diff options
| -rw-r--r-- | libass/ass.c | 50 |
1 files changed, 31 insertions, 19 deletions
diff --git a/libass/ass.c b/libass/ass.c index f6fabdc..19e1b53 100644 --- a/libass/ass.c +++ b/libass/ass.c @@ -1242,33 +1242,45 @@ int ass_read_styles(ASS_Track *track, char *fname, char *codepage) long long ass_step_sub(ASS_Track *track, long long now, int movement) { int i; + ASS_Event *best = NULL; + long long target = now; + int direction = movement > 0 ? 1 : -1; if (movement == 0) return 0; if (track->n_events == 0) return 0; - if (movement < 0) - for (i = 0; - (i < track->n_events) - && - ((long long) (track->events[i].Start + - track->events[i].Duration) <= now); ++i) { - } else - for (i = track->n_events - 1; - (i >= 0) && ((long long) (track->events[i].Start) > now); - --i) { + while (movement) { + ASS_Event *closest = NULL; + long long closest_time = now; + for (i = 0; i < track->n_events; i++) { + if (direction < 0) { + long long end = + track->events[i].Start + track->events[i].Duration; + if (end < target) { + if (!closest || end > closest_time) { + closest = &track->events[i]; + closest_time = end; + } + } + } else { + long long start = track->events[i].Start; + if (start > target) { + if (!closest || start < closest_time) { + closest = &track->events[i]; + closest_time = start; + } + } + } } + target = closest_time + direction; + movement -= direction; + if (closest) + best = closest; + } - // -1 and n_events are ok - assert(i >= -1); - assert(i <= track->n_events); - i += movement; - if (i < 0) - i = 0; - if (i >= track->n_events) - i = track->n_events - 1; - return ((long long) track->events[i].Start) - now; + return best ? best->Start - now : 0; } ASS_Track *ass_new_track(ASS_Library *library) |