My friend and frequent podcast co-host, Don Melton, has recently updated his excellent scripts for transcoding video on the Mac. He cares about every pixel and every bit, and wants the very best results possible. Based on the feedback to date, so do a lot of other people. If you're one of them, here's the intro from the latest version, fresh from GitHub:
Hi, I'm Don Melton. I wrote these scripts to transcode my collection of Blu-ray Discs and DVDs into a smaller, more portable format while remaining high enough quality to be mistaken for the originals.
While I've used rougher versions of these scripts for many years, I didn't publish any of them until I was featured in, "How to rip and transcode video for the best quality possible," a podcast with Rene Ritchie. Those initial scripts were only available as separate Gists on GitHub. Now they're all collected in this repository:
All of these scripts are written in Bash and leverage excellent Open Source and cross-platform software like HandBrake, MKVToolNix, MPlayer, FFmpeg, and MP4v2. These scripts are essentially intelligent wrappers around these other tools, designed to be executed from the command line shell.
Even if you don't use any of these scripts, you may find their source code or this "README" document helpful.
Go read the whole thing, and if you're into transcoding, give them a shot.
Source: Don Melton