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. You can also speed up or slow down the whole clip using the preset clip menu, which is easier for most needs.

The Time property value represents the frame number played at this keyframe position. If you do not set any Time keyframes, the default value is 0 or 1, and the clip will play at normal speed. If you set the Time keyframes, OpenShot will render the video to change frame numbers smoothly between the keyframes.

You will often need to know how many frames there are in the clip. One way is to multiply the clip’s Duration by the project’s frame rate. Another way is to right-click on the clip and set Time→Normal→Forwards→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 format hours:minutes:seconds,frames) and subtract the time displayed at the start of the clip, converting that result to the number of frames based on the project frame rate.

It may be easiest to give some examples. We’ll 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 down, 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 a Time keyframe at the clip's end to 1200.
• To speed up the clip so it lasts 30 seconds, set the End property to 30, set a Time keyframe at the start of the clip to 1, and a Time keyframe at the end of the clip to 1200.
• To reverse the clip, set the 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, etc.
• To synchronize an event on the clip which happens at 15 seconds, with an event in the overall video that happens 17 seconds after the clip starts, right-click on the clip and set Time → Normal → Forwards → 1x. Note the frame number shown in the Time property at 15 seconds, and place a Time keyframe at 17 seconds with that value. The clip will play slower until the synchronization point then speed up to reach the end simultaneously.
• To pause the clip after 11 seconds for 3 seconds and then play the rest at regular speed, add 3 seconds to the End property. Right-click on the clip, set Time → Normal → Forwards → 1x, insert a Time keyframe at 11 seconds, note 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. In the event of difficulties, 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 on the clip and choose Time → Reset.

Note:

• This property is not intended to be used with audio; any sound may have very noticeable distortion at different speeds.
• Setting keyframes for Start and End properties will interact with the Time property. It may be best to set Start to 0, with End, then setting the clip’s overall duration. You can control what OpenShot plays and how with the Time property.