timers: Remove GetRelativeTime()

Move the code calculating time delta since last query out of the
platform-specific drivers and into mplayer.c. The platform-specific
drivers now return absolute values only.

The way the code in timer-darwin.c uses doubles in wrapping arithmetic
looks questionable and this change might make problems in it more
visible.

mp_core.h

@@ -70,6 +70,11 @@ typedef struct MPContext {
     // by the audio CPU usage meter.
     double delay;
 
+    // Timestamp from the last time some timing functions read the
+    // current time, in (occasionally wrapping) microseconds. Used
+    // to turn a new time value to a delta from last time.
+    unsigned int last_time;
+
     // Used to communicate the parameters of a seek between parts
     float rel_seek_secs;
     int abs_seek_pos;

mplayer.c

@@ -369,6 +369,14 @@ int mpctx_get_osd_function(MPContext *mpctx)
     return mpctx->osd_function;
 }
 
+static float get_relative_time(struct MPContext *mpctx)
+{
+    unsigned int new_time = GetTimer();
+    unsigned int delta = new_time - mpctx->last_time;
+    mpctx->last_time = new_time;
+    return delta * 0.000001;
+}
+
 static int is_valid_metadata_type(struct MPContext *mpctx, metadata_t type) {
   switch (type)
   {
@@ -1758,7 +1766,7 @@ static int generate_video_frame(struct MPContext *mpctx)
     int rtc_fd = -1;
 #endif
 
-static float timing_sleep(float time_frame)
+static float timing_sleep(struct MPContext *mpctx, float time_frame)
 {
 #ifdef HAVE_RTC
     if (rtc_fd >= 0){
@@ -1768,7 +1776,7 @@ static float timing_sleep(float time_frame)
 	    unsigned long rtc_ts;
 	    if (read(rtc_fd, &rtc_ts, sizeof(rtc_ts)) <= 0)
 		mp_msg(MSGT_CPLAYER, MSGL_ERR, MSGTR_LinuxRTCReadError, strerror(errno));
-    	    time_frame -= GetRelativeTime();
+            time_frame -= get_relative_time(mpctx);
 	}
     } else
 #endif
@@ -1779,14 +1787,14 @@ static float timing_sleep(float time_frame)
 	current_module = "sleep_timer";
 	while (time_frame > margin) {
 	    usec_sleep(1000000 * (time_frame - margin));
-	    time_frame -= GetRelativeTime();
+            time_frame -= get_relative_time(mpctx);
 	}
 	if (softsleep){
 	    current_module = "sleep_soft";
 	    if (time_frame < 0)
 		mp_msg(MSGT_AVSYNC, MSGL_WARN, MSGTR_SoftsleepUnderflow);
 	    while (time_frame > 0)
-		time_frame-=GetRelativeTime(); // burn the CPU
+                time_frame -= get_relative_time(mpctx); // burn the CPU
 	}
     }
     return time_frame;
@@ -2073,7 +2081,7 @@ static int sleep_until_update(struct MPContext *mpctx, float *time_frame,
     int frame_time_remaining = 0;
     current_module="calc_sleep_time";
 
-    *time_frame -= GetRelativeTime(); // reset timer
+    *time_frame -= get_relative_time(mpctx); // reset timer
 
     if (mpctx->sh_audio && !mpctx->d_audio->eof) {
 	float delay = mpctx->audio_out->get_delay();
@@ -2120,7 +2128,7 @@ static int sleep_until_update(struct MPContext *mpctx, float *time_frame,
 
     // flag 256 means: libvo driver does its timing (dvb card)
     if (*time_frame > 0.001 && !(mpctx->sh_video->output_flags&256))
-	*time_frame = timing_sleep(*time_frame);
+	*time_frame = timing_sleep(mpctx, *time_frame);
     return frame_time_remaining;
 }
 
@@ -2372,7 +2380,7 @@ static void pause_loop(struct MPContext *mpctx)
         mpctx->audio_out->resume();	// resume audio
     if (mpctx->video_out && mpctx->sh_video && mpctx->video_out->config_ok)
         vo_control(mpctx->video_out, VOCTRL_RESUME, NULL);	// resume video
-    (void)GetRelativeTime();	// ignore time that passed during pause
+    (void)get_relative_time(mpctx);	// ignore time that passed during pause
 #ifdef HAVE_NEW_GUI
     if (use_gui) {
 	if (guiIntfStruct.Playing == guiSetStop)
@@ -3683,6 +3691,8 @@ if (mpctx->stream->type == STREAMTYPE_DVDNAV) {
 }
 #endif
 
+ get_relative_time(mpctx); // reset current delta
+
 while(!mpctx->eof){
     float aq_sleep_time=0;
 

osdep/timer-darwin.c

@@ -27,7 +27,6 @@
 #include "timer.h"
 
 /* global variables */
-static double relative_time, startup_time;
 static double timebase_ratio;
 
 const char timer_name[] = "Darwin accurate";
@@ -54,30 +53,17 @@ int usec_sleep(int usec_delay)
 /* current time in microseconds */
 unsigned int GetTimer()
 {
-  return (unsigned int)((mach_absolute_time() * timebase_ratio - startup_time)
+  return (unsigned int)((mach_absolute_time() * timebase_ratio)
 			* 1e6);
 }
 
 /* current time in milliseconds */
 unsigned int GetTimerMS()
 {
-  return (unsigned int)((mach_absolute_time() * timebase_ratio - startup_time)
+  return (unsigned int)((mach_absolute_time() * timebase_ratio)
                         * 1e3);
 }
 
-/* time spent between now and last call in seconds */
-float GetRelativeTime()
-{
-  double last_time = relative_time;
-  
-  if (!relative_time)
-    InitTimer();
-  
-  relative_time = mach_absolute_time() * timebase_ratio;
-
-  return (float)(relative_time-last_time);
-}
-
 /* initialize timer, must be called at least once at start */
 void InitTimer()
 {
@@ -86,9 +72,6 @@ void InitTimer()
   mach_timebase_info(&timebase);
   timebase_ratio = (double)timebase.numer / (double)timebase.denom 
     * (double)1e-9;
-    
-  relative_time = startup_time = 
-    (double)(mach_absolute_time() * timebase_ratio);
 }
 
 #if 0

osdep/timer-linux.c

@@ -46,21 +46,8 @@ unsigned int GetTimerMS(void){
   return (tv.tv_sec*1000+tv.tv_usec/1000);
 }  
 
-static unsigned int RelativeTime=0;
-
-// Returns time spent between now and last call in seconds
-float GetRelativeTime(void){
-unsigned int t,r;
-  t=GetTimer();
-//  t*=16;printf("time=%ud\n",t);
-  r=t-RelativeTime;
-  RelativeTime=t;
-  return (float)r * 0.000001F;
-}
-
 // Initialize timer, must be called at least once at start
 void InitTimer(void){
-  GetRelativeTime();
 }
 
 

osdep/timer-win2.c

@@ -25,16 +25,5 @@ int usec_sleep(int usec_delay){
   return 0;
 }
 
-static DWORD RelativeTime = 0;
-
-float GetRelativeTime(){
-  DWORD t, r;
-  t = GetTimer();
-  r = t - RelativeTime;
-  RelativeTime = t;
-  return (float) r *0.000001F;
-}
-
 void InitTimer(){
-  GetRelativeTime();
 }

osdep/timer.h

@@ -7,7 +7,6 @@ void InitTimer(void);
 unsigned int GetTimer(void);
 unsigned int GetTimerMS(void);
 //int uGetTimer();
-float GetRelativeTime(void);
 
 int usec_sleep(int usec_delay);