1b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org/* 2b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved. 3b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * 4b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * Use of this source code is governed by a BSD-style license 5b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * that can be found in the LICENSE file in the root of the source 6b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * tree. An additional intellectual property rights grant can be found 7b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * in the file PATENTS. All contributing project authors may 8b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * be found in the AUTHORS file in the root of the source tree. 9b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org */ 10b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 11b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org/****************************************************************** 12b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 13b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org iLBC Speech Coder ANSI-C Source Code 14b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 15b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org WebRtcIlbcfix_Chebyshev.h 16b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 17b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org******************************************************************/ 18b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 19b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org#ifndef WEBRTC_MODULES_AUDIO_CODING_CODECS_ILBC_MAIN_SOURCE_CHEBYSHEV_H_ 20b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org#define WEBRTC_MODULES_AUDIO_CODING_CODECS_ILBC_MAIN_SOURCE_CHEBYSHEV_H_ 21b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 22b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org#include "defines.h" 23b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 24b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org/*------------------------------------------------------------------* 25b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * Calculate the Chevyshev polynomial series 26b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * F(w) = 2*exp(-j5w)*C(x) 27b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * C(x) = (T_0(x) + f(1)T_1(x) + ... + f(4)T_1(x) + f(5)/2) 28b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * T_i(x) is the i:th order Chebyshev polynomial 29b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org *------------------------------------------------------------------*/ 30b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 31fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.orgint16_t WebRtcIlbcfix_Chebyshev( 32b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org /* (o) Result of C(x) */ 33fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.org int16_t x, /* (i) Value to the Chevyshev polynomial */ 34fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.org int16_t *f /* (i) The coefficients in the polynomial */ 35b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org ); 36b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 37b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org#endif 38