/* * 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 "modules/audio_coding/codecs/ilbc/defines.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
