Mercurial > sdl-ios-xcode
view test/loopwave.c @ 2661:d38309be5178 gsoc2008_audio_resampling
The windowed sinc filter generation code seems to be working fine. The FIR filtering code is also now working reasonably well. Occasionally the FIR filter will pop, but setting the normalization factor lower seems to help this. I suspect the problem is in the fixed point multiply/add. I also have a hunch the zero stuffing/sample discarding code is not correct, and I'll look at that soon to get it sorted out.
author | Aaron Wishnick <schnarf@gmail.com> |
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date | Wed, 02 Jul 2008 08:04:50 +0000 |
parents | 8b76cc268771 |
children | aecbdf3362c3 |
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/* Program to load a wave file and loop playing it using SDL sound */ /* loopwaves.c is much more robust in handling WAVE files -- This is only for simple WAVEs */ #include "SDL_config.h" #include <stdio.h> #include <stdlib.h> #if HAVE_SIGNAL_H #include <signal.h> #endif #include "SDL.h" #include "SDL_audio.h" struct { SDL_AudioSpec spec; Uint8 *sound; /* Pointer to wave data */ Uint32 soundlen; /* Length of wave data */ int soundpos; /* Current play position */ } wave; /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */ static void quit(int rc) { SDL_Quit(); exit(rc); } void SDLCALL fillerup(void *unused, Uint8 * stream, int len) { Uint8 *waveptr; int waveleft; /* Set up the pointers */ waveptr = wave.sound + wave.soundpos; waveleft = wave.soundlen - wave.soundpos; /* Go! */ while (waveleft <= len) { SDL_memcpy(stream, waveptr, waveleft); stream += waveleft; len -= waveleft; waveptr = wave.sound; waveleft = wave.soundlen; wave.soundpos = 0; } SDL_memcpy(stream, waveptr, len); wave.soundpos += len; } static int done = 0; void poked(int sig) { done = 1; } int main(int argc, char *argv[]) { /* Load the SDL library */ if (SDL_Init(SDL_INIT_AUDIO) < 0) { fprintf(stderr, "Couldn't initialize SDL: %s\n", SDL_GetError()); return (1); } if (argv[1] == NULL) { argv[1] = "sample.wav"; } /* Load the wave file into memory */ if (SDL_LoadWAV(argv[1], &wave.spec, &wave.sound, &wave.soundlen) == NULL) { fprintf(stderr, "Couldn't load %s: %s\n", argv[1], SDL_GetError()); quit(1); } wave.spec.callback = fillerup; #if HAVE_SIGNAL_H /* Set the signals */ #ifdef SIGHUP signal(SIGHUP, poked); #endif signal(SIGINT, poked); #ifdef SIGQUIT signal(SIGQUIT, poked); #endif signal(SIGTERM, poked); #endif /* HAVE_SIGNAL_H */ /* Initialize fillerup() variables */ if (SDL_OpenAudio(&wave.spec, NULL) < 0) { fprintf(stderr, "Couldn't open audio: %s\n", SDL_GetError()); SDL_FreeWAV(wave.sound); quit(2); } SDL_PauseAudio(0); /* Let the audio run */ while (!done && (SDL_GetAudioStatus() == SDL_AUDIO_PLAYING)) SDL_Delay(1000); /* Clean up on signal */ SDL_CloseAudio(); SDL_FreeWAV(wave.sound); SDL_Quit(); return (0); }