I have a Scientific Atlanta 8300 HD. I didn't have much luck trying to accomplish this.

The problem is that the fast forward starts slow and gets faster. The manual says that pressing the fast forward three times plays the video at 32x normal speed but creating a macro that presses the button three times, waits one second then presses play didn't result in a 32 second advance. In fact, it did almost nothing. On the other hand waiting longer (4 or 5 seconds) resulted in an advance of several minutes. While the macro is running you cannot press any other button so I would end up watching my show return from commercial break and keep on going and going and going. In the end the best I could do was create a macro that presses the fast forward three times. Then I watch and when it looks like my show is going to come back on I press play myself.

For anyone who wonders why I don’t just press the button three times myself, the Pronto is slow and it almost always results in only two presses.

If anyone has actually got the duration down to a science I would love to hear about it.