One last thought on video compression: Under normal circumstances, I never use the "two pass" encoding feature of ffmpeg, because I rarely need the absolute lowest bit rate, and multiple passes takes a lot more encoding time. However, when you're done with all editing, and you're ready to publish your best & final video, you should use ffmpeg's "two pass" capability. By using 2 passes, the encoder can "look ahead" to see what the video during the next few seconds is going to look like, and to tailor its decisions based on that additional information. Just as Knuth's TeX can optimize its font caching by looking ahead, video compressors can do roughly the same thing.