examples/altonegen.c

   1 /*
   2  * OpenAL Tone Generator Test
   3  *
   4  * Copyright (c) 2015 by Chris Robinson <chris.kcat@gmail.com>
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24
  25 /* This file contains a test for generating waveforms and plays them for a
  26  * given length of time. Intended to inspect the behavior of the mixer by
  27  * checking the output with a spectrum analyzer and oscilloscope.
  28  *
  29  * TODO: This would actually be nicer as a GUI app with buttons to start and
  30  * stop individual waveforms, include additional whitenoise and pinknoise
  31  * generators, and have the ability to hook up EFX filters and effects.
  32  */
  33
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <assert.h>
  38 #include <limits.h>
  39 #include <math.h>
  40
  41 #include "AL/al.h"
  42 #include "AL/alc.h"
  43 #include "AL/alext.h"
  44
  45 #include "common/alhelpers.h"
  46
  47 #ifndef M_PI
  48 #define M_PI    (3.14159265358979323846)
  49 #endif
  50
  51 enum WaveType {
  52     WT_Sine,
  53     WT_Square,
  54     WT_Sawtooth,
  55     WT_Triangle,
  56     WT_Impulse,
  57     WT_WhiteNoise,
  58 };
  59
  60 static const char *GetWaveTypeName(enum WaveType type)
  61 {
  62     switch(type)
  63     {
  64         case WT_Sine: return "sine";
  65         case WT_Square: return "square";
  66         case WT_Sawtooth: return "sawtooth";
  67         case WT_Triangle: return "triangle";
  68         case WT_Impulse: return "impulse";
  69         case WT_WhiteNoise: return "noise";
  70     }
  71     return "(unknown)";
  72 }
  73
  74 static inline ALuint dither_rng(ALuint *seed)
  75 {
  76     *seed = (*seed * 96314165) + 907633515;
  77     return *seed;
  78 }
  79
  80 static void ApplySin(ALfloat *data, ALdouble g, ALuint srate, ALuint freq)
  81 {
  82     ALdouble smps_per_cycle = (ALdouble)srate / freq;
  83     ALuint i;
  84     for(i = 0;i < srate;i++)
  85         data[i] += (ALfloat)(sin(i/smps_per_cycle * 2.0*M_PI) * g);
  86 }
  87
  88 /* Generates waveforms using additive synthesis. Each waveform is constructed
  89  * by summing one or more sine waves, up to (and excluding) nyquist.
  90  */
  91 static ALuint CreateWave(enum WaveType type, ALuint freq, ALuint srate)
  92 {
  93     ALuint seed = 22222;
  94     ALint data_size;
  95     ALfloat *data;
  96     ALuint buffer;
  97     ALenum err;
  98     ALuint i;
  99
 100     data_size = srate * sizeof(ALfloat);
 101     data = calloc(1, data_size);
 102     switch(type)
 103     {
 104         case WT_Sine:
 105             ApplySin(data, 1.0, srate, freq);
 106             break;
 107         case WT_Square:
 108             for(i = 1;freq*i < srate/2;i+=2)
 109                 ApplySin(data, 4.0/M_PI * 1.0/i, srate, freq*i);
 110             break;
 111         case WT_Sawtooth:
 112             for(i = 1;freq*i < srate/2;i++)
 113                 ApplySin(data, 2.0/M_PI * ((i&1)*2 - 1.0) / i, srate, freq*i);
 114             break;
 115         case WT_Triangle:
 116             for(i = 1;freq*i < srate/2;i+=2)
 117                 ApplySin(data, 8.0/(M_PI*M_PI) * (1.0 - (i&2)) / (i*i), srate, freq*i);
 118             break;
 119         case WT_Impulse:
 120             /* NOTE: Impulse isn't handled using additive synthesis, and is
 121              * instead just a non-0 sample at a given rate. This can still be
 122              * useful to test (other than resampling, the ALSOFT_DEFAULT_REVERB
 123              * environment variable can prove useful here to test the reverb
 124              * response).
 125              */
 126             for(i = 0;i < srate;i++)
 127                 data[i] = (i%(srate/freq)) ? 0.0f : 1.0f;
 128             break;
 129         case WT_WhiteNoise:
 130             /* NOTE: WhiteNoise is just uniform set of uncorrelated values, and
 131              * is not influenced by the waveform frequency.
 132              */
 133             for(i = 0;i < srate;i++)
 134             {
 135                 ALuint rng0 = dither_rng(&seed);
 136                 ALuint rng1 = dither_rng(&seed);
 137                 data[i] = (ALfloat)(rng0*(1.0/UINT_MAX) - rng1*(1.0/UINT_MAX));
 138             }
 139             break;
 140     }
 141
 142     /* Buffer the audio data into a new buffer object. */
 143     buffer = 0;
 144     alGenBuffers(1, &buffer);
 145     alBufferData(buffer, AL_FORMAT_MONO_FLOAT32, data, data_size, srate);
 146     free(data);
 147
 148     /* Check if an error occured, and clean up if so. */
 149     err = alGetError();
 150     if(err != AL_NO_ERROR)
 151     {
 152         fprintf(stderr, "OpenAL Error: %s\n", alGetString(err));
 153         if(alIsBuffer(buffer))
 154             alDeleteBuffers(1, &buffer);
 155         return 0;
 156     }
 157
 158     return buffer;
 159 }
 160
 161
 162 int main(int argc, char *argv[])
 163 {
 164     enum WaveType wavetype = WT_Sine;
 165     const char *appname = argv[0];
 166     ALuint source, buffer;
 167     ALint last_pos, num_loops;
 168     ALint max_loops = 4;
 169     ALint srate = -1;
 170     ALint tone_freq = 1000;
 171     ALCint dev_rate;
 172     ALenum state;
 173     int i;
 174
 175     argv++; argc--;
 176     if(InitAL(&argv, &argc) != 0)
 177         return 1;
 178
 179     if(!alIsExtensionPresent("AL_EXT_FLOAT32"))
 180     {
 181         fprintf(stderr, "Required AL_EXT_FLOAT32 extension not supported on this device!\n");
 182         CloseAL();
 183         return 1;
 184     }
 185
 186     for(i = 0;i < argc;i++)
 187     {
 188         if(strcmp(argv[i], "-h") == 0 || strcmp(argv[i], "--help") == 0)
 189         {
 190             fprintf(stderr, "OpenAL Tone Generator\n"
 191 "\n"
 192 "Usage: %s [-device <name>] <options>\n"
 193 "\n"
 194 "Available options:\n"
 195 "  --help/-h                 This help text\n"
 196 "  -t <seconds>              Time to play a tone (default 5 seconds)\n"
 197 "  --waveform/-w <type>      Waveform type: sine (default), square, sawtooth,\n"
 198 "                                triangle, impulse, noise\n"
 199 "  --freq/-f <hz>            Tone frequency (default 1000 hz)\n"
 200 "  --srate/-s <sample rate>  Sampling rate (default output rate)\n",
 201                 appname
 202             );
 203             CloseAL();
 204             return 1;
 205         }
 206         else if(i+1 < argc && strcmp(argv[i], "-t") == 0)
 207         {
 208             i++;
 209             max_loops = atoi(argv[i]) - 1;
 210         }
 211         else if(i+1 < argc && (strcmp(argv[i], "--waveform") == 0 || strcmp(argv[i], "-w") == 0))
 212         {
 213             i++;
 214             if(strcmp(argv[i], "sine") == 0)
 215                 wavetype = WT_Sine;
 216             else if(strcmp(argv[i], "square") == 0)
 217                 wavetype = WT_Square;
 218             else if(strcmp(argv[i], "sawtooth") == 0)
 219                 wavetype = WT_Sawtooth;
 220             else if(strcmp(argv[i], "triangle") == 0)
 221                 wavetype = WT_Triangle;
 222             else if(strcmp(argv[i], "impulse") == 0)
 223                 wavetype = WT_Impulse;
 224             else if(strcmp(argv[i], "noise") == 0)
 225                 wavetype = WT_WhiteNoise;
 226             else
 227                 fprintf(stderr, "Unhandled waveform: %s\n", argv[i]);
 228         }
 229         else if(i+1 < argc && (strcmp(argv[i], "--freq") == 0 || strcmp(argv[i], "-f") == 0))
 230         {
 231             i++;
 232             tone_freq = atoi(argv[i]);
 233             if(tone_freq < 1)
 234             {
 235                 fprintf(stderr, "Invalid tone frequency: %s (min: 1hz)\n", argv[i]);
 236                 tone_freq = 1;
 237             }
 238         }
 239         else if(i+1 < argc && (strcmp(argv[i], "--srate") == 0 || strcmp(argv[i], "-s") == 0))
 240         {
 241             i++;
 242             srate = atoi(argv[i]);
 243             if(srate < 40)
 244             {
 245                 fprintf(stderr, "Invalid sample rate: %s (min: 40hz)\n", argv[i]);
 246                 srate = 40;
 247             }
 248         }
 249     }
 250
 251     {
 252         ALCdevice *device = alcGetContextsDevice(alcGetCurrentContext());
 253         alcGetIntegerv(device, ALC_FREQUENCY, 1, &dev_rate);
 254         assert(alcGetError(device)==ALC_NO_ERROR && "Failed to get device sample rate");
 255     }
 256     if(srate < 0)
 257         srate = dev_rate;
 258
 259     /* Load the sound into a buffer. */
 260     buffer = CreateWave(wavetype, tone_freq, srate);
 261     if(!buffer)
 262     {
 263         CloseAL();
 264         return 1;
 265     }
 266
 267     printf("Playing %dhz %s-wave tone with %dhz sample rate and %dhz output, for %d second%s...\n",
 268            tone_freq, GetWaveTypeName(wavetype), srate, dev_rate, max_loops+1, max_loops?"s":"");
 269     fflush(stdout);
 270
 271     /* Create the source to play the sound with. */
 272     source = 0;
 273     alGenSources(1, &source);
 274     alSourcei(source, AL_BUFFER, buffer);
 275     assert(alGetError()==AL_NO_ERROR && "Failed to setup sound source");
 276
 277     /* Play the sound for a while. */
 278     num_loops = 0;
 279     last_pos = 0;
 280     alSourcei(source, AL_LOOPING, (max_loops > 0) ? AL_TRUE : AL_FALSE);
 281     alSourcePlay(source);
 282     do {
 283         ALint pos;
 284         al_nssleep(10000000);
 285         alGetSourcei(source, AL_SAMPLE_OFFSET, &pos);
 286         alGetSourcei(source, AL_SOURCE_STATE, &state);
 287         if(pos < last_pos && state == AL_PLAYING)
 288         {
 289             ++num_loops;
 290             if(num_loops >= max_loops)
 291                 alSourcei(source, AL_LOOPING, AL_FALSE);
 292             printf("%d...\n", max_loops - num_loops + 1);
 293             fflush(stdout);
 294         }
 295         last_pos = pos;
 296     } while(alGetError() == AL_NO_ERROR && state == AL_PLAYING);
 297
 298     /* All done. Delete resources, and close OpenAL. */
 299     alDeleteSources(1, &source);
 300     alDeleteBuffers(1, &buffer);
 301
 302     /* Close up OpenAL. */
 303     CloseAL();
 304
 305     return 0;
 306 }