Take the 2-minute tour ×
Video Production Stack Exchange is a question and answer site for engineers, producers, editors, and enthusiasts spanning the fields of video, and media creation. It's 100% free, no registration required.

I would like to convert some short videos to .MJP format, and none of my preferred tools for video conversion can do this. Can anybody suggest free software that can achieve this? OSX preferred, but Windows is available if necessary.

EDIT:

All I can tell you is that I have a (newish) device that has a video screen and contains a memory card holding four .MJP files that can be shown on the screen.

The videos play, with sound, so I know the files are valid. If I copy them over to my Mac, no software that I've found can play them.

I would like to replace the video files that the device shows, but this requires converting my videos to .MJP format. I have put one of the existing files at https://app.box.com/s/kbtvfbpowqwbp1aym88m if anybody wants to examine it.

share|improve this question
    
What is the MJP file format? All I can find about it are some very, very legacy formats that don't appear that they were ever widely used. I doubt you will find anything for working with them that is current since I can't even find a current player for them. –  AJ Henderson Dec 31 '13 at 16:37
    
All I can tell you is that I have a (newish) device that has a video screen and contains a memory card holding four .MJP files that can be shown on the screen. The videos play, with sound, so I know the files are valid. If I copy them over to my Mac, no software that I've found can play them. I would like to replace the video files that the device shows, but this requires converting my videos to .MJP format. I can put the existing files on a public directory if anybody wants to see them. –  Michael Stern Dec 31 '13 at 20:15
    
That and/or the name of the device might help identify what the files are. It might just be that they renamed the extension on some other format. –  AJ Henderson Dec 31 '13 at 20:18
    
Ok, posting some more details I found. Apparently mjp is a form of Motion JPEG in an LG specific container. –  AJ Henderson Dec 31 '13 at 20:22
    
I found a similar device and have the same question. The MJP format appears to be different than the one for the VIGIL software. I am wondering if it is similar to the LG phone video format that I've seen mentioned. It appears that the download link for that is long since deactivated. –  user5633 Feb 28 at 21:16
add comment

2 Answers

http://www.openthefile.com/ext/mjp/4458 and http://www.fileinfo.com/extension/mjp both suggest mplayerx (http://mplayerx.org/) can play them. It would make sense to post a file for people to examine. If mplayer or ffmpeg can play them, chances are mencoder or ffmpeg can encode to the format.

share|improve this answer
    
unfortunately, MPlayerx can not play these files. I have put one of the files at app.box.com/s/kbtvfbpowqwbp1aym88m Thanks in advance for any additional insight. –  Michael Stern Jan 6 at 0:52
    
I had a quick look with a hex editor. The file starts with ffd8 followedby a JFIF version 1.1 segment header. It is possible if you encode a a single frame to JFIF 1.1 the device might display it as a still image. It might be just a sequence of JFIF segments prefixed by ffd8. I don't have time to look more at the moment. –  Julian Jan 6 at 8:47
    
Thanks for your attention, but whatever these files are, they're more than just a sequence of still images — they also play sound. –  Michael Stern Jan 6 at 12:03
    
Valid point. This might be relevant groups.google.com/forum/#!topic/vancouverhackspace/4veroun0HR4 If the player at 3xlogic.com/software plays your files we will at least have identified the format. –  Julian Jan 6 at 17:40
    
Good find! Unfortunately, when I try to open one of the files with the 3xLogic DV Player, it freezes and I get an error box that reads "Digital Video Player has stopped working. A problem caused the program to stop working correctly. Windows will close the program and notify you if a solution is available." To be fair, the program is marked as working only through Windows 7 and I tried to use it in Windows 8. Unfortunately, I don't have a Windows 7 installation handy. –  Michael Stern Jan 6 at 21:06
add comment

You can try using either of the two Motion JPEG codec's available with Quicktime and see if either of those works after renaming the extension. Motion JPEGs are kind of a major pain though because it's literally just a sequence of JPEG images for each frame within the video and the exact specifications of the container can vary. This can result in files not being recognized or result in incorrect playback rates or poor audio sync.

The best bet would probably be to see if LG has any utilities for converting videos to their format for your device, though it is possible no such software exists.

share|improve this answer
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.