This CL includes part of changes in a larger one. The final goal is to allow multiple delay estimators using the same reference (far-end) to save computational complexity.

BUG=None

Review URL: https://webrtc-codereview.appspot.com/1024010

git-svn-id: http://webrtc.googlecode.com/svn/trunk@3391 4adac7df-926f-26a2-2b94-8c16560cd09d

4 files changed, 37 insertions, 19 deletions

diff --git a/webrtc/modules/audio_processing/utility/delay_estimator.c b/webrtc/modules/audio_processing/utility/delay_estimator.c
index 355a6b9447..59909c12b7 100644
--- a/webrtc/modules/audio_processing/utility/delay_estimator.c
+++ b/webrtc/modules/audio_processing/utility/delay_estimator.c
@@ -151,15 +151,8 @@ void WebRtc_InitBinaryDelayEstimator(BinaryDelayEstimator* handle) {
   handle->last_delay = -2;
 }
 
-int WebRtc_ProcessBinarySpectrum(BinaryDelayEstimator* handle,
-                                 uint32_t binary_far_spectrum,
-                                 uint32_t binary_near_spectrum) {
-  int i = 0;
-  int candidate_delay = -1;
-
-  int32_t value_best_candidate = 32 << 9;  // 32 in Q9, (max |mean_bit_counts|).
-  int32_t value_worst_candidate = 0;
-
+void WebRtc_AddBinaryFarSpectrum(BinaryDelayEstimator* handle,
+                                 uint32_t binary_far_spectrum) {
   assert(handle != NULL);
   // Shift binary spectrum history and insert current |binary_far_spectrum|.
   memmove(&(handle->binary_far_history[1]), &(handle->binary_far_history[0]),
@@ -171,7 +164,17 @@ int WebRtc_ProcessBinarySpectrum(BinaryDelayEstimator* handle,
   memmove(&(handle->far_bit_counts[1]), &(handle->far_bit_counts[0]),
           (handle->history_size - 1) * sizeof(int));
   handle->far_bit_counts[0] = BitCount(binary_far_spectrum);
+}
 
+int WebRtc_ProcessBinarySpectrum(BinaryDelayEstimator* handle,
+                                 uint32_t binary_near_spectrum) {
+  int i = 0;
+  int candidate_delay = -1;
+
+  int32_t value_best_candidate = 32 << 9;  // 32 in Q9, (max |mean_bit_counts|).
+  int32_t value_worst_candidate = 0;
+
+  assert(handle != NULL);
   if (handle->near_history_size > 1) {
     // If we apply lookahead, shift near-end binary spectrum history. Insert
     // current |binary_near_spectrum| and pull out the delayed one.
diff --git a/webrtc/modules/audio_processing/utility/delay_estimator.h b/webrtc/modules/audio_processing/utility/delay_estimator.h
index 97456d195d..da46e72863 100644
--- a/webrtc/modules/audio_processing/utility/delay_estimator.h
+++ b/webrtc/modules/audio_processing/utility/delay_estimator.h
@@ -65,12 +65,26 @@ BinaryDelayEstimator* WebRtc_CreateBinaryDelayEstimator(int max_delay,
 //
 void WebRtc_InitBinaryDelayEstimator(BinaryDelayEstimator* handle);
 
-// Estimates and returns the delay between the binary far-end and binary near-
-// end spectra. The value will be offset by the lookahead (i.e. the lookahead
-// should be subtracted from the returned value).
+// Adds the binary far-end spectrum to the internal buffer. This spectrum is
+// used as reference when calculating the delay using
+// WebRtc_ProcessBinarySpectrum().
 // Inputs:
 //    - handle                : Pointer to the delay estimation instance.
 //    - binary_far_spectrum   : Far-end binary spectrum.
+//
+// Output:
+//    - handle                : Updated instance.
+//
+void WebRtc_AddBinaryFarSpectrum(BinaryDelayEstimator* handle,
+                                 uint32_t binary_far_spectrum);
+
+// Estimates and returns the delay between the binary far-end and binary near-
+// end spectra. It is assumed the binary far-end spectrum has been added using
+// WebRtc_AddBinaryFarSpectrum() prior to this call. The value will be offset by
+// the lookahead (i.e. the lookahead should be subtracted from the returned
+// value).
+// Inputs:
+//    - handle                : Pointer to the delay estimation instance.
 //    - binary_near_spectrum  : Near-end binary spectrum of the current block.
 //
 // Output:
@@ -82,7 +96,6 @@ void WebRtc_InitBinaryDelayEstimator(BinaryDelayEstimator* handle);
 //                              -2    - Insufficient data for estimation.
 //
 int WebRtc_ProcessBinarySpectrum(BinaryDelayEstimator* handle,
-                                 uint32_t binary_far_spectrum,
                                  uint32_t binary_near_spectrum);
 
 // Returns the last calculated delay updated by the function
diff --git a/webrtc/modules/audio_processing/utility/delay_estimator_unittest.cc b/webrtc/modules/audio_processing/utility/delay_estimator_unittest.cc
index 58599a35ef..43504effbb 100644
--- a/webrtc/modules/audio_processing/utility/delay_estimator_unittest.cc
+++ b/webrtc/modules/audio_processing/utility/delay_estimator_unittest.cc
@@ -291,8 +291,8 @@ TEST_F(DelayEstimatorTest, ExactDelayEstimate) {
   for (int offset = -kLookahead; offset < kMaxDelay; offset++) {
     InitBinary();
     for (int i = kLookahead; i < (sequence_length + kLookahead); i++) {
+      WebRtc_AddBinaryFarSpectrum(binary_handle_, binary_spectrum[i + offset]);
       int delay = WebRtc_ProcessBinarySpectrum(binary_handle_,
-                                               binary_spectrum[i + offset],
                                                binary_spectrum[i]);
 
       // Verify that we WebRtc_binary_last_delay() returns correct delay.
diff --git a/webrtc/modules/audio_processing/utility/delay_estimator_wrapper.c b/webrtc/modules/audio_processing/utility/delay_estimator_wrapper.c
index 474cb69ba7..3a6f5b11e9 100644
--- a/webrtc/modules/audio_processing/utility/delay_estimator_wrapper.c
+++ b/webrtc/modules/audio_processing/utility/delay_estimator_wrapper.c
@@ -248,8 +248,9 @@ int WebRtc_DelayEstimatorProcessFix(void* handle,
                                            near_q,
                                            &(self->near_spectrum_initialized));
 
+  WebRtc_AddBinaryFarSpectrum(self->binary_handle, binary_far_spectrum);
+
   return WebRtc_ProcessBinarySpectrum(self->binary_handle,
-                                      binary_far_spectrum,
                                       binary_near_spectrum);
 }
 
@@ -281,12 +282,13 @@ int WebRtc_DelayEstimatorProcessFloat(void* handle,
   binary_far_spectrum = BinarySpectrumFloat(far_spectrum,
                                             self->mean_far_spectrum,
                                             &(self->far_spectrum_initialized));
-  binary_near_spectrum = BinarySpectrumFloat(near_spectrum,
-                                             self->mean_near_spectrum,
-                                             &(self->near_spectrum_initialized));
+  binary_near_spectrum =
+      BinarySpectrumFloat(near_spectrum, self->mean_near_spectrum,
+                          &(self->near_spectrum_initialized));
+
+  WebRtc_AddBinaryFarSpectrum(self->binary_handle, binary_far_spectrum);
 
   return WebRtc_ProcessBinarySpectrum(self->binary_handle,
-                                      binary_far_spectrum,
                                       binary_near_spectrum);
 }