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A7S video corrupt when battery dies - any solutions ?

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When the battery dies during recording XAVC-S video on the Sony A7S the camera does not have time to write the associated XML file that is needed to access that file.The video is saved as a corrupt file. The video is there but it cant be read without its XML twin.

Does anyone have a way of recovering these video files and making them readable ?

There is one online company I have found that will recover these "corrupt" files but it costs a lot.

As this must be a common problem surely there is a piece of software I can get that is cheap or free.

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There's a RECOVER DATABASE option in the menu someplace but I've never needed the XML file (Mac) to play any video - I'm using the 7SII camera. In fact I don't even copy the XML files when transferring the vid files. I've had a battery die and it's never corrupted the file as the camera will set the closing instructions before the whole shebang goes dark. A long time ago I opened a corrupt video file in a text editor and made the data at the end match a known good file and got access to the vid that way but that was some 8 years ago and don't recall what I did. See if VLC will play the file.

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Thanks for the replies.

This might be a A7s version 1 problem then - perhaps they sorted it in version 2. If the battery fails during video recording in my A7s (1) it doesnt write the closing instructions (which I assume is all the XML file is. Without the XML file I cant play the XAVC-S video with any player or in any edit suite.

Perhaps I could just write my own XML file by copy and pasting the contents of a previous one in text editor ?

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Ok so following replies I took a look at the video files and the XML files with a text editor and compared the playable video files to the "corrupt" one. **(First of all dont use text editor on a mac - these files are too big for it - I used Hex Fiend)**

Technically the XML file that the A7S lays down at the end of recording is just a copy of the instructions that the camera writes at the end of the video file to make it playable. All my good video files had their XML file text in their file content at the end. The XML files seem to be just confirmation that the instructions have been written in the video file.

My "corrupt" file has all the video content intact but because the battery died suddenly during recording the access instructions were not written at the end of the video file and hence no XML file showing these instructions.

I tried copy and pasting the instructions from a good video file to the one that wouldn't play but unfortunately this didn't work.


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By chance will VLC Player directly play the video file? (Not the XML file)


One thing I recall doing is opening a corrupt video file in a text editor, copying the data, creating a new document, pasting that data, then saving the file as a text document, then changing the extension from .txt to .mov and the file played fine.

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  • 2 weeks later...

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The thing SONY engineers need to do is automatically halt any video recording prior to complete battery discharge.


Camera should be able to predict, based upon discharge rate, ten seconds remaining and automatically issue a STOP RECORD command. Face it, 10 secs downrange the whole shebang will have to stop anyways in order to replace battery. This RECORDUS INTERRUPTUS as least leaves a viable video file to contend with instead of a useless file that can't be recovered.

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  • 4 weeks later...
  • 2 weeks later...

Started doing some testing in case we ever run into a similar issue with our A7R2.

Ran a short clip and buttoned "off" so I had a reference file.

Then simulated "running out of battery" by literally dropping the battery out of the slot while recording after about 20-30 seconds of video should have been on card....

both times I did this the video file showed 0 bytes, as well as being no xml file. 

There's no coming back from that.


Then ran the camera for a longer period, about 90 seconds, since OP (tonyyates) mentioned that the data was in fact there.

This time I did have some data on the card, but no XML, and the clip won't play as reported above.  Nothing I tried will recognise it (VLC, Handbrake, Resolve etc).


A quick google came up with this page...



this is the software it referred to:


I ran the demo version as they describe.... using the reference clip I'd recorded plus the damaged clip, low and behold it did a "repair" on the video and I had a partial playback of the corrupted video (due to demo only recreating 50%.. but they discuss a way of getting around that on first linked page).  Fair enough for a one-off... but if works for you and its worth having as a safety net I'd recommend buying it, not too expensive if it saves your butt.     :)




BTW, this worked when I took the card straight out of the camera after the "battery failure" without trying to do a "repair" in the camera.... Using the camera's card repair might screw up the file you are trying to save... haven't tested that.

** So it looks like "repairing" the card in-camera will screw up any chance of repairing the corrupted file.  I put the SD card back in the camera, camera wanted to "repair it" automatically so OK'd that.  Removed card... the software could no longer "repair" the corrupt clip.

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