static const int C = 320;
static const int R = 240;
static const int NPOINTS = C*R;

struct Joint {
  int32_t id;
  float x,y,z;
};
struct Marker {
  char name[255];
  float x,y,z;
};

struct Frame {
  int32_t   MAGIC_NUMBER;
  int32_t   frame_number;
  float     points[NPOINTS][3];
  
  int32_t   nmarkers;
  struct Marker    markers[32]; // first nmarkers will be filled with markers
  
  int32_t   njoints;
  struct Joint     joints[32];  // first njoints will be filled with joints
};