Move the Config DelayCorrection struct to audio_processing.h.
TBR=bjornv
Review URL: https://webrtc-codereview.appspot.com/2304005
git-svn-id: http://webrtc.googlecode.com/svn/trunk@4849 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/modules/audio_processing/include/audio_processing.h b/webrtc/modules/audio_processing/include/audio_processing.h
index b01cbb3..1babe43 100644
--- a/webrtc/modules/audio_processing/include/audio_processing.h
+++ b/webrtc/modules/audio_processing/include/audio_processing.h
@@ -30,6 +30,30 @@
class NoiseSuppression;
class VoiceDetection;
+// Use to enable the delay correction feature. This now engages an extended
+// filter mode in the AEC, along with robustness measures around the reported
+// system delays. It comes with a significant increase in AEC complexity, but is
+// much more robust to unreliable reported delays.
+//
+// Detailed changes to the algorithm:
+// - The filter length is changed from 48 to 128 ms. This comes with tuning of
+// several parameters: i) filter adaptation stepsize and error threshold;
+// ii) non-linear processing smoothing and overdrive.
+// - Option to ignore the reported delays on platforms which we deem
+// sufficiently unreliable. See WEBRTC_UNTRUSTED_DELAY in echo_cancellation.c.
+// - Faster startup times by removing the excessive "startup phase" processing
+// of reported delays.
+// - Much more conservative adjustments to the far-end read pointer. We smooth
+// the delay difference more heavily, and back off from the difference more.
+// Adjustments force a readaptation of the filter, so they should be avoided
+// except when really necessary.
+struct DelayCorrection {
+ DelayCorrection() : enabled(false) {}
+ DelayCorrection(bool enabled) : enabled(enabled) {}
+
+ bool enabled;
+};
+
// The Audio Processing Module (APM) provides a collection of voice processing
// components designed for real-time communications software.
//