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1 /* ------------------------------------------------------------------
2  * Copyright (C) 1998-2009 PacketVideo
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
13  * express or implied.
14  * See the License for the specific language governing permissions
15  * and limitations under the License.
16  * -------------------------------------------------------------------
17  */
18 /****************************************************************************************
19 Portions of this file are derived from the following 3GPP standard:
20 
21     3GPP TS 26.073
22     ANSI-C code for the Adaptive Multi-Rate (AMR) speech codec
23     Available from http://www.3gpp.org
24 
25 (C) 2004, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC)
26 Permission to distribute, modify and use this file under the standard license
27 terms listed above has been obtained from the copyright holder.
28 ****************************************************************************************/
29 /*
30 ------------------------------------------------------------------------------
31 
32 
33 
34  Filename: /audio/gsm_amr/c/src/include/c_g_aver.h
35 
36      Date: 12/29/2002
37 
38 ------------------------------------------------------------------------------
39  REVISION HISTORY
40 
41  Description: Moved _cplusplus #ifdef after Include section.
42 
43  Description:
44 
45 ------------------------------------------------------------------------------
46  INCLUDE DESCRIPTION
47 
48       File             : calc_en.h
49       Purpose          : calculation of energy coefficients for quantizers
50 
51 ------------------------------------------------------------------------------
52 */
53 
54 #ifndef _CALC_EN_H_
55 #define _CALC_EN_H_
56 #define calc_en_h "$Id $"
57 
58 /*----------------------------------------------------------------------------
59 ; INCLUDES
60 ----------------------------------------------------------------------------*/
61 #include "typedef.h"
62 #include "mode.h"
63 
64 /*--------------------------------------------------------------------------*/
65 #ifdef __cplusplus
66 extern "C"
67 {
68 #endif
69 
70     /*----------------------------------------------------------------------------
71     ; MACROS
72     ; [Define module specific macros here]
73     ----------------------------------------------------------------------------*/
74 
75     /*----------------------------------------------------------------------------
76     ; DEFINES
77     ; [Include all pre-processor statements here.]
78     ----------------------------------------------------------------------------*/
79 
80 
81     /*----------------------------------------------------------------------------
82     ; EXTERNAL VARIABLES REFERENCES
83     ; [Declare variables used in this module but defined elsewhere]
84     ----------------------------------------------------------------------------*/
85 
86     /*----------------------------------------------------------------------------
87     ; SIMPLE TYPEDEF'S
88     ----------------------------------------------------------------------------*/
89 
90     /*----------------------------------------------------------------------------
91     ; ENUMERATED TYPEDEF'S
92     ----------------------------------------------------------------------------*/
93 
94     /*----------------------------------------------------------------------------
95     ; STRUCTURES TYPEDEF'S
96     ----------------------------------------------------------------------------*/
97 
98 
99     /*----------------------------------------------------------------------------
100     ; GLOBAL FUNCTION DEFINITIONS
101     ; [List function prototypes here]
102     ----------------------------------------------------------------------------*/
103     /*
104      * FUNCTION: calc_unfilt_energies
105      *
106      * PURPOSE:  calculation of several energy coefficients for unfiltered
107      *           excitation signals and the LTP coding gain
108      *
109      *       frac_en[0]*2^exp_en[0] = <res res>   // LP residual energy
110      *       frac_en[1]*2^exp_en[1] = <exc exc>   // LTP residual energy
111      *       frac_en[2]*2^exp_en[2] = <exc code>  // LTP/CB innovation dot product
112      *       frac_en[3]*2^exp_en[3] = <lres lres> // LTP residual energy
113      *                                            // (lres = res - gain_pit*exc)
114      *       ltpg = log2(LP_res_en / LTP_res_en)
115      */
116     void
117     calc_unfilt_energies(
118         Word16 res[],     /* i  : LP residual,                               Q0  */
119         Word16 exc[],     /* i  : LTP excitation (unfiltered),               Q0  */
120         Word16 code[],    /* i  : CB innovation (unfiltered),                Q13 */
121         Word16 gain_pit,  /* i  : pitch gain,                                Q14 */
122         Word16 L_subfr,   /* i  : Subframe length                                */
123 
124         Word16 frac_en[], /* o  : energy coefficients (3), fraction part,    Q15 */
125         Word16 exp_en[],  /* o  : energy coefficients (3), exponent part,    Q0  */
126         Word16 *ltpg,     /* o  : LTP coding gain (log2()),                  Q13 */
127         Flag   *pOverflow
128     );
129 
130     /*
131      * FUNCTION: calc_filt_energies
132      *
133      * PURPOSE:  calculation of several energy coefficients for filtered
134      *           excitation signals
135      *
136      *     Compute coefficients need for the quantization and the optimum
137      *     codebook gain gcu (for MR475 only).
138      *
139      *      coeff[0] =    y1 y1
140      *      coeff[1] = -2 xn y1
141      *      coeff[2] =    y2 y2
142      *      coeff[3] = -2 xn y2
143      *      coeff[4] =  2 y1 y2
144      *
145      *
146      *      gcu = <xn2, y2> / <y2, y2> (0 if <xn2, y2> <= 0)
147      *
148      *     Product <y1 y1> and <xn y1> have been computed in G_pitch() and
149      *     are in vector g_coeff[].
150      */
151     void
152     calc_filt_energies(
153         enum Mode mode,     /* i  : coder mode                                   */
154         Word16 xn[],        /* i  : LTP target vector,                       Q0  */
155         Word16 xn2[],       /* i  : CB target vector,                        Q0  */
156         Word16 y1[],        /* i  : Adaptive codebook,                       Q0  */
157         Word16 Y2[],        /* i  : Filtered innovative vector,              Q12 */
158         Word16 g_coeff[],   /* i  : Correlations <xn y1> <y1 y1>                 */
159         /*      computed in G_pitch()                        */
160 
161         Word16 frac_coeff[],/* o  : energy coefficients (5), fraction part,  Q15 */
162         Word16 exp_coeff[], /* o  : energy coefficients (5), exponent part,  Q0  */
163         Word16 *cod_gain_frac,/* o: optimum codebook gain (fraction part),   Q15 */
164         Word16 *cod_gain_exp, /* o: optimum codebook gain (exponent part),   Q0  */
165         Flag   *pOverflow
166     );
167 
168     /*
169      * FUNCTION: calc_target_energy
170      *
171      * PURPOSE:  calculation of target energy
172      *
173      *      en = <xn, xn>
174      */
175     void
176     calc_target_energy(
177         Word16 xn[],     /* i: LTP target vector,                       Q0  */
178         Word16 *en_exp,  /* o: optimum codebook gain (exponent part),   Q0  */
179         Word16 *en_frac,  /* o: optimum codebook gain (fraction part),   Q15 */
180         Flag   *pOverflow
181     );
182 
183 #ifdef __cplusplus
184 }
185 #endif
186 
187 #endif  /* _CALC_EN_H_ */
188 
189 
190 
191 
192 
193