GNU Radio 3.5.3.2 C++ API
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00001 /* 00002 * This source code is a product of Sun Microsystems, Inc. and is provided 00003 * for unrestricted use. Users may copy or modify this source code without 00004 * charge. 00005 * 00006 * SUN SOURCE CODE IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING 00007 * THE WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR 00008 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE. 00009 * 00010 * Sun source code is provided with no support and without any obligation on 00011 * the part of Sun Microsystems, Inc. to assist in its use, correction, 00012 * modification or enhancement. 00013 * 00014 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE 00015 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY THIS SOFTWARE 00016 * OR ANY PART THEREOF. 00017 * 00018 * In no event will Sun Microsystems, Inc. be liable for any lost revenue 00019 * or profits or other special, indirect and consequential damages, even if 00020 * Sun has been advised of the possibility of such damages. 00021 * 00022 * Sun Microsystems, Inc. 00023 * 2550 Garcia Avenue 00024 * Mountain View, California 94043 00025 */ 00026 00027 /* 00028 * g72x.h 00029 * 00030 * Header file for CCITT conversion routines. 00031 * 00032 */ 00033 #ifndef _G72X_H 00034 #define _G72X_H 00035 00036 #define AUDIO_ENCODING_ULAW (1) /* ISDN u-law */ 00037 #define AUDIO_ENCODING_ALAW (2) /* ISDN A-law */ 00038 #define AUDIO_ENCODING_LINEAR (3) /* PCM 2's-complement (0-center) */ 00039 00040 /* 00041 * The following is the definition of the state structure 00042 * used by the G.721/G.723 encoder and decoder to preserve their internal 00043 * state between successive calls. The meanings of the majority 00044 * of the state structure fields are explained in detail in the 00045 * CCITT Recommendation G.721. The field names are essentially indentical 00046 * to variable names in the bit level description of the coding algorithm 00047 * included in this Recommendation. 00048 */ 00049 struct g72x_state { 00050 long yl; /* Locked or steady state step size multiplier. */ 00051 short yu; /* Unlocked or non-steady state step size multiplier. */ 00052 short dms; /* Short term energy estimate. */ 00053 short dml; /* Long term energy estimate. */ 00054 short ap; /* Linear weighting coefficient of 'yl' and 'yu'. */ 00055 00056 short a[2]; /* Coefficients of pole portion of prediction filter. */ 00057 short b[6]; /* Coefficients of zero portion of prediction filter. */ 00058 short pk[2]; /* 00059 * Signs of previous two samples of a partially 00060 * reconstructed signal. 00061 */ 00062 short dq[6]; /* 00063 * Previous 6 samples of the quantized difference 00064 * signal represented in an internal floating point 00065 * format. 00066 */ 00067 short sr[2]; /* 00068 * Previous 2 samples of the quantized difference 00069 * signal represented in an internal floating point 00070 * format. 00071 */ 00072 char td; /* delayed tone detect, new in 1988 version */ 00073 }; 00074 00075 /* External function definitions. */ 00076 00077 extern void g72x_init_state(struct g72x_state *); 00078 extern int g721_encoder( 00079 int sample, 00080 int in_coding, 00081 struct g72x_state *state_ptr); 00082 extern int g721_decoder( 00083 int code, 00084 int out_coding, 00085 struct g72x_state *state_ptr); 00086 extern int g723_24_encoder( 00087 int sample, 00088 int in_coding, 00089 struct g72x_state *state_ptr); 00090 extern int g723_24_decoder( 00091 int code, 00092 int out_coding, 00093 struct g72x_state *state_ptr); 00094 extern int g723_40_encoder( 00095 int sample, 00096 int in_coding, 00097 struct g72x_state *state_ptr); 00098 extern int g723_40_decoder( 00099 int code, 00100 int out_coding, 00101 struct g72x_state *state_ptr); 00102 00103 00104 extern int 00105 quantize( 00106 int d, 00107 int y, 00108 short *table, 00109 int size); 00110 extern int reconstruct(int,int,int);void 00111 00112 extern update( 00113 int code_size, 00114 int y, 00115 int wi, 00116 int fi, 00117 int dq, 00118 int sr, 00119 int dqsez, 00120 struct g72x_state *state_ptr); 00121 extern int 00122 tandem_adjust_alaw( 00123 int sr, 00124 int se, 00125 int y, 00126 int i, 00127 int sign, 00128 short *qtab); 00129 00130 extern int 00131 tandem_adjust_ulaw( 00132 int sr, 00133 int se, 00134 int y, 00135 int i, 00136 int sign, 00137 short *qtab); 00138 00139 extern unsigned char 00140 linear2alaw( 00141 int pcm_val); 00142 00143 extern int 00144 alaw2linear( 00145 unsigned char a_val); 00146 00147 extern unsigned char 00148 linear2ulaw(int pcm_val); 00149 00150 extern int ulaw2linear( unsigned char u_val); 00151 00152 extern int predictor_zero(struct g72x_state *state_ptr); 00153 00154 extern int predictor_pole( struct g72x_state *state_ptr); 00155 extern int step_size( struct g72x_state *state_ptr); 00156 #endif /* !_G72X_H */