OSD: support displaying fractional part of current position

Add option -osd-fractions which enables display of fractional seconds
when showing the current playback time on OSD.

Based on a patch from Christian <herr.mitterlehner@gsmpaaiml.com> but
with several modifications.

DOCS/man/de/mplayer.1

@@ -2408,6 +2408,24 @@ Deaktiviert das automatische Laden von Untertiteln.
 Setzt die Anzeigedauer der OSD-Meldungen in ms (Standard: 1000).
 .
 .TP
+.B \-osd\-fractions <0\-2>
+Setzt die Art der Anzeige von Nachkommastellen des aktuellen Zeitstempels im
+OSD:
+.PD 0
+.RSs
+.IPs 0
+Keine Anzeige der Nachkommastellen (Standard).
+.IPs 1
+Zeige die ersten beiden Nachkommastellen.
+.IPs 2
+Zeige genäherte Framezahl an.
+Die angezeigte Framezahl ist nicht exakt, sondern nur genähert.
+Für variable FPS ist die Näherung weit von der tatsächlichen Framezahl
+entfernt.
+.RE
+.PD 1
+.
+.TP
 .B \-osdlevel <0\-3> (nur bei MPlayer)
 Gibt den Modus an, in dem das OSD startet:
 .PD 0

DOCS/man/en/mplayer.1

@@ -2298,6 +2298,23 @@ Turns off automatic subtitle file loading.
 Set the duration of the OSD messages in ms (default: 1000).
 .
 .TP
+.B \-osd\-fractions <0\-2>
+Set how fractions of seconds of the current timestamp are printed on the OSD:
+.PD 0
+.RSs
+.IPs 0
+Do not display fractions (default).
+.IPs 1
+Show the first two decimals.
+.IPs 2
+Show approximate frame count within current second.
+This frame count is not accurate but only an approximation.
+For variable fps, the approximation is known to be far off the correct frame
+count.
+.RE
+.PD 1
+.
+.TP
 .B \-osdlevel <0\-3>
 Specifies which mode the OSD should start in.
 .PD 0

cfg-mplayer.h

@@ -216,6 +216,7 @@ const m_option_t mplayer_opts[]={
 #endif
     OPT_INTRANGE("osdlevel", osd_level, 0, 0, 3),
     OPT_INTRANGE("osd-duration", osd_duration, 0, 0, 3600000),
+    OPT_INTRANGE("osd-fractions", osd_fractions, 0, 0, 2),
 #ifdef CONFIG_MENU
     {"menu", &use_menu, CONF_TYPE_FLAG, CONF_GLOBAL, 0, 1, NULL},
     {"nomenu", &use_menu, CONF_TYPE_FLAG, CONF_GLOBAL, 1, 0, NULL},

mplayer.c

@@ -1639,7 +1639,9 @@ static void update_osd_msg(struct MPContext *mpctx)
             int len = get_time_length(mpctx);
             int percentage = -1;
             char percentage_text[10];
-            int pts = get_current_time(mpctx);
+            char fractions_text[4];
+            double fpts = get_current_time(mpctx);
+            int pts = fpts;
 
             if (mpctx->osd_show_percentage_until)
                 percentage = get_percent_pos(mpctx);
@@ -1649,15 +1651,41 @@ static void update_osd_msg(struct MPContext *mpctx)
             else
                 percentage_text[0] = 0;
 
+            if (opts->osd_fractions == 1) {
+                //print fractions as sub-second timestamp
+                snprintf(fractions_text, sizeof(fractions_text), ".%02d",
+                         (int)((fpts - pts) * 100));
+            } else if (opts->osd_fractions == 2) {
+                /* Print fractions by estimating the frame count within the
+                 * second.
+                 *
+                 * Rounding or cutting off numbers after the decimal point
+                 * causes problems because of float's precision and movies
+                 * whose first frame is not exactly at timestamp 0. Therefore,
+                 * we add 0.2 and cut off at the decimal point, which proved
+                 * to be good heuristic.
+                 */
+                double fps = mpctx->sh_video->fps;
+                if (fps <= 1 || fps > 99)
+                    strcpy(fractions_text, ".??");
+                else
+                    snprintf(fractions_text, sizeof(fractions_text), ".%02d",
+                             (int) ( (fpts - pts) * fps + 0.2 ) );
+            } else {
+                //do not print fractions
+                fractions_text[0] = 0;
+            }
+
             if (opts->osd_level == 3)
                 snprintf(osd_text_timer, 63,
-                         "%c %02d:%02d:%02d / %02d:%02d:%02d%s",
+                         "%c %02d:%02d:%02d%s / %02d:%02d:%02d%s",
                          mpctx->osd_function,pts/3600,(pts/60)%60,pts%60,
-                         len/3600,(len/60)%60,len%60,percentage_text);
+                         fractions_text, len/3600, (len/60)%60, len%60,
+                         percentage_text);
             else
-                snprintf(osd_text_timer, 63, "%c %02d:%02d:%02d%s",
+                snprintf(osd_text_timer, 63, "%c %02d:%02d:%02d%s%s",
                          mpctx->osd_function,pts/3600,(pts/60)%60,
-                         pts%60,percentage_text);
+                         pts%60, fractions_text, percentage_text);
         } else
             osd_text_timer[0]=0;
 

options.h

@@ -31,6 +31,7 @@ typedef struct MPOpts {
 
     int osd_level;
     int osd_duration;
+    int osd_fractions;
     int auto_quality;
     int benchmark;
     char *stream_dump_name;