include/core/framerate.hpp

   1 #ifndef _framerate__hpp__included__
   2 #define _framerate__hpp__included__
   3
   4 #include <cstdint>
   5
   6 /**
   7  * Number clocks per field/frame on NTSC/PAL
   8  */
   9 #define DURATION_NTSC_FRAME 357366
  10 #define DURATION_NTSC_FIELD 357368
  11 #define DURATION_PAL_FRAME 425568
  12 #define DURATION_PAL_FIELD 425568
  13
  14 /**
  15  * Sets the nominal frame rate. Framerate limiting tries to maintain the nominal framerate when there is no other
  16  * explict framerate to maintain.
  17  */
  18 void set_nominal_framerate(double fps) throw();
  19
  20 /**
  21  * Returns the current realized framerate.
  22  *
  23  * returns: The framerate the system is currently archiving.
  24  */
  25 double get_framerate() throw();
  26
  27 /**
  28  * Freeze time.
  29  *
  30  * Parameter usec: Current time in microseconds.
  31  */
  32 void freeze_time(uint64_t usec);
  33
  34 /**
  35  * Unfreeze time.
  36  *
  37  * Parameter usec: Current time in microseconds.
  38  */
  39 void unfreeze_time(uint64_t usec);
  40
  41 /**
  42  * Acknowledge frame start for timing purposes. If time is frozen, it is automatically unfrozen.
  43  *
  44  * parameter usec: Current time (relative to some unknown epoch) in microseconds.
  45  */
  46 void ack_frame_tick(uint64_t usec) throw();
  47
  48 /**
  49  * Computes the number of microseconds to wait for next frame.
  50  *
  51  * parameter usec: Current time (relative to some unknown epoch) in microseconds.
  52  * returns: Number of more microseconds to wait.
  53  */
  54 uint64_t to_wait_frame(uint64_t usec) throw();
  55
  56 /**
  57  * Return microsecond-resolution time since unix epoch.
  58  */
  59 uint64_t get_utime();
  60
  61 /**
  62  * Wait specified number of microseconds.
  63  */
  64 void wait_usec(uint64_t usec);
  65
  66 #endif