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authorPatrick McHardy <kaber@trash.net>2009-05-06 18:41:57 +0200
committerPatrick McHardy <kaber@trash.net>2009-05-06 18:41:57 +0200
commit0406a88b39a9c978d47ababf9fd93d9e244e1a4a (patch)
tree89a082e027d10bb77c9f817cbdc1accb72424ec4 /src/ccitt-adpcm/g72x.h
Import libdect
Signed-off-by: Patrick McHardy <kaber@trash.net>
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+/*
+ * 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 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);
+
+extern int quantize(
+ int d,
+ int y,
+ short *table,
+ int size);
+extern int reconstruct(
+ int sign,
+ int dqln,
+ int y);
+extern void 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 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 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 unsigned char alaw2ulaw(unsigned char aval);
+extern unsigned char ulaw2alaw(unsigned char uval);
+
+#endif /* !_G72X_H */