player: add ab-loop-count option/property

As requested I guess. It behaves quite similar to the --loop* options.

Not quite happy with the idea that 1) the option is mutated on each
operation (but at least it's consistent with --loop* and doesn't require
more properties), and 2) the ab-loop command will do nothing once all
loop iterations are done. As a concession, the OSD shows something about
"disabled".

Fixes: #7360

DOCS/man/options.rst

@@ -346,6 +346,14 @@ Playback Control
     The loop-points can be adjusted at runtime with the corresponding
     properties. See also ``ab-loop`` command.
 
+``--ab-loop-count=<N|inf>``
+    Run A-B loops only N times, then ignore the A-B loop points (default: inf).
+    Every finished loop iteration will decrement this option by 1 (unless it is
+    set to ``inf`` or 0). ``inf`` means that looping goes on forever. If this
+    option is set to 0, A-B looping is ignored, and even the ``ab-loop`` command
+    will not enable looping again (the command will show ``(disabled)`` on the
+    OSD message if both loop points are set, but ``ab-loop-count`` is 0).
+
 ``--ordered-chapters``, ``--no-ordered-chapters``
     Enabled by default.
     Disable support for Matroska ordered chapters. mpv will not load or

options/options.c

@@ -427,6 +427,8 @@ static const m_option_t mp_opts[] = {
 
     OPT_TIME("ab-loop-a", ab_loop[0], 0, .min = MP_NOPTS_VALUE),
     OPT_TIME("ab-loop-b", ab_loop[1], 0, .min = MP_NOPTS_VALUE),
+    OPT_CHOICE_OR_INT("ab-loop-count", ab_loop_count, 0, 0, INT_MAX,
+                      ({"inf", -1})),
 
     OPT_CHOICE_OR_INT("playlist-start", playlist_pos, 0, 0, INT_MAX,
                       ({"auto", -1}, {"no", -1})),
@@ -940,6 +942,7 @@ static const struct MPOpts mp_default_opts = {
     .cache_pause = 1,
     .cache_pause_wait = 1.0,
     .ab_loop = {MP_NOPTS_VALUE, MP_NOPTS_VALUE},
+    .ab_loop_count = -1,
     .edition_id = -1,
     .default_max_pts_correction = -1,
     .correct_pts = 1,

options/options.h

@@ -232,6 +232,7 @@ typedef struct MPOpts {
     int rebase_start_time;
     int play_frames;
     double ab_loop[2];
+    int ab_loop_count;
     double step_sec;
     int position_resume;
     int position_check_mtime;

player/command.c

@@ -3731,7 +3731,8 @@ static const struct property_osd_display {
     {"vf", "Video filters", .msg = "Video filters:\n${vf}"},
     {"af", "Audio filters", .msg = "Audio filters:\n${af}"},
     {"ab-loop-a", "A-B loop start"},
-    {"ab-loop-b", .msg = "A-B loop: ${ab-loop-a} - ${ab-loop-b}"},
+    {"ab-loop-b", .msg = "A-B loop: ${ab-loop-a} - ${ab-loop-b}"
+                            "${?=ab-loop-count==0: (disabled)}"},
     {"audio-device", "Audio device"},
     {"hwdec", .msg = "Hardware decoding: ${hwdec-current}"},
     {"video-aspect-override", "Aspect ratio override"},

player/misc.c

@@ -123,6 +123,9 @@ bool get_ab_loop_times(struct MPContext *mpctx, double t[2])
     t[0] = opts->ab_loop[0];
     t[1] = opts->ab_loop[1];
 
+    if (!opts->ab_loop_count)
+        return false;
+
     if (t[0] == MP_NOPTS_VALUE || t[1] == MP_NOPTS_VALUE || t[0] == t[1])
         return false;
 

player/playloop.c

@@ -885,6 +885,10 @@ static void handle_loop_file(struct MPContext *mpctx)
 
     double ab[2];
     if (get_ab_loop_times(mpctx, ab) && mpctx->ab_loop_clip) {
+        if (opts->ab_loop_count > 0) {
+            opts->ab_loop_count--;
+            m_config_notify_change_opt_ptr(mpctx->mconfig, &opts->ab_loop_count);
+        }
         target = ab[0];
         prec = MPSEEK_EXACT;
     } else if (opts->loop_file) {