Stutter
Also known as: playback stutter, dropped playback
Playback that cannot keep up, pausing and jumping rather than running evenly, which is about the machine rather than the file.
Updated
What it means
Stutter is a performance failure. The player is being asked to decode more than the hardware can manage in the time available, so frames arrive late and the picture lurches instead of running evenly from one to the next.
It is not Judder, which is a frame rate dividing unevenly into a refresh rate. One is a machine that cannot cope and the other is arithmetic, and they look similar enough to be confused constantly.
The same file can stutter on one device and play perfectly on another, which is the clearest sign that the file itself is not the problem being described.
How it works in practice
Hardware decoding is the first thing to check. A format the chip accelerates plays effortlessly, and the same format in software produces exactly this, which is what Hardware decoding settles.
Proxies solve it for editing. Proxy editing replaces the demanding files with light ones, and a timeline that lurched becomes responsive without anything at all about the original files changing.
Disk speed is the other cause. Several streams of high bitrate footage from a slow drive starve the decoder, and the symptom is identical to a processor that cannot keep up with the decoding.
What to watch out for
It gets reported as a quality problem. Somebody describing a video as being bad is frequently describing stutter and nothing else, which no change to the encode fixes, because the encode was never the thing that failed.
Browsers make it worse. A tab decoding 4K in software stutters and drains a battery, and Browser playback is where most people meet this problem for the very first time.
Background load is invisible. A machine syncing files or running an update stutters on video that played perfectly an hour earlier, which makes the fault look intermittent and unexplainable.
How RawClip handles it
Delivered files are encoded at a resolution and in a codec that ordinary hardware decodes without effort, because a result that lurches is read as a bad edit. A lower-resolution version exists for the devices that still struggle with the first one.