Repairing mp4 headers manually.

[Wojo J]

Hello to everyone!
**DISCLAMER: Long background for my question, if your not interested look at the following portion of this post, thanks**
First, I want to say that, yes, I just registered to ask a question in hopes of being able to learn how to fix my problem. I do have a genuine interest in learning more about video editing in the future, beyond this problem, and plan to frequent this site in the future. But this problem is the kicker, and has done nothing but frustrate me to no end. It also seems, in searching for a solution, that many share this problem.

I have tried for weeks on end to find this information online, and I have learned a great deal, but I can not find the answer to what I am looking for. All my searches eventually bring me to this page, and from reading through the forum, it seems that I have a good chance of finding someone here that can help. Please lend your knowledge, or at least point me in the right direction! I don't mind doing the homework! I have just hit a wall in searching for information, for all I know the info I am looking for might be readily available, I just don't know what to look for.
**END OF LENGTHY DISCLAMER**

I have absolutely ZERO experience in what I am trying to accomplish. Only what I have gathered in my research. Please forgive my ignorance in my explanation of the problem.

I have a recovered video file, a 3gpp2 file to be exact, that is "corrupt". I say corrupt, but to be as exact as possible, the bottom part of the data (as viewed in a hex editor) is missing. I have compared the video file to ones recorded from the same source that are in working condition. The card is not corrupted. The media was accidentally deleted. Nothing was written to the card before the recovery.

I have looked over several working videos, and comparing them to the corrupt video, the bottom "header" (not sure if that is actually what its called) is the defining difference between them. All the working videos have an apparent end to the data, all beginning with moov and following with similar coding. The corrupt video is missing that entirely, possibly some of the footage as well, I am not sure. I have had some luck in finding a frame from the video, using the treasure application, so I know that the media is somewhat intact. My next step, logically, was to cut and paste the bottom portion from a working media file to the corrupt, several attempts failed.

I am sure that if I were to post a working vid with the "corrupt" video, one of you could just instant fix.

But thats the problem, the video is personal. Secondly, I would like to learn how to fix this myself, in case this happens in the future. If someone here would be willing to work with me, or at least point me to something I could learn from it would be greatly appreciated!

I have tried several recovery programs in attempt to recover more of the file, with no luck. I have tried several media players, and they all come up with the same thing, a video that isn't recognized by any media player. I am working with, based on a working media file:

Video: MPEG-4 Video, 320 x 240, 14.28 fps
Audio: Qualcomm QCELP, Mono, 8000 Hz

This of course does not show in the corrupt file's info.

From what I have gathered, this format is the most difficult to "repair".

Sorry for writing a book here! If there is anyone here that would be interested in lending me some help, it would be greatly appreciated! I tried to include everything that seemed relevant, but if you do want to help me out, and there is information that you need to better understand the situation, let me know! I will be checking this forum frequently.

Thanks to everyone in advance!

-J

[AlanHK]

Try Avidemux, if it can read it then you can resave it, with video and audio set to "copy". That usually fixes any glitches with no quality loss.

[redwudz]

As you have found, some formats write the index information for the video at the end of the file. If that's damaged, very hard to fix. At least I haven't had any luck with it. Being able to play it is usually the main test. I use VLC for that as it can bypass some corruption.

Try AlanHK's method and see if that will work for you. Beyond that, maybe another member with experience with your specific problem could give some further advice.

And welcome to our forums.

[Wojo J]

*EDIT*

Well, I tried AlanHK's method with the corrupt file, but it didn't read it. I was however, able to cut and copy the corrupt data to a working media file, removing the exact amount of lines in the working media and pasting the corrupt media in its place using hexedit. It works, but the video is all distorted, and no sound.. Any ideas?

[Wojo J]

Does anyone have any knowledge of the structure of an mpeg-4 (3gpp2) video in hexedit? Or how to alter the settings within? That would help me greatly! Thanks!

[Wojo J]

*BUMP*

[felixwings]

did u try this tool.....a marvellous one but needs to be purchased for full repair....but half of the video will be repaired freely by demo version
http://grauonline.de/cmsimple2_6/en/?Solutions:HD_Video_Repair_Utility