Repairing a truncated mp4 file?

[MightyMorris]

So, I have an mp4 file which is missing the end part of the file. I have tried a whole host of different 'mp4 fixer' programs, all of which cannot fix the file. VLC and Windows Media Player cannot read the file. avidemux can't read it. The site mp4repair.org also could not repair it (although they did tell me that the format is h264). Mediainfo just has this to say about it:

Format : MPEG-4
Format profile : Base Media
Codec ID : isom
File size : 3.05 MiB

I'm not sure that the file is totally beyond repair though, even though it is only 3mb, as one of the video repair tools I used somehow managed to extract some audio (aac), which, while not perfect, after some messing around in Audacity plays pretty great. The raw audio data is 223kb.

I have also tried some messing around with a hex editor on some copies of the file, with no success (but I'm not at all experienced in such things.)

Now, the main problem I have with this is that I do not have a healthy 'reference' mp4 file that I can be sure was created with exactly the same settings to use as a base, which most mp4 repair tools seem to rely on. The errors are 'moov atom not found', 'no moov box', ect, and as I understand it, these are the parts which describe exactly how the file should be played, so without these the file is pretty useless, and as I don't have a 'healthy' file with the exact same settings, there is no base from which to reconstruct them.

So, I come here to ask you this: is it worth it to try and save this file (is there any chance at all this can be saved or is it completely hopeless?), or should I just be happy that I managed to get at least salvage something (the audio) and leave it at that?
From what I gather mp4 is apparently a tricky format to repair.

Thanks in advance for any advice!


Edit: I see that in other, similar threads people have put links to their files, so here is this one: https://www.dropbox.com/s/uk36ef3lbpxwuxh/ZM.mp4?dl=0
I don't know if any mp4 experts here just want to take a quick look at the file/hex and tell me what they think the chances of saving this are? It would be much appreciated!

[redwudz]

Generally, if done correctly, a HEX editor is about the last resort. What you would be looking for is data, mostly just a jumble of numbers.
If instead, you see many lines of blank text with just zeros, most likely there is no data to recover in those lines.

Maybe someone here can take a look at your sample file and give better advice.

And welcome to our forums.

[MightyMorris]

Ah, I see. Well, the hex data isn't blank, so perhaps that is promising

And thank you for the welcome! Nice to be here!

[compscistudent]

I just recovered an mp4 file that had the encoder settings in the beginning but no moov atom, but I knew the height and width which is really important to recover an mp4.

Can you tell me the approximate height and width and any encoder options you know of? If it is constant fps and used preset normal or high profile options, I might be able to recover just the video part(I haven't started working on audio yet).

In a hex editor I see that the first NALU is a 17009 byte long key frame. It also looks like the video chunks only have one slice, so it is one sample of video and then a chunk of audio.

[ribsplitter]

In my case, which is very similar, I am only interested in the audio, I'm assuming height and width won't matter at all at this point.

Miklos

[ribsplitter]

Generally, if done correctly, a HEX editor is about the last resort. What you would be looking for is data, mostly just a jumble of numbers.
If instead, you see many lines of blank text with just zeros, most likely there is no data to recover in those lines.

Maybe someone here can take a look at your sample file and give better advice.

And welcome to our forums.

Redwuz, can he / we simply start removing each line of empty data until the file plays, in the Op's original, the video, and mine, just the audio?

Stupid question, but worth a shot I suppose.

Mik