ringmod.c

   1 #include "modules.h"
   2 #include "graph.h"
   3 #include "errors.h"
   4 #include "math.h"
   5
   6 #define M_PI 3.1415926535897931
   7
   8 struct ringmod {
   9     struct graphpin *in_pin, *out_pin;
  10     float pos;
  11 };
  12
  13 static bool is_acceptable_input_format(struct graphnode *node, struct graphpin *pin, const struct aformat *af)
  14 {
  15     return af->media == MT_AUDIO_32F;
  16 }
  17
  18 static err_t get_ideal_input_format(struct graphnode *node, struct graphpin *pin, struct aformat *af)
  19 {
  20     af->media = MT_AUDIO_32F;
  21     af->srate = 44100;
  22     af->channels = 2;
  23     return EOK;
  24 }
  25
  26 static err_t run(struct graphnode *node)
  27 {
  28     struct ringmod *rm = node->extra;
  29     float *src, *dest, pos;
  30     err_t err;
  31     int i;
  32
  33     err = buffer_alloc(&rm->out_pin->edge->buf, rm->in_pin->edge->buf.n_samples);
  34     if (err != EOK){
  35         return err;
  36     }
  37
  38     src = rm->in_pin->edge->buf.data;
  39     dest = rm->out_pin->edge->buf.data;
  40     pos = rm->pos;
  41
  42     for (i = rm->in_pin->edge->buf.n_samples * rm->in_pin->edge->buf.format.channels;
  43       i; --i){
  44         *dest = *src * cos((pos * M_PI * 2) / 441.0);
  45         ++dest, ++src, ++pos;
  46     }
  47
  48     rm->pos = pos;
  49
  50     return EOK;
  51 }
  52
  53 static const struct graphnode_functab functab = {
  54     is_acceptable_input_format,
  55     get_ideal_input_format,
  56     NULL,       // set_output_format
  57     NULL,       // set_buffer
  58     run,
  59 };
  60
  61 err_t ringmod_create(struct graphnode **node_out)
  62 {
  63     struct graphnode *node;
  64     struct ringmod *restrict rm;
  65     err_t err;
  66
  67     err = graphnode_create(&node, &functab, sizeof *rm);
  68     if (err != EOK){
  69         return err;
  70     }
  71
  72     rm = node->extra;
  73     rm->pos = 0.0;
  74
  75     err = graphnode_add_pin(node, &rm->in_pin);
  76     if (err != EOK){
  77         graphnode_free(node);
  78         return err;
  79     }
  80     rm->in_pin->dir = DIR_IN;
  81     rm->in_pin->name = "in";
  82
  83     err = graphnode_add_pin(node, &rm->out_pin);
  84     if (err != EOK){
  85         graphnode_free(node);
  86         return err;
  87     }
  88     rm->out_pin->dir = DIR_OUT;
  89     rm->out_pin->name = "out";
  90
  91     *node_out = node;
  92     return EOK;
  93 }