What FFmpeg is good at
FFmpeg is the open source toolkit behind a large share of the world's video processing. It decodes almost anything, encodes to H.264, HEVC, VP9 and AV1, converts audio, burns subtitles, extracts frames, concatenates clips and packages HLS and DASH output. Filter graphs deserve special mention. Scaling, cropping, overlays, loudness normalization, deinterlacing and subtitle burn-in are all expressed as filter chains, and the order of those filters changes both output and speed.
That flexibility is also the risk. A command line with forty flags is hard to review, and small changes shift quality or compatibility. We wrap FFmpeg behind typed job definitions, keep presets in version control and compare output using objective measures such as VMAF alongside visual checks. We emit structured logs, capture FFmpeg exit codes and stderr, and track per-job duration and output size so a silent regression in a preset is noticed within a day.