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_GainDequant.c 16b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 17b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org******************************************************************/ 18b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 19b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org#include "defines.h" 20b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org#include "constants.h" 21b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 22b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org/*----------------------------------------------------------------* 23b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * decoder for quantized gains in the gain-shape coding of 24b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * residual 25b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org *---------------------------------------------------------------*/ 26b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 27fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.orgint16_t WebRtcIlbcfix_GainDequant( 28b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org /* (o) quantized gain value (Q14) */ 29fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.org int16_t index, /* (i) quantization index */ 30fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.org int16_t maxIn, /* (i) maximum of unquantized gain (Q14) */ 31fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.org int16_t stage /* (i) The stage of the search */ 32b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org ){ 33fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.org int16_t scale; 34fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.org const int16_t *gain; 35b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 36b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org /* obtain correct scale factor */ 37b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 38b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org scale=WEBRTC_SPL_ABS_W16(maxIn); 39b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org scale = WEBRTC_SPL_MAX(1638, scale); /* if lower than 0.1, set it to 0.1 */ 40b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 41b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org /* select the quantization table and return the decoded value */ 42b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org gain = WebRtcIlbcfix_kGain[stage]; 43b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 44fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.org return((int16_t)((WEBRTC_SPL_MUL_16_16(scale, gain[index])+8192)>>14)); 45b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org} 46