_cmd, _opt, _lpr)    (lls_string_val(0, WRITE_CMD_OPT_RESULT(_cmd, _opt, (_lpr))))

Functions
int	check_writer_arg_or_die (const char *wa, struct lls_parse_result **lprp)
	Check if the given string is a valid command line for any writer. More...
const struct writer *	writer_get (int wid)
	Return the writer structure from a writer ID. More...
const char *	writer_name (int wid)
	Return name of the writer identified by a writer ID. More...
void	register_writer_node (struct writer_node *wn, struct btr_node *parent, struct sched *s)
	Open a writer node and register the corresponding task. More...
int	get_btr_sample_rate (struct btr_node *btrn, int32_t *result)
	Ask parent btr nodes for the sample rate of the current stream. More...
int	get_btr_channels (struct btr_node *btrn, int32_t *result)
	Ask parent btr nodes for the channel count of the current stream. More...
int	get_btr_sample_format (struct btr_node *btrn, int32_t *result)
	Ask parent btr nodes for the number of bits per sample and the byte sex. More...
void	print_writer_helps (bool detailed)
	Print the help text of all writers to stdout. More...

Detailed Description

Writer-related structures.

Macro Definition Documentation

WRITE_CMD

#define WRITE_CMD

(

_num

)

(lls_cmd(_num, write_cmd_suite))

WRITE_CMD_OPT_RESULT

#define WRITE_CMD_OPT_RESULT	(		_cmd,
			_opt,
			_lpr
	)		(lls_opt_result(LSG_WRITE_CMD_ ## _cmd ## _OPT_ ## _opt, _lpr))

WRITE_CMD_OPT_GIVEN

#define WRITE_CMD_OPT_GIVEN	(		_cmd,
			_opt,
			_lpr
	)		(lls_opt_given(WRITE_CMD_OPT_RESULT(_cmd, _opt, _lpr)))

WRITE_CMD_OPT_UINT32_VAL

#define WRITE_CMD_OPT_UINT32_VAL	(		_cmd,
			_opt,
			_lpr
	)		(lls_uint32_val(0, WRITE_CMD_OPT_RESULT(_cmd, _opt, (_lpr))))

WRITE_CMD_OPT_STRING_VAL

#define WRITE_CMD_OPT_STRING_VAL	(		_cmd,
			_opt,
			_lpr
	)		(lls_string_val(0, WRITE_CMD_OPT_RESULT(_cmd, _opt, (_lpr))))

Function Documentation

check_writer_arg_or_die()

int check_writer_arg_or_die	(	const char *	wa,
		struct lls_parse_result **	lprp
	)

Check if the given string is a valid command line for any writer.

Parameters

wa	String of the form writer_name options.
lprp	Contains the parsed command line on success.

If wa is NULL, the (configuration-dependent) default writer is assumed. Otherwise, the function checks whether wa starts with the name of a supported writer. If a valid writer name was found, the rest of the command line is passed to the config parser of this writer.

Returns

On success, the positive writer ID is returned. Otherwise the function prints an error message and calls exit().

writer_get()

const struct writer* writer_get

(

int

wid

)

Return the writer structure from a writer ID.

Parameters

wid	If non-positive, a pointer to the default writer is returned.

Returns

Pointer to a (constant) struct writer.

Referenced by register_writer_node().

writer_name()

const char* writer_name

(

int

wid

)

Return name of the writer identified by a writer ID.

Parameters

wid	If non-positive, the name of the default writer is returned.

Returns

The returned buffer must not be freed by the caller.

Referenced by register_writer_node().

register_writer_node()

void register_writer_node	(	struct writer_node *	wn,
		struct btr_node *	parent,
		struct sched *	s
	)

Open a writer node and register the corresponding task.

Parameters

wn	The writer node to open.
parent	The parent btr node (the source for the writer node).
s	The scheduler instance to register the task to.

References btr_new_node(), writer_node::btrn, EMBRACE, writer::execute, writer::post_monitor, writer::pre_monitor, writer_node::task, task_register(), writer_node::wid, writer_get(), and writer_name().

get_btr_sample_rate()

int get_btr_sample_rate	(	struct btr_node *	btrn,
		int32_t *	result
	)

Ask parent btr nodes for the sample rate of the current stream.

Parameters

btrn	Where to start the search.
result	Filled in by this function.

Returns

Standard.

get_btr_channels()

int get_btr_channels	(	struct btr_node *	btrn,
		int32_t *	result
	)

Ask parent btr nodes for the channel count of the current stream.

Parameters

btrn	See get_btr_sample_rate.
result	See get_btr_sample_rate.

Returns

Standard.

get_btr_sample_format()

int get_btr_sample_format	(	struct btr_node *	btrn,
		int32_t *	result
	)

Ask parent btr nodes for the number of bits per sample and the byte sex.

Parameters

btrn	See get_btr_sample_rate.
result	Contains the sample format as an enum sample_format type.

Returns

Standard.

print_writer_helps()

void print_writer_helps

(

bool

detailed

)

Print the help text of all writers to stdout.

Parameters

detailed

Whether to print the short or the detailed help.

References FOR_EACH_WRITER.