player: refactor display-sync frame duration calculations

Get rid of get_past_frame_durations(), which was a bit too messy. Add
a past_frames array, which contains the same information in a more
reasonable way. This also means that we can get the exact current and
past frame durations without going through awful stuff. (The main
problem is that vo_pts_history contains future frames as well, which is
needed for frame backstepping etc., but gets in the way here.)

Also disable the automatic disabling of display-sync if the frame
duration changes, and extend the frame durations allowed for display
sync. To allow arbitrarily high durations, vo.c needs to be changed
to pause and potentially redraw OSD while showing a single frame, so
they're still limited.

In an attempt to deal with VFR, calculate the overall speed using the
average FPS. The frame scheduling itself does not use the average FPS,
but the duration of the current frame. This does not work too well,
but provides a good base for further improvements.

Where this commit actually helps a lot is dealing with rounded
timestamps, e.g. if the container framerate is wrong or unknown, or
if the muxer wrote incorrectly rounded timestamps. While the rounding
errors apparently can't be get rid of completely in the general case,
this is still much better than e.g. disabling display-sync completely
just because some frame durations go out of bounds.

1 files changed, 0 insertions, 21 deletions

diff --git a/player/playloop.c b/player/playloop.c
index f5463e2622..643f290c48 100644
--- a/player/playloop.c
+++ b/player/playloop.c
@@ -693,27 +693,6 @@ void add_frame_pts(struct MPContext *mpctx, double pts)
     mpctx->vo_pts_history_pts[0] = pts;
 }
 
-// Return the last (at most num) frame duration in fd[]. Return the number of
-// entries written to fd[] (range [0, num]). fd[0] is the most recent frame.
-int get_past_frame_durations(struct MPContext *mpctx, double *fd, int num)
-{
-    double next_pts = mpctx->vo_pts_history_pts[0];
-    if (mpctx->vo_pts_history_seek[0] != mpctx->vo_pts_history_seek_ts ||
-        next_pts == MP_NOPTS_VALUE)
-        return 0;
-    int num_ret = 0;
-    for (int n = 1; n < MAX_NUM_VO_PTS && num_ret < num; n++) {
-        double frame_pts = mpctx->vo_pts_history_pts[n];
-        // Discontinuity -> refuse to return a value.
-        if (mpctx->vo_pts_history_seek[n] != mpctx->vo_pts_history_seek_ts ||
-            next_pts <= frame_pts || frame_pts == MP_NOPTS_VALUE)
-            break;
-        fd[num_ret++] = next_pts - frame_pts;
-        next_pts = frame_pts;
-    }
-    return num_ret;
-}
-
 static double find_previous_pts(struct MPContext *mpctx, double pts)
 {
     for (int n = 0; n < MAX_NUM_VO_PTS - 1; n++) {