TABLE OF CONTENTS
OpenShot's Time Property
When you use the Time feature to adjust the playback speed of a video clip on the Timeline, it may result in some unwanted frames appearing. To fix this problem, you can export the affected part of your project as a separate video file, adjust the playback speed of the individual video, and then import it back into your original project as a new clip. This will allow you to change the speed without affecting the rest of the Timeline.
The following steps show how to adjust the playback speed of your clip:
- Identify the portion of the project to adjust playback speed and prepare it for export.
- Position the cursor over the desired clip, perform a right-click action, and select the "Properties" option from the dropdown menu.
- Scroll through the Properties window until locating the "Frame Number" property.
- Perform a right-click action on the value next to "Frame Number" (the default value will read "None") and choose "Timeline."
- Advance the play-head (identified as a red vertical line on the Timeline) to the first frame of the selected clip.
- Note the number appearing in the upper left-hand corner of the preview screen, which indicates the first frame.
- Position the play-head on the final desired frame.
- Record the number in the preview screen's upper left-hand corner, indicating the last frame.
- Return the play-head to the first frame of the chosen clip.
- Execute a right-click action on the value adjacent to "Frame Number" and select "None" to deactivate the display of frame numbers.
- Initiate the "Export Video" function by clicking the corresponding button, represented as a small red circle icon, located in the toolbar at the top of the Main window, opening the Export Video window.
- Enter a unique name for the section to export in the "File Name:" field.
- Specify a destination folder for the exported section in the "Folder Path:" field.
- Under the "Simple" tab:
- Review the settings for "Target," "Video Profile," and "Quality."
- Ensure the settings for "Target," "Video Profile," and "Quality" are congruent with those of the source clip.
- Under the "Advanced" tab:
- Adjust the "Start Frame" to correspond with the clip's first frame.
- Adjust the "End Frame" to fit with the last frame of the clip.
- Click the "Export Video" button to export the selected portion of the project.
- Initiate a new project and import only the clip requiring a change in playback speed.
- Adjust the speed of this clip and export it as a separate video file.
- Integrate the newly modified clip into the original project by adding it to the Timeline.
Here are simplified steps for non-technical users to adjust the playback speed of a video clip in OpenShot:
- Export the part of your video that you want to change the playback speed for:
- Right-click the clip you want to export and select "Properties."
- Scroll down to the "Frame Number" property and select "Timeline" from the dropdown menu.
- Move the play-head to the clip's first frame and note the number in the preview screen.
- Move the play-head to the clip's last frame and note the number in the preview screen.
- Right-click the "Frame Number" property and select "None" to turn off the frame numbers displaying.
- Click the "Export Video" button and enter a new name and destination for the exported video.
- Review the settings on the "Simple" tab and ensure they match the source clip.
- On the "Advanced" tab, change the "Start Frame" to the first frame and the "End Frame" to the last frame.
- Click the "Export Video" button to export the video clip.
- Create a new project and import the exported clip:
- Open a new project in OpenShot.
- Click "File" and select "Import Files" to import the exported clip.
- Adjust the speed of the imported clip:
- Right-click the clip and select "Time."
- Adjust the speed as desired.
- Export the modified clip:
- Click the "Export Video" button and enter a new name and destination for the modified clip.
- Review the settings and ensure they match the source clip.
- Click the "Export Video" button to export the modified clip.
- Add the modified clip to your original project:
- Open your original project in OpenShot.
- Click "File" and select "Import Files" to import the modified clip.
- Drag and drop the modified clip to the Timeline where desired.
The method above uses the clip's Right-click Menu, which has preset values. Suppose you do not want to use the preset values. In that case, you can perform the calculations yourself and manually enter the values in the Time property of your clip.
The Time property allows you to change the speed at which the clip plays – forward, backward, or both. It allows great flexibility and relies on the animation system.
The Time value stands for the frame number playing at this keyframe position. If you did not set Time keyframes, the default values are 0 or 1, and the clip plays at regular speed. OpenShot renders the video to change frame numbers smoothly between the keyframes if you set Time keyframes.
You often need to know how many frames there are in the clip. One way is multiplying the clip's Duration by the project's frame rate. Another way is to right-click the clip and set Time » Normal » Forward » 1x, which sets the start Time keyframe to 1 and the end Time keyframe to the last frame, which you can read by jumping to that keyframe. You can also jump to the end of the clip and note the time shown on the Timeline (in the hours:minutes:seconds,frames format). Subtract the time displayed at the clip's start and convert that result to the number of frames based on the project frame rate.
It may be easiest to give examples. Take a clip that is 40 seconds long, with a project frame rate of 30 fps. The clip therefore has 40 x 30 = 1200 frames:
- To slow the clip so it lasts for 55 seconds, set the End property to 55 (so the clip's duration is now 55 seconds), set a Time keyframe at the clip's start to 1, and the clip's end to 1200.
- To speed up the clip so it lasts for 30 seconds, set the End property to 30, set a Time keyframe at the clip's start to 1, and the clip's end to 1200.
- To play the clip in reverse, set a Time keyframe at the clip's start to 1200 and the clip's end to 1. OpenShot renders the frames in order: 1200, 1199, 1198, 1197, and so on.
- To synchronize an event on the clip that happens at 15 seconds with an event in the overall video that happens 17 seconds after the clip starts, right-click and set Time » Normal » Forward » 1x. Note the frame number shown in the Time property at 15 seconds, and insert a Time keyframe at 17 seconds with that value. The clip plays slower until the synchronization point, then speed up to reach the end simultaneously, assuming the change in speed looks acceptable.
- To pause the clip after 11 seconds for 3 seconds and then play the rest of the clip regularly, add 3 seconds to the End property. Right-click on the clip, set Time » Normal » Forward » 1x, insert a Time keyframe at 11 seconds, noting the value, and set a new Time keyframe at 11 + 3 = 14 seconds to that value. If your clip has audio, you might need to set Volume keyframes to mute the sound.
- To play the clip halfway, then play it reverse back to the start, set Time keyframes at the beginning and the end to 1 and a Time keyframe in the middle (at 20 seconds) to 1200/2 = 600.
- To play the clip and hold the last frame image frozen for another 5 seconds, add 5 seconds onto the End property; you do not need to set the Time property.
If you find that changes to clip speed are too abrupt, you can smooth the changes by choosing a Bezier curve in the animation system. If you have difficulties with this, you might need to create a second (duplicate) Time keyframe in the next frame.
A quick way to remove all Time keyframes is to right-click the clip and choose Time » Reset.
- OpenShot does not intend for you to use the Time property with audio clips. Any sound may have a very noticeable distortion at different speeds.
- Setting keyframes for Start and End properties interacts with the Time property. You may find it best to set Start to 0, with End determining the clip's overall Duration; the Time property can control what is playing and how.
This passage describes the Time property in OpenShot, which allows users to change the speed at which a video clip plays forward, backward, or both. The Time value shows the frame number playing at the keyframe position, and users can set Time keyframes to customize the playback speed. OpenShot renders the video to transition smoothly between keyframes. Users can multiply the clip's duration by the project's frame rate to find the number of frames in a clip. Users can also set Time keyframes to the first and last frames and calculate the difference based on the project frame rate.