Provided are a method, system, and article of manufacture for generating a combined video stream from multiple input video streams. A first video stream including a first product commercial generated to be played at a first playback speed and a second video stream including a second product commercial generated to be played at a second playback speed are processed. The second playback speed is faster than the first playback speed. A combined video stream is generated including a first panel in each frame to display the first video stream and a second panel in each frame to display the second video stream. When the combined video stream is played at the first playback speed the second video stream is rendered to appear at a slower speed than the second playback speed for which it was generated. When the combined video stream is played at the second playback speed the first video speed is rendered to appear at a faster speed than the first playback speed for which it was generated.