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

   1 #ifndef foodefhfoo
   2 #define foodefhfoo
   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
  12   published by the Free Software Foundation; either version 2.1 of the
  13   License, 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   Lesser General Public License for more details.
  19
  20   You should have received a copy of the GNU Lesser General Public
  21   License 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 <inttypes.h>
  27 #include <sys/time.h>
  28 #include <time.h>
  29
  30 #include <pulse/cdecl.h>
  31 #include <pulse/sample.h>
  32
  33 /** \file
  34  * Global definitions */
  35
  36 PA_C_DECL_BEGIN
  37
  38 /** The state of a connection context */
  39 typedef enum pa_context_state {
  40     PA_CONTEXT_UNCONNECTED,    /**< The context hasn't been connected yet */
  41     PA_CONTEXT_CONNECTING,     /**< A connection is being established */
  42     PA_CONTEXT_AUTHORIZING,    /**< The client is authorizing itself to the daemon */
  43     PA_CONTEXT_SETTING_NAME,   /**< The client is passing its application name to the daemon */
  44     PA_CONTEXT_READY,          /**< The connection is established, the context is ready to execute operations */
  45     PA_CONTEXT_FAILED,         /**< The connection failed or was disconnected */
  46     PA_CONTEXT_TERMINATED      /**< The connection was terminated cleanly */
  47 } pa_context_state_t;
  48
  49 /** Return non-zero if the passed state is one of the connected states */
  50 static inline int PA_CONTEXT_IS_GOOD(pa_context_state_t x) {
  51     return
  52         x == PA_CONTEXT_CONNECTING ||
  53         x == PA_CONTEXT_AUTHORIZING ||
  54         x == PA_CONTEXT_SETTING_NAME ||
  55         x == PA_CONTEXT_READY;
  56 }
  57
  58 /** The state of a stream */
  59 typedef enum pa_stream_state {
  60     PA_STREAM_UNCONNECTED, /**< The stream is not yet connected to any sink or source */
  61     PA_STREAM_CREATING,     /**< The stream is being created */
  62     PA_STREAM_READY,        /**< The stream is established, you may pass audio data to it now */
  63     PA_STREAM_FAILED,       /**< An error occured that made the stream invalid */
  64     PA_STREAM_TERMINATED    /**< The stream has been terminated cleanly */
  65 } pa_stream_state_t;
  66
  67 /** Return non-zero if the passed state is one of the connected states */
  68 static inline int PA_STREAM_IS_GOOD(pa_stream_state_t x) {
  69     return
  70         x == PA_STREAM_CREATING ||
  71         x == PA_STREAM_READY;
  72 }
  73
  74 /** The state of an operation */
  75 typedef enum pa_operation_state {
  76     PA_OPERATION_RUNNING,      /**< The operation is still running */
  77     PA_OPERATION_DONE,         /**< The operation has been completed */
  78     PA_OPERATION_CANCELED      /**< The operation has been canceled */
  79 } pa_operation_state_t;
  80
  81 /** An invalid index */
  82 #define PA_INVALID_INDEX ((uint32_t) -1)
  83
  84 /** Some special flags for contexts. */
  85 typedef enum pa_context_flags {
  86     PA_CONTEXT_NOAUTOSPAWN = 1 /**< Disabled autospawning of the PulseAudio daemon if required */
  87 } pa_context_flags_t;
  88
  89 /** The direction of a pa_stream object */
  90 typedef enum pa_stream_direction {
  91     PA_STREAM_NODIRECTION,   /**< Invalid direction */
  92     PA_STREAM_PLAYBACK,      /**< Playback stream */
  93     PA_STREAM_RECORD,        /**< Record stream */
  94     PA_STREAM_UPLOAD         /**< Sample upload stream */
  95 } pa_stream_direction_t;
  96
  97 /** Some special flags for stream connections. */
  98 typedef enum pa_stream_flags {
  99     PA_STREAM_START_CORKED = 1,       /**< Create the stream corked, requiring an explicit pa_stream_cork() call to uncork it. */
 100     PA_STREAM_INTERPOLATE_TIMING = 2, /**< Interpolate the latency for
 101                                        * this stream. When enabled,
 102                                        * pa_stream_get_latency() and
 103                                        * pa_stream_get_time() will try
 104                                        * to estimate the current
 105                                        * record/playback time based on
 106                                        * the local time that passed
 107                                        * since the last timing info
 108                                        * update.  Using this option
 109                                        * has the advantage of not
 110                                        * requiring a whole roundtrip
 111                                        * when the current
 112                                        * playback/recording time is
 113                                        * needed. Consider using this
 114                                        * option when requesting
 115                                        * latency information
 116                                        * frequently. This is
 117                                        * especially useful on long
 118                                        * latency network
 119                                        * connections. It makes a lot
 120                                        * of sense to combine this
 121                                        * option with
 122                                        * PA_STREAM_AUTO_TIMING_UPDATE. */
 123     PA_STREAM_NOT_MONOTONIC = 4,    /**< Don't force the time to
 124                                       * increase monotonically. If
 125                                       * this option is enabled,
 126                                       * pa_stream_get_time() will not
 127                                       * necessarily return always
 128                                       * monotonically increasing time
 129                                       * values on each call. This may
 130                                       * confuse applications which
 131                                       * cannot deal with time going
 132                                       * 'backwards', but has the
 133                                       * advantage that bad transport
 134                                       * latency estimations that
 135                                       * caused the time to to jump
 136                                       * ahead can be corrected
 137                                       * quickly, without the need to
 138                                       * wait. (Please note that this
 139                                       * flag was named
 140                                       * PA_STREAM_NOT_MONOTONOUS in
 141                                       * releases prior to 0.9.11. The
 142                                       * old name is still defined too,
 143                                       * for compatibility reasons. */
 144     PA_STREAM_AUTO_TIMING_UPDATE = 8, /**< If set timing update requests
 145                                        * are issued periodically
 146                                        * automatically. Combined with
 147                                        * PA_STREAM_INTERPOLATE_TIMING
 148                                        * you will be able to query the
 149                                        * current time and latency with
 150                                        * pa_stream_get_time() and
 151                                        * pa_stream_get_latency() at
 152                                        * all times without a packet
 153                                        * round trip.*/
 154     PA_STREAM_NO_REMAP_CHANNELS = 16, /**< Don't remap channels by
 155                                        * their name, instead map them
 156                                        * simply by their
 157                                        * index. Implies
 158                                        * PA_STREAM_NO_REMIX_CHANNELS. Only
 159                                        * supported when the server is
 160                                        * at least PA 0.9.8. It is
 161                                        * ignored on older
 162                                        * servers.\since 0.9.8 */
 163     PA_STREAM_NO_REMIX_CHANNELS = 32, /**< When remapping channels by
 164                                        * name, don't upmix or downmix
 165                                        * them to related
 166                                        * channels. Copy them into
 167                                        * matching channels of the
 168                                        * device 1:1. Only supported
 169                                        * when the server is at least
 170                                        * PA 0.9.8. It is ignored on
 171                                        * older servers. \since
 172                                        * 0.9.8 */
 173     PA_STREAM_FIX_FORMAT = 64, /**< Use the sample format of the
 174                                 * sink/device this stream is being
 175                                 * connected to, and possibly ignore
 176                                 * the format the sample spec contains
 177                                 * -- but you still have to pass a
 178                                 * valid value in it as a hint to
 179                                 * PulseAudio what would suit your
 180                                 * stream best. If this is used you
 181                                 * should query the used sample format
 182                                 * after creating the stream by using
 183                                 * pa_stream_get_sample_spec(). Also,
 184                                 * if you specified manual buffer
 185                                 * metrics it is recommended to update
 186                                 * them with
 187                                 * pa_stream_set_buffer_attr() to
 188                                 * compensate for the changed frame
 189                                 * sizes. Only supported when the
 190                                 * server is at least PA 0.9.8. It is
 191                                 * ignored on older servers. \since
 192                                 * 0.9.8 */
 193
 194     PA_STREAM_FIX_RATE = 128, /**< Use the sample rate of the sink,
 195                                * and possibly ignore the rate the
 196                                * sample spec contains. Usage similar
 197                                * to PA_STREAM_FIX_FORMAT.Only
 198                                * supported when the server is at least
 199                                * PA 0.9.8. It is ignored on older
 200                                * servers. \since 0.9.8 */
 201
 202     PA_STREAM_FIX_CHANNELS = 256, /**< Use the number of channels and
 203                                * the channel map of the sink, and
 204                                * possibly ignore the number of
 205                                * channels and the map the sample spec
 206                                * and the passed channel map
 207                                * contains. Usage similar to
 208                                * PA_STREAM_FIX_FORMAT. Only supported
 209                                * when the server is at least PA
 210                                * 0.9.8. It is ignored on older
 211                                * servers. \since 0.9.8 */
 212     PA_STREAM_DONT_MOVE = 512, /**< Don't allow moving of this stream to
 213                               * another sink/device. Useful if you use
 214                               * any of the PA_STREAM_FIX_ flags and
 215                               * want to make sure that resampling
 216                               * never takes place -- which might
 217                               * happen if the stream is moved to
 218                               * another sink/source whith a different
 219                               * sample spec/channel map. Only
 220                               * supported when the server is at least
 221                               * PA 0.9.8. It is ignored on older
 222                               * servers. \since 0.9.8 */
 223     PA_STREAM_VARIABLE_RATE = 1024, /**< Allow dynamic changing of the
 224                                      * sampling rate during playback
 225                                      * with
 226                                      * pa_stream_update_sample_rate(). Only
 227                                      * supported when the server is at
 228                                      * least PA 0.9.8. It is ignored
 229                                      * on older servers. \since
 230                                      * 0.9.8 */
 231     PA_STREAM_PEAK_DETECT = 2048, /**< Find peaks instead of
 232                                    * resampling. \since 0.9.11 */
 233
 234     PA_STREAM_START_MUTED = 4096,  /**< Create in muted state. \since 0.9.11 */
 235
 236     PA_STREAM_ADJUST_LATENCY = 8192, /**< Try to adjust the latency of
 237                                       * the sink/source based on the
 238                                       * requested buffer metrics and
 239                                       * adjust buffer metrics
 240                                       * accordingly. See pa_buffer_attr \since 0.9.11 */
 241 } pa_stream_flags_t;
 242
 243
 244 /** English is an evil language */
 245 #define PA_STREAM_NOT_MONOTONOUS PA_STREAM_NOT_MONOTONIC
 246
 247 /** Playback and record buffer metrics */
 248 typedef struct pa_buffer_attr {
 249     uint32_t maxlength;      /**< Maximum length of the
 250                               * buffer. Setting this to (uint32_t) -1 will
 251                               * initialize this to the maximum value
 252                               * supported by server, which is
 253                               * recommended. */
 254     uint32_t tlength;        /**< Playback only: target length of the
 255                               * buffer. The server tries to assure
 256                               * that at least tlength bytes are always
 257                               * available in the per-stream
 258                               * server-side playback buffer. It is
 259                               * recommended to set this to (uint32_t)
 260                               * -1, which will initialize this to a
 261                               * value that is deemed sensible by the
 262                               * server. However, this value will
 263                               * default to something like 2s, i.e. for
 264                               * applications that have specific
 265                               * latency requirements this value should
 266                               * be set to the maximum latency that the
 267                               * application can deal with. When
 268                               * PA_STREAM_ADJUST_LATENCY is not set
 269                               * this value will influence only the
 270                               * per-stream playback buffer size. When
 271                               * PA_STREAM_ADJUST_LATENCY is set the
 272                               * overall latency of the sink plus the
 273                               * playback buffer size is configured to
 274                               * this value. Set
 275                               * PA_STREAM_ADJUST_LATENCY if you are
 276                               * interested in adjusting the overall
 277                               * latency. Don't set it if you are
 278                               * interested in configuring the
 279                               * server-sider per-stream playback
 280                               * buffer size. */
 281     uint32_t prebuf;         /**< Playback only: pre-buffering. The
 282                               * server does not start with playback
 283                               * before at least prebug bytes are
 284                               * available in the buffer. It is
 285                               * recommended to set this to (uint32_t)
 286                               * -1, which will initialize this to the
 287                               * same value as tlength, whatever that
 288                               * may be. Initialize to 0 to enable
 289                               * manual start/stop control of the
 290                               * stream. This means that playback will
 291                               * not stop on underrun and playback will
 292                               * not start automatically. Instead
 293                               * pa_stream_corked() needs to be called
 294                               * explicitly. If you set this value to 0
 295                               * you should also set
 296                               * PA_STREAM_START_CORKED. */
 297     uint32_t minreq;         /**< Playback only: minimum request. The
 298                               * server does not request less than
 299                               * minreq bytes from the client, instead
 300                               * waits until the buffer is free enough
 301                               * to request more bytes at once. It is
 302                               * recommended to set this to (uint32_t)
 303                               * -1, which will initialize this to a
 304                               * value that is deemed sensible by the
 305                               * server. This should be set to a value
 306                               * that gives PulseAudio enough time to
 307                               * move the data from the per-stream
 308                               * playback buffer into the hardware
 309                               * playback buffer. */
 310     uint32_t fragsize;       /**< Recording only: fragment size. The
 311                               * server sends data in blocks of
 312                               * fragsize bytes size. Large values
 313                               * deminish interactivity with other
 314                               * operations on the connection context
 315                               * but decrease control overhead. It is
 316                               * recommended to set this to (uint32_t)
 317                               * -1, which will initialize this to a
 318                               * value that is deemed sensible by the
 319                               * server. However, this value will
 320                               * default to something like 2s, i.e. for
 321                               * applications that have specific
 322                               * latency requirements this value should
 323                               * be set to the maximum latency that the
 324                               * application can deal with. If
 325                               * PA_STREAM_ADJUST_LATENCY is set the
 326                               * overall source latency will be
 327                               * adjusted according to this value. If
 328                               * it is not set the source latency is
 329                               * left unmodified. */
 330 } pa_buffer_attr;
 331
 332 /** Error values as used by pa_context_errno(). Use pa_strerror() to convert these values to human readable strings */
 333 enum {
 334     PA_OK = 0,                     /**< No error */
 335     PA_ERR_ACCESS,                 /**< Access failure */
 336     PA_ERR_COMMAND,                /**< Unknown command */
 337     PA_ERR_INVALID,                /**< Invalid argument */
 338     PA_ERR_EXIST,                  /**< Entity exists */
 339     PA_ERR_NOENTITY,               /**< No such entity */
 340     PA_ERR_CONNECTIONREFUSED,      /**< Connection refused */
 341     PA_ERR_PROTOCOL,               /**< Protocol error */
 342     PA_ERR_TIMEOUT,                /**< Timeout */
 343     PA_ERR_AUTHKEY,                /**< No authorization key */
 344     PA_ERR_INTERNAL,               /**< Internal error */
 345     PA_ERR_CONNECTIONTERMINATED,   /**< Connection terminated */
 346     PA_ERR_KILLED,                 /**< Entity killed */
 347     PA_ERR_INVALIDSERVER,          /**< Invalid server */
 348     PA_ERR_MODINITFAILED,          /**< Module initialization failed */
 349     PA_ERR_BADSTATE,               /**< Bad state */
 350     PA_ERR_NODATA,                 /**< No data */
 351     PA_ERR_VERSION,                /**< Incompatible protocol version */
 352     PA_ERR_TOOLARGE,               /**< Data too large */
 353     PA_ERR_NOTSUPPORTED,           /**< Operation not supported \since 0.9.5 */
 354     PA_ERR_UNKNOWN,                /**< The error code was unknown to the client */
 355     PA_ERR_MAX                     /**< Not really an error but the first invalid error code */
 356 };
 357
 358 /** Subscription event mask, as used by pa_context_subscribe() */
 359 typedef enum pa_subscription_mask {
 360     PA_SUBSCRIPTION_MASK_NULL = 0,               /**< No events */
 361     PA_SUBSCRIPTION_MASK_SINK = 1,               /**< Sink events */
 362     PA_SUBSCRIPTION_MASK_SOURCE = 2,             /**< Source events */
 363     PA_SUBSCRIPTION_MASK_SINK_INPUT = 4,         /**< Sink input events */
 364     PA_SUBSCRIPTION_MASK_SOURCE_OUTPUT = 8,      /**< Source output events */
 365     PA_SUBSCRIPTION_MASK_MODULE = 16,            /**< Module events */
 366     PA_SUBSCRIPTION_MASK_CLIENT = 32,            /**< Client events */
 367     PA_SUBSCRIPTION_MASK_SAMPLE_CACHE = 64,      /**< Sample cache events */
 368     PA_SUBSCRIPTION_MASK_SERVER = 128,           /**< Other global server changes. */
 369     PA_SUBSCRIPTION_MASK_AUTOLOAD = 256,         /**< Autoload table events. */
 370     PA_SUBSCRIPTION_MASK_ALL = 511               /**< Catch all events */
 371 } pa_subscription_mask_t;
 372
 373 /** Subscription event types, as used by pa_context_subscribe() */
 374 typedef enum pa_subscription_event_type {
 375     PA_SUBSCRIPTION_EVENT_SINK = 0,           /**< Event type: Sink */
 376     PA_SUBSCRIPTION_EVENT_SOURCE = 1,         /**< Event type: Source */
 377     PA_SUBSCRIPTION_EVENT_SINK_INPUT = 2,     /**< Event type: Sink input */
 378     PA_SUBSCRIPTION_EVENT_SOURCE_OUTPUT = 3,  /**< Event type: Source output */
 379     PA_SUBSCRIPTION_EVENT_MODULE = 4,         /**< Event type: Module */
 380     PA_SUBSCRIPTION_EVENT_CLIENT = 5,         /**< Event type: Client */
 381     PA_SUBSCRIPTION_EVENT_SAMPLE_CACHE = 6,   /**< Event type: Sample cache item */
 382     PA_SUBSCRIPTION_EVENT_SERVER = 7,         /**< Event type: Global server change, only occuring with PA_SUBSCRIPTION_EVENT_CHANGE. */
 383     PA_SUBSCRIPTION_EVENT_AUTOLOAD = 8,       /**< Event type: Autoload table changes. */
 384     PA_SUBSCRIPTION_EVENT_FACILITY_MASK = 15, /**< A mask to extract the event type from an event value */
 385
 386     PA_SUBSCRIPTION_EVENT_NEW = 0,            /**< A new object was created */
 387     PA_SUBSCRIPTION_EVENT_CHANGE = 16,        /**< A property of the object was modified */
 388     PA_SUBSCRIPTION_EVENT_REMOVE = 32,        /**< An object was removed */
 389     PA_SUBSCRIPTION_EVENT_TYPE_MASK = 16+32   /**< A mask to extract the event operation from an event value */
 390 } pa_subscription_event_type_t;
 391
 392 /** Return one if an event type t matches an event mask bitfield */
 393 #define pa_subscription_match_flags(m, t) (!!((m) & (1 << ((t) & PA_SUBSCRIPTION_EVENT_FACILITY_MASK))))
 394
 395 /** A structure for all kinds of timing information of a stream. See
 396  * pa_stream_update_timing_info() and pa_stream_get_timing_info(). The
 397  * total output latency a sample that is written with
 398  * pa_stream_write() takes to be played may be estimated by
 399  * sink_usec+buffer_usec+transport_usec. (where buffer_usec is defined
 400  * as pa_bytes_to_usec(write_index-read_index)) The output buffer
 401  * which buffer_usec relates to may be manipulated freely (with
 402  * pa_stream_write()'s seek argument, pa_stream_flush() and friends),
 403  * the buffers sink_usec and source_usec relate to are first-in
 404  * first-out (FIFO) buffers which cannot be flushed or manipulated in
 405  * any way. The total input latency a sample that is recorded takes to
 406  * be delivered to the application is:
 407  * source_usec+buffer_usec+transport_usec-sink_usec. (Take care of
 408  * sign issues!) When connected to a monitor source sink_usec contains
 409  * the latency of the owning sink. The two latency estimations
 410  * described here are implemented in pa_stream_get_latency(). Please
 411  * note that this structure can be extended as part of evolutionary
 412  * API updates at any time in any new release.*/
 413 typedef struct pa_timing_info {
 414     struct timeval timestamp; /**< The time when this timing info structure was current */
 415     int synchronized_clocks;  /**< Non-zero if the local and the
 416                                * remote machine have synchronized
 417                                * clocks. If synchronized clocks are
 418                                * detected transport_usec becomes much
 419                                * more reliable. However, the code that
 420                                * detects synchronized clocks is very
 421                                * limited und unreliable itself. */
 422
 423     pa_usec_t sink_usec;      /**< Time in usecs a sample takes to be played on the sink. For playback streams and record streams connected to a monitor source. */
 424     pa_usec_t source_usec;    /**< Time in usecs a sample takes from being recorded to being delivered to the application. Only for record streams. */
 425     pa_usec_t transport_usec; /**< Estimated time in usecs a sample takes to be transferred to/from the daemon. For both playback and record streams. */
 426
 427     int playing;              /**< Non-zero when the stream is
 428                                * currently not underrun and data is
 429                                * being passed on to the device. Only
 430                                * for playback streams. This field does
 431                                * not say whether the data is actually
 432                                * already being played. To determine
 433                                * this check whether since_underrun
 434                                * (converted to usec) is larger than
 435                                * sink_usec.*/
 436
 437     int write_index_corrupt;  /**< Non-zero if write_index is not
 438                                * up-to-date because a local write
 439                                * command that corrupted it has been
 440                                * issued in the time since this latency
 441                                * info was current . Only write
 442                                * commands with SEEK_RELATIVE_ON_READ
 443                                * and SEEK_RELATIVE_END can corrupt
 444                                * write_index. */
 445     int64_t write_index;      /**< Current write index into the
 446                                * playback buffer in bytes. Think twice before
 447                                * using this for seeking purposes: it
 448                                * might be out of date a the time you
 449                                * want to use it. Consider using
 450                                * PA_SEEK_RELATIVE instead.  */
 451
 452     int read_index_corrupt;   /**< Non-zero if read_index is not
 453                                * up-to-date because a local pause or
 454                                * flush request that corrupted it has
 455                                * been issued in the time since this
 456                                * latency info was current. */
 457
 458     int64_t read_index;       /**< Current read index into the
 459                                * playback buffer in bytes. Think twice before
 460                                * using this for seeking purposes: it
 461                                * might be out of date a the time you
 462                                * want to use it. Consider using
 463                                * PA_SEEK_RELATIVE_ON_READ
 464                                * instead. */
 465
 466     pa_usec_t configured_sink_usec;   /**< The configured latency for
 467                                 * the sink. \since 0.9.11 */
 468     pa_usec_t configured_source_usec; /**< The configured latency for
 469                                 * the source. \since 0.9.11 */
 470
 471     int64_t since_underrun;    /**< Bytes that were handed to the sink
 472                                   since the last underrun happened, or
 473                                   since playback started again after
 474                                   the last underrun. playing will tell
 475                                   you which case it is. \since
 476                                   0.9.11 */
 477
 478 } pa_timing_info;
 479
 480 /** A structure for the spawn api. This may be used to integrate auto
 481  * spawned daemons into your application. For more information see
 482  * pa_context_connect(). When spawning a new child process the
 483  * waitpid() is used on the child's PID. The spawn routine will not
 484  * block or ignore SIGCHLD signals, since this cannot be done in a
 485  * thread compatible way. You might have to do this in
 486  * prefork/postfork. */
 487 typedef struct pa_spawn_api {
 488     void (*prefork)(void);     /**< Is called just before the fork in the parent process. May be NULL. */
 489     void (*postfork)(void);    /**< Is called immediately after the fork in the parent process. May be NULL.*/
 490     void (*atfork)(void);      /**< Is called immediately after the
 491                                 * fork in the child process. May be
 492                                 * NULL. It is not safe to close all
 493                                 * file descriptors in this function
 494                                 * unconditionally, since a UNIX socket
 495                                 * (created using socketpair()) is
 496                                 * passed to the new process. */
 497 } pa_spawn_api;
 498
 499 /** Seek type for pa_stream_write(). */
 500 typedef enum pa_seek_mode {
 501     PA_SEEK_RELATIVE = 0,           /**< Seek relatively to the write index */
 502     PA_SEEK_ABSOLUTE = 1,           /**< Seek relatively to the start of the buffer queue */
 503     PA_SEEK_RELATIVE_ON_READ = 2,   /**< Seek relatively to the read index.  */
 504     PA_SEEK_RELATIVE_END = 3        /**< Seek relatively to the current end of the buffer queue. */
 505 } pa_seek_mode_t;
 506
 507 /** Special sink flags. */
 508 typedef enum pa_sink_flags {
 509     PA_SINK_HW_VOLUME_CTRL = 1,   /**< Supports hardware volume control */
 510     PA_SINK_LATENCY = 2,          /**< Supports latency querying */
 511     PA_SINK_HARDWARE = 4,         /**< Is a hardware sink of some kind, in contrast to "virtual"/software sinks \since 0.9.3 */
 512     PA_SINK_NETWORK = 8,          /**< Is a networked sink of some kind. \since 0.9.7 */
 513     PA_SINK_HW_MUTE_CTRL = 16,    /**< Supports hardware mute control \since 0.9.11 */
 514     PA_SINK_DECIBEL_VOLUME = 32   /**< Volume can be translated to dB with pa_sw_volume_to_dB() \since 0.9.11 */
 515 } pa_sink_flags_t;
 516
 517 /** Special source flags.  */
 518 typedef enum pa_source_flags {
 519     PA_SOURCE_HW_VOLUME_CTRL = 1,  /**< Supports hardware volume control */
 520     PA_SOURCE_LATENCY = 2,         /**< Supports latency querying */
 521     PA_SOURCE_HARDWARE = 4,        /**< Is a hardware source of some kind, in contrast to "virtual"/software source \since 0.9.3 */
 522     PA_SOURCE_NETWORK = 8,         /**< Is a networked sink of some kind. \since 0.9.7 */
 523     PA_SOURCE_HW_MUTE_CTRL = 16,   /**< Supports hardware mute control \since 0.9.11 */
 524     PA_SOURCE_DECIBEL_VOLUME = 32  /**< Volume can be translated to dB with pa_sw_volume_to_dB() \since 0.9.11 */
 525 } pa_source_flags_t;
 526
 527 /** A generic free() like callback prototype */
 528 typedef void (*pa_free_cb_t)(void *p);
 529
 530 PA_C_DECL_END
 531
 532 #endif