Simple setup functions
[PCM Interface]

Files
file	pcm_simple.c
	PCM Simple Interface.
Typedefs
typedef enum _snd_spcm_latency	snd_spcm_latency_t
typedef enum _snd_spcm_xrun_type	snd_spcm_xrun_type_t
typedef enum _snd_spcm_duplex_type	snd_spcm_duplex_type_t
Enumerations
enum	_snd_spcm_latency { SND_SPCM_LATENCY_STANDARD = 0, SND_SPCM_LATENCY_MEDIUM, SND_SPCM_LATENCY_REALTIME }
enum	_snd_spcm_xrun_type { SND_SPCM_XRUN_IGNORE = 0, SND_SPCM_XRUN_STOP }
enum	_snd_spcm_duplex_type { SND_SPCM_DUPLEX_LIBERAL = 0, SND_SPCM_DUPLEX_PEDANTIC }
Functions
int	snd_spcm_init (snd_pcm_t *pcm, unsigned int rate, unsigned int channels, snd_pcm_format_t format, snd_pcm_subformat_t subformat, snd_spcm_latency_t latency, snd_pcm_access_t _access, snd_spcm_xrun_type_t xrun_type)
	Set up a simple PCM.
int	snd_spcm_init_duplex (snd_pcm_t *playback_pcm, snd_pcm_t *capture_pcm, unsigned int rate, unsigned int channels, snd_pcm_format_t format, snd_pcm_subformat_t subformat, snd_spcm_latency_t latency, snd_pcm_access_t _access, snd_spcm_xrun_type_t xrun_type, snd_spcm_duplex_type_t duplex_type)
	Initialize simple PCMs in the duplex mode.
int	snd_spcm_init_get_params (snd_pcm_t *pcm, unsigned int *rate, snd_pcm_uframes_t *buffer_size, snd_pcm_uframes_t *period_size)
	Get the set up of simple PCM.

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Detailed Description

See the PCM (digital audio) interface page for more details.

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Enumeration Type Documentation

enum _snd_spcm_duplex_type

Simple PCM duplex type

Enumerator:

SND_SPCM_DUPLEX_LIBERAL	liberal duplex - the buffer and period sizes might not match
SND_SPCM_DUPLEX_PEDANTIC	pedantic duplex - the buffer and period sizes MUST match

enum _snd_spcm_latency

Simple PCM latency type

Enumerator:

SND_SPCM_LATENCY_STANDARD	standard latency - for standard playback or capture (estimated latency in one direction 350ms)
SND_SPCM_LATENCY_MEDIUM	medium latency - software phones etc. (estimated latency in one direction maximally 25ms
SND_SPCM_LATENCY_REALTIME	realtime latency - realtime applications (effect processors etc.) (estimated latency in one direction 5ms and better)

enum _snd_spcm_xrun_type

Simple PCM xrun type

Enumerator:

SND_SPCM_XRUN_IGNORE	driver / library will ignore all xruns, the stream runs forever
SND_SPCM_XRUN_STOP	driver / library stops the stream when an xrun occurs

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Function Documentation

int snd_spcm_init	(	snd_pcm_t *	pcm,
		unsigned int	rate,
		unsigned int	channels,
		snd_pcm_format_t	format,
		snd_pcm_subformat_t	subformat,
		snd_spcm_latency_t	latency,
		snd_pcm_access_t	access,
		snd_spcm_xrun_type_t	xrun_type
	)

Set up a simple PCM.

Parameters:

	pcm	PCM handle
	rate	Sample rate
	channels	Number of channels
	format	PCM format
	subformat	PCM subformat
	latency	Latency type
	access	PCM acceess type
	xrun_type	XRUN type

Returns:

0 if successful, or a negative error code

Warning:

The simple PCM API may be broken in the current release.

int snd_spcm_init_duplex	(	snd_pcm_t *	playback_pcm,
		snd_pcm_t *	capture_pcm,
		unsigned int	rate,
		unsigned int	channels,
		snd_pcm_format_t	format,
		snd_pcm_subformat_t	subformat,
		snd_spcm_latency_t	latency,
		snd_pcm_access_t	access,
		snd_spcm_xrun_type_t	xrun_type,
		snd_spcm_duplex_type_t	duplex_type
	)

Initialize simple PCMs in the duplex mode.

Parameters:

	playback_pcm	PCM handle for playback
	capture_pcm	PCM handle for capture
	rate	Sample rate
	channels	Number of channels
	format	PCM format
	subformat	PCM subformat
	latency	Latency type
	access	PCM acceess type
	xrun_type	XRUN type
	duplex_type	Duplex mode

Returns:

0 if successful, or a negative error code

Warning:

The simple PCM API may be broken in the current release.

int snd_spcm_init_get_params	(	snd_pcm_t *	pcm,
		unsigned int *	rate,
		snd_pcm_uframes_t *	buffer_size,
		snd_pcm_uframes_t *	period_size
	)

Get the set up of simple PCM.

Parameters:

	pcm	PCM handle
	rate	Pointer to store the current sample rate
	buffer_size	Pointer to store the current buffer size
	period_size	Pointer to store the current period size

Returns:

0 if successful, or a negative error code

Warning:

The simple PCM API may be broken in the current release.