It seems like Directory Opus has issues rating .mp4 files. Basically what happens is:
I first give the video a rating (1-5)
I then remove that rating from the video by setting the rating attribute through a button to zero. This does not have to happen immediately for this issue to occur. I've had this happen to me over months where I rated a video and then came back a few months later to remove the rating, only to find out the file is now ruined.
The video's thumbnail disappears and it no longer plays in VLC player, Media Player Classic, windows media player, or the new windows 10 player. It is broken
I have done extensive testing with this. The first time I reported this issue was 6 months ago, which I had talked about on the forum but needed more evidence to make a decisive conclusion.
Please note that so far this issue only occurs with .MP4 files. I have tested MKV, AVI, WMV, and Webm video file formats and none of the exhibit this issue.
In addition, the same issue seems to also happen in windows explorer. If I rate an MP4 video through the details pane and then remove that rating it will make the file unplayable.
I have converted an MKV file I know that doesn't exhibit this issue to an MP4 and the issue does occur when it is in MP4 format. I have also tried the inverse, converting an MP4 to an MKV and it does fix the rating issue, but obviously converting all your files and reducing their quality isn't an amicable solution.
Any help with this would be greatly appreciated! I don't want to loose any more videos!
I can confirm seeing the same thing, but it also looks like the reason this happens in both Opus and Explorer is that it is a bug in the operating system:
The Windows mfmp4srcsnk.dll is what is updating the MP4 file's properties, and what is going wrong when the rating is removed.
It may be possible to swap that DLL out with another property handler for MP4 files which does a better job. It's possible alternatives would have been written by third parties back in the days before Windows had built-in MP4 support.
We may also be able to switch Opus to using custom code for MP4 files instead of relying on Windows for them, but I don't know enough about the video tagging library we use to say for sure, so that will need some more investigation (or Jon's better knowledge of the tagging code).
Yeah I am looking around for an MP4 handler but I haven't found a good one yet. I found a codec pack called Shark007 codec pack that was supposed to include a metadata handler for MP4 but it isn't working for me. The users on the forums for the above mentioned codec pack seem to be aware of the buggy windows MP4 handler. I'm seeing forum posts dating back to 2012 talking about the issue.
Yeah, it would be great if you could implement a fix. If it's a problem that's been around since 2012 I'm guessing Microsoft is in no hurry to fix it. I will file a bug report with them regardless as well.
Just an update, I found a program called audio shell that does include an MP4 handler but it does not work with windows 10 unless you edit the registry. According to them, windows 10 introduced protections to the default handler so that it would stick with Microsoft's handlers. The registry hack doesn't look hard at all but I personally don't want to go through the process of possibly bricking my system. In addition, this program unfortunately doesn't state windows 10 support. What I don't get is why they don't just created a restore point and ask the user to elevate to admin mode to install the registry edits for them. Was this not possible on older versions of windows? I think windows XP was the first to introduce restore points.
Just an update to this, I was able to not only fix the .mp4 files being corrupted but also a similar issue with .flac files which I posted about awhile ago. It seems as though Icaros fixes them both. It's pretty bad that Microsoft seems content to leave bugs in it's software for so long.