Mixing Footage with Different Codecs

A codec, or compressor, is the algorithm used to compress video to a smaller size and then decode the video for playback. A sequence clip whose codec doesn’t match the sequence codec can be played back in real time as long as the following is true:

When playing back video in the Viewer and Canvas, or via Digital Cinema Desktop Preview, Final Cut Pro decompresses each sequence clip’s codec and shows the decoded video on your display. However, when rendering and outputting, each sequence clip is also recompressed into the selected sequence codec, requiring additional processing power. Because rendering is not a real-time process, this is not an issue, but for real-time playback to an external video device, mixed codecs can add additional processing overhead. For more information, see External Monitoring and Output.

For more information about rendering mixed-format sequences, see Rendering Mixed-Format Sequences.