82 lines
2.5 KiB
C
82 lines
2.5 KiB
C
#include "minisdl_audio.h"
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#define TSF_IMPLEMENTATION
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#include "../tsf.h"
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// Holds the global instance pointer
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static tsf* g_TinySoundFont;
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// A Mutex so we don't call note_on/note_off while rendering audio samples
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static SDL_mutex* g_Mutex;
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static void AudioCallback(void* data, Uint8 *stream, int len)
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{
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// Render the audio samples in float format
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int SampleCount = (len / (2 * sizeof(float))); //2 output channels
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SDL_LockMutex(g_Mutex); //get exclusive lock
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tsf_render_float(g_TinySoundFont, (float*)stream, SampleCount, 0);
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SDL_UnlockMutex(g_Mutex);
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}
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int main(int argc, char *argv[])
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{
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int i, Notes[7] = { 48, 50, 52, 53, 55, 57, 59 };
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// Define the desired audio output format we request
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SDL_AudioSpec OutputAudioSpec;
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OutputAudioSpec.freq = 44100;
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OutputAudioSpec.format = AUDIO_F32;
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OutputAudioSpec.channels = 2;
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OutputAudioSpec.samples = 4096;
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OutputAudioSpec.callback = AudioCallback;
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// Initialize the audio system
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if (SDL_AudioInit(TSF_NULL) < 0)
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{
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fprintf(stderr, "Could not initialize audio hardware or driver\n");
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return 1;
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}
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// Load the SoundFont from a file
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g_TinySoundFont = tsf_load_filename("florestan-subset.sf2");
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if (!g_TinySoundFont)
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{
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fprintf(stderr, "Could not load SoundFont\n");
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return 1;
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}
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// Set the SoundFont rendering output mode
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tsf_set_output(g_TinySoundFont, TSF_STEREO_INTERLEAVED, OutputAudioSpec.freq, 0);
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// Create the mutex
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g_Mutex = SDL_CreateMutex();
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// Request the desired audio output format
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if (SDL_OpenAudio(&OutputAudioSpec, TSF_NULL) < 0)
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{
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fprintf(stderr, "Could not open the audio hardware or the desired audio output format\n");
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return 1;
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}
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// Start the actual audio playback here
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// The audio thread will begin to call our AudioCallback function
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SDL_PauseAudio(0);
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// Loop through all the presets in the loaded SoundFont
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for (i = 0; i < tsf_get_presetcount(g_TinySoundFont); i++)
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{
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//Get exclusive mutex lock, end the previous note and play a new note
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printf("Play note %d with preset #%d '%s'\n", Notes[i % 7], i, tsf_get_presetname(g_TinySoundFont, i));
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SDL_LockMutex(g_Mutex);
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tsf_note_off(g_TinySoundFont, i - 1, Notes[(i - 1) % 7]);
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tsf_note_on(g_TinySoundFont, i, Notes[i % 7], 1.0f);
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SDL_UnlockMutex(g_Mutex);
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SDL_Delay(1000);
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}
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// We could call tsf_close(g_TinySoundFont) and SDL_DestroyMutex(g_Mutex)
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// here to free the memory and resources but we just let the OS clean up
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// because the process ends here.
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return 0;
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}
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