1 files changed, 677 insertions, 0 deletions

diff --git a/src/modules/module-virtual-sink.c b/src/modules/module-virtual-sink.c
new file mode 100644
index 0000000..bc109d5
--- /dev/null
+++ b/src/modules/module-virtual-sink.c
@@ -0,0 +1,677 @@
+/***
+    This file is part of PulseAudio.
+
+    Copyright 2010 Intel Corporation
+    Contributor: Pierre-Louis Bossart <pierre-louis.bossart@intel.com>
+
+    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/>.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <pulse/gccmacro.h>
+#include <pulse/xmalloc.h>
+
+#include <pulsecore/i18n.h>
+#include <pulsecore/namereg.h>
+#include <pulsecore/sink.h>
+#include <pulsecore/module.h>
+#include <pulsecore/core-util.h>
+#include <pulsecore/modargs.h>
+#include <pulsecore/log.h>
+#include <pulsecore/rtpoll.h>
+#include <pulsecore/sample-util.h>
+#include <pulsecore/ltdl-helper.h>
+
+PA_MODULE_AUTHOR("Pierre-Louis Bossart");
+PA_MODULE_DESCRIPTION(_("Virtual sink"));
+PA_MODULE_VERSION(PACKAGE_VERSION);
+PA_MODULE_LOAD_ONCE(false);
+PA_MODULE_USAGE(
+        _("sink_name=<name for the sink> "
+          "sink_properties=<properties for the sink> "
+          "master=<name of sink to filter> "
+          "rate=<sample rate> "
+          "channels=<number of channels> "
+          "channel_map=<channel map> "
+          "use_volume_sharing=<yes or no> "
+          "force_flat_volume=<yes or no> "
+        ));
+
+#define MEMBLOCKQ_MAXLENGTH (16*1024*1024)
+
+struct userdata {
+    pa_module *module;
+
+    /* FIXME: Uncomment this and take "autoloaded" as a modarg if this is a filter */
+    /* bool autoloaded; */
+
+    pa_sink *sink;
+    pa_sink_input *sink_input;
+
+    pa_memblockq *memblockq;
+
+    bool auto_desc;
+    unsigned channels;
+};
+
+static const char* const valid_modargs[] = {
+    "sink_name",
+    "sink_properties",
+    "master",
+    "rate",
+    "channels",
+    "channel_map",
+    "use_volume_sharing",
+    "force_flat_volume",
+    NULL
+};
+
+/* Called from I/O thread context */
+static int sink_process_msg_cb(pa_msgobject *o, int code, void *data, int64_t offset, pa_memchunk *chunk) {
+    struct userdata *u = PA_SINK(o)->userdata;
+
+    switch (code) {
+
+        case PA_SINK_MESSAGE_GET_LATENCY:
+
+            /* The sink is _put() before the sink input is, so let's
+             * make sure we don't access it in that time. Also, the
+             * sink input is first shut down, the sink second. */
+            if (!PA_SINK_IS_LINKED(u->sink->thread_info.state) ||
+                !PA_SINK_INPUT_IS_LINKED(u->sink_input->thread_info.state)) {
+                *((int64_t*) data) = 0;
+                return 0;
+            }
+
+            *((int64_t*) data) =
+
+                /* Get the latency of the master sink */
+                pa_sink_get_latency_within_thread(u->sink_input->sink, true) +
+
+                /* Add the latency internal to our sink input on top */
+                pa_bytes_to_usec(pa_memblockq_get_length(u->sink_input->thread_info.render_memblockq), &u->sink_input->sink->sample_spec);
+
+            return 0;
+    }
+
+    return pa_sink_process_msg(o, code, data, offset, chunk);
+}
+
+/* Called from main context */
+static int sink_set_state_in_main_thread_cb(pa_sink *s, pa_sink_state_t state, pa_suspend_cause_t suspend_cause) {
+    struct userdata *u;
+
+    pa_sink_assert_ref(s);
+    pa_assert_se(u = s->userdata);
+
+    if (!PA_SINK_IS_LINKED(state) ||
+        !PA_SINK_INPUT_IS_LINKED(u->sink_input->state))
+        return 0;
+
+    pa_sink_input_cork(u->sink_input, state == PA_SINK_SUSPENDED);
+    return 0;
+}
+
+/* Called from the IO thread. */
+static int sink_set_state_in_io_thread_cb(pa_sink *s, pa_sink_state_t new_state, pa_suspend_cause_t new_suspend_cause) {
+    struct userdata *u;
+
+    pa_assert(s);
+    pa_assert_se(u = s->userdata);
+
+    /* When set to running or idle for the first time, request a rewind
+     * of the master sink to make sure we are heard immediately */
+    if (PA_SINK_IS_OPENED(new_state) && s->thread_info.state == PA_SINK_INIT) {
+        pa_log_debug("Requesting rewind due to state change.");
+        pa_sink_input_request_rewind(u->sink_input, 0, false, true, true);
+    }
+
+    return 0;
+}
+
+/* Called from I/O thread context */
+static void sink_request_rewind_cb(pa_sink *s) {
+    struct userdata *u;
+
+    pa_sink_assert_ref(s);
+    pa_assert_se(u = s->userdata);
+
+    if (!PA_SINK_IS_LINKED(u->sink->thread_info.state) ||
+        !PA_SINK_INPUT_IS_LINKED(u->sink_input->thread_info.state))
+        return;
+
+    /* Just hand this one over to the master sink */
+    pa_sink_input_request_rewind(u->sink_input,
+                                 s->thread_info.rewind_nbytes +
+                                 pa_memblockq_get_length(u->memblockq), true, false, false);
+}
+
+/* Called from I/O thread context */
+static void sink_update_requested_latency_cb(pa_sink *s) {
+    struct userdata *u;
+
+    pa_sink_assert_ref(s);
+    pa_assert_se(u = s->userdata);
+
+    if (!PA_SINK_IS_LINKED(u->sink->thread_info.state) ||
+        !PA_SINK_INPUT_IS_LINKED(u->sink_input->thread_info.state))
+        return;
+
+    /* Just hand this one over to the master sink */
+    pa_sink_input_set_requested_latency_within_thread(
+            u->sink_input,
+            pa_sink_get_requested_latency_within_thread(s));
+}
+
+/* Called from main context */
+static void sink_set_volume_cb(pa_sink *s) {
+    struct userdata *u;
+
+    pa_sink_assert_ref(s);
+    pa_assert_se(u = s->userdata);
+
+    if (!PA_SINK_IS_LINKED(s->state) ||
+        !PA_SINK_INPUT_IS_LINKED(u->sink_input->state))
+        return;
+
+    pa_sink_input_set_volume(u->sink_input, &s->real_volume, s->save_volume, true);
+}
+
+/* Called from main context */
+static void sink_set_mute_cb(pa_sink *s) {
+    struct userdata *u;
+
+    pa_sink_assert_ref(s);
+    pa_assert_se(u = s->userdata);
+
+    if (!PA_SINK_IS_LINKED(s->state) ||
+        !PA_SINK_INPUT_IS_LINKED(u->sink_input->state))
+        return;
+
+    pa_sink_input_set_mute(u->sink_input, s->muted, s->save_muted);
+}
+
+/* Called from I/O thread context */
+static int sink_input_pop_cb(pa_sink_input *i, size_t nbytes, pa_memchunk *chunk) {
+    struct userdata *u;
+    float *src, *dst;
+    size_t fs;
+    unsigned n, c;
+    pa_memchunk tchunk;
+    pa_usec_t current_latency PA_GCC_UNUSED;
+
+    pa_sink_input_assert_ref(i);
+    pa_assert(chunk);
+    pa_assert_se(u = i->userdata);
+
+    if (!PA_SINK_IS_LINKED(u->sink->thread_info.state))
+        return -1;
+
+    /* Hmm, process any rewind request that might be queued up */
+    pa_sink_process_rewind(u->sink, 0);
+
+    /* (1) IF YOU NEED A FIXED BLOCK SIZE USE
+     * pa_memblockq_peek_fixed_size() HERE INSTEAD. NOTE THAT FILTERS
+     * WHICH CAN DEAL WITH DYNAMIC BLOCK SIZES ARE HIGHLY
+     * PREFERRED. */
+    while (pa_memblockq_peek(u->memblockq, &tchunk) < 0) {
+        pa_memchunk nchunk;
+
+        pa_sink_render(u->sink, nbytes, &nchunk);
+        pa_memblockq_push(u->memblockq, &nchunk);
+        pa_memblock_unref(nchunk.memblock);
+    }
+
+    /* (2) IF YOU NEED A FIXED BLOCK SIZE, THIS NEXT LINE IS NOT
+     * NECESSARY */
+    tchunk.length = PA_MIN(nbytes, tchunk.length);
+    pa_assert(tchunk.length > 0);
+
+    fs = pa_frame_size(&i->sample_spec);
+    n = (unsigned) (tchunk.length / fs);
+
+    pa_assert(n > 0);
+
+    chunk->index = 0;
+    chunk->length = n*fs;
+    chunk->memblock = pa_memblock_new(i->sink->core->mempool, chunk->length);
+
+    pa_memblockq_drop(u->memblockq, chunk->length);
+
+    src = pa_memblock_acquire_chunk(&tchunk);
+    dst = pa_memblock_acquire(chunk->memblock);
+
+    /* (3) PUT YOUR CODE HERE TO DO SOMETHING WITH THE DATA */
+
+    /* As an example, copy input to output */
+    for (c = 0; c < u->channels; c++) {
+        pa_sample_clamp(PA_SAMPLE_FLOAT32NE,
+                        dst+c, u->channels * sizeof(float),
+                        src+c, u->channels * sizeof(float),
+                        n);
+    }
+
+    pa_memblock_release(tchunk.memblock);
+    pa_memblock_release(chunk->memblock);
+
+    pa_memblock_unref(tchunk.memblock);
+
+    /* (4) IF YOU NEED THE LATENCY FOR SOMETHING ACQUIRE IT LIKE THIS: */
+    current_latency =
+        /* Get the latency of the master sink */
+        pa_sink_get_latency_within_thread(i->sink, false) +
+
+        /* Add the latency internal to our sink input on top */
+        pa_bytes_to_usec(pa_memblockq_get_length(i->thread_info.render_memblockq), &i->sink->sample_spec);
+
+    return 0;
+}
+
+/* Called from I/O thread context */
+static void sink_input_process_rewind_cb(pa_sink_input *i, size_t nbytes) {
+    struct userdata *u;
+    size_t amount = 0;
+
+    pa_sink_input_assert_ref(i);
+    pa_assert_se(u = i->userdata);
+
+    /* If the sink is not yet linked, there is nothing to rewind */
+    if (!PA_SINK_IS_LINKED(u->sink->thread_info.state))
+        return;
+
+    if (u->sink->thread_info.rewind_nbytes > 0) {
+        size_t max_rewrite;
+
+        max_rewrite = nbytes + pa_memblockq_get_length(u->memblockq);
+        amount = PA_MIN(u->sink->thread_info.rewind_nbytes, max_rewrite);
+        u->sink->thread_info.rewind_nbytes = 0;
+
+        if (amount > 0) {
+            pa_memblockq_seek(u->memblockq, - (int64_t) amount, PA_SEEK_RELATIVE, true);
+
+            /* (5) PUT YOUR CODE HERE TO RESET YOUR FILTER  */
+        }
+    }
+
+    pa_sink_process_rewind(u->sink, amount);
+    pa_memblockq_rewind(u->memblockq, nbytes);
+}
+
+/* Called from I/O thread context */
+static void sink_input_update_max_rewind_cb(pa_sink_input *i, size_t nbytes) {
+    struct userdata *u;
+
+    pa_sink_input_assert_ref(i);
+    pa_assert_se(u = i->userdata);
+
+    /* FIXME: Too small max_rewind:
+     * https://bugs.freedesktop.org/show_bug.cgi?id=53709 */
+    pa_memblockq_set_maxrewind(u->memblockq, nbytes);
+    pa_sink_set_max_rewind_within_thread(u->sink, nbytes);
+}
+
+/* Called from I/O thread context */
+static void sink_input_update_max_request_cb(pa_sink_input *i, size_t nbytes) {
+    struct userdata *u;
+
+    pa_sink_input_assert_ref(i);
+    pa_assert_se(u = i->userdata);
+
+    /* (6) IF YOU NEED A FIXED BLOCK SIZE ROUND nbytes UP TO MULTIPLES
+     * OF IT HERE. THE PA_ROUND_UP MACRO IS USEFUL FOR THAT. */
+
+    pa_sink_set_max_request_within_thread(u->sink, nbytes);
+}
+
+/* Called from I/O thread context */
+static void sink_input_update_sink_latency_range_cb(pa_sink_input *i) {
+    struct userdata *u;
+
+    pa_sink_input_assert_ref(i);
+    pa_assert_se(u = i->userdata);
+
+    pa_sink_set_latency_range_within_thread(u->sink, i->sink->thread_info.min_latency, i->sink->thread_info.max_latency);
+}
+
+/* Called from I/O thread context */
+static void sink_input_update_sink_fixed_latency_cb(pa_sink_input *i) {
+    struct userdata *u;
+
+    pa_sink_input_assert_ref(i);
+    pa_assert_se(u = i->userdata);
+
+    /* (7) IF YOU NEED A FIXED BLOCK SIZE ADD THE LATENCY FOR ONE
+     * BLOCK MINUS ONE SAMPLE HERE. pa_usec_to_bytes_round_up() IS
+     * USEFUL FOR THAT. */
+
+    pa_sink_set_fixed_latency_within_thread(u->sink, i->sink->thread_info.fixed_latency);
+}
+
+/* Called from I/O thread context */
+static void sink_input_detach_cb(pa_sink_input *i) {
+    struct userdata *u;
+
+    pa_sink_input_assert_ref(i);
+    pa_assert_se(u = i->userdata);
+
+    if (PA_SINK_IS_LINKED(u->sink->thread_info.state))
+        pa_sink_detach_within_thread(u->sink);
+
+    pa_sink_set_rtpoll(u->sink, NULL);
+}
+
+/* Called from I/O thread context */
+static void sink_input_attach_cb(pa_sink_input *i) {
+    struct userdata *u;
+
+    pa_sink_input_assert_ref(i);
+    pa_assert_se(u = i->userdata);
+
+    pa_sink_set_rtpoll(u->sink, i->sink->thread_info.rtpoll);
+    pa_sink_set_latency_range_within_thread(u->sink, i->sink->thread_info.min_latency, i->sink->thread_info.max_latency);
+
+    /* (8.1) IF YOU NEED A FIXED BLOCK SIZE ADD THE LATENCY FOR ONE
+     * BLOCK MINUS ONE SAMPLE HERE. SEE (7) */
+    pa_sink_set_fixed_latency_within_thread(u->sink, i->sink->thread_info.fixed_latency);
+
+    /* (8.2) IF YOU NEED A FIXED BLOCK SIZE ROUND
+     * pa_sink_input_get_max_request(i) UP TO MULTIPLES OF IT
+     * HERE. SEE (6) */
+    pa_sink_set_max_request_within_thread(u->sink, pa_sink_input_get_max_request(i));
+
+    /* FIXME: Too small max_rewind:
+     * https://bugs.freedesktop.org/show_bug.cgi?id=53709 */
+    pa_sink_set_max_rewind_within_thread(u->sink, pa_sink_input_get_max_rewind(i));
+
+    if (PA_SINK_IS_LINKED(u->sink->thread_info.state))
+        pa_sink_attach_within_thread(u->sink);
+}
+
+/* Called from main context */
+static void sink_input_kill_cb(pa_sink_input *i) {
+    struct userdata *u;
+
+    pa_sink_input_assert_ref(i);
+    pa_assert_se(u = i->userdata);
+
+    /* The order here matters! We first kill the sink so that streams
+     * can properly be moved away while the sink input is still connected
+     * to the master. */
+    pa_sink_input_cork(u->sink_input, true);
+    pa_sink_unlink(u->sink);
+    pa_sink_input_unlink(u->sink_input);
+
+    pa_sink_input_unref(u->sink_input);
+    u->sink_input = NULL;
+
+    pa_sink_unref(u->sink);
+    u->sink = NULL;
+
+    pa_module_unload_request(u->module, true);
+}
+
+/* Called from main context */
+static void sink_input_moving_cb(pa_sink_input *i, pa_sink *dest) {
+    struct userdata *u;
+
+    pa_sink_input_assert_ref(i);
+    pa_assert_se(u = i->userdata);
+
+    if (dest) {
+        pa_sink_set_asyncmsgq(u->sink, dest->asyncmsgq);
+        pa_sink_update_flags(u->sink, PA_SINK_LATENCY|PA_SINK_DYNAMIC_LATENCY, dest->flags);
+    } else
+        pa_sink_set_asyncmsgq(u->sink, NULL);
+
+    if (u->auto_desc && dest) {
+        const char *z;
+        pa_proplist *pl;
+
+        pl = pa_proplist_new();
+        z = pa_proplist_gets(dest->proplist, PA_PROP_DEVICE_DESCRIPTION);
+        pa_proplist_setf(pl, PA_PROP_DEVICE_DESCRIPTION, "Virtual Sink %s on %s",
+                         pa_proplist_gets(u->sink->proplist, "device.vsink.name"), z ? z : dest->name);
+
+        pa_sink_update_proplist(u->sink, PA_UPDATE_REPLACE, pl);
+        pa_proplist_free(pl);
+    }
+}
+
+/* Called from main context */
+static void sink_input_volume_changed_cb(pa_sink_input *i) {
+    struct userdata *u;
+
+    pa_sink_input_assert_ref(i);
+    pa_assert_se(u = i->userdata);
+
+    pa_sink_volume_changed(u->sink, &i->volume);
+}
+
+/* Called from main context */
+static void sink_input_mute_changed_cb(pa_sink_input *i) {
+    struct userdata *u;
+
+    pa_sink_input_assert_ref(i);
+    pa_assert_se(u = i->userdata);
+
+    pa_sink_mute_changed(u->sink, i->muted);
+}
+
+int pa__init(pa_module*m) {
+    struct userdata *u;
+    pa_sample_spec ss;
+    pa_channel_map map;
+    pa_modargs *ma;
+    pa_sink *master=NULL;
+    pa_sink_input_new_data sink_input_data;
+    pa_sink_new_data sink_data;
+    bool use_volume_sharing = true;
+    bool force_flat_volume = false;
+    pa_memchunk silence;
+
+    pa_assert(m);
+
+    if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
+        pa_log("Failed to parse module arguments.");
+        goto fail;
+    }
+
+    if (!(master = pa_namereg_get(m->core, pa_modargs_get_value(ma, "master", NULL), PA_NAMEREG_SINK))) {
+        pa_log("Master sink not found");
+        goto fail;
+    }
+
+    pa_assert(master);
+
+    ss = master->sample_spec;
+    ss.format = PA_SAMPLE_FLOAT32;
+    map = master->channel_map;
+    if (pa_modargs_get_sample_spec_and_channel_map(ma, &ss, &map, PA_CHANNEL_MAP_DEFAULT) < 0) {
+        pa_log("Invalid sample format specification or channel map");
+        goto fail;
+    }
+
+    if (pa_modargs_get_value_boolean(ma, "use_volume_sharing", &use_volume_sharing) < 0) {
+        pa_log("use_volume_sharing= expects a boolean argument");
+        goto fail;
+    }
+
+    if (pa_modargs_get_value_boolean(ma, "force_flat_volume", &force_flat_volume) < 0) {
+        pa_log("force_flat_volume= expects a boolean argument");
+        goto fail;
+    }
+
+    if (use_volume_sharing && force_flat_volume) {
+        pa_log("Flat volume can't be forced when using volume sharing.");
+        goto fail;
+    }
+
+    u = pa_xnew0(struct userdata, 1);
+    u->module = m;
+    m->userdata = u;
+    u->channels = ss.channels;
+
+    /* Create sink */
+    pa_sink_new_data_init(&sink_data);
+    sink_data.driver = __FILE__;
+    sink_data.module = m;
+    if (!(sink_data.name = pa_xstrdup(pa_modargs_get_value(ma, "sink_name", NULL))))
+        sink_data.name = pa_sprintf_malloc("%s.vsink", master->name);
+    pa_sink_new_data_set_sample_spec(&sink_data, &ss);
+    pa_sink_new_data_set_channel_map(&sink_data, &map);
+    pa_proplist_sets(sink_data.proplist, PA_PROP_DEVICE_MASTER_DEVICE, master->name);
+    pa_proplist_sets(sink_data.proplist, PA_PROP_DEVICE_CLASS, "filter");
+    pa_proplist_sets(sink_data.proplist, "device.vsink.name", sink_data.name);
+
+    if (pa_modargs_get_proplist(ma, "sink_properties", sink_data.proplist, PA_UPDATE_REPLACE) < 0) {
+        pa_log("Invalid properties");
+        pa_sink_new_data_done(&sink_data);
+        goto fail;
+    }
+
+    if ((u->auto_desc = !pa_proplist_contains(sink_data.proplist, PA_PROP_DEVICE_DESCRIPTION))) {
+        const char *z;
+
+        z = pa_proplist_gets(master->proplist, PA_PROP_DEVICE_DESCRIPTION);
+        pa_proplist_setf(sink_data.proplist, PA_PROP_DEVICE_DESCRIPTION, "Virtual Sink %s on %s", sink_data.name, z ? z : master->name);
+    }
+
+    u->sink = pa_sink_new(m->core, &sink_data, (master->flags & (PA_SINK_LATENCY|PA_SINK_DYNAMIC_LATENCY))
+                                               | (use_volume_sharing ? PA_SINK_SHARE_VOLUME_WITH_MASTER : 0));
+    pa_sink_new_data_done(&sink_data);
+
+    if (!u->sink) {
+        pa_log("Failed to create sink.");
+        goto fail;
+    }
+
+    u->sink->parent.process_msg = sink_process_msg_cb;
+    u->sink->set_state_in_main_thread = sink_set_state_in_main_thread_cb;
+    u->sink->set_state_in_io_thread = sink_set_state_in_io_thread_cb;
+    u->sink->update_requested_latency = sink_update_requested_latency_cb;
+    u->sink->request_rewind = sink_request_rewind_cb;
+    pa_sink_set_set_mute_callback(u->sink, sink_set_mute_cb);
+    if (!use_volume_sharing) {
+        pa_sink_set_set_volume_callback(u->sink, sink_set_volume_cb);
+        pa_sink_enable_decibel_volume(u->sink, true);
+    }
+    /* Normally this flag would be enabled automatically be we can force it. */
+    if (force_flat_volume)
+        u->sink->flags |= PA_SINK_FLAT_VOLUME;
+    u->sink->userdata = u;
+
+    pa_sink_set_asyncmsgq(u->sink, master->asyncmsgq);
+
+    /* Create sink input */
+    pa_sink_input_new_data_init(&sink_input_data);
+    sink_input_data.driver = __FILE__;
+    sink_input_data.module = m;
+    pa_sink_input_new_data_set_sink(&sink_input_data, master, false, true);
+    sink_input_data.origin_sink = u->sink;
+    pa_proplist_setf(sink_input_data.proplist, PA_PROP_MEDIA_NAME, "Virtual Sink Stream from %s", pa_proplist_gets(u->sink->proplist, PA_PROP_DEVICE_DESCRIPTION));
+    pa_proplist_sets(sink_input_data.proplist, PA_PROP_MEDIA_ROLE, "filter");
+    pa_sink_input_new_data_set_sample_spec(&sink_input_data, &ss);
+    pa_sink_input_new_data_set_channel_map(&sink_input_data, &map);
+    sink_input_data.flags |= PA_SINK_INPUT_START_CORKED;
+
+    pa_sink_input_new(&u->sink_input, m->core, &sink_input_data);
+    pa_sink_input_new_data_done(&sink_input_data);
+
+    if (!u->sink_input)
+        goto fail;
+
+    u->sink_input->pop = sink_input_pop_cb;
+    u->sink_input->process_rewind = sink_input_process_rewind_cb;
+    u->sink_input->update_max_rewind = sink_input_update_max_rewind_cb;
+    u->sink_input->update_max_request = sink_input_update_max_request_cb;
+    u->sink_input->update_sink_latency_range = sink_input_update_sink_latency_range_cb;
+    u->sink_input->update_sink_fixed_latency = sink_input_update_sink_fixed_latency_cb;
+    u->sink_input->kill = sink_input_kill_cb;
+    u->sink_input->attach = sink_input_attach_cb;
+    u->sink_input->detach = sink_input_detach_cb;
+    u->sink_input->moving = sink_input_moving_cb;
+    u->sink_input->volume_changed = use_volume_sharing ? NULL : sink_input_volume_changed_cb;
+    u->sink_input->mute_changed = sink_input_mute_changed_cb;
+    u->sink_input->userdata = u;
+
+    u->sink->input_to_master = u->sink_input;
+
+    pa_sink_input_get_silence(u->sink_input, &silence);
+    u->memblockq = pa_memblockq_new("module-virtual-sink memblockq", 0, MEMBLOCKQ_MAXLENGTH, 0, &ss, 1, 1, 0, &silence);
+    pa_memblock_unref(silence.memblock);
+
+    /* (9) INITIALIZE ANYTHING ELSE YOU NEED HERE */
+
+    /* The order here is important. The input must be put first,
+     * otherwise streams might attach to the sink before the sink
+     * input is attached to the master. */
+    pa_sink_input_put(u->sink_input);
+    pa_sink_put(u->sink);
+    pa_sink_input_cork(u->sink_input, false);
+
+    pa_modargs_free(ma);
+
+    return 0;
+
+fail:
+    if (ma)
+        pa_modargs_free(ma);
+
+    pa__done(m);
+
+    return -1;
+}
+
+int pa__get_n_used(pa_module *m) {
+    struct userdata *u;
+
+    pa_assert(m);
+    pa_assert_se(u = m->userdata);
+
+    return pa_sink_linked_by(u->sink);
+}
+
+void pa__done(pa_module*m) {
+    struct userdata *u;
+
+    pa_assert(m);
+
+    if (!(u = m->userdata))
+        return;
+
+    /* See comments in sink_input_kill_cb() above regarding
+     * destruction order! */
+
+    if (u->sink_input)
+        pa_sink_input_cork(u->sink_input, true);
+
+    if (u->sink)
+        pa_sink_unlink(u->sink);
+
+    if (u->sink_input) {
+        pa_sink_input_unlink(u->sink_input);
+        pa_sink_input_unref(u->sink_input);
+    }
+
+    if (u->sink)
+        pa_sink_unref(u->sink);
+
+    if (u->memblockq)
+        pa_memblockq_free(u->memblockq);
+
+    pa_xfree(u);
+}