I introduce you to the "speed control" effect strip and also show you how to change the pitch of audio to make it synchronize with the video strip speed. in addition, i show you how to snap strips. Changing the playback speed of video. by default, blender assumes that one frame of your input videos will equal one frame of your output/produced video, but you can change that default by adding. import the video material into blender's video sequencer. it will be selected by default. from the add menu, select effect strip, then speed control.. Blender 2.79 manual getting started; remember to click the refresh sequencer button in the header of the video sequence editor’s strip view or your changes will not take effect. changing video frame rates