Makefile 444 1750 12 1071 5250514235 5563 # Makefile for CCITT subroutines and sample programs # # Modify the CC definition to invoke your ANSI-C compiler # CC = acc # Rules to build sample programs do not depend on a UNIX library program # ALL = encode decode all: $(ALL) OBJECTS = g711.o g72x.o g721.o g723_24.o g723_40.o encode: $(OBJECTS) $(CC) -o $@ encode.c $(OBJECTS) decode: $(OBJECTS) $(CC) -o $@ decode.c $(OBJECTS) # Library rules for UNIX systems # LIB = ccitt.a lib: $(LIB) $(LIB): $(OBJECTS) @rm -f $(LIB) ar cr $(LIB) $(OBJECTS) @ranlib $(LIB) clean: /bin/rm -f $(LIB) $(ALL) *.o README 444 1750 12 6221 5250514235 5005 The files in this directory comprise ANSI-C language reference implementations of the CCITT (International Telegraph and Telephone Consultative Committee) G.711, G.721 and G.723 voice compressions. They have been tested on Sun SPARCstations and passed 82 out of 84 test vectors published by CCITT (Dec. 20, 1988) for G.721 and G.723. [The two remaining test vectors, which the G.721 decoder implementation for u-law samples did not pass, may be in error because they are identical to two other vectors for G.723_40.] This source code is released by Sun Microsystems, Inc. to the public domain. Please give your acknowledgement in product literature if this code is used in your product implementation. Sun Microsystems supports some CCITT audio formats in Solaris 2.0 system software. However, Sun's implementations have been optimized for higher performance on SPARCstations. The source files for CCITT conversion routines in this directory are: g72x.h header file for g721.c, g723_24.c and g723_40.c g711.c CCITT G.711 u-law and A-law compression g72x.c common denominator of G.721 and G.723 ADPCM codes g721.c CCITT G.721 32Kbps ADPCM coder (with g72x.c) g723_24.c CCITT G.723 24Kbps ADPCM coder (with g72x.c) g723_40.c CCITT G.723 40Kbps ADPCM coder (with g72x.c) Simple conversions between u-law, A-law, and 16-bit linear PCM are invoked as follows: unsigned char ucode, acode; short pcm_val; ucode = linear2ulaw(pcm_val); ucode = alaw2ulaw(acode); acode = linear2alaw(pcm_val); acode = ulaw2alaw(ucode); pcm_val = ulaw2linear(ucode); pcm_val = alaw2linear(acode); The other CCITT compression routines are invoked as follows: #include "g72x.h" struct g72x_state state; int sample, code; g72x_init_state(&state); code = {g721,g723_24,g723_40}_encoder(sample, coding, &state); sample = {g721,g723_24,g723_40}_decoder(code, coding, &state); where coding = AUDIO_ENCODING_ULAW for 8-bit u-law samples AUDIO_ENCODING_ALAW for 8-bit A-law samples AUDIO_ENCODING_LINEAR for 16-bit linear PCM samples This directory also includes the following sample programs: encode.c CCITT ADPCM encoder decode.c CCITT ADPCM decoder Makefile makefile for the sample programs The sample programs contain examples of how to call the various compression routines and pack/unpack the bits. The sample programs read byte streams from stdin and write to stdout. The input/output data is raw data (no file header or other identifying information is embedded). The sample programs are invoked as follows: encode [-3|4|5] [-a|u|l] outfile decode [-3|4|5] [-a|u|l] outfile where: -3 encode to (decode from) G.723 24kbps (3-bit) data -4 encode to (decode from) G.721 32kbps (4-bit) data [the default] -5 encode to (decode from) G.723 40kbps (5-bit) data -a encode from (decode to) A-law data -u encode from (decode to) u-law data [the default] -l encode from (decode to) 16-bit linear data Examples: # Read 16-bit linear and output G.721 encode -4 -l g721file # Read 40Kbps G.723 and output A-law decode -5 -a alawfile # Compress and then decompress u-law data using 24Kbps G.723 encode -3 ulawout decode.c 444 1750 12 4737 5250514235 5526 /* * decode.c * * CCITT ADPCM decoder * * Usage : decode [-3|4|5] [-a|u|l] < infile > outfile */ #include #include "g72x.h" /* * Unpack input codes and pass them back as bytes. * Returns 1 if there is residual input, returns -1 if eof, else returns 0. */ int unpack_input( unsigned char *code, int bits) { static unsigned int in_buffer = 0; static int in_bits = 0; unsigned char in_byte; if (in_bits < bits) { if (fread(&in_byte, sizeof (char), 1, stdin) != 1) { *code = 0; return (-1); } in_buffer |= (in_byte << in_bits); in_bits += 8; } *code = in_buffer & ((1 << bits) - 1); in_buffer >>= bits; in_bits -= bits; return (in_bits > 0); } main( int argc, char **argv) { short sample; unsigned char code; int n; struct g72x_state state; int out_coding; int out_size; int (*dec_routine)(); int dec_bits; g72x_init_state(&state); out_coding = AUDIO_ENCODING_ULAW; out_size = sizeof (char); dec_routine = g721_decoder; dec_bits = 4; /* Process encoding argument, if any */ while ((argc > 1) && (argv[1][0] == '-')) { switch (argv[1][1]) { case '3': dec_routine = g723_24_decoder; dec_bits = 3; break; case '4': dec_routine = g721_decoder; dec_bits = 4; break; case '5': dec_routine = g723_40_decoder; dec_bits = 5; break; case 'u': out_coding = AUDIO_ENCODING_ULAW; out_size = sizeof (char); break; case 'a': out_coding = AUDIO_ENCODING_ALAW; out_size = sizeof (char); break; case 'l': out_coding = AUDIO_ENCODING_LINEAR; out_size = sizeof (short); break; default: fprintf(stderr, "CCITT ADPCM Decoder -- usage:\n"); fprintf(stderr, "\tdecode [-3|4|5] [-a|u|l] < infile > outfile\n"); fprintf(stderr, "where:\n"); fprintf(stderr, "\t-3\tProcess G.723 24kbps (3-bit) input data\n"); fprintf(stderr, "\t-4\tProcess G.721 32kbps (4-bit) input data [default]\n"); fprintf(stderr, "\t-5\tProcess G.723 40kbps (5-bit) input data\n"); fprintf(stderr, "\t-a\tGenerate 8-bit A-law data\n"); fprintf(stderr, "\t-u\tGenerate 8-bit u-law data [default]\n"); fprintf(stderr, "\t-l\tGenerate 16-bit linear PCM data\n"); exit(1); } argc--; argv++; } /* Read and unpack input codes and process them */ while (unpack_input(&code, dec_bits) >= 0) { sample = (*dec_routine)(code, out_coding, &state); if (out_size == 2) { fwrite(&sample, out_size, 1, stdout); } else { code = (unsigned char)sample; fwrite(&code, out_size, 1, stdout); } } fclose(stdout); } 1, stdin) != 1) { *code = 0; encode.c 444 1750 12 5273 5250514235 5534 /* * encode.c * * CCITT ADPCM encoder * * Usage : encode [-3|4|5] [-a|u|l] < infile > outfile */ #include #include "g72x.h" /* * Pack output codes into bytes and write them to stdout. * Returns 1 if there is residual output, else returns 0. */ int pack_output( unsigned code, int bits) { static unsigned int out_buffer = 0; static int out_bits = 0; unsigned char out_byte; out_buffer |= (code << out_bits); out_bits += bits; if (out_bits >= 8) { out_byte = out_buffer & 0xff; out_bits -= 8; out_buffer >>= 8; fwrite(&out_byte, sizeof (char), 1, stdout); } return (out_bits > 0); } main( int argc, char **argv) { struct g72x_state state; unsigned char sample_char; short sample_short; unsigned char code; int resid; int in_coding; int in_size; unsigned *in_buf; int (*enc_routine)(); int enc_bits; g72x_init_state(&state); /* Set defaults to u-law input, G.721 output */ in_coding = AUDIO_ENCODING_ULAW; in_size = sizeof (char); in_buf = (unsigned *)&sample_char; enc_routine = g721_encoder; enc_bits = 4; /* Process encoding argument, if any */ while ((argc > 1) && (argv[1][0] == '-')) { switch (argv[1][1]) { case '3': enc_routine = g723_24_encoder; enc_bits = 3; break; case '4': enc_routine = g721_encoder; enc_bits = 4; break; case '5': enc_routine = g723_40_encoder; enc_bits = 5; break; case 'u': in_coding = AUDIO_ENCODING_ULAW; in_size = sizeof (char); in_buf = (unsigned *)&sample_char; break; case 'a': in_coding = AUDIO_ENCODING_ALAW; in_size = sizeof (char); in_buf = (unsigned *)&sample_char; break; case 'l': in_coding = AUDIO_ENCODING_LINEAR; in_size = sizeof (short); in_buf = (unsigned *)&sample_short; break; default: fprintf(stderr, "CCITT ADPCM Encoder -- usage:\n"); fprintf(stderr, "\tencode [-3|4|5] [-a|u|l] < infile > outfile\n"); fprintf(stderr, "where:\n"); fprintf(stderr, "\t-3\tGenerate G.723 24kbps (3-bit) data\n"); fprintf(stderr, "\t-4\tGenerate G.721 32kbps (4-bit) data [default]\n"); fprintf(stderr, "\t-5\tGenerate G.723 40kbps (5-bit) data\n"); fprintf(stderr, "\t-a\tProcess 8-bit A-law input data\n"); fprintf(stderr, "\t-u\tProcess 8-bit u-law input data [default]\n"); fprintf(stderr, "\t-l\tProcess 16-bit linear PCM input data\n"); exit(1); } argc--; argv++; } /* Read input file and process */ while (fread(in_buf, in_size, 1, stdin) == 1) { code = (*enc_routine)(in_size == 2 ? sample_short : sample_char, in_coding, &state); resid = pack_output(code, enc_bits); } /* Write zero codes until all residual codes are written out */ while (resid) { resid = pack_output(0, enc_bits); } fclose(stdout); } ta [the default] -5 encode to (decode from) G.723 40kbps (5-bit) data -a encode from (decode to) A-law data -u encode from (decode to) u-law data [the default] -l encode from (decode to) 16-bit linear data Examples: # Read 16-bit linear and output G.721 encode -4 -l g721file # Read 40Kbps G.723 and outputg711.c 444 1750 12 16541 5250514235 4776 /* * 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))); } g721.c 444 1750 12 12211 5250514235 4765 /* * 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 */ /* * g721.c * * Description: * * g721_encoder(), g721_decoder() * * These routines comprise an implementation of the CCITT G.721 ADPCM * coding algorithm. Essentially, this implementation is identical to * the bit level description except for a few deviations which * take advantage of work station attributes, such as hardware 2's * complement arithmetic and large memory. Specifically, certain time * consuming operations such as multiplications are replaced * with lookup tables and software 2's complement operations are * replaced with hardware 2's complement. * * The deviation from the bit level specification (lookup tables) * preserves the bit level performance specifications. * * As outlined in the G.721 Recommendation, the algorithm is broken * down into modules. Each section of code below is preceded by * the name of the module which it is implementing. * */ #include "g72x.h" static short qtab_721[7] = {-124, 80, 178, 246, 300, 349, 400}; /* * Maps G.721 code word to reconstructed scale factor normalized log * magnitude values. */ static short _dqlntab[16] = {-2048, 4, 135, 213, 273, 323, 373, 425, 425, 373, 323, 273, 213, 135, 4, -2048}; /* Maps G.721 code word to log of scale factor multiplier. */ static short _witab[16] = {-12, 18, 41, 64, 112, 198, 355, 1122, 1122, 355, 198, 112, 64, 41, 18, -12}; /* * Maps G.721 code words to a set of values whose long and short * term averages are computed and then compared to give an indication * how stationary (steady state) the signal is. */ static short _fitab[16] = {0, 0, 0, 0x200, 0x200, 0x200, 0x600, 0xE00, 0xE00, 0x600, 0x200, 0x200, 0x200, 0, 0, 0}; /* * g721_encoder() * * Encodes the input vale of linear PCM, A-law or u-law data sl and returns * the resulting code. -1 is returned for unknown input coding value. */ int g721_encoder( int sl, int in_coding, struct g72x_state *state_ptr) { short sezi, se, sez; /* ACCUM */ short d; /* SUBTA */ short sr; /* ADDB */ short y; /* MIX */ short dqsez; /* ADDC */ short dq, i; switch (in_coding) { /* linearize input sample to 14-bit PCM */ case AUDIO_ENCODING_ALAW: sl = alaw2linear(sl) >> 2; break; case AUDIO_ENCODING_ULAW: sl = ulaw2linear(sl) >> 2; break; case AUDIO_ENCODING_LINEAR: sl >>= 2; /* 14-bit dynamic range */ break; default: return (-1); } sezi = predictor_zero(state_ptr); sez = sezi >> 1; se = (sezi + predictor_pole(state_ptr)) >> 1; /* estimated signal */ d = sl - se; /* estimation difference */ /* quantize the prediction difference */ y = step_size(state_ptr); /* quantizer step size */ i = quantize(d, y, qtab_721, 7); /* i = ADPCM code */ dq = reconstruct(i & 8, _dqlntab[i], y); /* quantized est diff */ sr = (dq < 0) ? se - (dq & 0x3FFF) : se + dq; /* reconst. signal */ dqsez = sr + sez - se; /* pole prediction diff. */ update(4, y, _witab[i] << 5, _fitab[i], dq, sr, dqsez, state_ptr); return (i); } /* * g721_decoder() * * Description: * * Decodes a 4-bit code of G.721 encoded data of i and * returns the resulting linear PCM, A-law or u-law value. * return -1 for unknown out_coding value. */ int g721_decoder( int i, int out_coding, struct g72x_state *state_ptr) { short sezi, sei, sez, se; /* ACCUM */ short y; /* MIX */ short sr; /* ADDB */ short dq; short dqsez; i &= 0x0f; /* mask to get proper bits */ sezi = predictor_zero(state_ptr); sez = sezi >> 1; sei = sezi + predictor_pole(state_ptr); se = sei >> 1; /* se = estimated signal */ y = step_size(state_ptr); /* dynamic quantizer step size */ dq = reconstruct(i & 0x08, _dqlntab[i], y); /* quantized diff. */ sr = (dq < 0) ? (se - (dq & 0x3FFF)) : se + dq; /* reconst. signal */ dqsez = sr - se + sez; /* pole prediction diff. */ update(4, y, _witab[i] << 5, _fitab[i], dq, sr, dqsez, state_ptr); switch (out_coding) { case AUDIO_ENCODING_ALAW: return (tandem_adjust_alaw(sr, se, y, i, 8, qtab_721)); case AUDIO_ENCODING_ULAW: return (tandem_adjust_ulaw(sr, se, y, i, 8, qtab_721)); case AUDIO_ENCODING_LINEAR: return (sr << 2); /* sr was 14-bit dynamic range */ default: return (-1); } } evel specification (lookup tables) * preserves the bit level performance specifications. * * As outlined in the G.721 Recommendation, the algorithm is broken * down into modules. Each section of code below is preceded by * the name of the module which it is implementing. * */ #include "g72x.h" static short qtab_721[7] = {-124, 80, 178, 246, 300, 349, 400}; /* * Mg723_24.c 444 1750 12 11035 5250514235 5277 /* * 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 */ /* * g723_24.c * * Description: * * g723_24_encoder(), g723_24_decoder() * * These routines comprise an implementation of the CCITT G.723 24 Kbps * ADPCM coding algorithm. Essentially, this implementation is identical to * the bit level description except for a few deviations which take advantage * of workstation attributes, such as hardware 2's complement arithmetic. * */ #include "g72x.h" /* * Maps G.723_24 code word to reconstructed scale factor normalized log * magnitude values. */ static short _dqlntab[8] = {-2048, 135, 273, 373, 373, 273, 135, -2048}; /* Maps G.723_24 code word to log of scale factor multiplier. */ static short _witab[8] = {-128, 960, 4384, 18624, 18624, 4384, 960, -128}; /* * Maps G.723_24 code words to a set of values whose long and short * term averages are computed and then compared to give an indication * how stationary (steady state) the signal is. */ static short _fitab[8] = {0, 0x200, 0x400, 0xE00, 0xE00, 0x400, 0x200, 0}; static short qtab_723_24[3] = {8, 218, 331}; /* * g723_24_encoder() * * Encodes a linear PCM, A-law or u-law input sample and returns its 3-bit code. * Returns -1 if invalid input coding value. */ int g723_24_encoder( int sl, int in_coding, struct g72x_state *state_ptr) { short sei, sezi, se, sez; /* ACCUM */ short d; /* SUBTA */ short y; /* MIX */ short sr; /* ADDB */ short dqsez; /* ADDC */ short dq, i; switch (in_coding) { /* linearize input sample to 14-bit PCM */ case AUDIO_ENCODING_ALAW: sl = alaw2linear(sl) >> 2; break; case AUDIO_ENCODING_ULAW: sl = ulaw2linear(sl) >> 2; break; case AUDIO_ENCODING_LINEAR: sl >>= 2; /* sl of 14-bit dynamic range */ break; default: return (-1); } sezi = predictor_zero(state_ptr); sez = sezi >> 1; sei = sezi + predictor_pole(state_ptr); se = sei >> 1; /* se = estimated signal */ d = sl - se; /* d = estimation diff. */ /* quantize prediction difference d */ y = step_size(state_ptr); /* quantizer step size */ i = quantize(d, y, qtab_723_24, 3); /* i = ADPCM code */ dq = reconstruct(i & 4, _dqlntab[i], y); /* quantized diff. */ sr = (dq < 0) ? se - (dq & 0x3FFF) : se + dq; /* reconstructed signal */ dqsez = sr + sez - se; /* pole prediction diff. */ update(3, y, _witab[i], _fitab[i], dq, sr, dqsez, state_ptr); return (i); } /* * g723_24_decoder() * * Decodes a 3-bit CCITT G.723_24 ADPCM code and returns * the resulting 16-bit linear PCM, A-law or u-law sample value. * -1 is returned if the output coding is unknown. */ int g723_24_decoder( int i, int out_coding, struct g72x_state *state_ptr) { short sezi, sei, sez, se; /* ACCUM */ short y; /* MIX */ short sr; /* ADDB */ short dq; short dqsez; i &= 0x07; /* mask to get proper bits */ sezi = predictor_zero(state_ptr); sez = sezi >> 1; sei = sezi + predictor_pole(state_ptr); se = sei >> 1; /* se = estimated signal */ y = step_size(state_ptr); /* adaptive quantizer step size */ dq = reconstruct(i & 0x04, _dqlntab[i], y); /* unquantize pred diff */ sr = (dq < 0) ? (se - (dq & 0x3FFF)) : (se + dq); /* reconst. signal */ dqsez = sr - se + sez; /* pole prediction diff. */ update(3, y, _witab[i], _fitab[i], dq, sr, dqsez, state_ptr); switch (out_coding) { case AUDIO_ENCODING_ALAW: return (tandem_adjust_alaw(sr, se, y, i, 4, qtab_723_24)); case AUDIO_ENCODING_ULAW: return (tandem_adjust_ulaw(sr, se, y, i, 4, qtab_723_24)); case AUDIO_ENCODING_LINEAR: return (sr << 2); /* sr was of 14-bit dynamic range */ default: return (-1); } } g723_40.c 444 1750 12 12631 5250514235 5300 /* * 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 */ /* * g723_40.c * * Description: * * g723_40_encoder(), g723_40_decoder() * * These routines comprise an implementation of the CCITT G.723 40Kbps * ADPCM coding algorithm. Essentially, this implementation is identical to * the bit level description except for a few deviations which * take advantage of workstation attributes, such as hardware 2's * complement arithmetic. * * The deviation from the bit level specification (lookup tables), * preserves the bit level performance specifications. * * As outlined in the G.723 Recommendation, the algorithm is broken * down into modules. Each section of code below is preceded by * the name of the module which it is implementing. * */ #include "g72x.h" /* * Maps G.723_40 code word to ructeconstructed scale factor normalized log * magnitude values. */ static short _dqlntab[32] = {-2048, -66, 28, 104, 169, 224, 274, 318, 358, 395, 429, 459, 488, 514, 539, 566, 566, 539, 514, 488, 459, 429, 395, 358, 318, 274, 224, 169, 104, 28, -66, -2048}; /* Maps G.723_40 code word to log of scale factor multiplier. */ static short _witab[32] = {448, 448, 768, 1248, 1280, 1312, 1856, 3200, 4512, 5728, 7008, 8960, 11456, 14080, 16928, 22272, 22272, 16928, 14080, 11456, 8960, 7008, 5728, 4512, 3200, 1856, 1312, 1280, 1248, 768, 448, 448}; /* * Maps G.723_40 code words to a set of values whose long and short * term averages are computed and then compared to give an indication * how stationary (steady state) the signal is. */ static short _fitab[32] = {0, 0, 0, 0, 0, 0x200, 0x200, 0x200, 0x200, 0x200, 0x400, 0x600, 0x800, 0xA00, 0xC00, 0xC00, 0xC00, 0xC00, 0xA00, 0x800, 0x600, 0x400, 0x200, 0x200, 0x200, 0x200, 0x200, 0, 0, 0, 0, 0}; static short qtab_723_40[15] = {-122, -16, 68, 139, 198, 250, 298, 339, 378, 413, 445, 475, 502, 528, 553}; /* * g723_40_encoder() * * Encodes a 16-bit linear PCM, A-law or u-law input sample and retuens * the resulting 5-bit CCITT G.723 40Kbps code. * Returns -1 if the input coding value is invalid. */ int g723_40_encoder( int sl, int in_coding, struct g72x_state *state_ptr) { short sei, sezi, se, sez; /* ACCUM */ short d; /* SUBTA */ short y; /* MIX */ short sr; /* ADDB */ short dqsez; /* ADDC */ short dq, i; switch (in_coding) { /* linearize input sample to 14-bit PCM */ case AUDIO_ENCODING_ALAW: sl = alaw2linear(sl) >> 2; break; case AUDIO_ENCODING_ULAW: sl = ulaw2linear(sl) >> 2; break; case AUDIO_ENCODING_LINEAR: sl >>= 2; /* sl of 14-bit dynamic range */ break; default: return (-1); } sezi = predictor_zero(state_ptr); sez = sezi >> 1; sei = sezi + predictor_pole(state_ptr); se = sei >> 1; /* se = estimated signal */ d = sl - se; /* d = estimation difference */ /* quantize prediction difference */ y = step_size(state_ptr); /* adaptive quantizer step size */ i = quantize(d, y, qtab_723_40, 15); /* i = ADPCM code */ dq = reconstruct(i & 0x10, _dqlntab[i], y); /* quantized diff */ sr = (dq < 0) ? se - (dq & 0x7FFF) : se + dq; /* reconstructed signal */ dqsez = sr + sez - se; /* dqsez = pole prediction diff. */ update(5, y, _witab[i], _fitab[i], dq, sr, dqsez, state_ptr); return (i); } /* * g723_40_decoder() * * Decodes a 5-bit CCITT G.723 40Kbps code and returns * the resulting 16-bit linear PCM, A-law or u-law sample value. * -1 is returned if the output coding is unknown. */ int g723_40_decoder( int i, int out_coding, struct g72x_state *state_ptr) { short sezi, sei, sez, se; /* ACCUM */ short y, dif; /* MIX */ short sr; /* ADDB */ short dq; short dqsez; i &= 0x1f; /* mask to get proper bits */ sezi = predictor_zero(state_ptr); sez = sezi >> 1; sei = sezi + predictor_pole(state_ptr); se = sei >> 1; /* se = estimated signal */ y = step_size(state_ptr); /* adaptive quantizer step size */ dq = reconstruct(i & 0x10, _dqlntab[i], y); /* estimation diff. */ sr = (dq < 0) ? (se - (dq & 0x7FFF)) : (se + dq); /* reconst. signal */ dqsez = sr - se + sez; /* pole prediction diff. */ update(5, y, _witab[i], _fitab[i], dq, sr, dqsez, state_ptr); switch (out_coding) { case AUDIO_ENCODING_ALAW: return (tandem_adjust_alaw(sr, se, y, i, 0x10, qtab_723_40)); case AUDIO_ENCODING_ULAW: return (tandem_adjust_ulaw(sr, se, y, i, 0x10, qtab_723_40)); case AUDIO_ENCODING_LINEAR: return (sr << 2); /* sr was of 14-bit dynamic range */ default: return (-1); } } g72x.c 444 1750 12 34060 5250514235 5102 /* * 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.c * * Common routines for G.721 and G.723 conversions. */ #include "g72x.h" static short power2[15] = {1, 2, 4, 8, 0x10, 0x20, 0x40, 0x80, 0x100, 0x200, 0x400, 0x800, 0x1000, 0x2000, 0x4000}; /* * quan() * * quantizes the input val against the table of size short integers. * It returns i if table[i - 1] <= val < table[i]. * * Using linear search for simple coding. */ static int quan( int val, short *table, int size) { int i; for (i = 0; i < size; i++) if (val < *table++) break; return (i); } /* * fmult() * * returns the integer product of the 14-bit integer "an" and * "floating point" representation (4-bit exponent, 6-bit mantessa) "srn". */ static int fmult( int an, int srn) { short anmag, anexp, anmant; short wanexp, wanmag, wanmant; short retval; anmag = (an > 0) ? an : ((-an) & 0x1FFF); anexp = quan(anmag, power2, 15) - 6; anmant = (anmag == 0) ? 32 : (anexp >= 0) ? anmag >> anexp : anmag << -anexp; wanexp = anexp + ((srn >> 6) & 0xF) - 13; wanmant = (anmant * (srn & 077) + 0x30) >> 4; retval = (wanexp >= 0) ? ((wanmant << wanexp) & 0x7FFF) : (wanmant >> -wanexp); return (((an ^ srn) < 0) ? -retval : retval); } /* * g72x_init_state() * * This routine initializes and/or resets the g72x_state structure * pointed to by 'state_ptr'. * All the initial state values are specified in the CCITT G.721 document. */ void g72x_init_state( struct g72x_state *state_ptr) { int cnta; state_ptr->yl = 34816; state_ptr->yu = 544; state_ptr->dms = 0; state_ptr->dml = 0; state_ptr->ap = 0; for (cnta = 0; cnta < 2; cnta++) { state_ptr->a[cnta] = 0; state_ptr->pk[cnta] = 0; state_ptr->sr[cnta] = 32; } for (cnta = 0; cnta < 6; cnta++) { state_ptr->b[cnta] = 0; state_ptr->dq[cnta] = 32; } state_ptr->td = 0; } /* * predictor_zero() * * computes the estimated signal from 6-zero predictor. * */ int predictor_zero( struct g72x_state *state_ptr) { int i; int sezi; sezi = fmult(state_ptr->b[0] >> 2, state_ptr->dq[0]); for (i = 1; i < 6; i++) /* ACCUM */ sezi += fmult(state_ptr->b[i] >> 2, state_ptr->dq[i]); return (sezi); } /* * predictor_pole() * * computes the estimated signal from 2-pole predictor. * */ int predictor_pole( struct g72x_state *state_ptr) { return (fmult(state_ptr->a[1] >> 2, state_ptr->sr[1]) + fmult(state_ptr->a[0] >> 2, state_ptr->sr[0])); } /* * step_size() * * computes the quantization step size of the adaptive quantizer. * */ int step_size( struct g72x_state *state_ptr) { int y; int dif; int al; if (state_ptr->ap >= 256) return (state_ptr->yu); else { y = state_ptr->yl >> 6; dif = state_ptr->yu - y; al = state_ptr->ap >> 2; if (dif > 0) y += (dif * al) >> 6; else if (dif < 0) y += (dif * al + 0x3F) >> 6; return (y); } } /* * quantize() * * Given a raw sample, 'd', of the difference signal and a * quantization step size scale factor, 'y', this routine returns the * ADPCM codeword to which that sample gets quantized. The step * size scale factor division operation is done in the log base 2 domain * as a subtraction. */ int quantize( int d, /* Raw difference signal sample */ int y, /* Step size multiplier */ short *table, /* quantization table */ int size) /* table size of short integers */ { short dqm; /* Magnitude of 'd' */ short exp; /* Integer part of base 2 log of 'd' */ short mant; /* Fractional part of base 2 log */ short dl; /* Log of magnitude of 'd' */ short dln; /* Step size scale factor normalized log */ int i; /* * LOG * * Compute base 2 log of 'd', and store in 'dl'. */ dqm = abs(d); exp = quan(dqm >> 1, power2, 15); mant = ((dqm << 7) >> exp) & 0x7F; /* Fractional portion. */ dl = (exp << 7) + mant; /* * SUBTB * * "Divide" by step size multiplier. */ dln = dl - (y >> 2); /* * QUAN * * Obtain codword i for 'd'. */ i = quan(dln, table, size); if (d < 0) /* take 1's complement of i */ return ((size << 1) + 1 - i); else if (i == 0) /* take 1's complement of 0 */ return ((size << 1) + 1); /* new in 1988 */ else return (i); } /* * reconstruct() * * Returns reconstructed difference signal 'dq' obtained from * codeword 'i' and quantization step size scale factor 'y'. * Multiplication is performed in log base 2 domain as addition. */ int reconstruct( int sign, /* 0 for non-negative value */ int dqln, /* G.72x codeword */ int y) /* Step size multiplier */ { short dql; /* Log of 'dq' magnitude */ short dex; /* Integer part of log */ short dqt; short dq; /* Reconstructed difference signal sample */ dql = dqln + (y >> 2); /* ADDA */ if (dql < 0) { return ((sign) ? -0x8000 : 0); } else { /* ANTILOG */ dex = (dql >> 7) & 15; dqt = 128 + (dql & 127); dq = (dqt << 7) >> (14 - dex); return ((sign) ? (dq - 0x8000) : dq); } } /* * update() * * updates the state variables for each output code */ void update( int code_size, /* distinguish 723_40 with others */ int y, /* quantizer step size */ int wi, /* scale factor multiplier */ int fi, /* for long/short term energies */ int dq, /* quantized prediction difference */ int sr, /* reconstructed signal */ int dqsez, /* difference from 2-pole predictor */ struct g72x_state *state_ptr) /* coder state pointer */ { int cnt; short mag, exp, mant; /* Adaptive predictor, FLOAT A */ short a2p; /* LIMC */ short a1ul; /* UPA1 */ short ua2, pks1; /* UPA2 */ short uga2a, fa1; short uga2b; char tr; /* tone/transition detector */ short ylint, thr2, dqthr; short ylfrac, thr1; short pk0; pk0 = (dqsez < 0) ? 1 : 0; /* needed in updating predictor poles */ mag = dq & 0x7FFF; /* prediction difference magnitude */ /* TRANS */ ylint = state_ptr->yl >> 15; /* exponent part of yl */ ylfrac = (state_ptr->yl >> 10) & 0x1F; /* fractional part of yl */ thr1 = (32 + ylfrac) << ylint; /* threshold */ thr2 = (ylint > 9) ? 31 << 10 : thr1; /* limit thr2 to 31 << 10 */ dqthr = (thr2 + (thr2 >> 1)) >> 1; /* dqthr = 0.75 * thr2 */ if (state_ptr->td == 0) /* signal supposed voice */ tr = 0; else if (mag <= dqthr) /* supposed data, but small mag */ tr = 0; /* treated as voice */ else /* signal is data (modem) */ tr = 1; /* * Quantizer scale factor adaptation. */ /* FUNCTW & FILTD & DELAY */ /* update non-steady state step size multiplier */ state_ptr->yu = y + ((wi - y) >> 5); /* LIMB */ if (state_ptr->yu < 544) /* 544 <= yu <= 5120 */ state_ptr->yu = 544; else if (state_ptr->yu > 5120) state_ptr->yu = 5120; /* FILTE & DELAY */ /* update steady state step size multiplier */ state_ptr->yl += state_ptr->yu + ((-state_ptr->yl) >> 6); /* * Adaptive predictor coefficients. */ if (tr == 1) { /* reset a's and b's for modem signal */ state_ptr->a[0] = 0; state_ptr->a[1] = 0; state_ptr->b[0] = 0; state_ptr->b[1] = 0; state_ptr->b[2] = 0; state_ptr->b[3] = 0; state_ptr->b[4] = 0; state_ptr->b[5] = 0; } else { /* update a's and b's */ pks1 = pk0 ^ state_ptr->pk[0]; /* UPA2 */ /* update predictor pole a[1] */ a2p = state_ptr->a[1] - (state_ptr->a[1] >> 7); if (dqsez != 0) { fa1 = (pks1) ? state_ptr->a[0] : -state_ptr->a[0]; if (fa1 < -8191) /* a2p = function of fa1 */ a2p -= 0x100; else if (fa1 > 8191) a2p += 0xFF; else a2p += fa1 >> 5; if (pk0 ^ state_ptr->pk[1]) /* LIMC */ if (a2p <= -12160) a2p = -12288; else if (a2p >= 12416) a2p = 12288; else a2p -= 0x80; else if (a2p <= -12416) a2p = -12288; else if (a2p >= 12160) a2p = 12288; else a2p += 0x80; } /* TRIGB & DELAY */ state_ptr->a[1] = a2p; /* UPA1 */ /* update predictor pole a[0] */ state_ptr->a[0] -= state_ptr->a[0] >> 8; if (dqsez != 0) if (pks1 == 0) state_ptr->a[0] += 192; else state_ptr->a[0] -= 192; /* LIMD */ a1ul = 15360 - a2p; if (state_ptr->a[0] < -a1ul) state_ptr->a[0] = -a1ul; else if (state_ptr->a[0] > a1ul) state_ptr->a[0] = a1ul; /* UPB : update predictor zeros b[6] */ for (cnt = 0; cnt < 6; cnt++) { if (code_size == 5) /* for 40Kbps G.723 */ state_ptr->b[cnt] -= state_ptr->b[cnt] >> 9; else /* for G.721 and 24Kbps G.723 */ state_ptr->b[cnt] -= state_ptr->b[cnt] >> 8; if (dq & 0x7FFF) { /* XOR */ if ((dq ^ state_ptr->dq[cnt]) >= 0) state_ptr->b[cnt] += 128; else state_ptr->b[cnt] -= 128; } } } for (cnt = 5; cnt > 0; cnt--) state_ptr->dq[cnt] = state_ptr->dq[cnt-1]; /* FLOAT A : convert dq[0] to 4-bit exp, 6-bit mantissa f.p. */ if (mag == 0) { state_ptr->dq[0] = (dq >= 0) ? 0x20 : 0xFC20; } else { exp = quan(mag, power2, 15); state_ptr->dq[0] = (dq >= 0) ? (exp << 6) + ((mag << 6) >> exp) : (exp << 6) + ((mag << 6) >> exp) - 0x400; } state_ptr->sr[1] = state_ptr->sr[0]; /* FLOAT B : convert sr to 4-bit exp., 6-bit mantissa f.p. */ if (sr == 0) { state_ptr->sr[0] = 0x20; } else if (sr > 0) { exp = quan(sr, power2, 15); state_ptr->sr[0] = (exp << 6) + ((sr << 6) >> exp); } else if (sr > -32768) { mag = -sr; exp = quan(mag, power2, 15); state_ptr->sr[0] = (exp << 6) + ((mag << 6) >> exp) - 0x400; } else state_ptr->sr[0] = 0xFC20; /* DELAY A */ state_ptr->pk[1] = state_ptr->pk[0]; state_ptr->pk[0] = pk0; /* TONE */ if (tr == 1) /* this sample has been treated as data */ state_ptr->td = 0; /* next one will be treated as voice */ else if (a2p < -11776) /* small sample-to-sample correlation */ state_ptr->td = 1; /* signal may be data */ else /* signal is voice */ state_ptr->td = 0; /* * Adaptation speed control. */ state_ptr->dms += (fi - state_ptr->dms) >> 5; /* FILTA */ state_ptr->dml += (((fi << 2) - state_ptr->dml) >> 7); /* FILTB */ if (tr == 1) state_ptr->ap = 256; else if (y < 1536) /* SUBTC */ state_ptr->ap += (0x200 - state_ptr->ap) >> 4; else if (state_ptr->td == 1) state_ptr->ap += (0x200 - state_ptr->ap) >> 4; else if (abs((state_ptr->dms << 2) - state_ptr->dml) >= (state_ptr->dml >> 3)) state_ptr->ap += (0x200 - state_ptr->ap) >> 4; else state_ptr->ap += (-state_ptr->ap) >> 4; } /* * tandem_adjust(sr, se, y, i, sign) * * At the end of ADPCM decoding, it simulates an encoder which may be receiving * the output of this decoder as a tandem process. If the output of the * simulated encoder differs from the input to this decoder, the decoder output * is adjusted by one level of A-law or u-law codes. * * Input: * sr decoder output linear PCM sample, * se predictor estimate sample, * y quantizer step size, * i decoder input code, * sign sign bit of code i * * Return: * adjusted A-law or u-law compressed sample. */ int tandem_adjust_alaw( int sr, /* decoder output linear PCM sample */ int se, /* predictor estimate sample */ int y, /* quantizer step size */ int i, /* decoder input code */ int sign, short *qtab) { unsigned char sp; /* A-law compressed 8-bit code */ short dx; /* prediction error */ char id; /* quantized prediction error */ int sd; /* adjusted A-law decoded sample value */ int im; /* biased magnitude of i */ int imx; /* biased magnitude of id */ if (sr <= -32768) sr = -1; sp = linear2alaw((sr >> 1) << 3); /* short to A-law compression */ dx = (alaw2linear(sp) >> 2) - se; /* 16-bit prediction error */ id = quantize(dx, y, qtab, sign - 1); if (id == i) { /* no adjustment on sp */ return (sp); } else { /* sp adjustment needed */ /* ADPCM codes : 8, 9, ... F, 0, 1, ... , 6, 7 */ im = i ^ sign; /* 2's complement to biased unsigned */ imx = id ^ sign; if (imx > im) { /* sp adjusted to next lower value */ if (sp & 0x80) { sd = (sp == 0xD5) ? 0x55 : ((sp ^ 0x55) - 1) ^ 0x55; } else { sd = (sp == 0x2A) ? 0x2A : ((sp ^ 0x55) + 1) ^ 0x55; } } else { /* sp adjusted to next higher value */ if (sp & 0x80) sd = (sp == 0xAA) ? 0xAA : ((sp ^ 0x55) + 1) ^ 0x55; else sd = (sp == 0x55) ? 0xD5 : ((sp ^ 0x55) - 1) ^ 0x55; } return (sd); } } int tandem_adjust_ulaw( int sr, /* decoder output linear PCM sample */ int se, /* predictor estimate sample */ int y, /* quantizer step size */ int i, /* decoder input code */ int sign, short *qtab) { unsigned char sp; /* u-law compressed 8-bit code */ short dx; /* prediction error */ char id; /* quantized prediction error */ int sd; /* adjusted u-law decoded sample value */ int im; /* biased magnitude of i */ int imx; /* biased magnitude of id */ if (sr <= -32768) sr = 0; sp = linear2ulaw(sr << 2); /* short to u-law compression */ dx = (ulaw2linear(sp) >> 2) - se; /* 16-bit prediction error */ id = quantize(dx, y, qtab, sign - 1); if (id == i) { return (sp); } else { /* ADPCM codes : 8, 9, ... F, 0, 1, ... , 6, 7 */ im = i ^ sign; /* 2's complement to biased unsigned */ imx = id ^ sign; if (imx > im) { /* sp adjusted to next lower value */ if (sp & 0x80) sd = (sp == 0xFF) ? 0x7E : sp + 1; else sd = (sp == 0) ? 0 : sp - 1; } else { /* sp adjusted to next higher value */ if (sp & 0x80) sd = (sp == 0x80) ? 0x80 : sp - 1; else sd = (sp == 0x7F) ? 0xFE : sp + 1; } return (sd); } } hort term energies */ int dq, /* quantized prediction difference */ int sr, /* reconstructed signal */ int dqsez, /* difference from 2-pole predictor */ struct g72x_state *state_ptr) /* coder state pointer */ { int cnt; short mag, exp, mant; /* Adaptive predictor, FLOAT A */ short a2p; /* LIMC */ short a1ul; /* UPA1 */ short ua2, pks1; /* UPA2 */ short uga2a, fa1; short uga2b; char tr; /* tone/transition detector */ short ylint, g72x.h 444 1750 12 6407 5250514235 5073 /* * 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_stat(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); #endif /* !_G72X_H */ 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. ode i * * Return: * adjusted A-law or u-law compressed sample. */ int tandem_adjust_alaw( int sr, /* decoder output linear PCM sample */ int se, /* predictor estimate sample */ int y, /* quantizer step size */ int i, /* decoder input code */ int sign, short *qtab) { unsigned char sp; /* A-law compressed 8-bit code */ short dx; /* prediction error */ char id; /* quantized prediction error */ int sd; /* adjusted A-law decoded sample value */ int im; /* biased magnitude of i */ int imx; /* biased magnitude of id */ if (sr <= -32768) sr = -1; sp = linear2alaw((sr >> 1) << 3); /* short to A-law compression */ dx = (alaw2linear(sp) >> 2) - se; /* 16-bit prediction error */ id = quantize(dx, y, qtab, sign - 1); if (id == i) { /* no adjustment on sp */ return (sp); } else { /* sp adjustment needed */ /* ADPCM codes : 8, 9, ... F, 0, 1, ... , 6, 7 */ im = i ^ sign; /* 2's complement to biased unsigned */ imx = id ^ sign; if (imx > im) { /* sp adjusted to next lower value */ if (sp & 0x80) { sd = (sp == 0xD5) ? 0x55 : ((sp ^ 0x55) - 1) ^ 0x55; } else { sd = (sp == 0x2A) ? 0x2A : ((sp ^ 0x55) + 1) ^ 0x55; } } else { /* sp adjusted to next higher value */ if (sp & 0x80) sd = (sp == 0xAA) ? 0xAA : ((sp ^ 0x55) + 1) ^ 0x55; else sd = (sp == 0x55) ? 0xD5 : ((sp ^ 0x55) - 1) ^ 0x55; } return (sd); } } int tandem_adjust_ulaw( int sr, /* decoder output linear PCM sample */ int se, /* predictor estimate sample */ int y, /* quantizer step size */ int i, /* decoder input code */ int sign, short *qtab) { unsigned char sp; /* u-law compressed 8-bit code */ short dx; /* prediction error */ char id; /* quantized prediction error */ int sd; /* adjusted u-law decoded sample value */ int im; /* biased magnitude of i */ int imx; /* biased magnitude of id */ if (sr <= -32768) sr = 0; sp = linear2ulaw(sr << 2); /* short to u-law compression */ dx = (ulaw2linear(sp) >> 2) - se; /* 16-bit prediction error */ id = quantize(dx, y, qtab, sign - 1); if (id == i) { return (sp); } else { /* ADPCM codes : 8, 9, ... F, 0, 1, ... , 6, 7 */ im = i ^ sign; /* 2's complement to biased unsigned */ imx = id ^ sign; if (imx > im) { /* sp adjusted to next lower value */ if (sp & 0x80) sd = (sp == 0xFF) ? 0x7E : sp + 1; else sd = (sp == 0) ? 0 : sp - 1; } else { /* sp adjusted to next higher value */ if (sp & 0x80) sd = (sp == 0x80) ? 0x80 : sp - 1; else sd = (sp == 0x7F) ? 0xFE : sp + 1; } return (sd); } } hort term energies */ int dq, /* quantized prediction difference */ int sr, /* reconstructed signal */ int dqsez, /* difference from 2-pole predictor */ struct g72x_state *state_ptr) /* coder state pointer */ { int cnt; short mag, exp, mant; /* Adaptive predictor, FLOAT A */ short a2p; /* LIMC */ short a1ul; /* UPA1 */ short ua2, pks1; /* UPA2 */ short uga2a, fa1; short uga2b; char tr; /* tone/transition detector */ short ylint, g72x.h 444 1750 12 6407 5250514235 5073 /* * 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_stat(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