Adding upstream version 14.2.upstream/14.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2393 insertions, 0 deletions

diff --git a/src/modules/echo-cancel/module-echo-cancel.c b/src/modules/echo-cancel/module-echo-cancel.c
new file mode 100644
index 0000000..f239492
--- /dev/null
+++ b/src/modules/echo-cancel/module-echo-cancel.c
@@ -0,0 +1,2393 @@
+/***
+    This file is part of PulseAudio.
+
+    Copyright 2010 Wim Taymans <wim.taymans@gmail.com>
+
+    Based on module-virtual-sink.c
+             module-virtual-source.c
+             module-loopback.c
+
+        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 <stdio.h>
+#include <math.h>
+
+#include "echo-cancel.h"
+
+#include <pulse/xmalloc.h>
+#include <pulse/timeval.h>
+#include <pulse/rtclock.h>
+
+#include <pulsecore/i18n.h>
+#include <pulsecore/atomic.h>
+#include <pulsecore/macro.h>
+#include <pulsecore/namereg.h>
+#include <pulsecore/sink.h>
+#include <pulsecore/module.h>
+#include <pulsecore/core-rtclock.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("Wim Taymans");
+PA_MODULE_DESCRIPTION("Echo Cancellation");
+PA_MODULE_VERSION(PACKAGE_VERSION);
+PA_MODULE_LOAD_ONCE(false);
+PA_MODULE_USAGE(
+        _("source_name=<name for the source> "
+          "source_properties=<properties for the source> "
+          "source_master=<name of source to filter> "
+          "sink_name=<name for the sink> "
+          "sink_properties=<properties for the sink> "
+          "sink_master=<name of sink to filter> "
+          "adjust_time=<how often to readjust rates in s> "
+          "adjust_threshold=<how much drift to readjust after in ms> "
+          "format=<sample format> "
+          "rate=<sample rate> "
+          "channels=<number of channels> "
+          "channel_map=<channel map> "
+          "aec_method=<implementation to use> "
+          "aec_args=<parameters for the AEC engine> "
+          "save_aec=<save AEC data in /tmp> "
+          "autoloaded=<set if this module is being loaded automatically> "
+          "use_volume_sharing=<yes or no> "
+          "use_master_format=<yes or no> "
+        ));
+
+/* NOTE: Make sure the enum and ec_table are maintained in the correct order */
+typedef enum {
+    PA_ECHO_CANCELLER_INVALID = -1,
+    PA_ECHO_CANCELLER_NULL,
+#ifdef HAVE_SPEEX
+    PA_ECHO_CANCELLER_SPEEX,
+#endif
+#ifdef HAVE_ADRIAN_EC
+    PA_ECHO_CANCELLER_ADRIAN,
+#endif
+#ifdef HAVE_WEBRTC
+    PA_ECHO_CANCELLER_WEBRTC,
+#endif
+} pa_echo_canceller_method_t;
+
+#ifdef HAVE_WEBRTC
+#define DEFAULT_ECHO_CANCELLER "webrtc"
+#else
+#define DEFAULT_ECHO_CANCELLER "speex"
+#endif
+
+static const pa_echo_canceller ec_table[] = {
+    {
+        /* Null, Dummy echo canceller (just copies data) */
+        .init                   = pa_null_ec_init,
+        .run                    = pa_null_ec_run,
+        .done                   = pa_null_ec_done,
+    },
+#ifdef HAVE_SPEEX
+    {
+        /* Speex */
+        .init                   = pa_speex_ec_init,
+        .run                    = pa_speex_ec_run,
+        .done                   = pa_speex_ec_done,
+    },
+#endif
+#ifdef HAVE_ADRIAN_EC
+    {
+        /* Adrian Andre's NLMS implementation */
+        .init                   = pa_adrian_ec_init,
+        .run                    = pa_adrian_ec_run,
+        .done                   = pa_adrian_ec_done,
+    },
+#endif
+#ifdef HAVE_WEBRTC
+    {
+        /* WebRTC's audio processing engine */
+        .init                   = pa_webrtc_ec_init,
+        .play                   = pa_webrtc_ec_play,
+        .record                 = pa_webrtc_ec_record,
+        .set_drift              = pa_webrtc_ec_set_drift,
+        .run                    = pa_webrtc_ec_run,
+        .done                   = pa_webrtc_ec_done,
+    },
+#endif
+};
+
+#define DEFAULT_RATE 32000
+#define DEFAULT_CHANNELS 1
+#define DEFAULT_ADJUST_TIME_USEC (1*PA_USEC_PER_SEC)
+#define DEFAULT_ADJUST_TOLERANCE (5*PA_USEC_PER_MSEC)
+#define DEFAULT_SAVE_AEC false
+#define DEFAULT_AUTOLOADED false
+#define DEFAULT_USE_MASTER_FORMAT false
+
+#define MEMBLOCKQ_MAXLENGTH (16*1024*1024)
+
+#define MAX_LATENCY_BLOCKS 10
+
+/* Can only be used in main context */
+#define IS_ACTIVE(u) (((u)->source->state == PA_SOURCE_RUNNING) && \
+                      ((u)->sink->state == PA_SINK_RUNNING))
+
+/* This module creates a new (virtual) source and sink.
+ *
+ * The data sent to the new sink is kept in a memblockq before being
+ * forwarded to the real sink_master.
+ *
+ * Data read from source_master is matched against the saved sink data and
+ * echo canceled data is then pushed onto the new source.
+ *
+ * Both source and sink masters have their own threads to push/pull data
+ * respectively. We however perform all our actions in the source IO thread.
+ * To do this we send all played samples to the source IO thread where they
+ * are then pushed into the memblockq.
+ *
+ * Alignment is performed in two steps:
+ *
+ * 1) when something happens that requires quick adjustment of the alignment of
+ *    capture and playback samples, we perform a resync. This adjusts the
+ *    position in the playback memblock to the requested sample. Quick
+ *    adjustments include moving the playback samples before the capture
+ *    samples (because else the echo canceller does not work) or when the
+ *    playback pointer drifts too far away.
+ *
+ * 2) periodically check the difference between capture and playback. We use a
+ *    low and high watermark for adjusting the alignment. Playback should always
+ *    be before capture and the difference should not be bigger than one frame
+ *    size. We would ideally like to resample the sink_input but most driver
+ *    don't give enough accuracy to be able to do that right now.
+ */
+
+struct userdata;
+
+struct pa_echo_canceller_msg {
+    pa_msgobject parent;
+    bool dead;
+    struct userdata *userdata;
+};
+
+PA_DEFINE_PRIVATE_CLASS(pa_echo_canceller_msg, pa_msgobject);
+#define PA_ECHO_CANCELLER_MSG(o) (pa_echo_canceller_msg_cast(o))
+
+struct snapshot {
+    pa_usec_t sink_now;
+    pa_usec_t sink_latency;
+    size_t sink_delay;
+    int64_t send_counter;
+
+    pa_usec_t source_now;
+    pa_usec_t source_latency;
+    size_t source_delay;
+    int64_t recv_counter;
+    size_t rlen;
+    size_t plen;
+};
+
+struct userdata {
+    pa_core *core;
+    pa_module *module;
+
+    bool dead;
+    bool save_aec;
+
+    pa_echo_canceller *ec;
+    uint32_t source_output_blocksize;
+    uint32_t source_blocksize;
+    uint32_t sink_blocksize;
+
+    bool need_realign;
+
+    /* to wakeup the source I/O thread */
+    pa_asyncmsgq *asyncmsgq;
+    pa_rtpoll_item *rtpoll_item_read, *rtpoll_item_write;
+
+    pa_source *source;
+    bool source_auto_desc;
+    pa_source_output *source_output;
+    pa_memblockq *source_memblockq; /* echo canceller needs fixed sized chunks */
+    size_t source_skip;
+
+    pa_sink *sink;
+    bool sink_auto_desc;
+    pa_sink_input *sink_input;
+    pa_memblockq *sink_memblockq;
+    int64_t send_counter;          /* updated in sink IO thread */
+    int64_t recv_counter;
+    size_t sink_skip;
+
+    /* Bytes left over from previous iteration */
+    size_t sink_rem;
+    size_t source_rem;
+
+    pa_atomic_t request_resync;
+
+    pa_time_event *time_event;
+    pa_usec_t adjust_time;
+    int adjust_threshold;
+
+    FILE *captured_file;
+    FILE *played_file;
+    FILE *canceled_file;
+    FILE *drift_file;
+
+    bool use_volume_sharing;
+
+    struct {
+        pa_cvolume current_volume;
+    } thread_info;
+};
+
+static void source_output_snapshot_within_thread(struct userdata *u, struct snapshot *snapshot);
+
+static const char* const valid_modargs[] = {
+    "source_name",
+    "source_properties",
+    "source_master",
+    "sink_name",
+    "sink_properties",
+    "sink_master",
+    "adjust_time",
+    "adjust_threshold",
+    "format",
+    "rate",
+    "channels",
+    "channel_map",
+    "aec_method",
+    "aec_args",
+    "save_aec",
+    "autoloaded",
+    "use_volume_sharing",
+    "use_master_format",
+    NULL
+};
+
+enum {
+    SOURCE_OUTPUT_MESSAGE_POST = PA_SOURCE_OUTPUT_MESSAGE_MAX,
+    SOURCE_OUTPUT_MESSAGE_REWIND,
+    SOURCE_OUTPUT_MESSAGE_LATENCY_SNAPSHOT,
+    SOURCE_OUTPUT_MESSAGE_APPLY_DIFF_TIME
+};
+
+enum {
+    SINK_INPUT_MESSAGE_LATENCY_SNAPSHOT
+};
+
+enum {
+    ECHO_CANCELLER_MESSAGE_SET_VOLUME,
+};
+
+static int64_t calc_diff(struct userdata *u, struct snapshot *snapshot) {
+    int64_t diff_time, buffer_latency;
+    pa_usec_t plen, rlen, source_delay, sink_delay, recv_counter, send_counter;
+
+    /* get latency difference between playback and record */
+    plen = pa_bytes_to_usec(snapshot->plen, &u->sink_input->sample_spec);
+    rlen = pa_bytes_to_usec(snapshot->rlen, &u->source_output->sample_spec);
+    if (plen > rlen)
+        buffer_latency = plen - rlen;
+    else
+        buffer_latency = 0;
+
+    source_delay = pa_bytes_to_usec(snapshot->source_delay, &u->source_output->sample_spec);
+    sink_delay = pa_bytes_to_usec(snapshot->sink_delay, &u->sink_input->sample_spec);
+    buffer_latency += source_delay + sink_delay;
+
+    /* add the latency difference due to samples not yet transferred */
+    send_counter = pa_bytes_to_usec(snapshot->send_counter, &u->sink->sample_spec);
+    recv_counter = pa_bytes_to_usec(snapshot->recv_counter, &u->sink->sample_spec);
+    if (recv_counter <= send_counter)
+        buffer_latency += (int64_t) (send_counter - recv_counter);
+    else
+        buffer_latency = PA_CLIP_SUB(buffer_latency, (int64_t) (recv_counter - send_counter));
+
+    /* capture and playback are perfectly aligned when diff_time is 0 */
+    diff_time = (snapshot->sink_now + snapshot->sink_latency - buffer_latency) -
+          (snapshot->source_now - snapshot->source_latency);
+
+    pa_log_debug("Diff %lld (%lld - %lld + %lld) %lld %lld %lld %lld", (long long) diff_time,
+        (long long) snapshot->sink_latency,
+        (long long) buffer_latency, (long long) snapshot->source_latency,
+        (long long) source_delay, (long long) sink_delay,
+        (long long) (send_counter - recv_counter),
+        (long long) (snapshot->sink_now - snapshot->source_now));
+
+    return diff_time;
+}
+
+/* Called from main context */
+static void time_callback(pa_mainloop_api *a, pa_time_event *e, const struct timeval *t, void *userdata) {
+    struct userdata *u = userdata;
+    uint32_t old_rate, base_rate, new_rate;
+    int64_t diff_time;
+    /*size_t fs*/
+    struct snapshot latency_snapshot;
+
+    pa_assert(u);
+    pa_assert(a);
+    pa_assert(u->time_event == e);
+    pa_assert_ctl_context();
+
+    if (!IS_ACTIVE(u))
+        return;
+
+    /* update our snapshots */
+    pa_asyncmsgq_send(u->source_output->source->asyncmsgq, PA_MSGOBJECT(u->source_output), SOURCE_OUTPUT_MESSAGE_LATENCY_SNAPSHOT, &latency_snapshot, 0, NULL);
+    pa_asyncmsgq_send(u->sink_input->sink->asyncmsgq, PA_MSGOBJECT(u->sink_input), SINK_INPUT_MESSAGE_LATENCY_SNAPSHOT, &latency_snapshot, 0, NULL);
+
+    /* calculate drift between capture and playback */
+    diff_time = calc_diff(u, &latency_snapshot);
+
+    /*fs = pa_frame_size(&u->source_output->sample_spec);*/
+    old_rate = u->sink_input->sample_spec.rate;
+    base_rate = u->source_output->sample_spec.rate;
+
+    if (diff_time < 0) {
+        /* recording before playback, we need to adjust quickly. The echo
+         * canceller does not work in this case. */
+        pa_asyncmsgq_post(u->asyncmsgq, PA_MSGOBJECT(u->source_output), SOURCE_OUTPUT_MESSAGE_APPLY_DIFF_TIME,
+            NULL, diff_time, NULL, NULL);
+        /*new_rate = base_rate - ((pa_usec_to_bytes(-diff_time, &u->source_output->sample_spec) / fs) * PA_USEC_PER_SEC) / u->adjust_time;*/
+        new_rate = base_rate;
+    }
+    else {
+        if (diff_time > u->adjust_threshold) {
+            /* diff too big, quickly adjust */
+            pa_asyncmsgq_post(u->asyncmsgq, PA_MSGOBJECT(u->source_output), SOURCE_OUTPUT_MESSAGE_APPLY_DIFF_TIME,
+                NULL, diff_time, NULL, NULL);
+        }
+
+        /* recording behind playback, we need to slowly adjust the rate to match */
+        /*new_rate = base_rate + ((pa_usec_to_bytes(diff_time, &u->source_output->sample_spec) / fs) * PA_USEC_PER_SEC) / u->adjust_time;*/
+
+        /* assume equal samplerates for now */
+        new_rate = base_rate;
+    }
+
+    /* make sure we don't make too big adjustments because that sounds horrible */
+    if (new_rate > base_rate * 1.1 || new_rate < base_rate * 0.9)
+        new_rate = base_rate;
+
+    if (new_rate != old_rate) {
+        pa_log_info("Old rate %lu Hz, new rate %lu Hz", (unsigned long) old_rate, (unsigned long) new_rate);
+
+        pa_sink_input_set_rate(u->sink_input, new_rate);
+    }
+
+    pa_core_rttime_restart(u->core, u->time_event, pa_rtclock_now() + u->adjust_time);
+}
+
+/* Called from source I/O thread context */
+static int source_process_msg_cb(pa_msgobject *o, int code, void *data, int64_t offset, pa_memchunk *chunk) {
+    struct userdata *u = PA_SOURCE(o)->userdata;
+
+    switch (code) {
+
+        case PA_SOURCE_MESSAGE_GET_LATENCY:
+
+            /* The source is _put() before the source output is, so let's
+             * make sure we don't access it in that time. Also, the
+             * source output is first shut down, the source second. */
+            if (!PA_SOURCE_IS_LINKED(u->source->thread_info.state) ||
+                !PA_SOURCE_OUTPUT_IS_LINKED(u->source_output->thread_info.state)) {
+                *((int64_t*) data) = 0;
+                return 0;
+            }
+
+            *((int64_t*) data) =
+
+                /* Get the latency of the master source */
+                pa_source_get_latency_within_thread(u->source_output->source, true) +
+                /* Add the latency internal to our source output on top */
+                pa_bytes_to_usec(pa_memblockq_get_length(u->source_output->thread_info.delay_memblockq), &u->source_output->source->sample_spec) +
+                /* and the buffering we do on the source */
+                pa_bytes_to_usec(u->source_output_blocksize, &u->source_output->source->sample_spec);
+
+            return 0;
+
+        case PA_SOURCE_MESSAGE_SET_VOLUME_SYNCED:
+            u->thread_info.current_volume = u->source->reference_volume;
+            break;
+    }
+
+    return pa_source_process_msg(o, code, data, offset, chunk);
+}
+
+/* Called from sink 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 source_set_state_in_main_thread_cb(pa_source *s, pa_source_state_t state, pa_suspend_cause_t suspend_cause) {
+    struct userdata *u;
+
+    pa_source_assert_ref(s);
+    pa_assert_se(u = s->userdata);
+
+    if (!PA_SOURCE_IS_LINKED(state) ||
+        !PA_SOURCE_OUTPUT_IS_LINKED(u->source_output->state))
+        return 0;
+
+    if (state == PA_SOURCE_RUNNING) {
+        /* restart timer when both sink and source are active */
+        if ((u->sink->state == PA_SINK_RUNNING) && u->adjust_time)
+            pa_core_rttime_restart(u->core, u->time_event, pa_rtclock_now() + u->adjust_time);
+
+        pa_atomic_store(&u->request_resync, 1);
+        pa_source_output_cork(u->source_output, false);
+    } else if (state == PA_SOURCE_SUSPENDED) {
+        pa_source_output_cork(u->source_output, true);
+    }
+
+    return 0;
+}
+
+/* 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;
+
+    if (state == PA_SINK_RUNNING) {
+        /* restart timer when both sink and source are active */
+        if ((u->source->state == PA_SOURCE_RUNNING) && u->adjust_time)
+            pa_core_rttime_restart(u->core, u->time_event, pa_rtclock_now() + u->adjust_time);
+
+        pa_atomic_store(&u->request_resync, 1);
+        pa_sink_input_cork(u->sink_input, false);
+    } else if (state == PA_SINK_SUSPENDED) {
+        pa_sink_input_cork(u->sink_input, true);
+    }
+
+    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 source I/O thread context */
+static void source_update_requested_latency_cb(pa_source *s) {
+    struct userdata *u;
+    pa_usec_t latency;
+
+    pa_source_assert_ref(s);
+    pa_assert_se(u = s->userdata);
+
+    if (!PA_SOURCE_IS_LINKED(u->source->thread_info.state) ||
+        !PA_SOURCE_OUTPUT_IS_LINKED(u->source_output->thread_info.state))
+        return;
+
+    pa_log_debug("Source update requested latency");
+
+    /* Cap the maximum latency so we don't have to process too large chunks */
+    latency = PA_MIN(pa_source_get_requested_latency_within_thread(s),
+                     pa_bytes_to_usec(u->source_blocksize, &s->sample_spec) * MAX_LATENCY_BLOCKS);
+
+    pa_source_output_set_requested_latency_within_thread(u->source_output, latency);
+}
+
+/* Called from sink I/O thread context */
+static void sink_update_requested_latency_cb(pa_sink *s) {
+    struct userdata *u;
+    pa_usec_t latency;
+
+    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;
+
+    pa_log_debug("Sink update requested latency");
+
+    /* Cap the maximum latency so we don't have to process too large chunks */
+    latency = PA_MIN(pa_sink_get_requested_latency_within_thread(s),
+                     pa_bytes_to_usec(u->sink_blocksize, &s->sample_spec) * MAX_LATENCY_BLOCKS);
+
+    pa_sink_input_set_requested_latency_within_thread(u->sink_input, latency);
+}
+
+/* Called from sink 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;
+
+    pa_log_debug("Sink request rewind %lld", (long long) s->thread_info.rewind_nbytes);
+
+    /* Just hand this one over to the master sink */
+    pa_sink_input_request_rewind(u->sink_input,
+                                 s->thread_info.rewind_nbytes, true, false, false);
+}
+
+/* Called from main context */
+static void source_set_volume_cb(pa_source *s) {
+    struct userdata *u;
+
+    pa_source_assert_ref(s);
+    pa_assert_se(u = s->userdata);
+
+    if (!PA_SOURCE_IS_LINKED(s->state) ||
+        !PA_SOURCE_OUTPUT_IS_LINKED(u->source_output->state))
+        return;
+
+    pa_source_output_set_volume(u->source_output, &s->real_volume, s->save_volume, true);
+}
+
+/* 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 source_get_volume_cb(pa_source *s) {
+    struct userdata *u;
+    pa_cvolume v;
+
+    pa_source_assert_ref(s);
+    pa_assert_se(u = s->userdata);
+
+    if (!PA_SOURCE_IS_LINKED(s->state) ||
+        !PA_SOURCE_OUTPUT_IS_LINKED(u->source_output->state))
+        return;
+
+    pa_source_output_get_volume(u->source_output, &v, true);
+
+    if (pa_cvolume_equal(&s->real_volume, &v))
+        /* no change */
+        return;
+
+    s->real_volume = v;
+    pa_source_set_soft_volume(s, NULL);
+}
+
+/* Called from main context */
+static void source_set_mute_cb(pa_source *s) {
+    struct userdata *u;
+
+    pa_source_assert_ref(s);
+    pa_assert_se(u = s->userdata);
+
+    if (!PA_SOURCE_IS_LINKED(s->state) ||
+        !PA_SOURCE_OUTPUT_IS_LINKED(u->source_output->state))
+        return;
+
+    pa_source_output_set_mute(u->source_output, s->muted, s->save_muted);
+}
+
+/* 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 source I/O thread context. */
+static void apply_diff_time(struct userdata *u, int64_t diff_time) {
+    int64_t diff;
+
+    if (diff_time < 0) {
+        diff = pa_usec_to_bytes(-diff_time, &u->sink_input->sample_spec);
+
+        if (diff > 0) {
+            /* add some extra safety samples to compensate for jitter in the
+             * timings */
+            diff += 10 * pa_frame_size (&u->sink_input->sample_spec);
+
+            pa_log("Playback after capture (%lld), drop sink %lld", (long long) diff_time, (long long) diff);
+
+            u->sink_skip = diff;
+            u->source_skip = 0;
+        }
+    } else if (diff_time > 0) {
+        diff = pa_usec_to_bytes(diff_time, &u->source_output->sample_spec);
+
+        if (diff > 0) {
+            pa_log("Playback too far ahead (%lld), drop source %lld", (long long) diff_time, (long long) diff);
+
+            u->source_skip = diff;
+            u->sink_skip = 0;
+        }
+    }
+}
+
+/* Called from source I/O thread context. */
+static void do_resync(struct userdata *u) {
+    int64_t diff_time;
+    struct snapshot latency_snapshot;
+
+    pa_log("Doing resync");
+
+    /* update our snapshot */
+    /* 1. Get sink input latency snapshot, might cause buffers to be sent to source thread */
+    pa_asyncmsgq_send(u->sink_input->sink->asyncmsgq, PA_MSGOBJECT(u->sink_input), SINK_INPUT_MESSAGE_LATENCY_SNAPSHOT, &latency_snapshot, 0, NULL);
+    /* 2. Pick up any in-flight buffers (and discard if needed) */
+    while (pa_asyncmsgq_process_one(u->asyncmsgq))
+        ;
+    /* 3. Now get the source output latency snapshot */
+    source_output_snapshot_within_thread(u, &latency_snapshot);
+
+    /* calculate drift between capture and playback */
+    diff_time = calc_diff(u, &latency_snapshot);
+
+    /* and adjust for the drift */
+    apply_diff_time(u, diff_time);
+}
+
+/* 1. Calculate drift at this point, pass to canceller
+ * 2. Push out playback samples in blocksize chunks
+ * 3. Push out capture samples in blocksize chunks
+ * 4. ???
+ * 5. Profit
+ *
+ * Called from source I/O thread context.
+ */
+static void do_push_drift_comp(struct userdata *u) {
+    size_t rlen, plen;
+    pa_memchunk rchunk, pchunk, cchunk;
+    uint8_t *rdata, *pdata, *cdata;
+    float drift;
+    int unused PA_GCC_UNUSED;
+
+    rlen = pa_memblockq_get_length(u->source_memblockq);
+    plen = pa_memblockq_get_length(u->sink_memblockq);
+
+    /* Estimate snapshot drift as follows:
+     *   pd: amount of data consumed since last time
+     *   rd: amount of data consumed since last time
+     *
+     *   drift = (pd - rd) / rd;
+     *
+     * We calculate pd and rd as the memblockq length less the number of
+     * samples left from the last iteration (to avoid double counting
+     * those remainder samples.
+     */
+    drift = ((float)(plen - u->sink_rem) - (rlen - u->source_rem)) / ((float)(rlen - u->source_rem));
+    u->sink_rem = plen % u->sink_blocksize;
+    u->source_rem = rlen % u->source_output_blocksize;
+
+    if (u->save_aec) {
+        if (u->drift_file)
+            fprintf(u->drift_file, "d %a\n", drift);
+    }
+
+    /* Send in the playback samples first */
+    while (plen >= u->sink_blocksize) {
+        pa_memblockq_peek_fixed_size(u->sink_memblockq, u->sink_blocksize, &pchunk);
+        pdata = pa_memblock_acquire(pchunk.memblock);
+        pdata += pchunk.index;
+
+        u->ec->play(u->ec, pdata);
+
+        if (u->save_aec) {
+            if (u->drift_file)
+                fprintf(u->drift_file, "p %d\n", u->sink_blocksize);
+            if (u->played_file)
+                unused = fwrite(pdata, 1, u->sink_blocksize, u->played_file);
+        }
+
+        pa_memblock_release(pchunk.memblock);
+        pa_memblockq_drop(u->sink_memblockq, u->sink_blocksize);
+        pa_memblock_unref(pchunk.memblock);
+
+        plen -= u->sink_blocksize;
+    }
+
+    /* And now the capture samples */
+    while (rlen >= u->source_output_blocksize) {
+        pa_memblockq_peek_fixed_size(u->source_memblockq, u->source_output_blocksize, &rchunk);
+
+        rdata = pa_memblock_acquire(rchunk.memblock);
+        rdata += rchunk.index;
+
+        cchunk.index = 0;
+        cchunk.length = u->source_output_blocksize;
+        cchunk.memblock = pa_memblock_new(u->source->core->mempool, cchunk.length);
+        cdata = pa_memblock_acquire(cchunk.memblock);
+
+        u->ec->set_drift(u->ec, drift);
+        u->ec->record(u->ec, rdata, cdata);
+
+        if (u->save_aec) {
+            if (u->drift_file)
+                fprintf(u->drift_file, "c %d\n", u->source_output_blocksize);
+            if (u->captured_file)
+                unused = fwrite(rdata, 1, u->source_output_blocksize, u->captured_file);
+            if (u->canceled_file)
+                unused = fwrite(cdata, 1, u->source_output_blocksize, u->canceled_file);
+        }
+
+        pa_memblock_release(cchunk.memblock);
+        pa_memblock_release(rchunk.memblock);
+
+        pa_memblock_unref(rchunk.memblock);
+
+        pa_source_post(u->source, &cchunk);
+        pa_memblock_unref(cchunk.memblock);
+
+        pa_memblockq_drop(u->source_memblockq, u->source_output_blocksize);
+        rlen -= u->source_output_blocksize;
+    }
+}
+
+/* This one's simpler than the drift compensation case -- we just iterate over
+ * the capture buffer, and pass the canceller blocksize bytes of playback and
+ * capture data. If playback is currently inactive, we just push silence.
+ *
+ * Called from source I/O thread context. */
+static void do_push(struct userdata *u) {
+    size_t rlen, plen;
+    pa_memchunk rchunk, pchunk, cchunk;
+    uint8_t *rdata, *pdata, *cdata;
+    int unused PA_GCC_UNUSED;
+
+    rlen = pa_memblockq_get_length(u->source_memblockq);
+    plen = pa_memblockq_get_length(u->sink_memblockq);
+
+    while (rlen >= u->source_output_blocksize) {
+
+        /* take fixed blocks from recorded and played samples */
+        pa_memblockq_peek_fixed_size(u->source_memblockq, u->source_output_blocksize, &rchunk);
+        pa_memblockq_peek_fixed_size(u->sink_memblockq, u->sink_blocksize, &pchunk);
+
+        /* we ran out of played data and pchunk has been filled with silence bytes */
+        if (plen < u->sink_blocksize)
+            pa_memblockq_seek(u->sink_memblockq, u->sink_blocksize - plen, PA_SEEK_RELATIVE, true);
+
+        rdata = pa_memblock_acquire(rchunk.memblock);
+        rdata += rchunk.index;
+        pdata = pa_memblock_acquire(pchunk.memblock);
+        pdata += pchunk.index;
+
+        cchunk.index = 0;
+        cchunk.length = u->source_blocksize;
+        cchunk.memblock = pa_memblock_new(u->source->core->mempool, cchunk.length);
+        cdata = pa_memblock_acquire(cchunk.memblock);
+
+        if (u->save_aec) {
+            if (u->captured_file)
+                unused = fwrite(rdata, 1, u->source_output_blocksize, u->captured_file);
+            if (u->played_file)
+                unused = fwrite(pdata, 1, u->sink_blocksize, u->played_file);
+        }
+
+        /* perform echo cancellation */
+        u->ec->run(u->ec, rdata, pdata, cdata);
+
+        if (u->save_aec) {
+            if (u->canceled_file)
+                unused = fwrite(cdata, 1, u->source_blocksize, u->canceled_file);
+        }
+
+        pa_memblock_release(cchunk.memblock);
+        pa_memblock_release(pchunk.memblock);
+        pa_memblock_release(rchunk.memblock);
+
+        /* drop consumed source samples */
+        pa_memblockq_drop(u->source_memblockq, u->source_output_blocksize);
+        pa_memblock_unref(rchunk.memblock);
+        rlen -= u->source_output_blocksize;
+
+        /* drop consumed sink samples */
+        pa_memblockq_drop(u->sink_memblockq, u->sink_blocksize);
+        pa_memblock_unref(pchunk.memblock);
+
+        if (plen >= u->sink_blocksize)
+            plen -= u->sink_blocksize;
+        else
+            plen = 0;
+
+        /* forward the (echo-canceled) data to the virtual source */
+        pa_source_post(u->source, &cchunk);
+        pa_memblock_unref(cchunk.memblock);
+    }
+}
+
+/* Called from source I/O thread context. */
+static void source_output_push_cb(pa_source_output *o, const pa_memchunk *chunk) {
+    struct userdata *u;
+    size_t rlen, plen, to_skip;
+    pa_memchunk rchunk;
+
+    pa_source_output_assert_ref(o);
+    pa_source_output_assert_io_context(o);
+    pa_assert_se(u = o->userdata);
+
+    if (!PA_SOURCE_IS_LINKED(u->source->thread_info.state))
+        return;
+
+    if (!PA_SOURCE_OUTPUT_IS_LINKED(u->source_output->thread_info.state)) {
+        pa_log("Push when no link?");
+        return;
+    }
+
+    /* handle queued messages, do any message sending of our own */
+    while (pa_asyncmsgq_process_one(u->asyncmsgq) > 0)
+        ;
+
+    pa_memblockq_push_align(u->source_memblockq, chunk);
+
+    rlen = pa_memblockq_get_length(u->source_memblockq);
+    plen = pa_memblockq_get_length(u->sink_memblockq);
+
+    /* Let's not do anything else till we have enough data to process */
+    if (rlen < u->source_output_blocksize)
+        return;
+
+    /* See if we need to drop samples in order to sync */
+    if (pa_atomic_cmpxchg (&u->request_resync, 1, 0)) {
+        do_resync(u);
+    }
+
+    /* Okay, skip cancellation for skipped source samples if needed. */
+    if (PA_UNLIKELY(u->source_skip)) {
+        /* The slightly tricky bit here is that we drop all but modulo
+         * blocksize bytes and then adjust for that last bit on the sink side.
+         * We do this because the source data is coming at a fixed rate, which
+         * means the only way to try to catch up is drop sink samples and let
+         * the canceller cope up with this. */
+        to_skip = rlen >= u->source_skip ? u->source_skip : rlen;
+        to_skip -= to_skip % u->source_output_blocksize;
+
+        if (to_skip) {
+            pa_memblockq_peek_fixed_size(u->source_memblockq, to_skip, &rchunk);
+            pa_source_post(u->source, &rchunk);
+
+            pa_memblock_unref(rchunk.memblock);
+            pa_memblockq_drop(u->source_memblockq, to_skip);
+
+            rlen -= to_skip;
+            u->source_skip -= to_skip;
+        }
+
+        if (rlen && u->source_skip % u->source_output_blocksize) {
+            u->sink_skip += (uint64_t) (u->source_output_blocksize - (u->source_skip % u->source_output_blocksize)) * u->sink_blocksize / u->source_output_blocksize;
+            u->source_skip -= (u->source_skip % u->source_output_blocksize);
+        }
+    }
+
+    /* And for the sink, these samples have been played back already, so we can
+     * just drop them and get on with it. */
+    if (PA_UNLIKELY(u->sink_skip)) {
+        to_skip = plen >= u->sink_skip ? u->sink_skip : plen;
+
+        pa_memblockq_drop(u->sink_memblockq, to_skip);
+
+        plen -= to_skip;
+        u->sink_skip -= to_skip;
+    }
+
+    /* process and push out samples */
+    if (u->ec->params.drift_compensation)
+        do_push_drift_comp(u);
+    else
+        do_push(u);
+}
+
+/* Called from sink I/O thread context. */
+static int sink_input_pop_cb(pa_sink_input *i, size_t nbytes, pa_memchunk *chunk) {
+    struct userdata *u;
+
+    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;
+
+    if (u->sink->thread_info.rewind_requested)
+        pa_sink_process_rewind(u->sink, 0);
+
+    pa_sink_render_full(u->sink, nbytes, chunk);
+
+    if (i->thread_info.underrun_for > 0) {
+        pa_log_debug("Handling end of underrun.");
+        pa_atomic_store(&u->request_resync, 1);
+    }
+
+    /* let source thread handle the chunk. pass the sample count as well so that
+     * the source IO thread can update the right variables. */
+    pa_asyncmsgq_post(u->asyncmsgq, PA_MSGOBJECT(u->source_output), SOURCE_OUTPUT_MESSAGE_POST,
+        NULL, 0, chunk, NULL);
+    u->send_counter += chunk->length;
+
+    return 0;
+}
+
+/* Called from source I/O thread context. */
+static void source_output_process_rewind_cb(pa_source_output *o, size_t nbytes) {
+    struct userdata *u;
+
+    pa_source_output_assert_ref(o);
+    pa_source_output_assert_io_context(o);
+    pa_assert_se(u = o->userdata);
+
+    /* If the source is not yet linked, there is nothing to rewind */
+    if (!PA_SOURCE_IS_LINKED(u->source->thread_info.state))
+        return;
+
+    pa_source_process_rewind(u->source, nbytes);
+
+    /* go back on read side, we need to use older sink data for this */
+    pa_memblockq_rewind(u->sink_memblockq, nbytes);
+
+    /* manipulate write index */
+    pa_memblockq_seek(u->source_memblockq, -nbytes, PA_SEEK_RELATIVE, true);
+
+    pa_log_debug("Source rewind (%lld) %lld", (long long) nbytes,
+        (long long) pa_memblockq_get_length (u->source_memblockq));
+}
+
+/* Called from sink I/O thread context. */
+static void sink_input_process_rewind_cb(pa_sink_input *i, size_t nbytes) {
+    struct userdata *u;
+
+    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;
+
+    pa_log_debug("Sink process rewind %lld", (long long) nbytes);
+
+    pa_sink_process_rewind(u->sink, nbytes);
+
+    pa_asyncmsgq_post(u->asyncmsgq, PA_MSGOBJECT(u->source_output), SOURCE_OUTPUT_MESSAGE_REWIND, NULL, (int64_t) nbytes, NULL, NULL);
+    u->send_counter -= nbytes;
+}
+
+/* Called from source I/O thread context. */
+static void source_output_snapshot_within_thread(struct userdata *u, struct snapshot *snapshot) {
+    size_t delay, rlen, plen;
+    pa_usec_t now, latency;
+
+    now = pa_rtclock_now();
+    latency = pa_source_get_latency_within_thread(u->source_output->source, false);
+    delay = pa_memblockq_get_length(u->source_output->thread_info.delay_memblockq);
+
+    delay = (u->source_output->thread_info.resampler ? pa_resampler_request(u->source_output->thread_info.resampler, delay) : delay);
+    rlen = pa_memblockq_get_length(u->source_memblockq);
+    plen = pa_memblockq_get_length(u->sink_memblockq);
+
+    snapshot->source_now = now;
+    snapshot->source_latency = latency;
+    snapshot->source_delay = delay;
+    snapshot->recv_counter = u->recv_counter;
+    snapshot->rlen = rlen + u->sink_skip;
+    snapshot->plen = plen + u->source_skip;
+}
+
+/* Called from source I/O thread context. */
+static int source_output_process_msg_cb(pa_msgobject *obj, int code, void *data, int64_t offset, pa_memchunk *chunk) {
+    struct userdata *u = PA_SOURCE_OUTPUT(obj)->userdata;
+
+    switch (code) {
+
+        case SOURCE_OUTPUT_MESSAGE_POST:
+
+            pa_source_output_assert_io_context(u->source_output);
+
+            if (u->source_output->source->thread_info.state == PA_SOURCE_RUNNING)
+                pa_memblockq_push_align(u->sink_memblockq, chunk);
+            else
+                pa_memblockq_flush_write(u->sink_memblockq, true);
+
+            u->recv_counter += (int64_t) chunk->length;
+
+            return 0;
+
+        case SOURCE_OUTPUT_MESSAGE_REWIND:
+            pa_source_output_assert_io_context(u->source_output);
+
+            /* manipulate write index, never go past what we have */
+            if (PA_SOURCE_IS_OPENED(u->source_output->source->thread_info.state))
+                pa_memblockq_seek(u->sink_memblockq, -offset, PA_SEEK_RELATIVE, true);
+            else
+                pa_memblockq_flush_write(u->sink_memblockq, true);
+
+            pa_log_debug("Sink rewind (%lld)", (long long) offset);
+
+            u->recv_counter -= offset;
+
+            return 0;
+
+        case SOURCE_OUTPUT_MESSAGE_LATENCY_SNAPSHOT: {
+            struct snapshot *snapshot = (struct snapshot *) data;
+
+            source_output_snapshot_within_thread(u, snapshot);
+            return 0;
+        }
+
+        case SOURCE_OUTPUT_MESSAGE_APPLY_DIFF_TIME:
+            apply_diff_time(u, offset);
+            return 0;
+
+    }
+
+    return pa_source_output_process_msg(obj, code, data, offset, chunk);
+}
+
+/* Called from sink I/O thread context. */
+static int sink_input_process_msg_cb(pa_msgobject *obj, int code, void *data, int64_t offset, pa_memchunk *chunk) {
+    struct userdata *u = PA_SINK_INPUT(obj)->userdata;
+
+    switch (code) {
+
+        case SINK_INPUT_MESSAGE_LATENCY_SNAPSHOT: {
+            size_t delay;
+            pa_usec_t now, latency;
+            struct snapshot *snapshot = (struct snapshot *) data;
+
+            pa_sink_input_assert_io_context(u->sink_input);
+
+            now = pa_rtclock_now();
+            latency = pa_sink_get_latency_within_thread(u->sink_input->sink, false);
+            delay = pa_memblockq_get_length(u->sink_input->thread_info.render_memblockq);
+
+            delay = (u->sink_input->thread_info.resampler ? pa_resampler_request(u->sink_input->thread_info.resampler, delay) : delay);
+
+            snapshot->sink_now = now;
+            snapshot->sink_latency = latency;
+            snapshot->sink_delay = delay;
+            snapshot->send_counter = u->send_counter;
+            return 0;
+        }
+    }
+
+    return pa_sink_input_process_msg(obj, code, data, offset, chunk);
+}
+
+/* Called from sink 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);
+
+    pa_log_debug("Sink input update max rewind %lld", (long long) nbytes);
+
+    /* FIXME: Too small max_rewind:
+     * https://bugs.freedesktop.org/show_bug.cgi?id=53709 */
+    pa_memblockq_set_maxrewind(u->sink_memblockq, nbytes);
+    pa_sink_set_max_rewind_within_thread(u->sink, nbytes);
+}
+
+/* Called from source I/O thread context. */
+static void source_output_update_max_rewind_cb(pa_source_output *o, size_t nbytes) {
+    struct userdata *u;
+
+    pa_source_output_assert_ref(o);
+    pa_assert_se(u = o->userdata);
+
+    pa_log_debug("Source output update max rewind %lld", (long long) nbytes);
+
+    pa_source_set_max_rewind_within_thread(u->source, nbytes);
+}
+
+/* Called from sink 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);
+
+    pa_log_debug("Sink input update max request %lld", (long long) nbytes);
+
+    pa_sink_set_max_request_within_thread(u->sink, nbytes);
+}
+
+/* Called from sink I/O thread context. */
+static void sink_input_update_sink_requested_latency_cb(pa_sink_input *i) {
+    struct userdata *u;
+    pa_usec_t latency;
+
+    pa_sink_input_assert_ref(i);
+    pa_assert_se(u = i->userdata);
+
+    latency = pa_sink_get_requested_latency_within_thread(i->sink);
+
+    pa_log_debug("Sink input update requested latency %lld", (long long) latency);
+}
+
+/* Called from source I/O thread context. */
+static void source_output_update_source_requested_latency_cb(pa_source_output *o) {
+    struct userdata *u;
+    pa_usec_t latency;
+
+    pa_source_output_assert_ref(o);
+    pa_assert_se(u = o->userdata);
+
+    latency = pa_source_get_requested_latency_within_thread(o->source);
+
+    pa_log_debug("Source output update requested latency %lld", (long long) latency);
+}
+
+/* Called from sink 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_log_debug("Sink input update latency range %lld %lld",
+        (long long) i->sink->thread_info.min_latency,
+        (long long) i->sink->thread_info.max_latency);
+
+    pa_sink_set_latency_range_within_thread(u->sink, i->sink->thread_info.min_latency, i->sink->thread_info.max_latency);
+}
+
+/* Called from source I/O thread context. */
+static void source_output_update_source_latency_range_cb(pa_source_output *o) {
+    struct userdata *u;
+
+    pa_source_output_assert_ref(o);
+    pa_assert_se(u = o->userdata);
+
+    pa_log_debug("Source output update latency range %lld %lld",
+        (long long) o->source->thread_info.min_latency,
+        (long long) o->source->thread_info.max_latency);
+
+    pa_source_set_latency_range_within_thread(u->source, o->source->thread_info.min_latency, o->source->thread_info.max_latency);
+}
+
+/* Called from sink 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);
+
+    pa_log_debug("Sink input update fixed latency %lld",
+        (long long) i->sink->thread_info.fixed_latency);
+
+    pa_sink_set_fixed_latency_within_thread(u->sink, i->sink->thread_info.fixed_latency);
+}
+
+/* Called from source I/O thread context. */
+static void source_output_update_source_fixed_latency_cb(pa_source_output *o) {
+    struct userdata *u;
+
+    pa_source_output_assert_ref(o);
+    pa_assert_se(u = o->userdata);
+
+    pa_log_debug("Source output update fixed latency %lld",
+        (long long) o->source->thread_info.fixed_latency);
+
+    pa_source_set_fixed_latency_within_thread(u->source, o->source->thread_info.fixed_latency);
+}
+
+/* Called from source I/O thread context. */
+static void source_output_attach_cb(pa_source_output *o) {
+    struct userdata *u;
+
+    pa_source_output_assert_ref(o);
+    pa_source_output_assert_io_context(o);
+    pa_assert_se(u = o->userdata);
+
+    pa_source_set_rtpoll(u->source, o->source->thread_info.rtpoll);
+    pa_source_set_latency_range_within_thread(u->source, o->source->thread_info.min_latency, o->source->thread_info.max_latency);
+    pa_source_set_fixed_latency_within_thread(u->source, o->source->thread_info.fixed_latency);
+    pa_source_set_max_rewind_within_thread(u->source, pa_source_output_get_max_rewind(o));
+
+    pa_log_debug("Source output %d attach", o->index);
+
+    if (PA_SOURCE_IS_LINKED(u->source->thread_info.state))
+        pa_source_attach_within_thread(u->source);
+
+    u->rtpoll_item_read = pa_rtpoll_item_new_asyncmsgq_read(
+            o->source->thread_info.rtpoll,
+            PA_RTPOLL_LATE,
+            u->asyncmsgq);
+}
+
+/* Called from sink 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));
+
+    pa_log_debug("Sink input %d attach", i->index);
+
+    u->rtpoll_item_write = pa_rtpoll_item_new_asyncmsgq_write(
+            i->sink->thread_info.rtpoll,
+            PA_RTPOLL_LATE,
+            u->asyncmsgq);
+
+    if (PA_SINK_IS_LINKED(u->sink->thread_info.state))
+        pa_sink_attach_within_thread(u->sink);
+}
+
+/* Called from source I/O thread context. */
+static void source_output_detach_cb(pa_source_output *o) {
+    struct userdata *u;
+
+    pa_source_output_assert_ref(o);
+    pa_source_output_assert_io_context(o);
+    pa_assert_se(u = o->userdata);
+
+    if (PA_SOURCE_IS_LINKED(u->source->thread_info.state))
+        pa_source_detach_within_thread(u->source);
+    pa_source_set_rtpoll(u->source, NULL);
+
+    pa_log_debug("Source output %d detach", o->index);
+
+    if (u->rtpoll_item_read) {
+        pa_rtpoll_item_free(u->rtpoll_item_read);
+        u->rtpoll_item_read = NULL;
+    }
+}
+
+/* Called from sink 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);
+
+    pa_log_debug("Sink input %d detach", i->index);
+
+    if (u->rtpoll_item_write) {
+        pa_rtpoll_item_free(u->rtpoll_item_write);
+        u->rtpoll_item_write = NULL;
+    }
+}
+
+/* Called from source I/O thread context except when cork() is called without valid source. */
+static void source_output_state_change_cb(pa_source_output *o, pa_source_output_state_t state) {
+    struct userdata *u;
+
+    pa_source_output_assert_ref(o);
+    pa_assert_se(u = o->userdata);
+
+    pa_log_debug("Source output %d state %d", o->index, state);
+}
+
+/* Called from sink I/O thread context. */
+static void sink_input_state_change_cb(pa_sink_input *i, pa_sink_input_state_t state) {
+    struct userdata *u;
+
+    pa_sink_input_assert_ref(i);
+    pa_assert_se(u = i->userdata);
+
+    pa_log_debug("Sink input %d state %d", i->index, state);
+}
+
+/* Called from main context. */
+static void source_output_kill_cb(pa_source_output *o) {
+    struct userdata *u;
+
+    pa_source_output_assert_ref(o);
+    pa_assert_ctl_context();
+    pa_assert_se(u = o->userdata);
+
+    u->dead = true;
+
+    /* The order here matters! We first kill the source so that streams can
+     * properly be moved away while the source output is still connected to
+     * the master. */
+    pa_source_output_cork(u->source_output, true);
+    pa_source_unlink(u->source);
+    pa_source_output_unlink(u->source_output);
+
+    pa_source_output_unref(u->source_output);
+    u->source_output = NULL;
+
+    pa_source_unref(u->source);
+    u->source = NULL;
+
+    pa_log_debug("Source output kill %d", o->index);
+
+    pa_module_unload_request(u->module, true);
+}
+
+/* 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);
+
+    u->dead = true;
+
+    /* 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_log_debug("Sink input kill %d", i->index);
+
+    pa_module_unload_request(u->module, true);
+}
+
+/* Called from main context. */
+static bool source_output_may_move_to_cb(pa_source_output *o, pa_source *dest) {
+    struct userdata *u;
+
+    pa_source_output_assert_ref(o);
+    pa_assert_ctl_context();
+    pa_assert_se(u = o->userdata);
+
+    if (u->dead)
+        return false;
+
+    return (u->source != dest) && (u->sink != dest->monitor_of);
+}
+
+/* Called from main context */
+static bool sink_input_may_move_to_cb(pa_sink_input *i, pa_sink *dest) {
+    struct userdata *u;
+
+    pa_sink_input_assert_ref(i);
+    pa_assert_se(u = i->userdata);
+
+    if (u->dead)
+        return false;
+
+    return u->sink != dest;
+}
+
+/* Called from main context. */
+static void source_output_moving_cb(pa_source_output *o, pa_source *dest) {
+    struct userdata *u;
+    uint32_t idx;
+    pa_source_output *output;
+
+    pa_source_output_assert_ref(o);
+    pa_assert_ctl_context();
+    pa_assert_se(u = o->userdata);
+
+    if (dest) {
+        pa_source_set_asyncmsgq(u->source, dest->asyncmsgq);
+        pa_source_update_flags(u->source, PA_SOURCE_LATENCY|PA_SOURCE_DYNAMIC_LATENCY, dest->flags);
+    } else
+        pa_source_set_asyncmsgq(u->source, NULL);
+
+    /* Propagate asyncmsq change to attached virtual sources */
+    PA_IDXSET_FOREACH(output, u->source->outputs, idx) {
+        if (output->destination_source && output->moving)
+            output->moving(output, u->source);
+    }
+
+    if (u->source_auto_desc && dest) {
+        const char *y, *z;
+        pa_proplist *pl;
+
+        pl = pa_proplist_new();
+        if (u->sink_input->sink) {
+            pa_proplist_sets(pl, PA_PROP_DEVICE_MASTER_DEVICE, u->sink_input->sink->name);
+            y = pa_proplist_gets(u->sink_input->sink->proplist, PA_PROP_DEVICE_DESCRIPTION);
+        } else
+            y = "<unknown>"; /* Probably in the middle of a move */
+        z = pa_proplist_gets(dest->proplist, PA_PROP_DEVICE_DESCRIPTION);
+        pa_proplist_setf(pl, PA_PROP_DEVICE_DESCRIPTION, "%s (echo cancelled with %s)", z ? z : dest->name,
+                y ? y : u->sink_input->sink->name);
+
+        pa_source_update_proplist(u->source, PA_UPDATE_REPLACE, pl);
+        pa_proplist_free(pl);
+    }
+}
+
+/* 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->sink_auto_desc && dest) {
+        const char *y, *z;
+        pa_proplist *pl;
+
+        pl = pa_proplist_new();
+        if (u->source_output->source) {
+            pa_proplist_sets(pl, PA_PROP_DEVICE_MASTER_DEVICE, u->source_output->source->name);
+            y = pa_proplist_gets(u->source_output->source->proplist, PA_PROP_DEVICE_DESCRIPTION);
+        } else
+            y = "<unknown>"; /* Probably in the middle of a move */
+        z = pa_proplist_gets(dest->proplist, PA_PROP_DEVICE_DESCRIPTION);
+        pa_proplist_setf(pl, PA_PROP_DEVICE_DESCRIPTION, "%s (echo cancelled with %s)", z ? z : dest->name,
+                         y ? y : u->source_output->source->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);
+}
+
+/* Called from main context */
+static int canceller_process_msg_cb(pa_msgobject *o, int code, void *userdata, int64_t offset, pa_memchunk *chunk) {
+    struct pa_echo_canceller_msg *msg;
+    struct userdata *u;
+
+    pa_assert(o);
+
+    msg = PA_ECHO_CANCELLER_MSG(o);
+
+    /* When the module is unloaded, there may still remain queued messages for
+     * the canceller. Messages are sent to the main thread using the master
+     * source's asyncmsgq, and that message queue isn't (and can't be, at least
+     * with the current asyncmsgq API) cleared from the canceller messages when
+     * module-echo-cancel is unloaded.
+     *
+     * The userdata may already have been freed at this point, but the
+     * asyncmsgq holds a reference to the pa_echo_canceller_msg object, which
+     * contains a flag to indicate that all remaining messages have to be
+     * ignored. */
+    if (msg->dead)
+        return 0;
+
+    u = msg->userdata;
+
+    switch (code) {
+        case ECHO_CANCELLER_MESSAGE_SET_VOLUME: {
+            pa_volume_t v = PA_PTR_TO_UINT(userdata);
+            pa_cvolume vol;
+
+            if (u->use_volume_sharing) {
+                pa_cvolume_set(&vol, u->source->sample_spec.channels, v);
+                pa_source_set_volume(u->source, &vol, true, false);
+            } else {
+                pa_cvolume_set(&vol, u->source_output->sample_spec.channels, v);
+                pa_source_output_set_volume(u->source_output, &vol, false, true);
+            }
+
+            break;
+        }
+
+        default:
+            pa_assert_not_reached();
+            break;
+    }
+
+    return 0;
+}
+
+/* Called by the canceller, so source I/O thread context. */
+pa_volume_t pa_echo_canceller_get_capture_volume(pa_echo_canceller *ec) {
+#ifndef ECHO_CANCEL_TEST
+    return pa_cvolume_avg(&ec->msg->userdata->thread_info.current_volume);
+#else
+    return PA_VOLUME_NORM;
+#endif
+}
+
+/* Called by the canceller, so source I/O thread context. */
+void pa_echo_canceller_set_capture_volume(pa_echo_canceller *ec, pa_volume_t v) {
+#ifndef ECHO_CANCEL_TEST
+    if (pa_cvolume_avg(&ec->msg->userdata->thread_info.current_volume) != v) {
+        pa_asyncmsgq_post(pa_thread_mq_get()->outq, PA_MSGOBJECT(ec->msg), ECHO_CANCELLER_MESSAGE_SET_VOLUME, PA_UINT_TO_PTR(v),
+                0, NULL, NULL);
+    }
+#endif
+}
+
+uint32_t pa_echo_canceller_blocksize_power2(unsigned rate, unsigned ms) {
+    unsigned nframes = (rate * ms) / 1000;
+    uint32_t y = 1 << ((8 * sizeof(uint32_t)) - 2);
+
+    pa_assert(rate >= 4000);
+    pa_assert(ms >= 1);
+
+    /* nframes should be a power of 2, round down to nearest power of two */
+    while (y > nframes)
+        y >>= 1;
+
+    pa_assert(y >= 1);
+    return y;
+}
+
+static pa_echo_canceller_method_t get_ec_method_from_string(const char *method) {
+    if (pa_streq(method, "null"))
+        return PA_ECHO_CANCELLER_NULL;
+#ifdef HAVE_SPEEX
+    if (pa_streq(method, "speex"))
+        return PA_ECHO_CANCELLER_SPEEX;
+#endif
+#ifdef HAVE_ADRIAN_EC
+    if (pa_streq(method, "adrian"))
+        return PA_ECHO_CANCELLER_ADRIAN;
+#endif
+#ifdef HAVE_WEBRTC
+    if (pa_streq(method, "webrtc"))
+        return PA_ECHO_CANCELLER_WEBRTC;
+#endif
+    return PA_ECHO_CANCELLER_INVALID;
+}
+
+/* Common initialisation bits between module-echo-cancel and the standalone
+ * test program.
+ *
+ * Called from main context. */
+static int init_common(pa_modargs *ma, struct userdata *u, pa_sample_spec *source_ss, pa_channel_map *source_map) {
+    const char *ec_string;
+    pa_echo_canceller_method_t ec_method;
+
+    if (pa_modargs_get_sample_spec_and_channel_map(ma, source_ss, source_map, PA_CHANNEL_MAP_DEFAULT) < 0) {
+        pa_log("Invalid sample format specification or channel map");
+        goto fail;
+    }
+
+    u->ec = pa_xnew0(pa_echo_canceller, 1);
+    if (!u->ec) {
+        pa_log("Failed to alloc echo canceller");
+        goto fail;
+    }
+
+    ec_string = pa_modargs_get_value(ma, "aec_method", DEFAULT_ECHO_CANCELLER);
+    if ((ec_method = get_ec_method_from_string(ec_string)) < 0) {
+        pa_log("Invalid echo canceller implementation '%s'", ec_string);
+        goto fail;
+    }
+
+    pa_log_info("Using AEC engine: %s", ec_string);
+
+    u->ec->init = ec_table[ec_method].init;
+    u->ec->play = ec_table[ec_method].play;
+    u->ec->record = ec_table[ec_method].record;
+    u->ec->set_drift = ec_table[ec_method].set_drift;
+    u->ec->run = ec_table[ec_method].run;
+    u->ec->done = ec_table[ec_method].done;
+
+    return 0;
+
+fail:
+    return -1;
+}
+
+/* Called from main context. */
+int pa__init(pa_module*m) {
+    struct userdata *u;
+    pa_sample_spec source_output_ss, source_ss, sink_ss;
+    pa_channel_map source_output_map, source_map, sink_map;
+    pa_modargs *ma;
+    pa_source *source_master=NULL;
+    pa_sink *sink_master=NULL;
+    bool autoloaded;
+    pa_source_output_new_data source_output_data;
+    pa_sink_input_new_data sink_input_data;
+    pa_source_new_data source_data;
+    pa_sink_new_data sink_data;
+    pa_memchunk silence;
+    uint32_t temp;
+    uint32_t nframes = 0;
+    bool use_master_format;
+    pa_usec_t blocksize_usec;
+
+    pa_assert(m);
+
+    if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
+        pa_log("Failed to parse module arguments.");
+        goto fail;
+    }
+
+    if (!(source_master = pa_namereg_get(m->core, pa_modargs_get_value(ma, "source_master", NULL), PA_NAMEREG_SOURCE))) {
+        pa_log("Master source not found");
+        goto fail;
+    }
+    pa_assert(source_master);
+
+    if (!(sink_master = pa_namereg_get(m->core, pa_modargs_get_value(ma, "sink_master", NULL), PA_NAMEREG_SINK))) {
+        pa_log("Master sink not found");
+        goto fail;
+    }
+    pa_assert(sink_master);
+
+    if (source_master->monitor_of == sink_master) {
+        pa_log("Can't cancel echo between a sink and its monitor");
+        goto fail;
+    }
+
+    /* Set to true if we just want to inherit sample spec and channel map from the sink and source master */
+    use_master_format = DEFAULT_USE_MASTER_FORMAT;
+    if (pa_modargs_get_value_boolean(ma, "use_master_format", &use_master_format) < 0) {
+        pa_log("use_master_format= expects a boolean argument");
+        goto fail;
+    }
+
+    source_ss = source_master->sample_spec;
+    sink_ss = sink_master->sample_spec;
+
+    if (use_master_format) {
+        source_map = source_master->channel_map;
+        sink_map = sink_master->channel_map;
+    } else {
+        source_ss = source_master->sample_spec;
+        source_ss.rate = DEFAULT_RATE;
+        source_ss.channels = DEFAULT_CHANNELS;
+        pa_channel_map_init_auto(&source_map, source_ss.channels, PA_CHANNEL_MAP_DEFAULT);
+
+        sink_ss = sink_master->sample_spec;
+        sink_ss.rate = DEFAULT_RATE;
+        sink_ss.channels = DEFAULT_CHANNELS;
+        pa_channel_map_init_auto(&sink_map, sink_ss.channels, PA_CHANNEL_MAP_DEFAULT);
+    }
+
+    u = pa_xnew0(struct userdata, 1);
+    if (!u) {
+        pa_log("Failed to alloc userdata");
+        goto fail;
+    }
+    u->core = m->core;
+    u->module = m;
+    m->userdata = u;
+    u->dead = false;
+
+    u->use_volume_sharing = true;
+    if (pa_modargs_get_value_boolean(ma, "use_volume_sharing", &u->use_volume_sharing) < 0) {
+        pa_log("use_volume_sharing= expects a boolean argument");
+        goto fail;
+    }
+
+    temp = DEFAULT_ADJUST_TIME_USEC / PA_USEC_PER_SEC;
+    if (pa_modargs_get_value_u32(ma, "adjust_time", &temp) < 0) {
+        pa_log("Failed to parse adjust_time value");
+        goto fail;
+    }
+
+    if (temp != DEFAULT_ADJUST_TIME_USEC / PA_USEC_PER_SEC)
+        u->adjust_time = temp * PA_USEC_PER_SEC;
+    else
+        u->adjust_time = DEFAULT_ADJUST_TIME_USEC;
+
+    temp = DEFAULT_ADJUST_TOLERANCE / PA_USEC_PER_MSEC;
+    if (pa_modargs_get_value_u32(ma, "adjust_threshold", &temp) < 0) {
+        pa_log("Failed to parse adjust_threshold value");
+        goto fail;
+    }
+
+    if (temp != DEFAULT_ADJUST_TOLERANCE / PA_USEC_PER_MSEC)
+        u->adjust_threshold = temp * PA_USEC_PER_MSEC;
+    else
+        u->adjust_threshold = DEFAULT_ADJUST_TOLERANCE;
+
+    u->save_aec = DEFAULT_SAVE_AEC;
+    if (pa_modargs_get_value_boolean(ma, "save_aec", &u->save_aec) < 0) {
+        pa_log("Failed to parse save_aec value");
+        goto fail;
+    }
+
+    autoloaded = DEFAULT_AUTOLOADED;
+    if (pa_modargs_get_value_boolean(ma, "autoloaded", &autoloaded) < 0) {
+        pa_log("Failed to parse autoloaded value");
+        goto fail;
+    }
+
+    if (init_common(ma, u, &source_ss, &source_map) < 0)
+        goto fail;
+
+    u->asyncmsgq = pa_asyncmsgq_new(0);
+    if (!u->asyncmsgq) {
+        pa_log("pa_asyncmsgq_new() failed.");
+        goto fail;
+    }
+
+    u->need_realign = true;
+
+    source_output_ss = source_ss;
+    source_output_map = source_map;
+
+    if (sink_ss.rate != source_ss.rate) {
+        pa_log_info("Sample rates of play and out stream differ. Adjusting rate of play stream.");
+        sink_ss.rate = source_ss.rate;
+    }
+
+    pa_assert(u->ec->init);
+    if (!u->ec->init(u->core, u->ec, &source_output_ss, &source_output_map, &sink_ss, &sink_map, &source_ss, &source_map, &nframes, pa_modargs_get_value(ma, "aec_args", NULL))) {
+        pa_log("Failed to init AEC engine");
+        goto fail;
+    }
+
+    pa_assert(source_output_ss.rate == source_ss.rate);
+    pa_assert(sink_ss.rate == source_ss.rate);
+
+    u->source_output_blocksize = nframes * pa_frame_size(&source_output_ss);
+    u->source_blocksize = nframes * pa_frame_size(&source_ss);
+    u->sink_blocksize = nframes * pa_frame_size(&sink_ss);
+
+    if (u->ec->params.drift_compensation)
+        pa_assert(u->ec->set_drift);
+
+    /* Create source */
+    pa_source_new_data_init(&source_data);
+    source_data.driver = __FILE__;
+    source_data.module = m;
+    if (!(source_data.name = pa_xstrdup(pa_modargs_get_value(ma, "source_name", NULL))))
+        source_data.name = pa_sprintf_malloc("%s.echo-cancel", source_master->name);
+    pa_source_new_data_set_sample_spec(&source_data, &source_ss);
+    pa_source_new_data_set_channel_map(&source_data, &source_map);
+    pa_proplist_sets(source_data.proplist, PA_PROP_DEVICE_MASTER_DEVICE, source_master->name);
+    pa_proplist_sets(source_data.proplist, PA_PROP_DEVICE_CLASS, "filter");
+    if (!autoloaded)
+        pa_proplist_sets(source_data.proplist, PA_PROP_DEVICE_INTENDED_ROLES, "phone");
+
+    if (pa_modargs_get_proplist(ma, "source_properties", source_data.proplist, PA_UPDATE_REPLACE) < 0) {
+        pa_log("Invalid properties");
+        pa_source_new_data_done(&source_data);
+        goto fail;
+    }
+
+    if ((u->source_auto_desc = !pa_proplist_contains(source_data.proplist, PA_PROP_DEVICE_DESCRIPTION))) {
+        const char *y, *z;
+
+        y = pa_proplist_gets(sink_master->proplist, PA_PROP_DEVICE_DESCRIPTION);
+        z = pa_proplist_gets(source_master->proplist, PA_PROP_DEVICE_DESCRIPTION);
+        pa_proplist_setf(source_data.proplist, PA_PROP_DEVICE_DESCRIPTION, "%s (echo cancelled with %s)",
+                z ? z : source_master->name, y ? y : sink_master->name);
+    }
+
+    u->source = pa_source_new(m->core, &source_data, (source_master->flags & (PA_SOURCE_LATENCY | PA_SOURCE_DYNAMIC_LATENCY))
+                                                     | (u->use_volume_sharing ? PA_SOURCE_SHARE_VOLUME_WITH_MASTER : 0));
+    pa_source_new_data_done(&source_data);
+
+    if (!u->source) {
+        pa_log("Failed to create source.");
+        goto fail;
+    }
+
+    u->source->parent.process_msg = source_process_msg_cb;
+    u->source->set_state_in_main_thread = source_set_state_in_main_thread_cb;
+    u->source->update_requested_latency = source_update_requested_latency_cb;
+    pa_source_set_set_mute_callback(u->source, source_set_mute_cb);
+    if (!u->use_volume_sharing) {
+        pa_source_set_get_volume_callback(u->source, source_get_volume_cb);
+        pa_source_set_set_volume_callback(u->source, source_set_volume_cb);
+        pa_source_enable_decibel_volume(u->source, true);
+    }
+    u->source->userdata = u;
+
+    pa_source_set_asyncmsgq(u->source, source_master->asyncmsgq);
+
+    /* 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.echo-cancel", sink_master->name);
+    pa_sink_new_data_set_sample_spec(&sink_data, &sink_ss);
+    pa_sink_new_data_set_channel_map(&sink_data, &sink_map);
+    pa_proplist_sets(sink_data.proplist, PA_PROP_DEVICE_MASTER_DEVICE, sink_master->name);
+    pa_proplist_sets(sink_data.proplist, PA_PROP_DEVICE_CLASS, "filter");
+    if (!autoloaded)
+        pa_proplist_sets(sink_data.proplist, PA_PROP_DEVICE_INTENDED_ROLES, "phone");
+
+    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->sink_auto_desc = !pa_proplist_contains(sink_data.proplist, PA_PROP_DEVICE_DESCRIPTION))) {
+        const char *y, *z;
+
+        y = pa_proplist_gets(source_master->proplist, PA_PROP_DEVICE_DESCRIPTION);
+        z = pa_proplist_gets(sink_master->proplist, PA_PROP_DEVICE_DESCRIPTION);
+        pa_proplist_setf(sink_data.proplist, PA_PROP_DEVICE_DESCRIPTION, "%s (echo cancelled with %s)",
+                z ? z : sink_master->name, y ? y : source_master->name);
+    }
+
+    u->sink = pa_sink_new(m->core, &sink_data, (sink_master->flags & (PA_SINK_LATENCY | PA_SINK_DYNAMIC_LATENCY))
+                                               | (u->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 (!u->use_volume_sharing) {
+        pa_sink_set_set_volume_callback(u->sink, sink_set_volume_cb);
+        pa_sink_enable_decibel_volume(u->sink, true);
+    }
+    u->sink->userdata = u;
+
+    pa_sink_set_asyncmsgq(u->sink, sink_master->asyncmsgq);
+
+    /* Create source output */
+    pa_source_output_new_data_init(&source_output_data);
+    source_output_data.driver = __FILE__;
+    source_output_data.module = m;
+    pa_source_output_new_data_set_source(&source_output_data, source_master, false, true);
+    source_output_data.destination_source = u->source;
+
+    pa_proplist_sets(source_output_data.proplist, PA_PROP_MEDIA_NAME, "Echo-Cancel Source Stream");
+    pa_proplist_sets(source_output_data.proplist, PA_PROP_MEDIA_ROLE, "filter");
+    pa_source_output_new_data_set_sample_spec(&source_output_data, &source_output_ss);
+    pa_source_output_new_data_set_channel_map(&source_output_data, &source_output_map);
+    source_output_data.flags |= PA_SOURCE_OUTPUT_START_CORKED;
+
+    if (autoloaded)
+        source_output_data.flags |= PA_SOURCE_OUTPUT_DONT_MOVE;
+
+    pa_source_output_new(&u->source_output, m->core, &source_output_data);
+    pa_source_output_new_data_done(&source_output_data);
+
+    if (!u->source_output)
+        goto fail;
+
+    u->source_output->parent.process_msg = source_output_process_msg_cb;
+    u->source_output->push = source_output_push_cb;
+    u->source_output->process_rewind = source_output_process_rewind_cb;
+    u->source_output->update_max_rewind = source_output_update_max_rewind_cb;
+    u->source_output->update_source_requested_latency = source_output_update_source_requested_latency_cb;
+    u->source_output->update_source_latency_range = source_output_update_source_latency_range_cb;
+    u->source_output->update_source_fixed_latency = source_output_update_source_fixed_latency_cb;
+    u->source_output->kill = source_output_kill_cb;
+    u->source_output->attach = source_output_attach_cb;
+    u->source_output->detach = source_output_detach_cb;
+    u->source_output->state_change = source_output_state_change_cb;
+    u->source_output->may_move_to = source_output_may_move_to_cb;
+    u->source_output->moving = source_output_moving_cb;
+    u->source_output->userdata = u;
+
+    u->source->output_from_master = u->source_output;
+
+    /* 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, sink_master, false, true);
+    sink_input_data.origin_sink = u->sink;
+    pa_proplist_sets(sink_input_data.proplist, PA_PROP_MEDIA_NAME, "Echo-Cancel Sink Stream");
+    pa_proplist_sets(sink_input_data.proplist, PA_PROP_MEDIA_ROLE, "filter");
+    pa_sink_input_new_data_set_sample_spec(&sink_input_data, &sink_ss);
+    pa_sink_input_new_data_set_channel_map(&sink_input_data, &sink_map);
+    sink_input_data.flags = PA_SINK_INPUT_VARIABLE_RATE | PA_SINK_INPUT_START_CORKED;
+
+    if (autoloaded)
+        sink_input_data.flags |= PA_SINK_INPUT_DONT_MOVE;
+
+    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->parent.process_msg = sink_input_process_msg_cb;
+    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_requested_latency = sink_input_update_sink_requested_latency_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->state_change = sink_input_state_change_cb;
+    u->sink_input->may_move_to = sink_input_may_move_to_cb;
+    u->sink_input->moving = sink_input_moving_cb;
+    if (!u->use_volume_sharing)
+        u->sink_input->volume_changed = 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->source_memblockq = pa_memblockq_new("module-echo-cancel source_memblockq", 0, MEMBLOCKQ_MAXLENGTH, 0,
+        &source_output_ss, 1, 1, 0, &silence);
+    u->sink_memblockq = pa_memblockq_new("module-echo-cancel sink_memblockq", 0, MEMBLOCKQ_MAXLENGTH, 0,
+        &sink_ss, 0, 1, 0, &silence);
+
+    pa_memblock_unref(silence.memblock);
+
+    if (!u->source_memblockq || !u->sink_memblockq) {
+        pa_log("Failed to create memblockq.");
+        goto fail;
+    }
+
+    if (u->adjust_time > 0 && !u->ec->params.drift_compensation)
+        u->time_event = pa_core_rttime_new(m->core, pa_rtclock_now() + u->adjust_time, time_callback, u);
+    else if (u->ec->params.drift_compensation) {
+        pa_log_info("Canceller does drift compensation -- built-in compensation will be disabled");
+        u->adjust_time = 0;
+        /* Perform resync just once to give the canceller a leg up */
+        pa_atomic_store(&u->request_resync, 1);
+    }
+
+    if (u->save_aec) {
+        pa_log("Creating AEC files in /tmp");
+        u->captured_file = fopen("/tmp/aec_rec.sw", "wb");
+        if (u->captured_file == NULL)
+            perror ("fopen failed");
+        u->played_file = fopen("/tmp/aec_play.sw", "wb");
+        if (u->played_file == NULL)
+            perror ("fopen failed");
+        u->canceled_file = fopen("/tmp/aec_out.sw", "wb");
+        if (u->canceled_file == NULL)
+            perror ("fopen failed");
+        if (u->ec->params.drift_compensation) {
+            u->drift_file = fopen("/tmp/aec_drift.txt", "w");
+            if (u->drift_file == NULL)
+                perror ("fopen failed");
+        }
+    }
+
+    u->ec->msg = pa_msgobject_new(pa_echo_canceller_msg);
+    u->ec->msg->parent.process_msg = canceller_process_msg_cb;
+    u->ec->msg->userdata = u;
+
+    u->thread_info.current_volume = u->source->reference_volume;
+
+    /* We don't want to deal with too many chunks at a time */
+    blocksize_usec = pa_bytes_to_usec(u->source_blocksize, &u->source->sample_spec);
+    if (u->source->flags & PA_SOURCE_DYNAMIC_LATENCY)
+        pa_source_set_latency_range(u->source, blocksize_usec, blocksize_usec * MAX_LATENCY_BLOCKS);
+    pa_source_output_set_requested_latency(u->source_output, blocksize_usec * MAX_LATENCY_BLOCKS);
+
+    blocksize_usec = pa_bytes_to_usec(u->sink_blocksize, &u->sink->sample_spec);
+    if (u->sink->flags & PA_SINK_DYNAMIC_LATENCY)
+        pa_sink_set_latency_range(u->sink, blocksize_usec, blocksize_usec * MAX_LATENCY_BLOCKS);
+    pa_sink_input_set_requested_latency(u->sink_input, blocksize_usec * MAX_LATENCY_BLOCKS);
+
+    /* The order here is important. The input/output must be put first,
+     * otherwise streams might attach to the sink/source before the
+     * sink input or source output is attached to the master. */
+    pa_sink_input_put(u->sink_input);
+    pa_source_output_put(u->source_output);
+
+    pa_sink_put(u->sink);
+    pa_source_put(u->source);
+
+    pa_source_output_cork(u->source_output, false);
+    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;
+}
+
+/* Called from main context. */
+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) + pa_source_linked_by(u->source);
+}
+
+/* Called from main context. */
+void pa__done(pa_module*m) {
+    struct userdata *u;
+
+    pa_assert(m);
+
+    if (!(u = m->userdata))
+        return;
+
+    u->dead = true;
+
+    /* See comments in source_output_kill_cb() above regarding
+     * destruction order! */
+
+    if (u->time_event)
+        u->core->mainloop->time_free(u->time_event);
+
+    if (u->source_output)
+        pa_source_output_cork(u->source_output, true);
+    if (u->sink_input)
+        pa_sink_input_cork(u->sink_input, true);
+
+    if (u->source)
+        pa_source_unlink(u->source);
+    if (u->sink)
+        pa_sink_unlink(u->sink);
+
+    if (u->source_output) {
+        pa_source_output_unlink(u->source_output);
+        pa_source_output_unref(u->source_output);
+    }
+
+    if (u->sink_input) {
+        pa_sink_input_unlink(u->sink_input);
+        pa_sink_input_unref(u->sink_input);
+    }
+
+    if (u->source)
+        pa_source_unref(u->source);
+    if (u->sink)
+        pa_sink_unref(u->sink);
+
+    if (u->source_memblockq)
+        pa_memblockq_free(u->source_memblockq);
+    if (u->sink_memblockq)
+        pa_memblockq_free(u->sink_memblockq);
+
+    if (u->ec) {
+        if (u->ec->done)
+            u->ec->done(u->ec);
+
+        if (u->ec->msg) {
+            u->ec->msg->dead = true;
+            pa_echo_canceller_msg_unref(u->ec->msg);
+        }
+
+        pa_xfree(u->ec);
+    }
+
+    if (u->asyncmsgq)
+        pa_asyncmsgq_unref(u->asyncmsgq);
+
+    if (u->save_aec) {
+        if (u->played_file)
+            fclose(u->played_file);
+        if (u->captured_file)
+            fclose(u->captured_file);
+        if (u->canceled_file)
+            fclose(u->canceled_file);
+        if (u->drift_file)
+            fclose(u->drift_file);
+    }
+
+    pa_xfree(u);
+}
+
+#ifdef ECHO_CANCEL_TEST
+/*
+ * Stand-alone test program for running in the canceller on pre-recorded files.
+ */
+int main(int argc, char* argv[]) {
+    struct userdata u;
+    pa_sample_spec source_output_ss, source_ss, sink_ss;
+    pa_channel_map source_output_map, source_map, sink_map;
+    pa_modargs *ma = NULL;
+    uint8_t *rdata = NULL, *pdata = NULL, *cdata = NULL;
+    int unused PA_GCC_UNUSED;
+    int ret = 0, i;
+    char c;
+    float drift;
+    uint32_t nframes;
+
+    if (!getenv("MAKE_CHECK"))
+        pa_log_set_level(PA_LOG_DEBUG);
+
+    pa_memzero(&u, sizeof(u));
+
+    if (argc < 4 || argc > 7) {
+        goto usage;
+    }
+
+    u.captured_file = fopen(argv[2], "rb");
+    if (u.captured_file == NULL) {
+        perror ("Could not open capture file");
+        goto fail;
+    }
+    u.played_file = fopen(argv[1], "rb");
+    if (u.played_file == NULL) {
+        perror ("Could not open play file");
+        goto fail;
+    }
+    u.canceled_file = fopen(argv[3], "wb");
+    if (u.canceled_file == NULL) {
+        perror ("Could not open canceled file");
+        goto fail;
+    }
+
+    u.core = pa_xnew0(pa_core, 1);
+    u.core->cpu_info.cpu_type = PA_CPU_X86;
+    u.core->cpu_info.flags.x86 |= PA_CPU_X86_SSE;
+
+    if (!(ma = pa_modargs_new(argc > 4 ? argv[4] : NULL, valid_modargs))) {
+        pa_log("Failed to parse module arguments.");
+        goto fail;
+    }
+
+    source_ss.format = PA_SAMPLE_FLOAT32LE;
+    source_ss.rate = DEFAULT_RATE;
+    source_ss.channels = DEFAULT_CHANNELS;
+    pa_channel_map_init_auto(&source_map, source_ss.channels, PA_CHANNEL_MAP_DEFAULT);
+
+    sink_ss.format = PA_SAMPLE_FLOAT32LE;
+    sink_ss.rate = DEFAULT_RATE;
+    sink_ss.channels = DEFAULT_CHANNELS;
+    pa_channel_map_init_auto(&sink_map, sink_ss.channels, PA_CHANNEL_MAP_DEFAULT);
+
+    if (init_common(ma, &u, &source_ss, &source_map) < 0)
+        goto fail;
+
+    source_output_ss = source_ss;
+    source_output_map = source_map;
+
+    if (!u.ec->init(u.core, u.ec, &source_output_ss, &source_output_map, &sink_ss, &sink_map, &source_ss, &source_map, &nframes,
+                     pa_modargs_get_value(ma, "aec_args", NULL))) {
+        pa_log("Failed to init AEC engine");
+        goto fail;
+    }
+    u.source_output_blocksize = nframes * pa_frame_size(&source_output_ss);
+    u.source_blocksize = nframes * pa_frame_size(&source_ss);
+    u.sink_blocksize = nframes * pa_frame_size(&sink_ss);
+
+    if (u.ec->params.drift_compensation) {
+        if (argc < 6) {
+            pa_log("Drift compensation enabled but drift file not specified");
+            goto fail;
+        }
+
+        u.drift_file = fopen(argv[5], "rt");
+
+        if (u.drift_file == NULL) {
+            perror ("Could not open drift file");
+            goto fail;
+        }
+    }
+
+    rdata = pa_xmalloc(u.source_output_blocksize);
+    pdata = pa_xmalloc(u.sink_blocksize);
+    cdata = pa_xmalloc(u.source_blocksize);
+
+    if (!u.ec->params.drift_compensation) {
+        while (fread(rdata, u.source_output_blocksize, 1, u.captured_file) > 0) {
+            if (fread(pdata, u.sink_blocksize, 1, u.played_file) == 0) {
+                perror("Played file ended before captured file");
+                goto fail;
+            }
+
+            u.ec->run(u.ec, rdata, pdata, cdata);
+
+            unused = fwrite(cdata, u.source_blocksize, 1, u.canceled_file);
+        }
+    } else {
+        while (fscanf(u.drift_file, "%c", &c) > 0) {
+            switch (c) {
+                case 'd':
+                    if (!fscanf(u.drift_file, "%a", &drift)) {
+                        perror("Drift file incomplete");
+                        goto fail;
+                    }
+
+                    u.ec->set_drift(u.ec, drift);
+
+                    break;
+
+                case 'c':
+                    if (!fscanf(u.drift_file, "%d", &i)) {
+                        perror("Drift file incomplete");
+                        goto fail;
+                    }
+
+                    if (fread(rdata, i, 1, u.captured_file) <= 0) {
+                        perror("Captured file ended prematurely");
+                        goto fail;
+                    }
+
+                    u.ec->record(u.ec, rdata, cdata);
+
+                    unused = fwrite(cdata, i, 1, u.canceled_file);
+
+                    break;
+
+                case 'p':
+                    if (!fscanf(u.drift_file, "%d", &i)) {
+                        perror("Drift file incomplete");
+                        goto fail;
+                    }
+
+                    if (fread(pdata, i, 1, u.played_file) <= 0) {
+                        perror("Played file ended prematurely");
+                        goto fail;
+                    }
+
+                    u.ec->play(u.ec, pdata);
+
+                    break;
+            }
+        }
+
+        if (fread(rdata, i, 1, u.captured_file) > 0)
+            pa_log("All capture data was not consumed");
+        if (fread(pdata, i, 1, u.played_file) > 0)
+            pa_log("All playback data was not consumed");
+    }
+
+    u.ec->done(u.ec);
+    u.ec->msg->dead = true;
+    pa_echo_canceller_msg_unref(u.ec->msg);
+
+out:
+    if (u.captured_file)
+        fclose(u.captured_file);
+    if (u.played_file)
+        fclose(u.played_file);
+    if (u.canceled_file)
+        fclose(u.canceled_file);
+    if (u.drift_file)
+        fclose(u.drift_file);
+
+    pa_xfree(rdata);
+    pa_xfree(pdata);
+    pa_xfree(cdata);
+
+    pa_xfree(u.ec);
+    pa_xfree(u.core);
+
+    if (ma)
+        pa_modargs_free(ma);
+
+    return ret;
+
+usage:
+    pa_log("Usage: %s play_file rec_file out_file [module args] [drift_file]", argv[0]);
+
+fail:
+    ret = -1;
+    goto out;
+}
+#endif /* ECHO_CANCEL_TEST */