examples/alhrtf.c

   1 /*
   2  * OpenAL HRTF Example
   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 an example for selecting an HRTF. */
  26
  27 #include <assert.h>
  28 #include <inttypes.h>
  29 #include <limits.h>
  30 #include <math.h>
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <string.h>
  34
  35 #include "sndfile.h"
  36
  37 #include "AL/al.h"
  38 #include "AL/alc.h"
  39 #include "AL/alext.h"
  40
  41 #include "common/alhelpers.h"
  42
  43
  44 #ifndef M_PI
  45 #define M_PI                         (3.14159265358979323846)
  46 #endif
  47
  48 static LPALCGETSTRINGISOFT alcGetStringiSOFT;
  49 static LPALCRESETDEVICESOFT alcResetDeviceSOFT;
  50
  51 /* LoadBuffer loads the named audio file into an OpenAL buffer object, and
  52  * returns the new buffer ID.
  53  */
  54 static ALuint LoadSound(const char *filename)
  55 {
  56     ALenum err, format;
  57     ALuint buffer;
  58     SNDFILE *sndfile;
  59     SF_INFO sfinfo;
  60     short *membuf;
  61     sf_count_t num_frames;
  62     ALsizei num_bytes;
  63
  64     /* Open the audio file and check that it's usable. */
  65     sndfile = sf_open(filename, SFM_READ, &sfinfo);
  66     if(!sndfile)
  67     {
  68         fprintf(stderr, "Could not open audio in %s: %s\n", filename, sf_strerror(sndfile));
  69         return 0;
  70     }
  71     if(sfinfo.frames < 1 || sfinfo.frames > (sf_count_t)(INT_MAX/sizeof(short))/sfinfo.channels)
  72     {
  73         fprintf(stderr, "Bad sample count in %s (%" PRId64 ")\n", filename, sfinfo.frames);
  74         sf_close(sndfile);
  75         return 0;
  76     }
  77
  78     /* Get the sound format, and figure out the OpenAL format */
  79     if(sfinfo.channels == 1)
  80         format = AL_FORMAT_MONO16;
  81     else if(sfinfo.channels == 2)
  82         format = AL_FORMAT_STEREO16;
  83     else
  84     {
  85         fprintf(stderr, "Unsupported channel count: %d\n", sfinfo.channels);
  86         sf_close(sndfile);
  87         return 0;
  88     }
  89
  90     /* Decode the whole audio file to a buffer. */
  91     membuf = malloc((size_t)(sfinfo.frames * sfinfo.channels) * sizeof(short));
  92
  93     num_frames = sf_readf_short(sndfile, membuf, sfinfo.frames);
  94     if(num_frames < 1)
  95     {
  96         free(membuf);
  97         sf_close(sndfile);
  98         fprintf(stderr, "Failed to read samples in %s (%" PRId64 ")\n", filename, num_frames);
  99         return 0;
 100     }
 101     num_bytes = (ALsizei)(num_frames * sfinfo.channels) * (ALsizei)sizeof(short);
 102
 103     /* Buffer the audio data into a new buffer object, then free the data and
 104      * close the file.
 105      */
 106     buffer = 0;
 107     alGenBuffers(1, &buffer);
 108     alBufferData(buffer, format, membuf, num_bytes, sfinfo.samplerate);
 109
 110     free(membuf);
 111     sf_close(sndfile);
 112
 113     /* Check if an error occured, and clean up if so. */
 114     err = alGetError();
 115     if(err != AL_NO_ERROR)
 116     {
 117         fprintf(stderr, "OpenAL Error: %s\n", alGetString(err));
 118         if(buffer && alIsBuffer(buffer))
 119             alDeleteBuffers(1, &buffer);
 120         return 0;
 121     }
 122
 123     return buffer;
 124 }
 125
 126
 127 int main(int argc, char **argv)
 128 {
 129     ALCdevice *device;
 130     ALCcontext *context;
 131     ALboolean has_angle_ext;
 132     ALuint source, buffer;
 133     const char *soundname;
 134     const char *hrtfname;
 135     ALCint hrtf_state;
 136     ALCint num_hrtf;
 137     ALdouble angle;
 138     ALenum state;
 139
 140     /* Print out usage if no arguments were specified */
 141     if(argc < 2)
 142     {
 143         fprintf(stderr, "Usage: %s [-device <name>] [-hrtf <name>] <soundfile>\n", argv[0]);
 144         return 1;
 145     }
 146
 147     /* Initialize OpenAL, and check for HRTF support. */
 148     argv++; argc--;
 149     if(InitAL(&argv, &argc) != 0)
 150         return 1;
 151
 152     context = alcGetCurrentContext();
 153     device = alcGetContextsDevice(context);
 154     if(!alcIsExtensionPresent(device, "ALC_SOFT_HRTF"))
 155     {
 156         fprintf(stderr, "Error: ALC_SOFT_HRTF not supported\n");
 157         CloseAL();
 158         return 1;
 159     }
 160
 161     /* Define a macro to help load the function pointers. */
 162 #define LOAD_PROC(d, T, x)  ((x) = (T)alcGetProcAddress((d), #x))
 163     LOAD_PROC(device, LPALCGETSTRINGISOFT, alcGetStringiSOFT);
 164     LOAD_PROC(device, LPALCRESETDEVICESOFT, alcResetDeviceSOFT);
 165 #undef LOAD_PROC
 166
 167     /* Check for the AL_EXT_STEREO_ANGLES extension to be able to also rotate
 168      * stereo sources.
 169      */
 170     has_angle_ext = alIsExtensionPresent("AL_EXT_STEREO_ANGLES");
 171     printf("AL_EXT_STEREO_ANGLES %sfound\n", has_angle_ext?"":"not ");
 172
 173     /* Check for user-preferred HRTF */
 174     if(strcmp(argv[0], "-hrtf") == 0)
 175     {
 176         hrtfname = argv[1];
 177         soundname = argv[2];
 178     }
 179     else
 180     {
 181         hrtfname = NULL;
 182         soundname = argv[0];
 183     }
 184
 185     /* Enumerate available HRTFs, and reset the device using one. */
 186     alcGetIntegerv(device, ALC_NUM_HRTF_SPECIFIERS_SOFT, 1, &num_hrtf);
 187     if(!num_hrtf)
 188         printf("No HRTFs found\n");
 189     else
 190     {
 191         ALCint attr[5];
 192         ALCint index = -1;
 193         ALCint i;
 194
 195         printf("Available HRTFs:\n");
 196         for(i = 0;i < num_hrtf;i++)
 197         {
 198             const ALCchar *name = alcGetStringiSOFT(device, ALC_HRTF_SPECIFIER_SOFT, i);
 199             printf("    %d: %s\n", i, name);
 200
 201             /* Check if this is the HRTF the user requested. */
 202             if(hrtfname && strcmp(name, hrtfname) == 0)
 203                 index = i;
 204         }
 205
 206         i = 0;
 207         attr[i++] = ALC_HRTF_SOFT;
 208         attr[i++] = ALC_TRUE;
 209         if(index == -1)
 210         {
 211             if(hrtfname)
 212                 printf("HRTF \"%s\" not found\n", hrtfname);
 213             printf("Using default HRTF...\n");
 214         }
 215         else
 216         {
 217             printf("Selecting HRTF %d...\n", index);
 218             attr[i++] = ALC_HRTF_ID_SOFT;
 219             attr[i++] = index;
 220         }
 221         attr[i] = 0;
 222
 223         if(!alcResetDeviceSOFT(device, attr))
 224             printf("Failed to reset device: %s\n", alcGetString(device, alcGetError(device)));
 225     }
 226
 227     /* Check if HRTF is enabled, and show which is being used. */
 228     alcGetIntegerv(device, ALC_HRTF_SOFT, 1, &hrtf_state);
 229     if(!hrtf_state)
 230         printf("HRTF not enabled!\n");
 231     else
 232     {
 233         const ALchar *name = alcGetString(device, ALC_HRTF_SPECIFIER_SOFT);
 234         printf("HRTF enabled, using %s\n", name);
 235     }
 236     fflush(stdout);
 237
 238     /* Load the sound into a buffer. */
 239     buffer = LoadSound(soundname);
 240     if(!buffer)
 241     {
 242         CloseAL();
 243         return 1;
 244     }
 245
 246     /* Create the source to play the sound with. */
 247     source = 0;
 248     alGenSources(1, &source);
 249     alSourcei(source, AL_SOURCE_RELATIVE, AL_TRUE);
 250     alSource3f(source, AL_POSITION, 0.0f, 0.0f, -1.0f);
 251     alSourcei(source, AL_BUFFER, (ALint)buffer);
 252     assert(alGetError()==AL_NO_ERROR && "Failed to setup sound source");
 253
 254     /* Play the sound until it finishes. */
 255     angle = 0.0;
 256     alSourcePlay(source);
 257     do {
 258         al_nssleep(10000000);
 259
 260         alcSuspendContext(context);
 261
 262         /* Rotate the source around the listener by about 1/4 cycle per second,
 263          * and keep it within -pi...+pi.
 264          */
 265         angle += 0.01 * M_PI * 0.5;
 266         if(angle > M_PI)
 267             angle -= M_PI*2.0;
 268
 269         /* This only rotates mono sounds. */
 270         alSource3f(source, AL_POSITION, (ALfloat)sin(angle), 0.0f, -(ALfloat)cos(angle));
 271
 272         if(has_angle_ext)
 273         {
 274             /* This rotates stereo sounds with the AL_EXT_STEREO_ANGLES
 275              * extension. Angles are specified counter-clockwise in radians.
 276              */
 277             ALfloat angles[2] = { (ALfloat)(M_PI/6.0 - angle), (ALfloat)(-M_PI/6.0 - angle) };
 278             alSourcefv(source, AL_STEREO_ANGLES, angles);
 279         }
 280         alcProcessContext(context);
 281
 282         alGetSourcei(source, AL_SOURCE_STATE, &state);
 283     } while(alGetError() == AL_NO_ERROR && state == AL_PLAYING);
 284
 285     /* All done. Delete resources, and close down OpenAL. */
 286     alDeleteSources(1, &source);
 287     alDeleteBuffers(1, &buffer);
 288     CloseAL();
 289
 290     return 0;
 291 }