Driver : .MJP Extension Mobile Video Player

This player will play all your MJP  mobile phone files with a file extension of mjp. This is the only MJP player that I have been able to find.

Driver : .MJP Extension Mobile Video Player

http://www.inetbridge.net/forum/driver-mjp-extension-mobile-video-player-vt1963.html

This codec allows for high-quality, realtime Motion JPEG encoding. It also enables you to view Motion JPEG files created on another computer, even if you do not have specialized hardware involved.

Motion JPEG codec is also perfect for manufacturers developing webcams, surveillance systems, and other video devices. The codec offers a complete, software-only solution which eliminates the need for expensive compression chipsets.

The Motion JPEG format (also known as MJPEG) was made popular by older video editing boards used to digitize analog video signals (for example, from a camcorder or VCR). Although Motion JPEG allows high compression and good quality, the problem is that the format is not standardized. Many manufacturers only supported their own variations of MJPEG. This meant that material edited on a system with a video editing board often could not be played on other computers that did not have the highly specialized software installed.
MainConcept’s Motion JPEG Codec offers wide compatibility. It is ideal for a variety of functions including videoconferencing, medical technology, or as an add-on for existing MJPEG capture cards. It is especially useful in environments where edited material needs to be played back on multiple computers without expensive capture cards installed.

Codec : Motion JPEG Codec 3.2.4