Fix Motion Tracker keyframes not applying after save/reload (#1854)

* Fix Motion Tracker keyframes not applying after save/reload

MotionTrackerModel::trackingData parsed each keyframe's time key with
QString::toInt, which only accepts integer frame numbers ("5"). When a
project is saved, Shotcut serializes animated properties (including the
opencv.tracker `results`) in clock time format (00:00:00.167). After a
save+reload, toInt then failed on every entry, trackingData returned an
empty list, and "Load Keyframes from Motion Tracker" silently applied
zero keyframes (the masked rect stayed static).

Accept both frame-number and clock/timecode keys. The parsed frame value
is not used downstream (only the rectangles are consumed by applyTracking
and reset), so fall back to the running index when toInt fails.

* Use time_to_frames to parse tracker keyframe times

Responding to review feedback: rather than falling back to the running
index when QString::toInt fails on a clock-time key, parse the keyframe
time with Mlt::Consumer::time_to_frames. It converts both the clock form
("00:00:00.167") and the frame-number form ("5") to the correct frame
using the project frame rate, so a project reloaded with clock-time
results no longer yields an empty list and the keyframes apply.

Author: skuznetsov

src/models/motiontrackermodel.cpp

@@ -264,18 +264,22 @@ QList<MotionTrackerModel::TrackingItem> MotionTrackerModel::trackingData(const Q
     QList<TrackingItem> result;
     auto s = m_data.value(key, {}).trackingData;
     auto l = s.split(';');
-    bool ok{false};
     Mlt::Properties props;
+    auto consumer = MLT.consumer();
 
     for (const auto &i : l) {
         auto pair = i.split("~=");
         if (pair.size() == 2) {
-            auto frame = pair.at(0).toInt(&ok);
+            // The keyframe time is serialized either as a frame number ("5") or
+            // as a clock value ("00:00:00.167"), depending on the time format
+            // MLT used when the project was written (animated properties are
+            // saved as time so they adapt to a frame-rate change). time_to_frames()
+            // parses both forms to the correct frame using the project frame rate.
+            int frame = consumer ? consumer->time_to_frames(pair.at(0).toUtf8().constData())
+                                 : pair.at(0).toInt();
             props.set("", pair.at(1).toLatin1().constData());
             auto rect = props.get_rect("");
-            if (ok) {
-                result << TrackingItem{frame, QRectF(rect.x, rect.y, rect.w, rect.h)};
-            }
+            result << TrackingItem{frame, QRectF(rect.x, rect.y, rect.w, rect.h)};
         }
     }
     return result;