libaf/af_sweep.c

   1 /*
   2  * Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
   3  *
   4  * This file is part of MPlayer.
   5  *
   6  * MPlayer is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * MPlayer is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <inttypes.h>
  25 #include <math.h>
  26
  27 #include "config.h"
  28 #include "af.h"
  29
  30 typedef struct af_sweep_s{
  31     double x;
  32     double delta;
  33 }af_sweept;
  34
  35
  36 // Initialization and runtime control
  37 static int control(struct af_instance_s* af, int cmd, void* arg)
  38 {
  39   af_sweept* s   = (af_sweept*)af->setup;
  40   af_data_t *data= (af_data_t*)arg;
  41
  42   switch(cmd){
  43   case AF_CONTROL_REINIT:
  44     af->data->nch    = data->nch;
  45     af->data->format = AF_FORMAT_S16_NE;
  46     af->data->bps    = 2;
  47     af->data->rate   = data->rate;
  48
  49     return AF_OK;
  50   case AF_CONTROL_COMMAND_LINE:
  51     sscanf((char*)arg,"%lf", &s->delta);
  52     return AF_OK;
  53 /*  case AF_CONTROL_RESAMPLE_RATE | AF_CONTROL_SET:
  54     af->data->rate = *(int*)arg;
  55     return AF_OK;*/
  56   }
  57   return AF_UNKNOWN;
  58 }
  59
  60 // Deallocate memory
  61 static void uninit(struct af_instance_s* af)
  62 {
  63     if(af->data)
  64         free(af->data);
  65     if(af->setup){
  66         af_sweept *s = af->setup;
  67         free(s);
  68     }
  69 }
  70
  71 // Filter data through filter
  72 static af_data_t* play(struct af_instance_s* af, af_data_t* data)
  73 {
  74   af_sweept *s = af->setup;
  75   int i, j;
  76   int16_t *in = (int16_t*)data->audio;
  77   int chans   = data->nch;
  78   int in_len  = data->len/(2*chans);
  79
  80   for(i=0; i<in_len; i++){
  81       for(j=0; j<chans; j++)
  82           in[i*chans+j]= 32000*sin(s->x*s->x);
  83       s->x += s->delta;
  84       if(2*s->x*s->delta >= 3.141592) s->x=0;
  85   }
  86
  87   return data;
  88 }
  89
  90 static int af_open(af_instance_t* af){
  91   af->control=control;
  92   af->uninit=uninit;
  93   af->play=play;
  94   af->mul=1;
  95   af->data=calloc(1,sizeof(af_data_t));
  96   af->setup=calloc(1,sizeof(af_sweept));
  97   return AF_OK;
  98 }
  99
 100 af_info_t af_info_sweep = {
 101   "sine sweep",
 102   "sweep",
 103   "Michael Niedermayer",
 104   "",
 105   AF_FLAGS_REENTRANT,
 106   af_open
 107 };
 108