How to open and repair an m4v or mp4 video file?
Solution 1
It is possible to repair the broken mp4 or m4v file using Untrunc.
For this method you need another video file from the same device which isn't broken.
How to install untrunc
For compilation you need a Linux installation (ideally Ubuntu) and basic ability to use a command line. You can also skip this part and run untrunc
via Docker (see the answer below), if you have that.
This is what to do:
-
Install some pre-requisite libraries with this command:
sudo apt-get install libavformat-dev libavcodec-dev libavutil-dev
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Get the source code for Untrunc from the GitHub repo (choose one method):
wget https://github.com/ponchio/untrunc/archive/master.zip && unzip master.zip && cd untrunc-master
- or
git clone https://github.com/ponchio/untrunc.git && cd untrunc
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Compile the source code using this command (all one line):
g++ -o untrunc file.cpp main.cpp track.cpp atom.cpp mp4.cpp -L/usr/local/lib -lavformat -lavcodec -lavutil
(you can try skipping this step and using the ready-provided executable, but it didn't work for me)
Then you can actually fix the video. You need both the broken video & an example working video.
How to fix the video
Find another working video, ideally from the same camera and preferably at least as long as the broken one; also the same resolution if possible (I believe this may help though is not essential).
Run this command in the folder where you have unzipped and compiled Untrunc but replace the /path/to/...
bits with your 2 video files:
./untrunc /path/to/working-video.m4v /path/to/broken-video.m4v
Then it should churn away and hopefully produce a playable file called broken-video_fixed.m4v
That's it you're done!
VLC Media Player should now be able to play the file. However it may be reporting the wrong length information (Untrunc tries to guess/work this out, but doesn't always get it right). To fix this try re-encoding the video through another program.
[Thanks to slhck's comment for the suggestion to try Untrunc.]
[Many thanks to Federico Ponchio for coding Untrunc in the first place, to solve this exact problem.]
Solution 2
If someone else stumbles on this, I also tried the app sparrowt was talking about, but it didn't work for me (see some bug-reports I created in the developers repository). Maybe this was because it wasn't a mp4 file but a MOV file ...
What helped for me was this post: http://muzso.hu/2012/11/14/how-to-fix-a-broken-mp4-mov-video-ffmpeg-reports-moov-atom-not-found
They link to a program called "HD Video Repair Utility" (http://grauonline.de/cmsimple2_6/en/?Solutions:HD_Video_Repair_Utility), which is far cheaper than Treasured (http://aeroquartet.com/movierepair/repair). They even pointed out, that there was an earlier version of it (version 1.5) that didn't cost anything (http://nagasoft.cn/download/videorepair1.5.zip)!
I tried repairing the file using the version 1.5 and got it partly working. After re-encoding with ffmpeg (got some errors there), I realized, that a part of the audio was gone. In the logs (gladly the Video Repair Utility has some), there was no further mentioning of audio after a given time. I'll take it as-is ...
Solution 3
You can install docker
(available for all major operating systems) and run:
docker run -v $(pwd):/vol -it synctree/untrunc /vol/GOOD-reference-file.MP4 /vol/BAD-corrupt-file.mdt
The syntax is for Bash under Linux or macOS. Here, GOOD-reference-file.MP4
and BAD-corrupt-file.md5
must both be in your current directory, and the directory will be mounted to /vol
in the Docker container.
Read the other comments around for more in-depth explanation.
This was the quickest for me!
Solution 4
@sparrowt Your current instructions did not work on my recent Ubuntu 16.10 installation. I got the following error while compilining untrunc:
track.cpp: In member function ‘int Codec::getLength(unsigned char*, int)’:
track.cpp:204:40: error: ‘avcodec_alloc_frame’ was not declared in this scope
AVFrame *frame = avcodec_alloc_frame();
As explained in the untrunc repository, you might need to download libav separately rather than using the version in the Ubuntu repository. The following code worked for me:
sudo apt-get install unzip yasm g++ zlib1g-dev libbz2-dev
cd /tmp/
wget https://github.com/ponchio/untrunc/archive/master.zip
unzip master.zip
cd untrunc-master
wget http://libav.org/releases/libav-12.2.tar.xz
tar xvf libav-12.2.tar.xz
cd libav-12.2
./configure
make
cd ..
g++ -o untrunc file.cpp main.cpp track.cpp atom.cpp mp4.cpp -I./libav-12.2 -L./libav-12.2/libavformat -lavformat -L./libav-12.2/libavcodec -lavcodec -L./libav-12.2/libavresample -lavresample -L./libav-12.2/libavutil -lavutil -lpthread -lz -lbz2
./untrunc /path/to/working-video.mp4 /path/to/broken-video.mp4
This created a file called broken-video_fixed.mp4 that worked for me. Thank you so much for initiating this thread.
Solution 5
In case untrunc doesn't support the codec inside your file, you can try to fix it with an hex editor:
- get another file with the same format, I got a bigger one but probably any length will work
- open both files in an hex editor
- replace the
mdat
section in the "ok" file with themdat
section in the "broken" file, without the header (i.e. copy only the bytes after 'mdat') - it would probably already work like that, if not, the 4 bytes before 'mdat' specify the size of the
mdat
section, the current value will be the old size ("ok" filemdat
section size), replace it with the new size ("broken" filemdat
section size)
I ended up coding a simple program to do it: https://github.com/golimarrrr/fix-3gp
Both the program and by hand using the hex editor should create the same fixed file
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Drake
CTO and Co-Founder of Crazy Web Studio Co.,Ltd., a web development company based in Phuket, Thailand, specialized in Web Design, SEO, Media Marketing and Custom Web Development. Former Software Architect at Electrolux with more than 15 years experience in designing, developing and testing Microsoft .NET Based Enterprise Applications.
Updated on September 18, 2022Comments
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Drake almost 2 years
Yesterday I was filming a scene with my phone but suddenly the application crashed and when I try to open the m4v generated it says that is corrupted.
I have downloaded the video files (around 36MB) on my PC and I am trying to open and repair it. Can you suggest me a way to do it?
FFMPEG info
As suggested in comments I try check what FFMPEG says me about that file with this command
ffmpeg.exe -i VID_20120425_144739.m4v -c:v copy -c:a copy out.mp4 2> log.txt
Here it is the result:
ffmpeg version N-40126-ga4b58fd Copyright (c) 2000-2012 the FFmpeg developers built on Apr 26 2012 03:29:50 with gcc 4.6.3 configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-runtime-cpudetect --enable-avisynth --enable-bzlib --enable-frei0r --enable-libass --enable-libcelt --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libfreetype --enable-libgsm --enable-libmp3lame --enable-libnut --enable-libopenjpeg --enable-librtmp --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libutvideo --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxavs --enable-libxvid --enable-zlib libavutil 51. 47.100 / 51. 47.100 libavcodec 54. 15.100 / 54. 15.100 libavformat 54. 3.100 / 54. 3.100 libavdevice 53. 4.100 / 53. 4.100 libavfilter 2. 72.100 / 2. 72.100 libswscale 2. 1.100 / 2. 1.100 libswresample 0. 11.100 / 0. 11.100 libpostproc 52. 0.100 / 52. 0.100 [mov,mp4,m4a,3gp,3g2,mj2 @ 003fc940] moov atom not found VID_20120425_144739.m4v: Invalid data found when processing input
Latest two lines are displayed in red.
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Drake about 12 yearsMy OS is Windows 7 but if necessary I can prepare a virtual machine with Linux-based distro.
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Drake about 12 years@slhck Thank you for help, I did what you suggested and updated question.
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slhck about 12 yearsAh, that's what I expected. The MOOV atom is a piece of data that's needed to access the raw video streams inside the MP4/M4V container. There are plenty of "video repair" tools online, but I wouldn't trust most of them. You can certainly give them a shot though – just don't pay for anything. What looks promising is Untrunk, which seems to be coded for this exact problem (namely a missing MOOV atom). Or AtomicParsley. Good luck!
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chovy almost 8 yearsHow do I fix a broken mp4 with AtomicParsley?
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SebMa about 4 years@Drake Ive just found mp4fixer, maybe you can give it a try.
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slhck about 11 yearsCool, thanks for providing the full instructions here!
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Sun over 9 yearsI think this may apply to AVI files where the index can be built into memory, but a MP4 file an error of "moov atom not found" during ffmpeg processing does not play anything in VLC.
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Alex over 9 yearsThis worked for me, however I had to use the most up-to-date code from Github here instead of the link provided.
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sparrowt over 9 yearsThanks @Alex I've updated the link. Amusingly the Readme on github is based on this answer!
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RogUE almost 9 yearsWould give a windows based solution. <superuser.com/questions/938185/recover-incomplete-video-files> as I do not have internet access in my linux distros.
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Lauren Smith almost 9 yearsYour method actually works. Thank you so much. :)
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Erdinc Ay over 8 yearsWORKS! Well done.
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rogerdpack over 8 yearsVLC fails to play it as well, in my case (.mov file)
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The Compiler over 8 yearsFWIW this didn't produce any playable videos for me - but running recover_mp4_to_h264 via wine worked well.
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Michael Kern about 8 yearsFrom arch linux you can install untrunc from the Arch User Repository: aur.archlinux.org/packages/untrunc-git
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whitewings almost 8 yearsUntrunc worked for me, but I had to put both video files in the subdirectory of the hidden .untrunc folder named
untrunc-master
. Then, run: ./untrunc goodfile.mp4 badfile.mp4 It took about 3 minutes for a 2gb file and I only had to resync the audio. Everything else was fine. -
Ajedi32 almost 8 yearsThanks, this worked! Though I did have to
sudo apt-get install unzip g++
in the VM I created to run Untrunc in; looks like those commands aren't on Ubuntu by default. The audio in the repaired file is also way out of sync with the video, with the video seeming to speed up and slow down at random. I guess that's because I was recording using a variable frame rate... video.stackexchange.com/q/19052/16308 -
Avio almost 8 yearsWorked also for me. I first tried ignorantly a couple of
dd if=ok-file.mp4 of=/tmp/broken-file.mp4 bs=1056 count=1 conv=notrunc
with increasing block size, with no luck. Then untrunc solved my problem quickly and flawlessly. -
T.Todua over 7 yearsDROPBOX url is dead. found alternative: nagasoft.cn/download/videorepair1.5.zip
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SimonSimCity over 7 years@T.Todua, thanks for notifying. I've replaced the dropbox-link by the link you provided.
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Andrew Smart over 7 yearsThank you! On the untrunc compilation line I had a few errors along the lines of "undefined reference to `BZ2_bzDecompressInit'", I had to add -lbz2
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Ken Sharp about 7 yearsIt can't handle large files. Just gives up.
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abourget over 6 yearsYou can use the Docker image here too: hub.docker.com/r/synctree/untrunc this way you don't need to install and compile all the things. A quick run and it solved it for me !!
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Ankush over 6 yearsDoes your libav containt a
h264dec.h
? becausetrack.cpp
is trying to include it and i cant find it anywhere :/ -
freeseek over 6 yearsThat dependency was added with commit github.com/ponchio/untrunc/commit/… on October 10th, 2017. I believe now you have to donwload libav-12.2 rather than libav-0.8.7
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Mark Berry over 6 yearsFinally got this to work on Ubuntu 14.04.5 LTS. Had to run
sudo apt-get install yasm
,sudo apt-get install libbz2-dev
and, to overcome an undefined reference to 'clock_gettime', add-lrt
to the end of theg++
command line (see stackoverflow.com/a/2418175/550712). It converted about 2/3 of my video. -
Tobia over 5 yearsI had to add
-lX11 -lvdpau
too, to make it compile. -
sparrowt almost 5 yearsThanks @slhck, the
Dockerfile
is available here if anyone wants to see what this will run before executing it on your computer: github.com/synctree/docker-untrunc There is also aDockerfile
in the actualuntrunc
repository now - I have not tested either or compared them in detail but mention it here for completeness: github.com/ponchio/untrunc/blob/master/Dockerfile -
RolandiXor about 4 yearsYour instructions are not straightforward for someone who doesn't know what they're doing. Care to explain further?
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RolandiXor about 4 yearsThese instructions are not very clear. Maybe screenshots or something could work.
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SuperSafie about 4 yearsFor someone who doesn't know what they're doing the best option is to clone or download the linked fix-3gp.c file and compile it with
gcc