jam sync. Synchronize and record time code on a tape or device with another tape or device by using a time code generator. Employed when time code is weak, broken, missing, or damaged or to create time code.
JPEG Joint Photographers Expert Group. A standard form of lossy data compression which compresses and decompresses video and audio into digital images. JPEG compression is designed and applied to still images like scanners, Web video, and desktop publications. A motion JPEG (M-JPEG) is used to compress shots for non-linear editing.
jump cut. A cut where objects or characters appear to jump because the shots are too similar. Technically, this is due to the camera angles of the two shots being less than 30 degrees apart.
junior. A four-plate KEM.