diff --git a/Makefile b/Makefile
index 27c87e3..2dc7129 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
 CFLAGS = -std=c11 -pedantic -Wall -Wextra -O2 -Ofast -D_DEFAULT_SOURCE -D_FORTIFY_SOURCE=2
-LDFLAGS = -lX11 -lGL -lGLEW -lm -lrt
+LDFLAGS = -lX11 -lGL -lGLEW -lm -lrt -lfftw3
 
 shadermeh: shadermeh.o window.o shader.o
 
diff --git a/shadermeh.c b/shadermeh.c
index 6dd8681..3b1bf32 100644
--- a/shadermeh.c
+++ b/shadermeh.c
@@ -10,6 +10,7 @@
 #include <errno.h>
 #define HAVE_ARCH_STRUCT_FLOCK
 #include <linux/fcntl.h>
+#include <fftw3.h>
 
 static GLfloat vertex_buffer[] = {
 	-1.0f, -1.0f, 0.0f,	/* lower left corner */
@@ -87,12 +88,46 @@ static int write_retry(int fd, const void *buffer, size_t size)
 
 #define SND_BUFFER_SIZE   512
 
+#define BBUFFER_S ((sizeof(float) * SND_BUFFER_SIZE))
+
+/* Read all available input. This function presumes fd to be O_NONBLOCK */
 static int read_audio_buffers(int fd, float buffer[SND_BUFFER_SIZE], 
 	unsigned int sampling_rate){
+
+	float temp_buf[sampling_rate];
+	size_t n = 0;
+	memset(temp_buf, 0, sizeof(temp_buf));
+	while(true){
+
+		int new_n = read(fd, temp_buf, sizeof(temp_buf));
+		if(new_n < 0){
+			if(errno == EAGAIN || errno == EWOULDBLOCK){
+				break;
+			}
+			perror("Read to audio buffer failed");
+			return -1;
+		}else if(new_n == 0){
+			break;
+		} else if(n < sizeof(temp_buf)){
+			n = new_n;
+			break;
+		}
+		/* Fall through and read the remaining buffer 
+		 * (last ditch effort to clear pipe) 
+		 */
+	}
+	if(n < BBUFFER_S){
+		memmove(buffer, buffer+n, BBUFFER_S - n);
+		memcpy(buffer+ BBUFFER_S - n, temp_buf, n);
+	}else{
+		memcpy(buffer, (temp_buf+n-BBUFFER_S), BBUFFER_S);
+	}
 	
 	return 0;
 }
 
+/* normalize the given input buffer from -1…1 in range (what alsa provides) to
+ * 0…1 in range (what the shadertoy shaders  */
 static void normalize_audio_buffers(float buffer_in[SND_BUFFER_SIZE], 
 	float buffer_out[SND_BUFFER_SIZE]){
 	
@@ -151,6 +186,13 @@ int main(int argc, char **argv)
 					 */
 	float in_samples[SND_BUFFER_SIZE];   /* Raw input floats from -1...1 */
 	float norm_samples[SND_BUFFER_SIZE]; /* Normalized samples from 0...1 */
+	fftw_complex fftw_in[SND_BUFFER_SIZE];
+	fftw_complex fftw_out[SND_BUFFER_SIZE];
+	fftw_plan plan = fftw_plan_dft_1d(SND_BUFFER_SIZE,
+                                      fftw_in,
+                                      fftw_out,
+                                      FFTW_FORWARD,
+                                      FFTW_ESTIMATE);
 
 	/******************** parse options ************************/
 	width = 800;
@@ -236,8 +278,8 @@ int main(int argc, char **argv)
 			}
 		}
 	}
-	if (sampling_rate != 0 && !isatty(STDIN_FILENO)){
-		fputs("Sampling rate specified and STDIN not a tty! "
+	if (sampling_rate != 0 && isatty(STDIN_FILENO)){
+		fputs("Sampling rate specified and STDIN a tty! "
 			"You habe been warnded!\n", stderr);
 	}
 	if(sampling_rate != 0){
@@ -367,6 +409,12 @@ int main(int argc, char **argv)
 				break;
 			}
 			normalize_audio_buffers(in_samples, norm_samples);
+			memset(fftw_in, 0, sizeof(fftw_in));
+			memset(fftw_out, 0, sizeof(fftw_out));
+			for(size_t i = 0; i < SND_BUFFER_SIZE; i++){
+				fftw_in[i][0] = norm_samples[i];
+			}
+			fftw_execute(plan);
 		}
 
 		/* update timers */
@@ -399,5 +447,6 @@ int main(int argc, char **argv)
 	free(fb32);
 	free(fb24);
 	window_destroy(wnd);
+	fftw_destroy_plan(plan);
 	return EXIT_SUCCESS;
 }