M-JPEG

M-JPEG (Motion-Join Photographic Experts Group) technology is a motion still image (or frame-by-frame) compression technique that is widely used in the field of nonlinear editing to precise frame editing and multi-layer image processing, and takes moving video sequences as continuous The still image is processed. This compression method compresses each frame individually and completely. Each frame can be stored randomly in the editing process, and frame-by-frame editing can be performed. In addition, compression and decompression of M-JPEG are symmetrical and can be the same. Hardware and software implementation. However, M-JPEG only compresses the intra-frame spatial redundancy. Does not compress the time between frames, so the compression efficiency is not high. With the M-JPEG digital compression format, when the compression ratio is 7:1, programs equivalent to Betecam SP quality images can be provided.

The algorithm on which the JPEG standard is based is based on DCT (Discrete Cosine Transform) and variable length coding. The key technologies of JPEG include transform coding, quantization, differential coding, motion compensation, Huffman coding, and run-length coding. The advantages of M-JPEG are that it is easy to make frame-by-frame editing and equipment mature. The disadvantage is that the compression efficiency is not high.

In addition, M-JPEG compression method is not a completely unified compression standard, different manufacturers of codec and storage methods do not have a uniform prescribed format. This means that each model of video server or encoder board has its own version of M-JPEG, so data transmission between servers and data transmission from the non-linear production network to the server is simply not possible.