FFmpeg filter_complex cuts transcoding passes from three to one

The immediate lesson is that video pipelines can fail or slow down because of library behavior and filesystem placement, not just the transcoding command itself. In this case, PHP buffering and container volume mounts created hidden costs that only showed up on a 170MB clip and during repeated FFmpeg writes. For streaming teams, the broader point is that upload/download paths and temp storage choices are load-bearing parts of the stack, especially when workloads involve large files and thousands of I/O operations. What to watch: whether temp files live inside the container or on a mounted project directory, and whether FFmpeg is decoding once or once per rendition.