Fixing Overlaps
Event overlaps occur when the start or end time of one Event conflicts with the timing of another Event in the same Event Group. These timing conflicts typically arise during manual editing when extending an Event duration causes it to encroach on the next Event, when merging Event Groups created by multiple team members with different timing approaches, or when applying timing adjustments that inadvertently shift Events into each other. Overlapping Events create problems during export and playback, as most subtitle renderers and caption decoders cannot properly display two Events simultaneously on screen.
Prerequisites​
Before fixing overlaps, it is helpful to identify where they exist in your Event Group. Enable Real Time Error Detection in your Event Group settings to highlight overlap violations directly in the Event List with visual indicators. You can also identify overlaps visually in the Timeline view, where overlapping Events appear as stacked or intersecting blocks on the timeline ruler.
Verify your project frame rate settings, as the Fix Overlap tool can optionally apply a minimum frame gap between consecutive Events based on frame-accurate calculations. Understanding your delivery specification for frame gaps helps you configure the tool appropriately for your target platform.
Navigation paths​
- Access the Fix Event Overlap tool:
Format > Fix Event Overlap - The tool operates on the currently selected Event Group
- All Events in the group are processed automatically
Workflow​
When you invoke Fix Event Overlap from the Format menu, the tool immediately processes all Events in the currently selected Event Group. The correction algorithm begins by sorting all Events by their start time to ensure they are processed in chronological order. This sorting step is important because overlaps can only be accurately resolved when Events are evaluated in the sequence they appear in the timeline.
The algorithm then iterates backward through the sorted Event list, comparing each Event with the previous Event to detect overlaps. An overlap is identified when the start time of an Event is less than or equal to the end time of the preceding Event. When an overlap is detected, the tool adjusts the end time of the earlier Event to match the start time of the later Event, effectively eliminating the conflict.
If you have configured a minimum frame gap value in the tool settings, the algorithm applies additional spacing between Events. Rather than setting the previous Event end time exactly equal to the next Event start time, the algorithm subtracts the frame gap duration to create the specified separation. The frame gap is calculated by dividing the number of frames by the project frame rate to convert the gap into seconds, ensuring frame-accurate spacing regardless of the frame rate standard.
The algorithm uses a loop structure that continues checking for overlaps until a complete pass through all Events finds no remaining conflicts. This iterative approach handles complex cases where fixing one overlap may create or reveal another overlap earlier in the Event sequence. In practice, most Event Groups resolve within one or two iterations, but the algorithm ensures complete overlap elimination regardless of how many passes are required.
After the Fix Overlap process completes, you should review your Event Group in the Timeline view to verify that the timing adjustments have not created unintended consequences. Pay particular attention to Events that may now have very short durations if they were significantly trimmed to resolve overlaps, as these Events may violate minimum duration requirements or create poor viewing experiences.
Use cases​
The Fix Overlap tool is essential after performing global timing operations that may create overlaps as a side effect. For example, when using Automatic Reading Speed Correction to extend Event durations for CPS compliance, the longer durations may cause Events to overlap with their successors. Running Fix Overlap after such operations cleans up these conflicts automatically.
When merging Event Groups created by multiple team members, especially in collaborative workflows where different users have worked on different segments of the same media, timing conflicts often occur at the merge boundaries or throughout the combined Event list. Fix Overlap provides a quick way to resolve all conflicts at once rather than manually adjusting each overlap individually.
The tool is also valuable during quality control passes when Real Time Error Detection identifies multiple overlap violations that need systematic correction. Rather than manually adjusting dozens or hundreds of Events, Fix Overlap resolves all violations in a single operation.
For broadcast deliverables that require specific frame gap specifications between caption Events, Fix Overlap ensures consistent spacing throughout the entire Event Group when configured with the appropriate frame gap parameter. This automation eliminates the tedious manual work of ensuring each Event maintains proper spacing from its neighbors.
Troubleshooting​
If fixing overlaps creates Events with extremely short durations that violate your minimum duration requirements, the overlap resolution may be revealing underlying problems with Event density or reading speed. Consider using Automatic Reading Speed Correction after Fix Overlap to rebalance Event timing, or manually review and consolidate Events that contain minimal text.
When the Fix Overlap process appears to create new timing problems rather than solving them, verify that your Events are properly ordered by time before running the tool. If Events are out of chronological sequence in your Event List, use Order Events By Time from the Format menu to sort them correctly, then retry Fix Overlap.
If specific Events continue showing overlap errors after running Fix Overlap, check whether those Events have identical start and end times or malformed timing data. The algorithm assumes valid timing values, so Events with corrupted timecode information may not be corrected properly and should be manually reviewed.
When working with frame gap specifications, ensure your frame gap value is appropriate for your frame rate. A two-frame gap at 24 fps represents a different duration than a two-frame gap at 29.97 fps. Calculate the actual gap duration in seconds to verify it meets your delivery requirements. For example, a two-frame gap at 29.97 fps equals approximately 0.067 seconds, while the same two-frame gap at 24 fps equals approximately 0.083 seconds.
If Fix Overlap eliminates required overlap for creative timing purposes, such as when intentionally overlapping dialogue captions for rapid conversation, you will need to manually restore those specific overlaps after running the tool. Consider whether your workflow truly requires overlapping Events or whether alternative presentation approaches better serve the accessibility goals of your subtitle file.