A multispeed playback system is described herein that allows for playback of smooth streaming media presentations at speeds other than the normal speed or direction, while still using an underlying platform that does not natively support multispeed. The system provides frames to the underlying platform so that the platform is still playing 1× content while the system manipulates video and/or audio samples being fed to the platform to make rendered data look appropriately for a selected speed and direction. The system may feed the underlying platform frames at a faster rate or skip every other frame for faster playback, or may feed each frame to the underlying platform multiple times for slower playback. Thus, the multispeed playback system allows a client application developer to provide users with expected multispeed playback at the client without encoding multiple different streams at the server.