pjpeg

PJPEG, also known as Motion JPEG, is a video compression format where each video frame is compressed individually as a Motion JPEG (MJPEG) file. It is essentially a sequence of JPEG images. This contrasts with many other video codecs that use interframe compression, meaning they only store differences between consecutive frames to reduce file size. Because each frame is independently compressed, decoding PJPEG can be computationally less intensive than codecs like MPEG-2 or H.264, as there's no need to reconstruct frames from previous or subsequent ones. This also allows for easy seeking to any frame within the video without requiring extensive processing.

However, the independent compression of each frame leads to significantly larger file sizes compared to more advanced video compression standards. PJPEG is not as efficient in terms of compression ratio. It is often used in applications where real-time playback, low decoding complexity, or frame-accurate editing are prioritized over minimal file size. Common uses include some older digital cameras, surveillance systems, and certain professional video editing workflows. While not as widely used for general video streaming today due to its inefficiency, its simplicity and accessibility have kept it relevant in specific niches.