Damaged MP4

[Krystman]

Hello,

I recorded some MP4 video files with XSplit. I’m using X.264 for video and AAC LC HQ for audio.

I recently realized that some of the files are not playable. It affects SOME of the files I recorded, not all of them. I have no idea what caused it. It might have been something that happened after a successful recording.

When I open them in VLC, I don’t get an error message and the file appears to play. VLC displays a correct timeline. However, there is no video, not even a black screen - it looks like an audio file. There is also no audio playing.

I already tried fixing them with common tools such as HD Video Repair Utility from Grau GmbH and FixMP4 from Remo Software. Sadly, no success so far. I got a partial result from HD Video Repair Utility. The tool generated a file with black video but audible audio. However, the timeline was off.

I tried extracting the streams using YAMB. The audio it generates is silent. The video it extracts doesn’t even get recognized by YAMB when I re-create an MP4 using it.

I contacted http://mp4repair.org. Judging from the preview, they seem to be able to fix this. However, with about 5 hours worth of footage affected, it would be a costly repair.

I'm still looking for a simpler solution. Any procedures or diagnostic tools somebody can recommend to me?

Here are some samples:

Damaged File:
https://www.dropbox.com/s/a8hcqdaqbrfd2nc/broken.mp4

Working File recorded with the same settings:
https://www.dropbox.com/s/dxculfu83t9pltq/notbroken.mp4

[davexnet]

Give the demo a try, it's right here:
https://www.videohelp.com/tools/Video-Repair-Toolhere:

This demo will fix up to 50% for free (if it's possible)

[Selur]

"VLC displays a correct timeline." that is only because the first headers are fine.
calling ffplay on the file shows a lot of problems.
mp4box -info "path to file"
indicates: 'File has no MPEG4 IOD/OD'

Sorry, no clue what software could fix your problem.

[Baldrick]

Give the demo a try, it's right here:
https://www.videohelp.com/tools/Video-Repair-Toolhere:

This demo will fix up to 50% for free (if it's possible)

Krystman has already tried it. https://www.videohelp.com/tools/Video-Repair-Tool = Video Repair Utility from Grau GmbH

[Krystman]

Thanks for the suggestion. However, as already said, I tried that tool and it didn't work.

[Selur]

Also wasn't that the tool which simply used mplayer and mencoder and ffmpeg to preview and remux the file?

[Baldrick]

Yep, it uses them. But it works pretty good on the files I have tried. But not all broken mp4s of course.

[Selur]

You could have simply used mplayer/mencoder/ffmpeg then also, but if this is how it worked for you that's fine.

[Baldrick]

It does something else also. Just mplayer and ffmpeg can't read/convert/remux the broken files I have tried.

[MaverickTse]

I managed to recover the audio, but no success on the video part, just the same as Krystman...
The raw video stream is also unusable.

The tool:
http://grauonline.de/cmsimple2_6/en/?Solutions:HD_Video_Repair_Utility

[Krystman]

Yes, that's a far as I got myself. It is a bit odd that the Video Repair Utility messes up the header. The original video displayed the right lenght. The repaired video doesn't.

[MaverickTse]

Yes, that's a far as I got myself. It is a bit odd that the Video Repair Utility messes up the header. The original video displayed the right lenght. The repaired video doesn't.

Actually that HD Video Repair Utility didn't mess up the header. It is the limitation of the trial version that limit the processing to half of the video. (Actually this limitation is easy to get around)

Just as what Selur said, the file has a lot of problem.
I have tried to demux the file with VLC and FFmpeg on the command line and they all throw error like:
AVC: nal size -######
No frame

Invalid resolution

Missing frame rate
...

While there is no solution to fix the file yet(and XSplit's forum was closed whole day.), I think you need to prevent this from happening... the following may be of value:
https://forums.station.sony.com/ps2/index.php?threads/twitch-tv-video-stream-is-corrupt.126833/

also, if your not streaming to twitch but simply recording to your HDD, perhaps it is time to run chkdsk to fix potential problem.

[Krystman]

Actually that HD Video Repair Utility didn't mess up the header. It is the limitation of the trial version that limit the processing to half of the video

I thought so too at first. But it shows just 3 seconds or so while the video is 6 minutes long. The playback continues long after the position marker reaches the end of the timeline.

I think you need to prevent this from happening... the following may be of value:
https://forums.station.sony.com/ps2/index.php?threads/twitch-tv-video-stream-is-corrupt.126833/

Interesting. I will try this. I'm not sure if it is related to my problem. This is from May 2013 my files started in October. Also, this error seems to show up on the stream. I actually streamed some of the recorded files and they turned out fine.

also, if your not streaming to twitch but simply recording to your HDD, perhaps it is time to run chkdsk to fix potential problem.

I agree, this was also my first instict. No errors found.

[MaverickTse]

I thought so too at first. But it shows just 3 seconds or so while the video is 6 minutes long. The playback continues long after the position marker reaches the end of the timeline.

This is strange.
When I play the (recovered)uploaded video(though sound only), it last 2:31. (approx. half of your expected length)
I am using K-lite mega+ MPC-HC (32bit), but also the same when using VLC-portable.
While on my PC (no XSplit installed) NONE of my AV application(Avidemux/Virtualdub/ProjectX/AviUtl/WMP/VLC), except that repair utility, can handle that broken file.

Perhaps this suggest XSplit is using a non-standard H264 codec and somehow your XSplit installation is corrupted???

[Krystman]

Used http://mp4repair.org after all. They were able to fix it.