Dealing with Video Too Long for DVD

One of the movies I wanted to transfer from TiVo to DVD was too long to fit. In order to reduce its size, the bitrate must be reduced (see section 2b):

maximum-bitrate (bits/second) = 4,500,000,000 (bytes) * 8 (bits/byte) / video-length (seconds)

You can get the duration from the output of ffmpeg:

ffmpeg -i movie.mpg delete-me.vob -fs 1

This maximum bitrate gets split between audio and video. Use 256,000 for the audio and the rest for video. The new ffmpeg command is:

ffmpeg -i movie.mpg -target ntsc-dvd -b <video bitrate> -ab <audio bitrate> movie.vob