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Diffstat (limited to 'gnuradio-core/src/lib/g72x/g72x.h')
| -rw-r--r-- | gnuradio-core/src/lib/g72x/g72x.h | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/gnuradio-core/src/lib/g72x/g72x.h b/gnuradio-core/src/lib/g72x/g72x.h new file mode 100644 index 000000000..33807171a --- /dev/null +++ b/gnuradio-core/src/lib/g72x/g72x.h @@ -0,0 +1,156 @@ +/* + * This source code is a product of Sun Microsystems, Inc. and is provided + * for unrestricted use. Users may copy or modify this source code without + * charge. + * + * SUN SOURCE CODE IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING + * THE WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR + * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE. + * + * Sun source code is provided with no support and without any obligation on + * the part of Sun Microsystems, Inc. to assist in its use, correction, + * modification or enhancement. + * + * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE + * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY THIS SOFTWARE + * OR ANY PART THEREOF. + * + * In no event will Sun Microsystems, Inc. be liable for any lost revenue + * or profits or other special, indirect and consequential damages, even if + * Sun has been advised of the possibility of such damages. + * + * Sun Microsystems, Inc. + * 2550 Garcia Avenue + * Mountain View, California 94043 + */ + +/* + * g72x.h + * + * Header file for CCITT conversion routines. + * + */ +#ifndef _G72X_H +#define _G72X_H + +#define AUDIO_ENCODING_ULAW (1) /* ISDN u-law */ +#define AUDIO_ENCODING_ALAW (2) /* ISDN A-law */ +#define AUDIO_ENCODING_LINEAR (3) /* PCM 2's-complement (0-center) */ + +/* + * The following is the definition of the state structure + * used by the G.721/G.723 encoder and decoder to preserve their internal + * state between successive calls. The meanings of the majority + * of the state structure fields are explained in detail in the + * CCITT Recommendation G.721. The field names are essentially indentical + * to variable names in the bit level description of the coding algorithm + * included in this Recommendation. + */ +struct g72x_state { + long yl; /* Locked or steady state step size multiplier. */ + short yu; /* Unlocked or non-steady state step size multiplier. */ + short dms; /* Short term energy estimate. */ + short dml; /* Long term energy estimate. */ + short ap; /* Linear weighting coefficient of 'yl' and 'yu'. */ + + short a[2]; /* Coefficients of pole portion of prediction filter. */ + short b[6]; /* Coefficients of zero portion of prediction filter. */ + short pk[2]; /* + * Signs of previous two samples of a partially + * reconstructed signal. + */ + short dq[6]; /* + * Previous 6 samples of the quantized difference + * signal represented in an internal floating point + * format. + */ + short sr[2]; /* + * Previous 2 samples of the quantized difference + * signal represented in an internal floating point + * format. + */ + char td; /* delayed tone detect, new in 1988 version */ +}; + +/* External function definitions. */ + +extern void g72x_init_state(struct g72x_state *); +extern int g721_encoder( + int sample, + int in_coding, + struct g72x_state *state_ptr); +extern int g721_decoder( + int code, + int out_coding, + struct g72x_state *state_ptr); +extern int g723_24_encoder( + int sample, + int in_coding, + struct g72x_state *state_ptr); +extern int g723_24_decoder( + int code, + int out_coding, + struct g72x_state *state_ptr); +extern int g723_40_encoder( + int sample, + int in_coding, + struct g72x_state *state_ptr); +extern int g723_40_decoder( + int code, + int out_coding, + struct g72x_state *state_ptr); + + +extern int +quantize( + int d, + int y, + short *table, + int size); +extern int reconstruct(int,int,int);void + +extern update( + int code_size, + int y, + int wi, + int fi, + int dq, + int sr, + int dqsez, + struct g72x_state *state_ptr); +extern int +tandem_adjust_alaw( + int sr, + int se, + int y, + int i, + int sign, + short *qtab); + +extern int +tandem_adjust_ulaw( + int sr, + int se, + int y, + int i, + int sign, + short *qtab); + +extern unsigned char +linear2alaw( + int pcm_val); + +extern int +alaw2linear( + unsigned char a_val); + +extern unsigned char +linear2ulaw(int pcm_val); + +extern int ulaw2linear( unsigned char u_val); + +extern int predictor_zero(struct g72x_state *state_ptr); + +extern int predictor_pole( struct g72x_state *state_ptr); +extern int step_size( struct g72x_state *state_ptr); +#endif /* !_G72X_H */ |