218158/af_volnorm.i.2

   1 typedef struct af_data_s {
   2         int format;
   3 } af_data_t;
   4 typedef struct af_info_s {
   5         const char *info;
   6         const char *name;
   7         const char *author;
   8         const char *comment;
   9         const int flags;
  10         int (*open) (struct af_instance_s * vf);
  11 } af_info_t;
  12 typedef struct af_instance_s {
  13         af_data_t *(*play) (struct af_instance_s * af, af_data_t * data);
  14         void *setup;
  15         af_data_t *data;
  16 } af_instance_t;
  17 typedef struct af_volume_s {
  18         int method;
  19         float mul;
  20         struct {
  21                 float avg;
  22                 int len;
  23         } mem[128];
  24         float mid_s16;
  25 } af_volnorm_t;
  26 static void method2_int16(af_volnorm_t * s, af_data_t * c)
  27 {
  28         register int i = 0;
  29         float avg = 0.0;
  30         int totallen = 0;
  31         for (i = 0; i < 128; i++) {
  32                 avg += s->mem[i].avg * (float)s->mem[i].len;
  33                 totallen += s->mem[i].len;
  34         }
  35         if (totallen > 32000)
  36                 if (avg >= (32767 * 0.01))
  37                         s->mul = s->mid_s16 / avg;
  38 }
  39 static af_data_t *play(struct af_instance_s *af, af_data_t * data)
  40 {
  41         af_volnorm_t *s = af->setup;
  42         if (af->data->format == (((0 << 2) | (0 << 1) | (1 << 3) | (0 << 0))))
  43                 if (s->method)
  44                         method2_int16(s, data);
  45 }
  46 static int af_open(af_instance_t * af)
  47 {
  48         af->play = play;
  49 }
  50
  51 af_info_t af_info_volnorm = {
  52         "Volume normalizer filter", "volnorm",
  53             "Alex Beregszaszi & Pierre Lombard", "", 0x00000001, af_open
  54 };