From ec010b19cac1d5aea5393a687a91431f2e541101 Mon Sep 17 00:00:00 2001
From: Thomas White <taw27@cam.ac.uk>
Date: Tue, 14 Oct 2008 23:20:29 +0100
Subject: Initial import

---
 src/audio.c | 159 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 159 insertions(+)
 create mode 100644 src/audio.c

(limited to 'src/audio.c')

diff --git a/src/audio.c b/src/audio.c
new file mode 100644
index 0000000..ed37a89
--- /dev/null
+++ b/src/audio.c
@@ -0,0 +1,159 @@
+/*
+ * audio.c
+ *
+ * Moo like a cow
+ *
+ * (c) 2008 Thomas White <taw27@srcf.ucam.org>
+ *
+ * This file is part of OpenMooCow - accelerometer moobox simulator
+ *
+ * OpenMooCow is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * OpenMooCow is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with OpenMooCow.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+//#ifdef HAVE_CONFIG_H
+//#include <config.h>
+//#endif
+
+#include <stdlib.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <SDL.h>
+#include <SDL_audio.h>
+#include <math.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <sys/wait.h>
+
+#include "types.h"
+
+static void audio_mix(void *data, Uint8 *stream8, int len) {
+
+	AudioContext *a = data;
+	int j;
+	Sint16 *stream = (Sint16 *)stream8;
+	Sint16 samp;
+	
+	len /= 2;	/* Number of samples to write */
+	
+	for ( j=0; j<len; j++ ) {
+		
+		stream[j] = 0;
+		
+		if ( a->moo_pos < a->moo_len ) {
+			samp = a->moo_buf[a->moo_pos++];
+			stream[j] += samp;
+		}
+		
+	}
+	
+}
+
+void audio_trigger_moo(AudioContext *a) {
+
+	if ( a->aplay_fallback ) {
+	
+		pid_t pid;
+		int status;
+		
+		pid = fork();
+		if ( !( (pid != 0) && (pid != -1) ) ) {
+			if ( pid == -1 ) {
+				fprintf(stderr, "fork() failed.\n");
+				return;
+			} else {
+				/* Forked successfully, child process */
+				execlp("aplay", "aplay", DATADIR"/openmoocow/moo.wav", NULL);
+			}
+		} /* else forked successfully, parent process */
+		printf("Waiting...\n"); fflush(stdout);
+		waitpid(pid, &status, 0);
+		printf("Done mooing\n"); fflush(stdout);
+
+	} else {
+		if ( a->moo_pos == a->moo_len ) {
+			a->moo_pos = 0;
+		}
+	}
+	
+}
+
+/* SDL audio initial setup */
+AudioContext *audio_setup() {
+	
+	AudioContext *a;
+	SDL_AudioSpec fmt;
+	SDL_AudioSpec wave;
+	Uint8 *data;
+	Uint32 dlen;
+	SDL_AudioCVT cvt;
+	
+	/* Create audio context */
+	a = malloc(sizeof(AudioContext));
+	if ( a == NULL ) return NULL;
+	
+	/* 16-bit mono audio at 44.1 kHz */
+	fmt.freq = 44100;
+	fmt.format = AUDIO_S16;
+	fmt.channels = 1;
+	fmt.samples = 512;
+	fmt.callback = audio_mix;
+	fmt.userdata = a;
+	fmt.silence = 0;
+	
+	if ( SDL_OpenAudio(&fmt, NULL) < 0 ) {
+		fprintf(stderr, "Unable to open audio: %s\n", SDL_GetError());
+		a->aplay_fallback = 1;
+		return a;
+	}
+	a->aplay_fallback = 0;
+	
+	if ( SDL_LoadWAV(DATADIR"/openmoocow/moo.wav", &wave, &data, &dlen) == NULL ) {
+		fprintf(stderr, "Couldn't load moo sound: %s\n", SDL_GetError());
+		return a;
+	}
+	SDL_BuildAudioCVT(&cvt, wave.format, wave.channels, wave.freq, AUDIO_S16, 1, 44100);
+	cvt.buf = malloc(dlen*cvt.len_mult);
+	if ( cvt.buf == NULL ) {
+		fprintf(stderr, "Not enough memory to convert audio \n");
+		return a;
+	}
+	memcpy(cvt.buf, data, dlen);
+	cvt.len = dlen;
+	SDL_ConvertAudio(&cvt);
+	SDL_FreeWAV(data);
+	
+	a->moo_len = cvt.len_cvt/2 - 2;	/* Convert bytes to samples */
+	a->moo_pos = a->moo_len;	/* Play nothing to start with */
+	a->moo_buf = (Sint16 *)cvt.buf;
+	
+	SDL_PauseAudio(0);
+	
+	return a;
+	
+}
+
+void audio_shutdown(AudioContext *a) {
+
+	if ( a == NULL ) return;
+	
+	if ( !a->aplay_fallback ) {
+		SDL_CloseAudio();
+	}
+	
+	/* Now this can be freed */
+	free(a);
+	
+}
+
-- 
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