Alexandre Lision | 7c6f4a6 | 2013-09-05 13:27:01 -0400 | [diff] [blame] | 1 | /* |
| 2 | ** Copyright (C) 1999-2011 Erik de Castro Lopo <erikd@mega-nerd.com> |
| 3 | ** |
| 4 | ** This program is free software; you can redistribute it and/or modify |
| 5 | ** it under the terms of the GNU General Public License as published by |
| 6 | ** the Free Software Foundation; either version 2 of the License, or |
| 7 | ** (at your option) any later version. |
| 8 | ** |
| 9 | ** This program is distributed in the hope that it will be useful, |
| 10 | ** but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | ** GNU General Public License for more details. |
| 13 | ** |
| 14 | ** You should have received a copy of the GNU General Public License |
| 15 | ** along with this program; if not, write to the Free Software |
| 16 | ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 17 | */ |
| 18 | |
| 19 | #include "sfconfig.h" |
| 20 | |
| 21 | #include <stdio.h> |
| 22 | #include <stdlib.h> |
| 23 | #include <string.h> |
| 24 | |
| 25 | #if HAVE_UNISTD_H |
| 26 | #include <unistd.h> |
| 27 | #endif |
| 28 | |
| 29 | #include <sndfile.h> |
| 30 | |
| 31 | #include "utils.h" |
| 32 | |
| 33 | #define BUFFER_SIZE (65536) |
| 34 | |
| 35 | static unsigned char ulaw_encode (int sample) ; |
| 36 | static int ulaw_decode (unsigned int ulawbyte) ; |
| 37 | |
| 38 | static short short_buffer [BUFFER_SIZE] ; |
| 39 | static unsigned char ulaw_buffer [BUFFER_SIZE] ; |
| 40 | |
| 41 | int |
| 42 | main (void) |
| 43 | { SNDFILE *file ; |
| 44 | SF_INFO sfinfo ; |
| 45 | const char *filename ; |
| 46 | int k ; |
| 47 | |
| 48 | print_test_name ("ulaw_test", "encoder") ; |
| 49 | |
| 50 | filename = "test.raw" ; |
| 51 | |
| 52 | sf_info_setup (&sfinfo, SF_FORMAT_RAW | SF_FORMAT_ULAW, 44100, 1) ; |
| 53 | |
| 54 | if ((file = sf_open (filename, SFM_WRITE, &sfinfo)) == NULL) |
| 55 | { printf ("sf_open_write failed with error : ") ; |
| 56 | fflush (stdout) ; |
| 57 | puts (sf_strerror (NULL)) ; |
| 58 | exit (1) ; |
| 59 | } ; |
| 60 | |
| 61 | /* Generate a file containing all possible 16 bit sample values |
| 62 | ** and write it to disk as ulaw encoded.frames. |
| 63 | */ |
| 64 | |
| 65 | for (k = 0 ; k < 0x10000 ; k++) |
| 66 | short_buffer [k] = k & 0xFFFF ; |
| 67 | |
| 68 | sf_write_short (file, short_buffer, BUFFER_SIZE) ; |
| 69 | sf_close (file) ; |
| 70 | |
| 71 | /* Now open that file and compare the ulaw encoded sample values |
| 72 | ** with what they should be. |
| 73 | */ |
| 74 | |
| 75 | if ((file = sf_open (filename, SFM_READ, &sfinfo)) == NULL) |
| 76 | { printf ("sf_open_write failed with error : ") ; |
| 77 | puts (sf_strerror (NULL)) ; |
| 78 | exit (1) ; |
| 79 | } ; |
| 80 | |
| 81 | check_log_buffer_or_die (file, __LINE__) ; |
| 82 | |
| 83 | if (sf_read_raw (file, ulaw_buffer, BUFFER_SIZE) != BUFFER_SIZE) |
| 84 | { printf ("sf_read_raw : ") ; |
| 85 | puts (sf_strerror (file)) ; |
| 86 | exit (1) ; |
| 87 | } ; |
| 88 | |
| 89 | for (k = 0 ; k < 0x10000 ; k++) |
| 90 | if (ulaw_encode (short_buffer [k]) != ulaw_buffer [k]) |
| 91 | { printf ("Encoder error : sample #%d (0x%02X should be 0x%02X)\n", k, ulaw_buffer [k], ulaw_encode (short_buffer [k])) ; |
| 92 | exit (1) ; |
| 93 | } ; |
| 94 | |
| 95 | sf_close (file) ; |
| 96 | |
| 97 | puts ("ok") ; |
| 98 | |
| 99 | print_test_name ("ulaw_test", "decoder") ; |
| 100 | |
| 101 | /* Now generate a file containing all possible 8 bit encoded |
| 102 | ** sample values and write it to disk as ulaw encoded.frames. |
| 103 | */ |
| 104 | |
| 105 | if (! (file = sf_open (filename, SFM_WRITE, &sfinfo))) |
| 106 | { printf ("sf_open_write failed with error : ") ; |
| 107 | puts (sf_strerror (NULL)) ; |
| 108 | exit (1) ; |
| 109 | } ; |
| 110 | |
| 111 | for (k = 0 ; k < 256 ; k++) |
| 112 | ulaw_buffer [k] = k & 0xFF ; |
| 113 | |
| 114 | sf_write_raw (file, ulaw_buffer, 256) ; |
| 115 | sf_close (file) ; |
| 116 | |
| 117 | /* Now open that file and compare the ulaw decoded sample values |
| 118 | ** with what they should be. |
| 119 | */ |
| 120 | |
| 121 | if (! (file = sf_open (filename, SFM_READ, &sfinfo))) |
| 122 | { printf ("sf_open_write failed with error : ") ; |
| 123 | puts (sf_strerror (NULL)) ; |
| 124 | exit (1) ; |
| 125 | } ; |
| 126 | |
| 127 | check_log_buffer_or_die (file, __LINE__) ; |
| 128 | |
| 129 | if (sf_read_short (file, short_buffer, 256) != 256) |
| 130 | { printf ("sf_read_short : ") ; |
| 131 | puts (sf_strerror (file)) ; |
| 132 | exit (1) ; |
| 133 | } ; |
| 134 | |
| 135 | |
| 136 | for (k = 0 ; k < 256 ; k++) |
| 137 | if (short_buffer [k] != ulaw_decode (ulaw_buffer [k])) |
| 138 | { printf ("Decoder error : sample #%d (0x%04X should be 0x%04X)\n", k, short_buffer [k], ulaw_decode (ulaw_buffer [k])) ; |
| 139 | exit (1) ; |
| 140 | } ; |
| 141 | |
| 142 | sf_close (file) ; |
| 143 | |
| 144 | puts ("ok") ; |
| 145 | |
| 146 | unlink (filename) ; |
| 147 | |
| 148 | return 0 ; |
| 149 | } /* main */ |
| 150 | |
| 151 | |
| 152 | /*================================================================================= |
| 153 | ** The following routines came from the sox-12.15 (Sound eXcahcnge) distribution. |
| 154 | ** |
| 155 | ** This code is not compiled into libsndfile. It is only used to test the |
| 156 | ** libsndfile lookup tables for correctness. |
| 157 | ** |
| 158 | ** I have included the original authors comments. |
| 159 | */ |
| 160 | |
| 161 | /* |
| 162 | ** This routine converts from linear to ulaw. |
| 163 | ** |
| 164 | ** Craig Reese: IDA/Supercomputing Research Center |
| 165 | ** Joe Campbell: Department of Defense |
| 166 | ** 29 September 1989 |
| 167 | ** |
| 168 | ** References: |
| 169 | ** 1) CCITT Recommendation G.711 (very difficult to follow) |
| 170 | ** 2) "A New Digital Technique for Implementation of Any |
| 171 | ** Continuous PCM Companding Law," Villeret, Michel, |
| 172 | ** et al. 1973 IEEE Int. Conf. on Communications, Vol 1, |
| 173 | ** 1973, pg. 11.12-11.17 |
| 174 | ** 3) MIL-STD-188-113,"Interoperability and Performance Standards |
| 175 | ** for Analog-to_Digital Conversion Techniques," |
| 176 | ** 17 February 1987 |
| 177 | ** |
| 178 | ** Input: Signed 16 bit linear sample |
| 179 | ** Output: 8 bit ulaw sample |
| 180 | */ |
| 181 | |
| 182 | #define uBIAS 0x84 /* define the add-in bias for 16 bit.frames */ |
| 183 | #define uCLIP 32635 |
| 184 | |
| 185 | static |
| 186 | unsigned char ulaw_encode (int sample) |
| 187 | { static int exp_lut [256] = |
| 188 | { 0, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, |
| 189 | 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, |
| 190 | 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, |
| 191 | 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, |
| 192 | 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, |
| 193 | 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, |
| 194 | 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, |
| 195 | 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, |
| 196 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, |
| 197 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, |
| 198 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, |
| 199 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, |
| 200 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, |
| 201 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, |
| 202 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, |
| 203 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7 |
| 204 | } ; |
| 205 | |
| 206 | int sign, exponent, mantissa ; |
| 207 | unsigned char ulawbyte ; |
| 208 | |
| 209 | /* Get the sample into sign-magnitude. */ |
| 210 | sign = (sample >> 8) & 0x80 ; /* set aside the sign */ |
| 211 | if ( sign != 0 ) |
| 212 | sample = -sample ; /* get magnitude */ |
| 213 | if ( sample > uCLIP ) |
| 214 | sample = uCLIP ; /* clip the magnitude */ |
| 215 | |
| 216 | /* Convert from 16 bit linear to ulaw. */ |
| 217 | sample = sample + uBIAS ; |
| 218 | exponent = exp_lut [( sample >> 7 ) & 0xFF] ; |
| 219 | mantissa = (sample >> ( exponent + 3 ) ) & 0x0F ; |
| 220 | ulawbyte = ~ (sign | ( exponent << 4 ) | mantissa) ; |
| 221 | |
| 222 | return ulawbyte ; |
| 223 | } /* ulaw_encode */ |
| 224 | |
| 225 | |
| 226 | /* |
| 227 | ** This routine converts from ulaw to 16 bit linear. |
| 228 | ** |
| 229 | ** Craig Reese: IDA/Supercomputing Research Center |
| 230 | ** 29 September 1989 |
| 231 | ** |
| 232 | ** References: |
| 233 | ** 1) CCITT Recommendation G.711 (very difficult to follow) |
| 234 | ** 2) MIL-STD-188-113,"Interoperability and Performance Standards |
| 235 | ** for Analog-to_Digital Conversion Techniques," |
| 236 | ** 17 February 1987 |
| 237 | ** |
| 238 | ** Input: 8 bit ulaw sample |
| 239 | ** Output: signed 16 bit linear sample |
| 240 | */ |
| 241 | |
| 242 | static |
| 243 | int ulaw_decode (unsigned int ulawbyte) |
| 244 | { static int exp_lut [8] = { 0, 132, 396, 924, 1980, 4092, 8316, 16764 } ; |
| 245 | int sign, exponent, mantissa, sample ; |
| 246 | |
| 247 | ulawbyte = ~ ulawbyte ; |
| 248 | sign = (ulawbyte & 0x80) ; |
| 249 | exponent = (ulawbyte >> 4) & 0x07 ; |
| 250 | mantissa = ulawbyte & 0x0F ; |
| 251 | sample = exp_lut [exponent] + (mantissa << (exponent + 3)) ; |
| 252 | if (sign != 0) |
| 253 | sample = -sample ; |
| 254 | |
| 255 | return sample ; |
| 256 | } /* ulaw_decode */ |
| 257 | |