From: Wim Taymans <wim.taymans@collabora.co.uk>
Date: Thu, 9 Sep 2010 10:39:15 +0000 (+0200)
Subject: echo-cancel: improve accuracy
X-Git-Tag: submit/2.0-panda/20130828.192557~962
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=7b873785ca40c7d1d3109f8cc8202b996ebe1522;p=profile%2Fivi%2Fpulseaudio-panda.git

echo-cancel: improve accuracy

Make the echo canceler drift up to 1ms now that things are more accurate.
Add 10 samples of headroom to allow for timing inaccuracies.
---

diff --git a/src/modules/echo-cancel/module-echo-cancel.c b/src/modules/echo-cancel/module-echo-cancel.c
index 4df77c3..467e216 100644
--- a/src/modules/echo-cancel/module-echo-cancel.c
+++ b/src/modules/echo-cancel/module-echo-cancel.c
@@ -295,7 +295,7 @@ static void time_callback(pa_mainloop_api *a, pa_time_event *e, const struct tim
         new_rate = base_rate;
     }
     else {
-        if (diff_time > 4000) {
+        if (diff_time > 1000) {
             /* 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);
@@ -594,6 +594,10 @@ 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) {
+            /* add some extra safety samples to compensate for jitter in the
+             * timings */
+            diff += 10 * pa_frame_size (&u->source_output->sample_spec);
+
             pa_log_info("Playback after capture (%lld), drop sink %lld", (long long) diff_time, (long long) diff);
 
             u->sink_skip = diff;