xref: /third_party/pulseaudio/src/pulse/scache.h (revision 53a5a1b3)

#ifndef fooscachehfoo
#define fooscachehfoo

/***
  This file is part of PulseAudio.

  Copyright 2004-2006 Lennart Poettering
  Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB

  PulseAudio is free software; you can redistribute it and/or modify
  it under the terms of the GNU Lesser General Public License as published
  by the Free Software Foundation; either version 2.1 of the License,
  or (at your option) any later version.

  PulseAudio is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
***/

#include <sys/types.h>

#include <pulse/context.h>
#include <pulse/stream.h>
#include <pulse/cdecl.h>
#include <pulse/version.h>

/** \page scache Sample Cache
 *
 * \section overv_sec Overview
 *
 * The sample cache provides a simple way of overcoming high network latencies
 * and reducing bandwidth. Instead of streaming a sound precisely when it
 * should be played, it is stored on the server and only the command to start
 * playing it needs to be sent.
 *
 * \section create_sec Creation
 *
 * To create a sample, the normal stream API is used (see \ref streams). The
 * function pa_stream_connect_upload() will make sure the stream is stored as
 * a sample on the server.
 *
 * To complete the upload, pa_stream_finish_upload() is called and the sample
 * will receive the same name as the stream. If the upload should be aborted,
 * simply call pa_stream_disconnect().
 *
 * \section play_sec Playing samples
 *
 * To play back a sample, simply call pa_context_play_sample():
 *
 * \code
 * pa_operation *o;
 *
 * o = pa_context_play_sample(my_context,
 *                            "sample2",       // Name of my sample
 *                            NULL,            // Use default sink
 *                            PA_VOLUME_NORM,  // Full volume
 *                            NULL,            // Don't need a callback
 *                            NULL
 *                            );
 * if (o)
 *     pa_operation_unref(o);
 * \endcode
 *
 * \section rem_sec Removing samples
 *
 * When a sample is no longer needed, it should be removed on the server to
 * save resources. The sample is deleted using pa_context_remove_sample().
 */

/** \file
 * All sample cache related routines
 *
 * See also \subpage scache
 */

PA_C_DECL_BEGIN

/** Callback prototype for pa_context_play_sample_with_proplist(). The
 * idx value is the index of the sink input object, or
 * PA_INVALID_INDEX on failure. \since 0.9.11 */
typedef void (*pa_context_play_sample_cb_t)(pa_context *c, uint32_t idx, void *userdata);

/** Make this stream a sample upload stream. Returns zero on success. */
int pa_stream_connect_upload(pa_stream *s, size_t length);

/** Finish the sample upload, the stream name will become the sample
 * name. You cancel a sample upload by issuing
 * pa_stream_disconnect(). Returns zero on success. */
int pa_stream_finish_upload(pa_stream *s);

/** Remove a sample from the sample cache. Returns an operation object which
 * may be used to cancel the operation while it is running. */
pa_operation* pa_context_remove_sample(pa_context *c, const char *name, pa_context_success_cb_t cb, void *userdata);

/** Play a sample from the sample cache to the specified device. If
 * the latter is NULL use the default sink. Returns an operation
 * object */
pa_operation* pa_context_play_sample(
        pa_context *c               /**< Context */,
        const char *name            /**< Name of the sample to play */,
        const char *dev             /**< Sink to play this sample on */,
        pa_volume_t volume          /**< Volume to play this sample with. Starting with 0.9.15 you may pass here PA_VOLUME_INVALID which will leave the decision about the volume to the server side, which is a good idea. */ ,
        pa_context_success_cb_t cb  /**< Call this function after successfully starting playback, or NULL */,
        void *userdata              /**< Userdata to pass to the callback */);

/** Play a sample from the sample cache to the specified device,
 * allowing specification of a property list for the playback
 * stream. If the latter is NULL use the default sink. Returns an
 * operation object. \since 0.9.11 */
pa_operation* pa_context_play_sample_with_proplist(
        pa_context *c                   /**< Context */,
        const char *name                /**< Name of the sample to play */,
        const char *dev                 /**< Sink to play this sample on */,
        pa_volume_t volume              /**< Volume to play this sample with. Starting with 0.9.15 you may pass here PA_VOLUME_INVALID which will leave the decision about the volume to the server side, which is a good idea.  */ ,
        const pa_proplist *proplist     /**< Property list for this sound. The property list of the cached entry will have this merged into it. */,
        pa_context_play_sample_cb_t cb  /**< Call this function after successfully starting playback, or NULL */,
        void *userdata                  /**< Userdata to pass to the callback */);

PA_C_DECL_END

#endif