1 files changed, 103 insertions, 0 deletions
diff --git a/audio/filter/af_sweep.c b/audio/filter/af_sweep.c
new file mode 100644
index 0000000000..6d1106fefc
--- /dev/null
+++ b/audio/filter/af_sweep.c
@@ -0,0 +1,103 @@
+/*
+ * Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * This file is part of MPlayer.
+ *
+ * MPlayer 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * MPlayer 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 MPlayer; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <inttypes.h>
+#include <math.h>
+
+#include "config.h"
+#include "af.h"
+
+typedef struct af_sweep_s{
+    double x;
+    double delta;
+}af_sweept;
+
+
+// Initialization and runtime control
+static int control(struct af_instance* af, int cmd, void* arg)
+{
+  af_sweept* s   = (af_sweept*)af->setup;
+  struct mp_audio *data= (struct mp_audio*)arg;
+
+  switch(cmd){
+  case AF_CONTROL_REINIT:
+    af->data->nch    = data->nch;
+    af->data->format = AF_FORMAT_S16_NE;
+    af->data->bps    = 2;
+    af->data->rate   = data->rate;
+
+    return AF_OK;
+  case AF_CONTROL_COMMAND_LINE:
+    sscanf((char*)arg,"%lf", &s->delta);
+    return AF_OK;
+/*  case AF_CONTROL_RESAMPLE_RATE | AF_CONTROL_SET:
+    af->data->rate = *(int*)arg;
+    return AF_OK;*/
+  }
+  return AF_UNKNOWN;
+}
+
+// Deallocate memory
+static void uninit(struct af_instance* af)
+{
+    free(af->data);
+    free(af->setup);
+}
+
+// Filter data through filter
+static struct mp_audio* play(struct af_instance* af, struct mp_audio* data)
+{
+  af_sweept *s = af->setup;
+  int i, j;
+  int16_t *in = (int16_t*)data->audio;
+  int chans   = data->nch;
+  int in_len  = data->len/(2*chans);
+
+  for(i=0; i<in_len; i++){
+      for(j=0; j<chans; j++)
+          in[i*chans+j]= 32000*sin(s->x*s->x);
+      s->x += s->delta;
+      if(2*s->x*s->delta >= 3.141592) s->x=0;
+  }
+
+  return data;
+}
+
+static int af_open(struct af_instance* af){
+  af->control=control;
+  af->uninit=uninit;
+  af->play=play;
+  af->mul=1;
+  af->data=calloc(1,sizeof(struct mp_audio));
+  af->setup=calloc(1,sizeof(af_sweept));
+  return AF_OK;
+}
+
+struct af_info af_info_sweep = {
+  "sine sweep",
+  "sweep",
+  "Michael Niedermayer",
+  "",
+  AF_FLAGS_REENTRANT,
+  af_open
+};