code.delx.au - pulseaudio/blob - src/pulse/simple.h

   1 #ifndef foosimplehfoo
   2 #define foosimplehfoo
   3
   4 /***
   5   This file is part of PulseAudio.
   6
   7   Copyright 2004-2006 Lennart Poettering
   8   Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
   9
  10   PulseAudio is free software; you can redistribute it and/or modify
  11   it under the terms of the GNU Lesser General Public License as published
  12   by the Free Software Foundation; either version 2.1 of the License,
  13   or (at your option) any later version.
  14
  15   PulseAudio is distributed in the hope that it will be useful, but
  16   WITHOUT ANY WARRANTY; without even the implied warranty of
  17   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18   General Public License for more details.
  19
  20   You should have received a copy of the GNU Lesser General Public License
  21   along with PulseAudio; if not, write to the Free Software
  22   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  23   USA.
  24 ***/
  25
  26 #include <sys/types.h>
  27
  28 #include <pulse/sample.h>
  29 #include <pulse/channelmap.h>
  30 #include <pulse/def.h>
  31 #include <pulse/cdecl.h>
  32 #include <pulse/version.h>
  33
  34 /** \page simple Simple API
  35  *
  36  * \section overv_sec Overview
  37  *
  38  * The simple API is designed for applications with very basic sound
  39  * playback or capture needs. It can only support a single stream per
  40  * connection and has no support for handling of complex features like
  41  * events, channel mappings and volume control. It is, however, very simple
  42  * to use and quite sufficient for many programs.
  43  *
  44  * \section conn_sec Connecting
  45  *
  46  * The first step before using the sound system is to connect to the
  47  * server. This is normally done this way:
  48  *
  49  * \code
  50  * pa_simple *s;
  51  * pa_sample_spec ss;
  52  *
  53  * ss.format = PA_SAMPLE_S16NE;
  54  * ss.channels = 2;
  55  * ss.rate = 44100;
  56  *
  57  * s = pa_simple_new(NULL,               // Use the default server.
  58  *                   "Fooapp",           // Our application's name.
  59  *                   PA_STREAM_PLAYBACK,
  60  *                   NULL,               // Use the default device.
  61  *                   "Music",            // Description of our stream.
  62  *                   &ss,                // Our sample format.
  63  *                   NULL,               // Use default channel map
  64  *                   NULL,               // Use default buffering attributes.
  65  *                   NULL,               // Ignore error code.
  66  *                   );
  67  * \endcode
  68  *
  69  * At this point a connected object is returned, or NULL if there was a
  70  * problem connecting.
  71  *
  72  * \section transfer_sec Transferring data
  73  *
  74  * Once the connection is established to the server, data can start flowing.
  75  * Using the connection is very similar to the normal read() and write()
  76  * system calls. The main difference is that they're called pa_simple_read()
  77  * and pa_simple_write(). Note that these operations always block.
  78  *
  79  * \section ctrl_sec Buffer control
  80  *
  81  * \li pa_simple_get_latency() - Will return the total latency of
  82  *                               the playback or record pipeline, respectively.
  83  * \li pa_simple_flush() - Will throw away all data currently in buffers.
  84  *
  85  * If a playback stream is used then the following operation is available:
  86  *
  87  * \li pa_simple_drain() - Will wait for all sent data to finish playing.
  88  *
  89  * \section cleanup_sec Cleanup
  90  *
  91  * Once playback or capture is complete, the connection should be closed
  92  * and resources freed. This is done through:
  93  *
  94  * \code
  95  * pa_simple_free(s);
  96  * \endcode
  97  */
  98
  99 /** \file
 100  * A simple but limited synchronous playback and recording
 101  * API. This is a synchronous, simplified wrapper around the standard
 102  * asynchronous API.
 103  *
 104  * See also \subpage simple
 105  */
 106
 107 /** \example pacat-simple.c
 108  * A simple playback tool using the simple API */
 109
 110 /** \example parec-simple.c
 111  * A simple recording tool using the simple API */
 112
 113 PA_C_DECL_BEGIN
 114
 115 /** \struct pa_simple
 116  * An opaque simple connection object */
 117 typedef struct pa_simple pa_simple;
 118
 119 /** Create a new connection to the server. */
 120 pa_simple* pa_simple_new(
 121     const char *server,                 /**< Server name, or NULL for default */
 122     const char *name,                   /**< A descriptive name for this client (application name, ...) */
 123     pa_stream_direction_t dir,          /**< Open this stream for recording or playback? */
 124     const char *dev,                    /**< Sink (resp. source) name, or NULL for default */
 125     const char *stream_name,            /**< A descriptive name for this stream (application name, song title, ...) */
 126     const pa_sample_spec *ss,           /**< The sample type to use */
 127     const pa_channel_map *map,          /**< The channel map to use, or NULL for default */
 128     const pa_buffer_attr *attr,         /**< Buffering attributes, or NULL for default */
 129     int *error                          /**< A pointer where the error code is stored when the routine returns NULL. It is OK to pass NULL here. */
 130     );
 131
 132 /** Close and free the connection to the server. The connection object becomes invalid when this is called. */
 133 void pa_simple_free(pa_simple *s);
 134
 135 /** Write some data to the server. */
 136 int pa_simple_write(pa_simple *s, const void *data, size_t bytes, int *error);
 137
 138 /** Wait until all data already written is played by the daemon. */
 139 int pa_simple_drain(pa_simple *s, int *error);
 140
 141 /** Read some data from the server. This function blocks until \a bytes amount
 142  * of data has been received from the server, or until an error occurs.
 143  * Returns a negative value on failure. */
 144 int pa_simple_read(
 145     pa_simple *s, /**< The connection object. */
 146     void *data,   /**< A pointer to a buffer. */
 147     size_t bytes, /**< The number of bytes to read. */
 148     int *error
 149     /**< A pointer where the error code is stored when the function returns
 150      * a negative value. It is OK to pass NULL here. */
 151     );
 152
 153 /** Return the playback or record latency. */
 154 pa_usec_t pa_simple_get_latency(pa_simple *s, int *error);
 155
 156 /** Flush the playback or record buffer. This discards any audio in the buffer. */
 157 int pa_simple_flush(pa_simple *s, int *error);
 158
 159 PA_C_DECL_END
 160
 161 #endif