How to Merge and Concatenate Videos with FFmpeg

FFmpeg can merge and concatenate videos in three ways: concat demuxer, concat filter, and concat protocol. The concat demuxer is the fastest but requires all input files to have the same codec, resolution, and frame rate. The concat filter re-encodes everything and handles mismatched inputs. Use the concat demuxer for identical files and the concat filter for mismatched files. This guide covers all three methods and provides working API examples.