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Added description of shm, null and rate plugins

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This commit is contained in:
Jaroslav Kysela 2002-01-22 14:27:25 +00:00
parent f14063a251
commit 2cc79806a2
6 changed files with 216 additions and 13 deletions
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64
src/pcm/pcm_null.c
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@ -1,3 +1,10 @@
/**
* \file pcm/pcm_null.c
* \ingroup PCM_Plugins
* \brief PCM Null Plugin Interface
* \author Abramo Bagnara <abramo@alsa-project.org>
* \date 2000-2001
*/
/*
* PCM - Null plugin
* Copyright (c) 2000 by Abramo Bagnara <abramo@alsa-project.org>
@ -30,6 +37,7 @@
const char *_snd_module_pcm_null = "";
#endif
#ifndef DOC_HIDDEN
typedef struct {
snd_timestamp_t trigger_tstamp;
snd_pcm_state_t state;
@ -38,6 +46,7 @@ typedef struct {
snd_pcm_uframes_t hw_ptr;
int poll_fd;
} snd_pcm_null_t;
#endif
static int snd_pcm_null_close(snd_pcm_t *pcm)
{
@ -295,7 +304,7 @@ static void snd_pcm_null_dump(snd_pcm_t *pcm, snd_output_t *out)
}
}
snd_pcm_ops_t snd_pcm_null_ops = {
static snd_pcm_ops_t snd_pcm_null_ops = {
close: snd_pcm_null_close,
info: snd_pcm_null_info,
hw_refine: snd_pcm_null_hw_refine,
@ -310,7 +319,7 @@ snd_pcm_ops_t snd_pcm_null_ops = {
munmap: snd_pcm_null_munmap,
};
snd_pcm_fast_ops_t snd_pcm_null_fast_ops = {
static snd_pcm_fast_ops_t snd_pcm_null_fast_ops = {
status: snd_pcm_null_status,
state: snd_pcm_null_state,
delay: snd_pcm_null_delay,
@ -330,6 +339,17 @@ snd_pcm_fast_ops_t snd_pcm_null_fast_ops = {
mmap_commit: snd_pcm_null_mmap_commit,
};
/**
* \brief Creates a new null PCM
* \param pcmp Returns created PCM handle
* \param name Name of PCM
* \param stream Stream type
* \param mode Stream mode
* \retval zero on success otherwise a negative error code
* \warning Using of this function might be dangerous in the sense
* of compatibility reasons. The prototype might be freely
* changed in future.
*/
int snd_pcm_null_open(snd_pcm_t **pcmp, const char *name, snd_pcm_stream_t stream, int mode)
{
snd_pcm_t *pcm;
@ -375,6 +395,44 @@ int snd_pcm_null_open(snd_pcm_t **pcmp, const char *name, snd_pcm_stream_t strea
return 0;
}
/*! \page pcm_plugins
\section pcm_plugins_null Plugin: Null
This plugin discards contents of a PCM stream or creates a stream with zero
samples.
Note: This implementation uses devices /dev/null (playback, must be writeable)
and /dev/full (capture, must be readable).
\code
pcm.name {
type null # Null PCM
}
\endcode
\subsection pcm_plugins_null_funcref Function reference
<UL>
<LI>snd_pcm_null_open()
<LI>_snd_pcm_null_open()
</UL>
*/
/**
* \brief Creates a new Null PCM
* \param pcmp Returns created PCM handle
* \param name Name of PCM
* \param root Root configuration node
* \param conf Configuration node with Null PCM description
* \param stream Stream type
* \param mode Stream mode
* \retval zero on success otherwise a negative error code
* \warning Using of this function might be dangerous in the sense
* of compatibility reasons. The prototype might be freely
* changed in future.
*/
int _snd_pcm_null_open(snd_pcm_t **pcmp, const char *name,
snd_config_t *conf,
snd_pcm_stream_t stream, int mode)
@ -392,4 +450,6 @@ int _snd_pcm_null_open(snd_pcm_t **pcmp, const char *name,
}
return snd_pcm_null_open(pcmp, name, stream, mode);
}
#ifndef DOC_HIDDEN
SND_DLSYM_BUILD_VERSION(_snd_pcm_null_open, SND_PCM_DLSYM_VERSION);
#endif