Saving MP4 corrupts file
Issue #122
wontfix
I have a 1.6GB mp4 that ends up with the following error: "The file is bigger than 4GB, but it was created with 32bit data chunk offset. Select 64bit data chunk offset in the save panel."
By this time the original file was corrupted and no mp4 fixing program seems to be able to recover the original file. I have also tried "save as" using the original uncorrupted file with the 64bit offset resulting in the same error message.
Comments (6)
-
reporter
-
repo owner
And the answer is, who knows? Can't say anything with so few info and without the original file.
-
repo owner
- changed status to wontfix
-
I hate to resurface such an old issue, but I am encountering exactly the same problem with a file that is actually bigger than 4GB (4.29 GB). Opening the file, Subler 1.5.8 reads it correctly and is able to find metadata + artwork for it. Saving it results in the error mentioned above. However, even though the save failed, the resulting file is corrupted: it is now 4.30 GB in size, and no longer openable in VLC, for example. Subler is also no longer able to read it when I close and reopen the same file. I can provide the file in question as a link if you would like. I'm able to reliably reproduce this issue, and it happens with another file that is also bigger than 4GB. Here's a log that shows me opening the file, finding metadata for it, attempting to save it, failing, closing the file, and finally attempting to reopen it:
1:13:39 Error: ReadAtom: "/Users/proever/Downloads/True-6/True.Detective.S03E05.1080p.WEB.H264-METCON copy 2.mp4": invalid atom size, extends outside parent atom - skipping to end of "" "mdat" 4326728569 vs 4294967295 1:14:1 Error: ReadAtom: "/Users/proever/Downloads/True-6/True.Detective.S03E05.1080p.WEB.H264-METCON copy 2.mp4": invalid atom size, extends outside parent atom - skipping to end of "" "mdat" 4326728569 vs 4294967295 1:14:1 Error: Write: assert failure: (false) (../src/atom_mdat.cpp,42) 1:14:1 File excedes 4 GB. 1:14:39 Error: ReadAtom: "/Users/proever/Downloads/True-6/True.Detective.S03E05.1080p.WEB.H264-METCON copy 2.mp4": invalid atom size, extends outside parent atom - skipping to end of "" "mdat" 4326728569 vs 4298894126 1:14:39 Warning: ReadChildAtoms: "/Users/proever/Downloads/True-6/True.Detective.S03E05.1080p.WEB.H264-METCON copy 2.mp4": In atom missing child atom moov 1:14:39 Error: FindIntegerProperty: no such property - moov.mvhd.modificationTime (../src/mp4file.cpp,747) 1:14:39 The movie could not be opened. 1:14:39 Error: ReadAtom: "/Users/proever/Downloads/True-6/True.Detective.S03E05.1080p.WEB.H264-METCON copy 2.mp4": invalid atom size, extends outside parent atom - skipping to end of "" "mdat" 4326728569 vs 4298894126 1:14:39 Warning: ReadChildAtoms: "/Users/proever/Downloads/True-6/True.Detective.S03E05.1080p.WEB.H264-METCON copy 2.mp4": In atom missing child atom moov 1:14:39 Error: FindIntegerProperty: no such property - moov.mvhd.modificationTime (../src/mp4file.cpp,747) 1:14:39 The movie could not be opened. -
It looks like the error comes from: https://github.com/sergiomb2/libmp4v2/blob/5e0265ebc3b097b2e8b2783494bfec034fd75999/src/atom_mdat.cpp#L42, although that's as far as I think I'll get in terms of debugging this.
-
Just wondering if you saw this @galad87, since the issue is closed and doesn't appear by default anymore. Sorry if you have and I'm just bothering.
- Log in to comment
Also of note: I have used Subler for hundreds of other files without issue. This is the first time, aside from x265 files, that Subler has not worked for me.