1 files changed, 38 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/chebyshev.h b/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/chebyshev.h
new file mode 100644
index 0000000000..8ba82927b8
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/chebyshev.h
@@ -0,0 +1,38 @@
+/*
+ *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+/******************************************************************
+
+ iLBC Speech Coder ANSI-C Source Code
+
+ WebRtcIlbcfix_Chebyshev.h
+
+******************************************************************/
+
+#ifndef MODULES_AUDIO_CODING_CODECS_ILBC_MAIN_SOURCE_CHEBYSHEV_H_
+#define MODULES_AUDIO_CODING_CODECS_ILBC_MAIN_SOURCE_CHEBYSHEV_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+/*------------------------------------------------------------------*
+ *  Calculate the Chevyshev polynomial series
+ *  F(w) = 2*exp(-j5w)*C(x)
+ *   C(x) = (T_0(x) + f(1)T_1(x) + ... + f(4)T_1(x) + f(5)/2)
+ *   T_i(x) is the i:th order Chebyshev polynomial
+ *------------------------------------------------------------------*/
+
+int16_t WebRtcIlbcfix_Chebyshev(
+    /* (o) Result of C(x) */
+    int16_t x, /* (i) Value to the Chevyshev polynomial */
+    int16_t* f /* (i) The coefficients in the polynomial */
+);
+
+#endif