ringmod.c

   1 #include "modules.h"
   2 #include "graph.h"
   3 #include "errors.h"
   4 #include "math.h"
   5
   6 struct ringmod {
   7     struct graphpin *in_pin, *out_pin;
   8     float pos;
   9 };
  10
  11 static bool is_acceptable_input_format(struct graphnode *node, struct graphpin *pin, const struct aformat *af)
  12 {
  13     return af->media == MT_AUDIO_32F;
  14 }
  15
  16 static err_t get_ideal_input_format(struct graphnode *node, struct graphpin *pin, struct aformat *af)
  17 {
  18     af->media = MT_AUDIO_32F;
  19     af->srate = 44100;
  20     af->channels = 2;
  21     return EOK;
  22 }
  23
  24 static err_t run(struct graphnode *node)
  25 {
  26     struct ringmod *rm = node->extra;
  27     float *src, *dest, pos;
  28     err_t err;
  29     int i;
  30
  31     err = buffer_alloc(&rm->out_pin->edge->buf, rm->in_pin->edge->buf.n_samples);
  32     if (err != EOK){
  33         return err;
  34     }
  35
  36     src = rm->in_pin->edge->buf.data;
  37     dest = rm->out_pin->edge->buf.data;
  38     pos = rm->pos;
  39
  40     for (i = rm->in_pin->edge->buf.n_samples * rm->in_pin->edge->buf.format.channels;
  41       i; --i){
  42         *dest = *src * cos((pos * M_PI * 2) / 441.0);
  43         ++dest, ++src, ++pos;
  44     }
  45
  46     rm->pos = pos;
  47
  48     return EOK;
  49 }
  50
  51 static const struct graphnode_functab functab = {
  52     is_acceptable_input_format,
  53     get_ideal_input_format,
  54     NULL,       // set_output_format
  55     NULL,       // set_buffer
  56     run,
  57 };
  58
  59 err_t ringmod_create(struct graphnode **node_out)
  60 {
  61     struct graphnode *node;
  62     struct ringmod *restrict rm;
  63     err_t err;
  64
  65     err = graphnode_create(&node, &functab, sizeof *rm);
  66     if (err != EOK){
  67         return err;
  68     }
  69
  70     rm = node->extra;
  71     rm->pos = 0.0;
  72
  73     err = graphnode_add_pin(node, &rm->in_pin);
  74     if (err != EOK){
  75         graphnode_free(node);
  76         return err;
  77     }
  78     rm->in_pin->dir = DIR_IN;
  79     rm->in_pin->name = "in";
  80
  81     err = graphnode_add_pin(node, &rm->out_pin);
  82     if (err != EOK){
  83         graphnode_free(node);
  84         return err;
  85     }
  86     rm->out_pin->dir = DIR_OUT;
  87     rm->out_pin->name = "out";
  88
  89     *node_out = node;
  90     return EOK;
  91 }