libaf/af_sweep.c

   1 // Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
   2 // #inlcude <GPL_v2.h>
   3
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7 #include <inttypes.h>
   8 #include <math.h>
   9
  10 #include "config.h"
  11 #include "af.h"
  12
  13 typedef struct af_sweep_s{
  14     double x;
  15     double delta;
  16 }af_sweept;
  17
  18
  19 // Initialization and runtime control
  20 static int control(struct af_instance_s* af, int cmd, void* arg)
  21 {
  22   af_sweept* s   = (af_sweept*)af->setup;
  23   af_data_t *data= (af_data_t*)arg;
  24
  25   switch(cmd){
  26   case AF_CONTROL_REINIT:
  27     af->data->nch    = data->nch;
  28     af->data->format = AF_FORMAT_S16_NE;
  29     af->data->bps    = 2;
  30     af->data->rate   = data->rate;
  31
  32     return AF_OK;
  33   case AF_CONTROL_COMMAND_LINE:
  34     sscanf((char*)arg,"%lf", &s->delta);
  35     return AF_OK;
  36 /*  case AF_CONTROL_RESAMPLE_RATE | AF_CONTROL_SET:
  37     af->data->rate = *(int*)arg;
  38     return AF_OK;*/
  39   }
  40   return AF_UNKNOWN;
  41 }
  42
  43 // Deallocate memory
  44 static void uninit(struct af_instance_s* af)
  45 {
  46     if(af->data)
  47         free(af->data);
  48     if(af->setup){
  49         af_sweept *s = af->setup;
  50         free(s);
  51     }
  52 }
  53
  54 // Filter data through filter
  55 static af_data_t* play(struct af_instance_s* af, af_data_t* data)
  56 {
  57   af_sweept *s = af->setup;
  58   int i, j;
  59   int16_t *in = (int16_t*)data->audio;
  60   int chans   = data->nch;
  61   int in_len  = data->len/(2*chans);
  62
  63   for(i=0; i<in_len; i++){
  64       for(j=0; j<chans; j++)
  65           in[i*chans+j]= 32000*sin(s->x*s->x);
  66       s->x += s->delta;
  67       if(2*s->x*s->delta >= 3.141592) s->x=0;
  68   }
  69
  70   return data;
  71 }
  72
  73 static int af_open(af_instance_t* af){
  74   af->control=control;
  75   af->uninit=uninit;
  76   af->play=play;
  77   af->mul.n=1;
  78   af->mul.d=1;
  79   af->data=calloc(1,sizeof(af_data_t));
  80   af->setup=calloc(1,sizeof(af_sweept));
  81   return AF_OK;
  82 }
  83
  84 af_info_t af_info_sweep = {
  85   "sine sweep",
  86   "sweep",
  87   "Michael Niedermayer",
  88   "",
  89   AF_FLAGS_REENTRANT,
  90   af_open
  91 };
  92