wavesource.c

   1 #include "graph.h"
   2 #include "wavefile.h"
   3
   4 struct wavefile_source {
   5     struct buffer *buf;
   6     struct wavefile wf;
   7     off_t pos;
   8 };
   9
  10 static err_t get_output_format(struct graphnode *node, struct graphpin *pin,
  11   struct aformat *af)
  12 {
  13     struct wavefile_source *ws = node->extra;
  14     af->media = MT_AUDIO_16I;
  15     af->srate = ws->wf.format.srate;
  16     af->channels = ws->wf.format.channels;
  17     return EOK;
  18 }
  19
  20 static err_t set_buffer(struct graphnode *node, struct graphpin *pin, struct buffer *buf)
  21 {
  22     struct wavefile_source *ws = node->extra;
  23     ws->buf = buf;
  24     return EOK;
  25 }
  26
  27 static err_t run(struct graphnode *node)
  28 {
  29     struct wavefile_source *ws = node->extra;
  30     err_t err;
  31
  32     err = buffer_alloc(ws->buf, 4410);
  33     if (err != EOK){
  34         return err;
  35     }
  36
  37     err = wavefile_read_at(&ws->wf, ws->pos, ws->buf->data, 4410);
  38     if (err != EOK){
  39         return err;
  40     }
  41
  42     ws->pos += 4410;
  43
  44     return EOK;
  45 }
  46
  47 static const struct graphnode_functab functab = {
  48     NULL,   // is_acceptable_input_format
  49     get_output_format,
  50     set_buffer,
  51     run,
  52 };
  53
  54 err_t wavesource_create(struct graphnode **node_out, const char *filename)
  55 {
  56     struct graphnode *node;
  57     struct graphpin *pin;
  58     struct wavefile_source *ws;
  59     err_t err;
  60
  61     err = graphnode_create(&node, &functab, sizeof *ws);
  62     if (err != EOK){
  63         return err;
  64     }
  65
  66     err = graphnode_add_pin(node, &pin);
  67     if (err != EOK){
  68         return err;
  69     }
  70     pin->dir = DIR_OUT;
  71     pin->name = "out";
  72
  73     ws = node->extra;
  74     err = wavefile_open(&ws->wf, filename);
  75     if (err != EOK){
  76         graphnode_free(node);
  77         return err;
  78     }
  79     ws->pos = 0;
  80
  81     *node_out = node;
  82     return EOK;
  83 }
  84