I've already covered how to download your Tivo recorded shows to your mac here. Now that you have the show you need to get rid of the commercials. First, download the MPEG Streamclip application. When you open the application you will get a screen that looks like this:
To edit a file just drag it to the screen or use the "Open Files" selection in the "File" menu. There are two basic editing functions you are going to use; trim and cut. First you need to select the sections of the show you want to edit out.
Drag the slider to the beginning of the show and type "I" for "Select In" then just hit command+T to trim out that section. Trimming a file will cut out everything you haven't selected.
Now move the cursor to the start of the first commercial break and hit the "I" key again. Move the cursor to the end of the commercial break and hit the "O" key for "Select Out." Just the commercials will be selected (as shown in the screen shot below). Then all you need to do is use the cut command (command+X) to get rid of the commercials. If you have trouble finding the right spot when you use the select in or select out location use the arrow keys on your keyboard. They will allow you to move a frame at a time to fine tune your selection location.
Just repeat this for all the commercials in the show. When you get to the end of the show type the "O" key and do a Trim again to get rid of the ending credits and trailing commercials. That's it!
Now a few comments about the whole process; One of the challenges I had with editing video was making sure that the audio was syncing. At times, after editing, the audio would get out of sync and there would be a split second delay when an actors mouth would move and the sound would come out. It's very annoying and can render the file unwatchable.
To make sure that things stay sync'd up here's some of hints that should help.
- Try to minimize edits. Only use one edit per commercial break and don't do a lot of little edits.
- Don't use the export function to save your video. Just do a "Save As." When you save it will save to the exact same format you used when you moved it from your Tivo to your Mac. Sometimes exporting to a different format will get the audio out of sync.
- Do a "Fix Timecode Breaks" (command+F in the Edit menu) when you first open the file. This may help.
From what I have read, the unsynchronized audio may be a result of a frame rate issue from the original video program. If you have issues with synchronization maybe try setting the frame rate to a different value when you move the file from your Tivo to your Mac.
Good luck and enjoy your shows!