X-Git-Url: https://code.delx.au/pulseaudio/blobdiff_plain/0429fe61537e1f3f184f16f9d7c128d159e41c7d..c93cfc1ca64a3d7e37a3ca63f42abb73ce72bfb6:/src/modules/echo-cancel/module-echo-cancel.c

diff --git a/src/modules/echo-cancel/module-echo-cancel.c b/src/modules/echo-cancel/module-echo-cancel.c
index 9ecd7878..9df2899d 100644
--- a/src/modules/echo-cancel/module-echo-cancel.c
+++ b/src/modules/echo-cancel/module-echo-cancel.c
@@ -31,6 +31,7 @@
 #endif
 
 #include <stdio.h>
+#include <math.h>
 
 #include "echo-cancel.h"
 
@@ -57,7 +58,7 @@
 PA_MODULE_AUTHOR("Wim Taymans");
 PA_MODULE_DESCRIPTION("Echo Cancellation");
 PA_MODULE_VERSION(PACKAGE_VERSION);
-PA_MODULE_LOAD_ONCE(FALSE);
+PA_MODULE_LOAD_ONCE(false);
 PA_MODULE_USAGE(
         _("source_name=<name for the source> "
           "source_properties=<properties for the source> "
@@ -66,6 +67,7 @@ PA_MODULE_USAGE(
           "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> "
@@ -80,35 +82,73 @@ PA_MODULE_USAGE(
 /* NOTE: Make sure the enum and ec_table are maintained in the correct order */
 typedef enum {
     PA_ECHO_CANCELLER_INVALID = -1,
-    PA_ECHO_CANCELLER_SPEEX = 0,
+    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_SAVE_AEC FALSE
-#define DEFAULT_AUTOLOADED FALSE
+#define DEFAULT_ADJUST_TOLERANCE (5*PA_USEC_PER_MSEC)
+#define DEFAULT_SAVE_AEC false
+#define DEFAULT_AUTOLOADED false
 
 #define MEMBLOCKQ_MAXLENGTH (16*1024*1024)
 
+/* Can only be used in main context */
+#define IS_ACTIVE(u) ((pa_source_get_state((u)->source) == PA_SOURCE_RUNNING) && \
+                      (pa_sink_get_state((u)->sink) == 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
@@ -131,13 +171,23 @@ static const pa_echo_canceller ec_table[] = {
  *    samples (because else the echo canceler 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
+ * 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;
+    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;
@@ -156,42 +206,55 @@ struct userdata {
     pa_core *core;
     pa_module *module;
 
-    pa_bool_t autoloaded;
-    pa_bool_t dead;
-    pa_bool_t save_aec;
+    bool autoloaded;
+    bool dead;
+    bool save_aec;
 
     pa_echo_canceller *ec;
-    uint32_t blocksize;
+    uint32_t source_output_blocksize;
+    uint32_t source_blocksize;
+    uint32_t sink_blocksize;
 
-    pa_bool_t need_realign;
+    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;
-    pa_bool_t source_auto_desc;
+    bool source_auto_desc;
     pa_source_output *source_output;
     pa_memblockq *source_memblockq; /* echo canceler needs fixed sized chunks */
     size_t source_skip;
 
     pa_sink *sink;
-    pa_bool_t sink_auto_desc;
+    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;
 
-    int active_mask;
     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);
@@ -204,6 +267,7 @@ static const char* const valid_modargs[] = {
     "sink_properties",
     "sink_master",
     "adjust_time",
+    "adjust_threshold",
     "format",
     "rate",
     "channels",
@@ -227,35 +291,43 @@ enum {
     SINK_INPUT_MESSAGE_LATENCY_SNAPSHOT
 };
 
-static int64_t calc_diff(struct userdata *u, struct snapshot *snapshot) {
-    int64_t buffer, diff_time, buffer_latency;
+enum {
+    ECHO_CANCELLER_MESSAGE_SET_VOLUME,
+};
 
-    /* get the number of samples between capture and playback */
-    if (snapshot->plen > snapshot->rlen)
-        buffer = snapshot->plen - snapshot->rlen;
+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 = 0;
+        buffer_latency = 0;
 
-    buffer += snapshot->source_delay + snapshot->sink_delay;
+    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 amount of samples not yet transferred to the source context */
-    if (snapshot->recv_counter <= snapshot->send_counter)
-        buffer += (int64_t) (snapshot->send_counter - snapshot->recv_counter);
+    /* 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 += PA_CLIP_SUB(buffer, (int64_t) (snapshot->recv_counter - snapshot->send_counter));
+        buffer_latency += PA_CLIP_SUB(buffer_latency, (int64_t) (recv_counter - send_counter));
 
-    /* convert to time */
-    buffer_latency = pa_bytes_to_usec(buffer, &u->source_output->sample_spec);
-
-    /* capture and playback samples are perfectly aligned when diff_time is 0 */
+    /* 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,
+    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) snapshot->source_delay, (long long) snapshot->sink_delay,
-        (long long) (snapshot->send_counter - snapshot->recv_counter),
+        (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;
@@ -274,7 +346,7 @@ static void time_callback(pa_mainloop_api *a, pa_time_event *e, const struct tim
     pa_assert(u->time_event == e);
     pa_assert_ctl_context();
 
-    if (u->active_mask != 3)
+    if (!IS_ACTIVE(u))
         return;
 
     /* update our snapshots */
@@ -297,7 +369,7 @@ static void time_callback(pa_mainloop_api *a, pa_time_event *e, const struct tim
         new_rate = base_rate;
     }
     else {
-        if (diff_time > 1000) {
+        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);
@@ -347,10 +419,13 @@ static int source_process_msg_cb(pa_msgobject *o, int code, void *data, int64_t
                 /* 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->blocksize, &u->source_output->source->sample_spec);
+                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);
@@ -387,7 +462,6 @@ static int sink_process_msg_cb(pa_msgobject *o, int code, void *data, int64_t of
     return pa_sink_process_msg(o, code, data, offset, chunk);
 }
 
-
 /* Called from main context */
 static int source_set_state_cb(pa_source *s, pa_source_state_t state) {
     struct userdata *u;
@@ -399,20 +473,17 @@ static int source_set_state_cb(pa_source *s, pa_source_state_t state) {
         !PA_SOURCE_OUTPUT_IS_LINKED(pa_source_output_get_state(u->source_output)))
         return 0;
 
-    pa_log_debug("Source state %d %d", state, u->active_mask);
-
     if (state == PA_SOURCE_RUNNING) {
         /* restart timer when both sink and source are active */
-        u->active_mask |= 1;
-        if (u->active_mask == 3 && u->adjust_time)
+        if (IS_ACTIVE(u) && 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);
+        pa_source_output_cork(u->source_output, false);
     } else if (state == PA_SOURCE_SUSPENDED) {
-        u->active_mask &= ~1;
-        pa_source_output_cork(u->source_output, TRUE);
+        pa_source_output_cork(u->source_output, true);
     }
+
     return 0;
 }
 
@@ -427,24 +498,21 @@ static int sink_set_state_cb(pa_sink *s, pa_sink_state_t state) {
         !PA_SINK_INPUT_IS_LINKED(pa_sink_input_get_state(u->sink_input)))
         return 0;
 
-    pa_log_debug("Sink state %d %d", state, u->active_mask);
-
     if (state == PA_SINK_RUNNING) {
         /* restart timer when both sink and source are active */
-        u->active_mask |= 2;
-        if (u->active_mask == 3 && u->adjust_time)
+        if (IS_ACTIVE(u) && 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);
+        pa_sink_input_cork(u->sink_input, false);
     } else if (state == PA_SINK_SUSPENDED) {
-        u->active_mask &= ~2;
-        pa_sink_input_cork(u->sink_input, TRUE);
+        pa_sink_input_cork(u->sink_input, true);
     }
+
     return 0;
 }
 
-/* Called from I/O thread context */
+/* Called from source I/O thread context */
 static void source_update_requested_latency_cb(pa_source *s) {
     struct userdata *u;
 
@@ -463,7 +531,7 @@ static void source_update_requested_latency_cb(pa_source *s) {
             pa_source_get_requested_latency_within_thread(s));
 }
 
-/* Called from I/O thread context */
+/* Called from sink I/O thread context */
 static void sink_update_requested_latency_cb(pa_sink *s) {
     struct userdata *u;
 
@@ -482,7 +550,7 @@ static void sink_update_requested_latency_cb(pa_sink *s) {
             pa_sink_get_requested_latency_within_thread(s));
 }
 
-/* Called from I/O thread context */
+/* Called from sink I/O thread context */
 static void sink_request_rewind_cb(pa_sink *s) {
     struct userdata *u;
 
@@ -497,7 +565,7 @@ static void sink_request_rewind_cb(pa_sink *s) {
 
     /* 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);
+                                 s->thread_info.rewind_nbytes, true, false, false);
 }
 
 /* Called from main context */
@@ -511,7 +579,7 @@ static void source_set_volume_cb(pa_source *s) {
         !PA_SOURCE_OUTPUT_IS_LINKED(pa_source_output_get_state(u->source_output)))
         return;
 
-    pa_source_output_set_volume(u->source_output, &s->real_volume, s->save_volume, TRUE);
+    pa_source_output_set_volume(u->source_output, &s->real_volume, s->save_volume, true);
 }
 
 /* Called from main context */
@@ -525,9 +593,10 @@ static void sink_set_volume_cb(pa_sink *s) {
         !PA_SINK_INPUT_IS_LINKED(pa_sink_input_get_state(u->sink_input)))
         return;
 
-    pa_sink_input_set_volume(u->sink_input, &s->real_volume, s->save_volume, TRUE);
+    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;
@@ -539,7 +608,7 @@ static void source_get_volume_cb(pa_source *s) {
         !PA_SOURCE_OUTPUT_IS_LINKED(pa_source_output_get_state(u->source_output)))
         return;
 
-    pa_source_output_get_volume(u->source_output, &v, TRUE);
+    pa_source_output_get_volume(u->source_output, &v, true);
 
     if (pa_cvolume_equal(&s->real_volume, &v))
         /* no change */
@@ -577,31 +646,17 @@ static void sink_set_mute_cb(pa_sink *s) {
     pa_sink_input_set_mute(u->sink_input, s->muted, s->save_muted);
 }
 
-/* Called from main context */
-static void source_get_mute_cb(pa_source *s) {
-    struct userdata *u;
-
-    pa_source_assert_ref(s);
-    pa_assert_se(u = s->userdata);
-
-    if (!PA_SOURCE_IS_LINKED(pa_source_get_state(s)) ||
-        !PA_SOURCE_OUTPUT_IS_LINKED(pa_source_output_get_state(u->source_output)))
-        return;
-
-    pa_source_output_get_mute(u->source_output);
-}
-
-/* must be called from the input thread context */
+/* 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->source_output->sample_spec);
+        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->source_output->sample_spec);
+            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);
 
@@ -612,7 +667,7 @@ static void apply_diff_time(struct userdata *u, int64_t diff_time) {
         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);
+            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;
@@ -620,7 +675,7 @@ static void apply_diff_time(struct userdata *u, int64_t diff_time) {
     }
 }
 
-/* must be called from the input thread */
+/* Called from source I/O thread context. */
 static void do_resync(struct userdata *u) {
     int64_t diff_time;
     struct snapshot latency_snapshot;
@@ -638,17 +693,195 @@ static void do_resync(struct userdata *u) {
     apply_diff_time(u, diff_time);
 }
 
-/* Called from input thread context */
+/* 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;
+
+    /* Now let the canceller work its drift compensation magic */
+    u->ec->set_drift(u->ec, drift);
+
+    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->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.
+ *
+ * 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;
+    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_OUTPUT_IS_LINKED(pa_source_output_get_state(u->source_output))) {
-        pa_log("push when no link?");
+        pa_log("Push when no link?");
+        return;
+    }
+
+    if (PA_UNLIKELY(u->source->thread_info.state != PA_SOURCE_RUNNING ||
+                    u->sink->thread_info.state != PA_SINK_RUNNING)) {
+        pa_source_post(u->source, chunk);
         return;
     }
 
@@ -656,106 +889,66 @@ static void source_output_push_cb(pa_source_output *o, const pa_memchunk *chunk)
     while (pa_asyncmsgq_process_one(u->asyncmsgq) > 0)
         ;
 
-    if (pa_atomic_cmpxchg (&u->request_resync, 1, 0)) {
-        do_resync(u);
-    }
-
     pa_memblockq_push_align(u->source_memblockq, chunk);
 
     rlen = pa_memblockq_get_length(u->source_memblockq);
     plen = pa_memblockq_get_length(u->sink_memblockq);
 
-    while (rlen >= u->blocksize) {
-        pa_memchunk rchunk, pchunk;
-
-        /* take fixed block from recorded samples */
-        pa_memblockq_peek_fixed_size(u->source_memblockq, u->blocksize, &rchunk);
-
-        if (plen > u->blocksize && u->source_skip == 0) {
-            uint8_t *rdata, *pdata, *cdata;
-            pa_memchunk cchunk;
-            int unused;
-
-            if (u->sink_skip) {
-                size_t to_skip;
-
-                if (u->sink_skip > plen)
-                    to_skip = plen;
-                else
-                    to_skip = u->sink_skip;
+    /* Let's not do anything else till we have enough data to process */
+    if (rlen < u->source_output_blocksize)
+        return;
 
-                pa_memblockq_drop(u->sink_memblockq, to_skip);
-                plen -= to_skip;
+    /* See if we need to drop samples in order to sync */
+    if (pa_atomic_cmpxchg (&u->request_resync, 1, 0)) {
+        do_resync(u);
+    }
 
-                u->sink_skip -= to_skip;
-            }
+    /* 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 (plen > u->blocksize && u->sink_skip == 0) {
-                /* take fixed block from played samples */
-                pa_memblockq_peek_fixed_size(u->sink_memblockq, u->blocksize, &pchunk);
-
-                rdata = pa_memblock_acquire(rchunk.memblock);
-                rdata += rchunk.index;
-                pdata = pa_memblock_acquire(pchunk.memblock);
-                pdata += pchunk.index;
-
-                cchunk.index = 0;
-                cchunk.length = u->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->blocksize, u->captured_file);
-                    if (u->played_file)
-                        unused = fwrite(pdata, 1, u->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->blocksize, u->canceled_file);
-                }
-
-                pa_memblock_release(cchunk.memblock);
-                pa_memblock_release(pchunk.memblock);
-                pa_memblock_release(rchunk.memblock);
-
-                /* drop consumed sink samples */
-                pa_memblockq_drop(u->sink_memblockq, u->blocksize);
-                pa_memblock_unref(pchunk.memblock);
-
-                pa_memblock_unref(rchunk.memblock);
-                /* the filtered samples now become the samples from our
-                 * source */
-                rchunk = cchunk;
-
-                plen -= u->blocksize;
-            }
+        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);
         }
+    }
 
-        /* forward the (echo-canceled) data to the virtual source */
-        pa_source_post(u->source, &rchunk);
-        pa_memblock_unref(rchunk.memblock);
+    /* 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->source_memblockq, u->blocksize);
-        rlen -= u->blocksize;
+        pa_memblockq_drop(u->sink_memblockq, to_skip);
 
-        if (u->source_skip) {
-            if (u->source_skip > u->blocksize) {
-                u->source_skip -= u->blocksize;
-            }
-            else {
-                u->sink_skip += (u->blocksize - u->source_skip);
-                u->source_skip = 0;
-            }
-        }
+        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 I/O thread context */
+/* 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;
 
@@ -782,7 +975,7 @@ static int sink_input_pop_cb(pa_sink_input *i, size_t nbytes, pa_memchunk *chunk
     return 0;
 }
 
-/* Called from input thread context */
+/* Called from source I/O thread context. */
 static void source_output_process_rewind_cb(pa_source_output *o, size_t nbytes) {
     struct userdata *u;
 
@@ -796,13 +989,13 @@ static void source_output_process_rewind_cb(pa_source_output *o, size_t nbytes)
     pa_memblockq_rewind(u->sink_memblockq, nbytes);
 
     /* manipulate write index */
-    pa_memblockq_seek(u->source_memblockq, -nbytes, PA_SEEK_RELATIVE, TRUE);
+    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 I/O thread context */
+/* Called from sink I/O thread context. */
 static void sink_input_process_rewind_cb(pa_sink_input *i, size_t nbytes) {
     struct userdata *u;
 
@@ -817,6 +1010,7 @@ static void sink_input_process_rewind_cb(pa_sink_input *i, size_t nbytes) {
     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;
@@ -837,8 +1031,7 @@ static void source_output_snapshot_within_thread(struct userdata *u, struct snap
     snapshot->plen = plen + u->source_skip;
 }
 
-
-/* Called from output thread context */
+/* 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;
 
@@ -848,10 +1041,10 @@ static int source_output_process_msg_cb(pa_msgobject *obj, int code, void *data,
 
             pa_source_output_assert_io_context(u->source_output);
 
-            if (PA_SOURCE_IS_OPENED(u->source_output->source->thread_info.state))
+            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);
+                pa_memblockq_flush_write(u->sink_memblockq, true);
 
             u->recv_counter += (int64_t) chunk->length;
 
@@ -862,9 +1055,9 @@ static int source_output_process_msg_cb(pa_msgobject *obj, int code, void *data,
 
             /* 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);
+                pa_memblockq_seek(u->sink_memblockq, -offset, PA_SEEK_RELATIVE, true);
             else
-                pa_memblockq_flush_write(u->sink_memblockq, TRUE);
+                pa_memblockq_flush_write(u->sink_memblockq, true);
 
             pa_log_debug("Sink rewind (%lld)", (long long) offset);
 
@@ -888,6 +1081,7 @@ static int source_output_process_msg_cb(pa_msgobject *obj, int code, void *data,
     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;
 
@@ -917,7 +1111,7 @@ static int sink_input_process_msg_cb(pa_msgobject *obj, int code, void *data, in
     return pa_sink_input_process_msg(obj, code, data, offset, chunk);
 }
 
-/* Called from I/O thread context */
+/* 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;
 
@@ -926,11 +1120,13 @@ static void sink_input_update_max_rewind_cb(pa_sink_input *i, size_t nbytes) {
 
     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 I/O thread context */
+/* 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;
 
@@ -942,7 +1138,7 @@ static void source_output_update_max_rewind_cb(pa_source_output *o, size_t nbyte
     pa_source_set_max_rewind_within_thread(u->source, nbytes);
 }
 
-/* Called from I/O thread context */
+/* 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;
 
@@ -954,7 +1150,7 @@ static void sink_input_update_max_request_cb(pa_sink_input *i, size_t nbytes) {
     pa_sink_set_max_request_within_thread(u->sink, nbytes);
 }
 
-/* Called from I/O thread context */
+/* 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;
@@ -967,7 +1163,7 @@ static void sink_input_update_sink_requested_latency_cb(pa_sink_input *i) {
     pa_log_debug("Sink input update requested latency %lld", (long long) latency);
 }
 
-/* Called from I/O thread context */
+/* 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;
@@ -977,10 +1173,10 @@ static void source_output_update_source_requested_latency_cb(pa_source_output *o
 
     latency = pa_source_get_requested_latency_within_thread(o->source);
 
-    pa_log_debug("source output update requested latency %lld", (long long) latency);
+    pa_log_debug("Source output update requested latency %lld", (long long) latency);
 }
 
-/* Called from I/O thread context */
+/* Called from sink I/O thread context. */
 static void sink_input_update_sink_latency_range_cb(pa_sink_input *i) {
     struct userdata *u;
 
@@ -994,7 +1190,7 @@ static void sink_input_update_sink_latency_range_cb(pa_sink_input *i) {
     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 */
+/* Called from source I/O thread context. */
 static void source_output_update_source_latency_range_cb(pa_source_output *o) {
     struct userdata *u;
 
@@ -1008,7 +1204,7 @@ static void source_output_update_source_latency_range_cb(pa_source_output *o) {
     pa_source_set_latency_range_within_thread(u->source, o->source->thread_info.min_latency, o->source->thread_info.max_latency);
 }
 
-/* Called from I/O thread context */
+/* Called from sink I/O thread context. */
 static void sink_input_update_sink_fixed_latency_cb(pa_sink_input *i) {
     struct userdata *u;
 
@@ -1021,7 +1217,7 @@ static void sink_input_update_sink_fixed_latency_cb(pa_sink_input *i) {
     pa_sink_set_fixed_latency_within_thread(u->sink, i->sink->thread_info.fixed_latency);
 }
 
-/* Called from I/O thread context */
+/* Called from source I/O thread context. */
 static void source_output_update_source_fixed_latency_cb(pa_source_output *o) {
     struct userdata *u;
 
@@ -1034,7 +1230,7 @@ static void source_output_update_source_fixed_latency_cb(pa_source_output *o) {
     pa_source_set_fixed_latency_within_thread(u->source, o->source->thread_info.fixed_latency);
 }
 
-/* Called from output thread context */
+/* Called from source I/O thread context. */
 static void source_output_attach_cb(pa_source_output *o) {
     struct userdata *u;
 
@@ -1057,7 +1253,7 @@ static void source_output_attach_cb(pa_source_output *o) {
             u->asyncmsgq);
 }
 
-/* Called from I/O thread context */
+/* Called from sink I/O thread context. */
 static void sink_input_attach_cb(pa_sink_input *i) {
     struct userdata *u;
 
@@ -1075,6 +1271,9 @@ static void sink_input_attach_cb(pa_sink_input *i) {
      * 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);
@@ -1087,8 +1286,7 @@ static void sink_input_attach_cb(pa_sink_input *i) {
     pa_sink_attach_within_thread(u->sink);
 }
 
-
-/* Called from output thread context */
+/* Called from source I/O thread context. */
 static void source_output_detach_cb(pa_source_output *o) {
     struct userdata *u;
 
@@ -1107,7 +1305,7 @@ static void source_output_detach_cb(pa_source_output *o) {
     }
 }
 
-/* Called from I/O thread context */
+/* Called from sink I/O thread context. */
 static void sink_input_detach_cb(pa_sink_input *i) {
     struct userdata *u;
 
@@ -1126,7 +1324,7 @@ static void sink_input_detach_cb(pa_sink_input *i) {
     }
 }
 
-/* Called from output thread context */
+/* Called from source I/O thread context. */
 static void source_output_state_change_cb(pa_source_output *o, pa_source_output_state_t state) {
     struct userdata *u;
 
@@ -1137,7 +1335,7 @@ static void source_output_state_change_cb(pa_source_output *o, pa_source_output_
     pa_log_debug("Source output %d state %d", o->index, state);
 }
 
-/* Called from IO thread context */
+/* 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;
 
@@ -1151,11 +1349,11 @@ static void sink_input_state_change_cb(pa_sink_input *i, pa_sink_input_state_t s
     if (PA_SINK_INPUT_IS_LINKED(state) &&
         i->thread_info.state == PA_SINK_INPUT_INIT) {
         pa_log_debug("Requesting rewind due to state change.");
-        pa_sink_input_request_rewind(i, 0, FALSE, TRUE, TRUE);
+        pa_sink_input_request_rewind(i, 0, false, true, true);
     }
 }
 
-/* Called from main thread */
+/* Called from main context. */
 static void source_output_kill_cb(pa_source_output *o) {
     struct userdata *u;
 
@@ -1163,7 +1361,7 @@ static void source_output_kill_cb(pa_source_output *o) {
     pa_assert_ctl_context();
     pa_assert_se(u = o->userdata);
 
-    u->dead = TRUE;
+    u->dead = true;
 
     /* The order here matters! We first kill the source output, followed
      * by the source. That means the source callbacks must be protected
@@ -1179,7 +1377,7 @@ static void source_output_kill_cb(pa_source_output *o) {
 
     pa_log_debug("Source output kill %d", o->index);
 
-    pa_module_unload_request(u->module, TRUE);
+    pa_module_unload_request(u->module, true);
 }
 
 /* Called from main context */
@@ -1189,7 +1387,7 @@ static void sink_input_kill_cb(pa_sink_input *i) {
     pa_sink_input_assert_ref(i);
     pa_assert_se(u = i->userdata);
 
-    u->dead = TRUE;
+    u->dead = true;
 
     /* The order here matters! We first kill the sink input, followed
      * by the sink. That means the sink callbacks must be protected
@@ -1205,37 +1403,37 @@ static void sink_input_kill_cb(pa_sink_input *i) {
 
     pa_log_debug("Sink input kill %d", i->index);
 
-    pa_module_unload_request(u->module, TRUE);
+    pa_module_unload_request(u->module, true);
 }
 
-/* Called from main thread */
-static pa_bool_t source_output_may_move_to_cb(pa_source_output *o, pa_source *dest) {
+/* 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;
+    if (u->dead || u->autoloaded)
+        return false;
 
     return (u->source != dest) && (u->sink != dest->monitor_of);
 }
 
 /* Called from main context */
-static pa_bool_t sink_input_may_move_to_cb(pa_sink_input *i, pa_sink *dest) {
+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;
+    if (u->dead || u->autoloaded)
+        return false;
 
     return u->sink != dest;
 }
 
-/* Called from main thread */
+/* Called from main context. */
 static void source_output_moving_cb(pa_source_output *o, pa_source *dest) {
     struct userdata *u;
 
@@ -1250,13 +1448,14 @@ static void source_output_moving_cb(pa_source_output *o, pa_source *dest) {
         pa_source_set_asyncmsgq(u->source, NULL);
 
     if (u->source_auto_desc && dest) {
-        const char *z;
+        const char *y, *z;
         pa_proplist *pl;
 
         pl = pa_proplist_new();
+        y = pa_proplist_gets(u->sink_input->sink->proplist, PA_PROP_DEVICE_DESCRIPTION);
         z = pa_proplist_gets(dest->proplist, PA_PROP_DEVICE_DESCRIPTION);
-        pa_proplist_setf(pl, PA_PROP_DEVICE_DESCRIPTION, "Echo-Cancel Source %s on %s",
-                         pa_proplist_gets(u->source->proplist, "device.echo-cancel.name"), z ? z : dest->name);
+        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);
@@ -1277,13 +1476,14 @@ static void sink_input_moving_cb(pa_sink_input *i, pa_sink *dest) {
         pa_sink_set_asyncmsgq(u->sink, NULL);
 
     if (u->sink_auto_desc && dest) {
-        const char *z;
+        const char *y, *z;
         pa_proplist *pl;
 
         pl = pa_proplist_new();
+        y = pa_proplist_gets(u->source_output->source->proplist, PA_PROP_DEVICE_DESCRIPTION);
         z = pa_proplist_gets(dest->proplist, PA_PROP_DEVICE_DESCRIPTION);
-        pa_proplist_setf(pl, PA_PROP_DEVICE_DESCRIPTION, "Echo-Cancel Sink %s on %s",
-                         pa_proplist_gets(u->sink->proplist, "device.echo-cancel.name"), z ? z : dest->name);
+        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);
@@ -1310,17 +1510,90 @@ static void sink_input_mute_changed_cb(pa_sink_input *i) {
     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);
+    u = msg->userdata;
+
+    switch (code) {
+        case ECHO_CANCELLER_MESSAGE_SET_VOLUME: {
+            pa_cvolume *v = (pa_cvolume *) userdata;
+
+            if (u->use_volume_sharing)
+                pa_source_set_volume(u->source, v, true, false);
+            else
+                pa_source_output_set_volume(u->source_output, v, false, true);
+
+            break;
+        }
+
+        default:
+            pa_assert_not_reached();
+            break;
+    }
+
+    return 0;
+}
+
+/* Called by the canceller, so source I/O thread context. */
+void pa_echo_canceller_get_capture_volume(pa_echo_canceller *ec, pa_cvolume *v) {
+    *v = ec->msg->userdata->thread_info.current_volume;
+}
+
+/* Called by the canceller, so source I/O thread context. */
+void pa_echo_canceller_set_capture_volume(pa_echo_canceller *ec, pa_cvolume *v) {
+    if (!pa_cvolume_equal(&ec->msg->userdata->thread_info.current_volume, v)) {
+        pa_cvolume *vol = pa_xnewdup(pa_cvolume, v, 1);
+
+        pa_asyncmsgq_post(pa_thread_mq_get()->outq, PA_MSGOBJECT(ec->msg), ECHO_CANCELLER_MESSAGE_SET_VOLUME, vol, 0, NULL,
+                pa_xfree);
+    }
+}
+
+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);
+
+    assert(rate >= 4000);
+    assert(ms >= 1);
+
+    /* nframes should be a power of 2, round down to nearest power of two */
+    while (y > nframes)
+        y >>= 1;
+
+    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;
-    else if (pa_streq(method, "adrian"))
+#endif
+#ifdef HAVE_ADRIAN_EC
+    if (pa_streq(method, "adrian"))
         return PA_ECHO_CANCELLER_ADRIAN;
-    else
-        return PA_ECHO_CANCELLER_INVALID;
+#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 */
+/* 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) {
@@ -1334,12 +1607,18 @@ static int init_common(pa_modargs *ma, struct userdata *u, pa_sample_spec *sourc
         goto fail;
     }
 
-    if ((ec_method = get_ec_method_from_string(pa_modargs_get_value(ma, "aec_method", DEFAULT_ECHO_CANCELLER))) < 0) {
-        pa_log("Invalid echo canceller implementation");
+    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;
 
@@ -1349,11 +1628,11 @@ fail:
     return -1;
 }
 
-
+/* Called from main context. */
 int pa__init(pa_module*m) {
     struct userdata *u;
-    pa_sample_spec source_ss, sink_ss;
-    pa_channel_map source_map, sink_map;
+    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;
@@ -1362,8 +1641,8 @@ int pa__init(pa_module*m) {
     pa_source_new_data source_data;
     pa_sink_new_data sink_data;
     pa_memchunk silence;
-    uint32_t adjust_time_sec;
-    pa_bool_t use_volume_sharing = TRUE;
+    uint32_t temp;
+    uint32_t nframes = 0;
 
     pa_assert(m);
 
@@ -1397,11 +1676,6 @@ int pa__init(pa_module*m) {
     sink_ss = sink_master->sample_spec;
     sink_map = sink_master->channel_map;
 
-    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;
-    }
-
     u = pa_xnew0(struct userdata, 1);
     if (!u) {
         pa_log("Failed to alloc userdata");
@@ -1410,19 +1684,36 @@ int pa__init(pa_module*m) {
     u->core = m->core;
     u->module = m;
     m->userdata = u;
-    u->dead = FALSE;
+    u->dead = false;
 
-    adjust_time_sec = DEFAULT_ADJUST_TIME_USEC / PA_USEC_PER_SEC;
-    if (pa_modargs_get_value_u32(ma, "adjust_time", &adjust_time_sec) < 0) {
+    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 (adjust_time_sec != DEFAULT_ADJUST_TIME_USEC / PA_USEC_PER_SEC)
-        u->adjust_time = adjust_time_sec * PA_USEC_PER_SEC;
+    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");
@@ -1435,19 +1726,36 @@ int pa__init(pa_module*m) {
         goto fail;
     }
 
-    if (init_common(ma, u, &source_ss, &source_map))
+    if (init_common(ma, u, &source_ss, &source_map) < 0)
         goto fail;
 
     u->asyncmsgq = pa_asyncmsgq_new(0);
-    u->need_realign = TRUE;
+    u->need_realign = true;
 
-    if (u->ec->init) {
-        if (!u->ec->init(u->core, u->ec, &source_ss, &source_map, &sink_ss, &sink_map, &u->blocksize, pa_modargs_get_value(ma, "aec_args", NULL))) {
-            pa_log("Failed to init AEC engine");
-            goto fail;
-        }
+    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__;
@@ -1460,7 +1768,6 @@ int pa__init(pa_module*m) {
     pa_proplist_sets(source_data.proplist, PA_PROP_DEVICE_CLASS, "filter");
     if (!u->autoloaded)
         pa_proplist_sets(source_data.proplist, PA_PROP_DEVICE_INTENDED_ROLES, "phone");
-    pa_proplist_sets(source_data.proplist, "device.echo-cancel.name", source_data.name);
 
     if (pa_modargs_get_proplist(ma, "source_properties", source_data.proplist, PA_UPDATE_REPLACE) < 0) {
         pa_log("Invalid properties");
@@ -1469,14 +1776,16 @@ int pa__init(pa_module*m) {
     }
 
     if ((u->source_auto_desc = !pa_proplist_contains(source_data.proplist, PA_PROP_DEVICE_DESCRIPTION))) {
-        const char *z;
+        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, "Echo-Cancel Source %s on %s", source_data.name, z ? z : source_master->name);
+        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))
-                                                     | (use_volume_sharing ? PA_SOURCE_SHARE_VOLUME_WITH_MASTER : 0));
+                                                     | (u->use_volume_sharing ? PA_SOURCE_SHARE_VOLUME_WITH_MASTER : 0));
     pa_source_new_data_done(&source_data);
 
     if (!u->source) {
@@ -1487,12 +1796,11 @@ int pa__init(pa_module*m) {
     u->source->parent.process_msg = source_process_msg_cb;
     u->source->set_state = source_set_state_cb;
     u->source->update_requested_latency = source_update_requested_latency_cb;
-    pa_source_set_get_mute_callback(u->source, source_get_mute_cb);
     pa_source_set_set_mute_callback(u->source, source_set_mute_cb);
-    if (!use_volume_sharing) {
+    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);
+        pa_source_enable_decibel_volume(u->source, true);
     }
     u->source->userdata = u;
 
@@ -1510,7 +1818,6 @@ int pa__init(pa_module*m) {
     pa_proplist_sets(sink_data.proplist, PA_PROP_DEVICE_CLASS, "filter");
     if (!u->autoloaded)
         pa_proplist_sets(sink_data.proplist, PA_PROP_DEVICE_INTENDED_ROLES, "phone");
-    pa_proplist_sets(sink_data.proplist, "device.echo-cancel.name", sink_data.name);
 
     if (pa_modargs_get_proplist(ma, "sink_properties", sink_data.proplist, PA_UPDATE_REPLACE) < 0) {
         pa_log("Invalid properties");
@@ -1519,14 +1826,16 @@ int pa__init(pa_module*m) {
     }
 
     if ((u->sink_auto_desc = !pa_proplist_contains(sink_data.proplist, PA_PROP_DEVICE_DESCRIPTION))) {
-        const char *z;
+        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, "Echo-Cancel Sink %s on %s", sink_data.name, z ? z : sink_master->name);
+        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))
-                                               | (use_volume_sharing ? PA_SINK_SHARE_VOLUME_WITH_MASTER : 0));
+                                               | (u->use_volume_sharing ? PA_SINK_SHARE_VOLUME_WITH_MASTER : 0));
     pa_sink_new_data_done(&sink_data);
 
     if (!u->sink) {
@@ -1539,9 +1848,9 @@ int pa__init(pa_module*m) {
     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) {
+    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);
+        pa_sink_enable_decibel_volume(u->sink, true);
     }
     u->sink->userdata = u;
 
@@ -1551,15 +1860,13 @@ int pa__init(pa_module*m) {
     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);
+    pa_source_output_new_data_set_source(&source_output_data, source_master, false);
     source_output_data.destination_source = u->source;
-    /* FIXME
-       source_output_data.flags = PA_SOURCE_OUTPUT_DONT_INHIBIT_AUTO_SUSPEND; */
 
     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_ss);
-    pa_source_output_new_data_set_channel_map(&source_output_data, &source_map);
+    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);
 
     pa_source_output_new(&u->source_output, m->core, &source_output_data);
     pa_source_output_new_data_done(&source_output_data);
@@ -1588,7 +1895,7 @@ int pa__init(pa_module*m) {
     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);
+    pa_sink_input_new_data_set_sink(&sink_input_data, sink_master, false);
     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");
@@ -1616,7 +1923,7 @@ int pa__init(pa_module*m) {
     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 (!use_volume_sharing)
+    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;
@@ -1626,9 +1933,9 @@ int pa__init(pa_module*m) {
     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_ss, 1, 1, 0, &silence);
+        &source_output_ss, 1, 1, 0, &silence);
     u->sink_memblockq = pa_memblockq_new("module-echo-cancel sink_memblockq", 0, MEMBLOCKQ_MAXLENGTH, 0,
-        &sink_ss, 1, 1, 0, &silence);
+        &sink_ss, 0, 1, 0, &silence);
 
     pa_memblock_unref(silence.memblock);
 
@@ -1637,11 +1944,14 @@ int pa__init(pa_module*m) {
         goto fail;
     }
 
-    /* our source and sink are not suspended when we create them */
-    u->active_mask = 3;
-
-    if (u->adjust_time > 0)
+    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");
@@ -1654,14 +1964,24 @@ int pa__init(pa_module*m) {
         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;
+
     pa_sink_put(u->sink);
     pa_source_put(u->source);
 
     pa_sink_input_put(u->sink_input);
     pa_source_output_put(u->source_output);
-
     pa_modargs_free(ma);
 
     return 0;
@@ -1675,6 +1995,7 @@ fail:
     return -1;
 }
 
+/* Called from main context. */
 int pa__get_n_used(pa_module *m) {
     struct userdata *u;
 
@@ -1684,6 +2005,7 @@ int pa__get_n_used(pa_module *m) {
     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;
 
@@ -1692,7 +2014,7 @@ void pa__done(pa_module*m) {
     if (!(u = m->userdata))
         return;
 
-    u->dead = TRUE;
+    u->dead = true;
 
     /* See comments in source_output_kill_cb() above regarding
      * destruction order! */
@@ -1735,6 +2057,17 @@ void pa__done(pa_module*m) {
     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);
 }
 
@@ -1744,37 +2077,38 @@ void pa__done(pa_module*m) {
  */
 int main(int argc, char* argv[]) {
     struct userdata u;
-    pa_sample_spec source_ss, sink_ss;
-    pa_channel_map source_map, sink_map;
+    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 ret = 0, unused;
+    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 > 6) {
+    if (argc < 4 || argc > 7) {
         goto usage;
     }
 
-    u.ec = pa_xnew0(pa_echo_canceller, 1);
-    if (!u.ec) {
-        pa_log("Failed to alloc echo canceller");
-        goto fail;
-    }
-
-    u.captured_file = fopen(argv[2], "r");
+    u.captured_file = fopen(argv[2], "rb");
     if (u.captured_file == NULL) {
-        perror ("fopen failed");
+        perror ("Could not open capture file");
         goto fail;
     }
-    u.played_file = fopen(argv[1], "r");
+    u.played_file = fopen(argv[1], "rb");
     if (u.played_file == NULL) {
-        perror ("fopen failed");
+        perror ("Could not open play file");
         goto fail;
     }
     u.canceled_file = fopen(argv[3], "wb");
     if (u.canceled_file == NULL) {
-        perror ("fopen failed");
+        perror ("Could not open canceled file");
         goto fail;
     }
 
@@ -1792,36 +2126,120 @@ int main(int argc, char* argv[]) {
     source_ss.channels = DEFAULT_CHANNELS;
     pa_channel_map_init_auto(&source_map, source_ss.channels, PA_CHANNEL_MAP_DEFAULT);
 
-    init_common(ma, &u, &source_ss, &source_map);
+    sink_ss.format = PA_SAMPLE_S16LE;
+    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 (!u.ec->init(u.core, u.ec, &source_ss, &source_map, &sink_ss, &sink_map, &u.blocksize,
-                     (argc > 4) ? argv[5] : NULL )) {
+    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;
+        }
 
-    rdata = pa_xmalloc(u.blocksize);
-    pdata = pa_xmalloc(u.blocksize);
-    cdata = pa_xmalloc(u.blocksize);
+        u.drift_file = fopen(argv[5], "rt");
 
-    while (fread(rdata, u.blocksize, 1, u.captured_file) > 0) {
-        if (fread(pdata, u.blocksize, 1, u.played_file) == 0) {
-            perror("played file ended before captured file");
-            break;
+        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->run(u.ec, rdata, pdata, cdata);
+                    u.ec->set_drift(u.ec, drift);
 
-        unused = fwrite(cdata, u.blocksize, 1, u.canceled_file);
+                    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);
 
-    fclose(u.captured_file);
-    fclose(u.played_file);
-    fclose(u.canceled_file);
-
 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);
@@ -1835,7 +2253,7 @@ out:
     return ret;
 
 usage:
-    pa_log("Usage: %s play_file rec_file out_file [module args] [aec_args]",argv[0]);
+    pa_log("Usage: %s play_file rec_file out_file [module args] [drift_file]", argv[0]);
 
 fail:
     ret = -1;