Comparing video files

[Nator]

As always, if this has already been answered, please point me in the right direction.

I've tried looking, and either I've overlooked it, or just didn't look for the right thing.

I have a few duplicate video files (size and basic content, but hashes don't match). Want a tool that will scan the files and then point out the differences (timestamp mostly, anything else is 'bonus' to me).

I've tried using a regular file comparison tool, but it just croaked on me, probably from the size of the files.

I believe that in the duplicates, one is a good copy, and any others have something messed up (like a bleep sound that shouldn't be there), and instead of watching both to look for the difference(s), be nice to have it shown to me.

Something that works on audio files would be great too.

[Baldrick]

Haven't seen any such tool. And identifying bad audio like bleeps must you do manually.

[Cornucopia]

For audio, you could:

Extract/Demux both audio tracks.
Decode both to WAV.
Load both into a multitrack audio editor.
Invert the phase polarity of one of the 2 files.
Mix/Bounce to a new file.
Close the originals.
Load the new file.
Normalize.

It'll then be obvious where there are any differences. You should have large areas of silence, punctated by a few spots of full-on material. Unfortunately, it won't tell you which of the 2 files (or even both) contributed to those differences.

Similar things could be done with video, but the "differencing" steps get much more complicated.

Scott

[thecoalman]

http://www.compression.ru/video/quality_measure/video_measurement_tool_en.html

Should pick out frames that differ. It's for comparing one codec to another but I don't see why it wouldn't work on the same. Can't say I've used, just came across it once.