ulaw

g711.c

@@ -0,0 +1,256 @@
+/*
+ * 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
+ */
+
+/*
+ * g711.c
+ *
+ * u-law, A-law and linear PCM conversions.
+ */
+#define SIGN_BIT (0x80)  /* Sign bit for a A-law byte. */
+#define QUANT_MASK (0xf) /* Quantization field mask. */
+#define NSEGS (8)        /* Number of A-law segments. */
+#define SEG_SHIFT (4)    /* Left shift for segment number. */
+#define SEG_MASK (0x70)  /* Segment field mask. */
+
+static short seg_end[8] = { 0xFF, 0x1FF, 0x3FF, 0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF };
+
+/* copy from CCITT G.711 specifications */
+unsigned char _u2a[128] = { /* u- to A-law conversions */
+                            1,   1,   2,   2,   3,   3,   4,   4,   5,   5,   6,   6,
+                            7,   7,   8,   8,   9,   10,  11,  12,  13,  14,  15,  16,
+                            17,  18,  19,  20,  21,  22,  23,  24,  25,  27,  29,  31,
+                            33,  34,  35,  36,  37,  38,  39,  40,  41,  42,  43,  44,
+                            46,  48,  49,  50,  51,  52,  53,  54,  55,  56,  57,  58,
+                            59,  60,  61,  62,  64,  65,  66,  67,  68,  69,  70,  71,
+                            72,  73,  74,  75,  76,  77,  78,  79,  81,  82,  83,  84,
+                            85,  86,  87,  88,  89,  90,  91,  92,  93,  94,  95,  96,
+                            97,  98,  99,  100, 101, 102, 103, 104, 105, 106, 107, 108,
+                            109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120,
+                            121, 122, 123, 124, 125, 126, 127, 128
+};
+
+unsigned char _a2u[128] = { /* A- to u-law conversions */
+                            1,   3,   5,   7,   9,   11,  13,  15,  16,  17,  18,  19,
+                            20,  21,  22,  23,  24,  25,  26,  27,  28,  29,  30,  31,
+                            32,  32,  33,  33,  34,  34,  35,  35,  36,  37,  38,  39,
+                            40,  41,  42,  43,  44,  45,  46,  47,  48,  48,  49,  49,
+                            50,  51,  52,  53,  54,  55,  56,  57,  58,  59,  60,  61,
+                            62,  63,  64,  64,  65,  66,  67,  68,  69,  70,  71,  72,
+                            73,  74,  75,  76,  77,  78,  79,  79,  80,  81,  82,  83,
+                            84,  85,  86,  87,  88,  89,  90,  91,  92,  93,  94,  95,
+                            96,  97,  98,  99,  100, 101, 102, 103, 104, 105, 106, 107,
+                            108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119,
+                            120, 121, 122, 123, 124, 125, 126, 127
+};
+
+static int search(int val, short* table, int size)
+{
+    int i;
+
+    for (i = 0; i < size; i++) {
+        if (val <= *table++)
+            return (i);
+    }
+    return (size);
+}
+
+/*
+ * linear2alaw() - Convert a 16-bit linear PCM value to 8-bit A-law
+ *
+ * linear2alaw() accepts an 16-bit integer and encodes it as A-law data.
+ *
+ *		Linear Input Code	Compressed Code
+ *	------------------------	---------------
+ *	0000000wxyza			000wxyz
+ *	0000001wxyza			001wxyz
+ *	000001wxyzab			010wxyz
+ *	00001wxyzabc			011wxyz
+ *	0001wxyzabcd			100wxyz
+ *	001wxyzabcde			101wxyz
+ *	01wxyzabcdef			110wxyz
+ *	1wxyzabcdefg			111wxyz
+ *
+ * For further information see John C. Bellamy's Digital Telephony, 1982,
+ * John Wiley & Sons, pps 98-111 and 472-476.
+ */
+unsigned char linear2alaw(int pcm_val) /* 2's complement (16-bit range) */
+{
+    int mask;
+    int seg;
+    unsigned char aval;
+
+    if (pcm_val >= 0) {
+        mask = 0xD5; /* sign (7th) bit = 1 */
+    } else {
+        mask = 0x55; /* sign bit = 0 */
+        pcm_val = -pcm_val - 8;
+    }
+
+    /* Convert the scaled magnitude to segment number. */
+    seg = search(pcm_val, seg_end, 8);
+
+    /* Combine the sign, segment, and quantization bits. */
+
+    if (seg >= 8) /* out of range, return maximum value. */
+        return (0x7F ^ mask);
+    else {
+        aval = seg << SEG_SHIFT;
+        if (seg < 2)
+            aval |= (pcm_val >> 4) & QUANT_MASK;
+        else
+            aval |= (pcm_val >> (seg + 3)) & QUANT_MASK;
+        return (aval ^ mask);
+    }
+}
+
+/*
+ * alaw2linear() - Convert an A-law value to 16-bit linear PCM
+ *
+ */
+int alaw2linear(unsigned char a_val)
+{
+    int t;
+    int seg;
+
+    a_val ^= 0x55;
+
+    t = (a_val & QUANT_MASK) << 4;
+    seg = ((unsigned)a_val & SEG_MASK) >> SEG_SHIFT;
+    switch (seg) {
+    case 0:
+        t += 8;
+        break;
+    case 1:
+        t += 0x108;
+        break;
+    default:
+        t += 0x108;
+        t <<= seg - 1;
+    }
+    return ((a_val & SIGN_BIT) ? t : -t);
+}
+
+#define BIAS (0x84) /* Bias for linear code. */
+
+/*
+ * linear2ulaw() - Convert a linear PCM value to u-law
+ *
+ * In order to simplify the encoding process, the original linear magnitude
+ * is biased by adding 33 which shifts the encoding range from (0 - 8158) to
+ * (33 - 8191). The result can be seen in the following encoding table:
+ *
+ *	Biased Linear Input Code	Compressed Code
+ *	------------------------	---------------
+ *	00000001wxyza			000wxyz
+ *	0000001wxyzab			001wxyz
+ *	000001wxyzabc			010wxyz
+ *	00001wxyzabcd			011wxyz
+ *	0001wxyzabcde			100wxyz
+ *	001wxyzabcdef			101wxyz
+ *	01wxyzabcdefg			110wxyz
+ *	1wxyzabcdefgh			111wxyz
+ *
+ * Each biased linear code has a leading 1 which identifies the segment
+ * number. The value of the segment number is equal to 7 minus the number
+ * of leading 0's. The quantization interval is directly available as the
+ * four bits wxyz.  * The trailing bits (a - h) are ignored.
+ *
+ * Ordinarily the complement of the resulting code word is used for
+ * transmission, and so the code word is complemented before it is returned.
+ *
+ * For further information see John C. Bellamy's Digital Telephony, 1982,
+ * John Wiley & Sons, pps 98-111 and 472-476.
+ */
+unsigned char linear2ulaw(int pcm_val) /* 2's complement (16-bit range) */
+{
+    int mask;
+    int seg;
+    unsigned char uval;
+
+    /* Get the sign and the magnitude of the value. */
+    if (pcm_val < 0) {
+        pcm_val = BIAS - pcm_val;
+        mask = 0x7F;
+    } else {
+        pcm_val += BIAS;
+        mask = 0xFF;
+    }
+
+    /* Convert the scaled magnitude to segment number. */
+    seg = search(pcm_val, seg_end, 8);
+
+    /*
+     * Combine the sign, segment, quantization bits;
+     * and complement the code word.
+     */
+    if (seg >= 8) /* out of range, return maximum value. */
+        return (0x7F ^ mask);
+    else {
+        uval = (seg << 4) | ((pcm_val >> (seg + 3)) & 0xF);
+        return (uval ^ mask);
+    }
+}
+
+/*
+ * ulaw2linear() - Convert a u-law value to 16-bit linear PCM
+ *
+ * First, a biased linear code is derived from the code word. An unbiased
+ * output can then be obtained by subtracting 33 from the biased code.
+ *
+ * Note that this function expects to be passed the complement of the
+ * original code word. This is in keeping with ISDN conventions.
+ */
+int ulaw2linear(unsigned char u_val)
+{
+    int t;
+
+    /* Complement to obtain normal u-law value. */
+    // u_val = ~u_val;
+
+    /*
+     * Extract and bias the quantization bits. Then
+     * shift up by the segment number and subtract out the bias.
+     */
+    t = ((u_val & QUANT_MASK) << 3) + BIAS;
+    t <<= ((unsigned)u_val & SEG_MASK) >> SEG_SHIFT;
+
+    return ((u_val & SIGN_BIT) ? (BIAS - t) : (t - BIAS));
+}
+
+/* A-law to u-law conversion */
+unsigned char alaw2ulaw(unsigned char aval)
+{
+    aval &= 0xff;
+    return ((aval & 0x80) ? (0xFF ^ _a2u[aval ^ 0xD5]) : (0x7F ^ _a2u[aval ^ 0x55]));
+}
+
+/* u-law to A-law conversion */
+unsigned char ulaw2alaw(unsigned char uval)
+{
+    uval &= 0xff;
+    return ((uval & 0x80) ? (0xD5 ^ (_u2a[0xFF ^ uval] - 1))
+                          : (0x55 ^ (_u2a[0x7F ^ uval] - 1)));
+}

g72x.h

@@ -0,0 +1,115 @@
+/*
+ * 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 identical
+ * 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. */
+
+void g72x_init_state(struct g72x_state*);
+int g721_encoder(int sample, int in_coding, struct g72x_state* state_ptr);
+int g721_decoder(int code, int out_coding, struct g72x_state* state_ptr);
+int g723_24_encoder(int sample, int in_coding, struct g72x_state* state_ptr);
+int g723_24_decoder(int code, int out_coding, struct g72x_state* state_ptr);
+int g723_40_encoder(int sample, int in_coding, struct g72x_state* state_ptr);
+int g723_40_decoder(int code, int out_coding, struct g72x_state* state_ptr);
+
+
+int quantize(int d, int y, short* table, int size);
+int reconstruct(int, int, int);
+void
+
+    update(int code_size,
+                  int y,
+                  int wi,
+                  int fi,
+                  int dq,
+                  int sr,
+                  int dqsez,
+                  struct g72x_state* state_ptr);
+int tandem_adjust_alaw(int sr, int se, int y, int i, int sign, short* qtab);
+
+int tandem_adjust_ulaw(int sr, int se, int y, int i, int sign, short* qtab);
+
+unsigned char linear2alaw(int pcm_val);
+
+int alaw2linear(unsigned char a_val);
+
+unsigned char linear2ulaw(int pcm_val);
+
+int ulaw2linear(unsigned char u_val);
+
+int predictor_zero(struct g72x_state* state_ptr);
+
+int predictor_pole(struct g72x_state* state_ptr);
+int step_size(struct g72x_state* state_ptr);
+#endif /* !_G72X_H */
+

virtual_portal.c

@@ -2,7 +2,7 @@
 
 #include <furi_hal.h>
 #include <stm32wbxx_ll_dma.h>
-
+#include "g72x.h"
 #include "string.h"
 #include "wav_player_hal.h"
 
@@ -577,13 +577,15 @@ void virtual_portal_process_audio_360(
     uint8_t* message,
     uint8_t len) {
     for (size_t i = 0; i < len; i++) {
-        int8_t int_8 = (int8_t)message[i];
+        
+        int16_t int_16 = (int16_t)ulaw2linear(message[i]);
 
-        float data = (float)int_8;
-        data /= INT8_MAX;  // scale -1..1
+        float data = ((float)int_16 / 256.0);
+        data /= UINT8_MAX / 2;  // scale -1..1
 
         data *= virtual_portal->volume;  // volume
         data = tanhf(data);              // hyperbolic tangent limiter
+
         data *= UINT8_MAX / 2;  // scale -128..127
         data += UINT8_MAX / 2;  // to unsigned