[mythtv-users] Some Videos Not Seen by Scan

[Michael T. Dean]

On 08/09/2017 10:04 AM, John Pilkington wrote:
> Or search 'mythtv video hash'
>
> Perhaps your ffmpeg processes gave identical results.

Yes, this is most likely the issue. The hash that's created to identify 
unique videos is done with only a small part of the file at the 
beginning and the end (because reading multiple gigabytes per file from 
disk and running the entire video through a hash algorithm would take 
ages to complete).  It's likely your test files are just too close to 
the same, so are being considered the same and only showed once (one or 
the other is shown and the one not shown is ignored).

There's no way to "fix" this as it's working as designed (and typical 
use cases don't involve multiple almost identical files). So, you can 
rotate them in and out to see them all.  Note, too, that the title of 
the video shown is not necessarily the name of the file being 
played--you'd have to look at the filename in the detailed metadata 
screen to know for sure which you're playing--and if you swap files the 
new file may show with the same title, even though it would now play the 
other file.

You may be able to work around this by creating test encodes of 
differing lengths/portions of the video.

Mike