Why Does Media Management Screw Things Up So Badly???

Open-ended question.....frequently I use Media Management to trim the fat and conserve archive drive storage space. Occasionally it just goes entirely bonkers. I have a number of projects that were never trimmed from the past 4-5 months because when I checked them (always do this with a safety copy), audio/video got mangled/time-codes changed/weird sync problems and the like (etc.).

Today I went in and decided I had to get these projects in order. It just took 2-3 hours probably to manually fix a 2 minute video.

I'm not a newb and not a Hollywood DR editor or colorist, but I basically know the software 4 years in. I've never really found an explanation or suggested process for this.....

Is there one or is it all just a crapshoot? Does Media Management give other people problems too????

Well, here is the best advice I found from a Hollywood colorist, our dear forum colleague Marc Wielage. I have nothing to add, other than we never experienced a problem with ProRes or BRAW files. GOP codecs can be a nightmare, though.

Marc: "I haven't generally found that to be a problem unless the effect involves varispeed or running footage backwards or something like that.

Long-GOP footage is problematic for a lot of reasons, but it does work better now than it used to.

Some Media Management tips that work for the way we use Resolve:

1) limit your session to just the files actually used in the session (that is, make sure no unnecessary files are sitting in bins)

2) Render-in-Place all H.264, JPG, TIFF, and PNG graphics clips to ProRes or DNxHR so that now the clips have embedded timecode and (preferably) unique file names

3) for camera clips with embedded audio, my opinion is you're better off if you strip the sound out as a WAV file that lives in the session

4) be aware that Titles can be a bit dodgy and don't always survive the changeover with Media Management. (I would say the same thing with Fusion sequences, which I would render out and treat as a separate transcoded element.)

The simpler you make your session, the better the potential for successful Media Management. The moment you have a filename clash or a timecode conflict, it can fail. I wish Resolve had better error trapping so that when it did encounter an error, it just popped up a message with a list of problems, rather than just bailing on the Media Management entirely.

If your file copying is failing for another reason, try Nikolai Waldman's Resolve Collect and I bet it'll get you at least 98% there without errors. His program has been a lifesaver for me over the last 6-7 years.

http://www.niwa.nu/resolve-collect/

Another possibility (which I haven't tried) is EditSpy for Windows:

http://edlspy.felixhuesken.de/

I just got caught with a terrible problem because I was dealing with somebody else's timeline, and they had linked some shots to Proxies and forgotten to relink them back to the original camera files. Media Management crashes and burned multiple times until I used a hammer and crowbar to force every clip to look at the real camera clip.

I continue to wish for a more robust Media Management that would just do the managing and then pop up an error at the end saying, "the following errors were encountered," rather than just bombing out of the process."

So a funny trade off. Media Management without the trim option will typically work for GOP codecs which are presumably much smaller files. You can transcode them to an I-frame codec such as ProRes, DNxHR or Cineform (?) which makes them much larger files and then Media Manage those with the trim option and that will work but depending on the clip to file length ratio, you may actually end of with larger storage needs than with the GOP source files without trim.

Sadly, at least as of beta 1, Resolve 19 does not appear to have improved in this aspect of the product (actually - it's worse for GOP codecs as of beta 1).

Marc's advice is really good. I haven't implemented it fully in my workflow, but I would for mission-critical projects. As a hobbyist I can afford to live dangerously, lol.

To answer your original question, Sean - Media Management is a nightmare with GOP codecs in my experience.

Which camera Steve?
Actually, in a recent project footage out of a Sony A7IV (H.265 10 bit 422) worked quite well in 18.6.6.

Which camera Steve?
Actually, in a recent project footage out of a Sony A7IV (H.265 10 bit 422) worked quite well in 18.6.6.

Works well in 18.6.6 with my Canon R6 Rec2020/CLog3 10-bit 422 footage (H265) as well, Uli as far as trimming goes. Totally broken in 19b1 (which is not relevant here, I suppose). Where media management goes wrong for me is when considering the whole picture - the case where you media manage a project to trim and relink to the trimmed clips - you lose some of the metadata you painstakingly added in the media pool - things like data level override (auto -> full) and properties such as gamma if using project level color management. Some of my H265 material recorded on a Ninja V are mis-identified by Resolve as 'video' level whereas they are 'full' and their gamma is mis-identified as Rec709 whereas it is Canon Log3 and these tweaks are lost during media management / relink to new files.

I sense that I cannot trust media management and when it goes wrong, the error reporting is very poor. I would think on a large project, the lack of confidence in this tool would be a show stopper unless you follow Marc's guidelines.

Btw - how best to do the following:

3) for camera clips with embedded audio, my opinion is you're better off if you strip the sound out as a WAV file that lives in the session

I thought it was an easy media storage option but I'm not seeing it. Maybe a senior's moment?

Add - I found it - select clip in media storage, right-click and select 'Extract Audio...' and it creates a WAV file beside the original file. Then you can bring the two files into Resovle's media pool and use 'Auto-Sync Audio' if you want to join them such that the video file references the external audio. Would prefer more of a single-click solution but it's not bad.

I admit that I also don't trust Media Management 100%, but at least Sony stuff with GOPs is recognised. Sony's often record Superwhites, but I expect that and just pull down the highlights without changing data levels in the attributes. After all, there are no Superblacks.
I can imagine that Ninja recordings are not treated properly, given the history between Atomos and BM. OTOH, full range for YUV recordings is pretty much off-standard.
Generally, trimming is needed much more for Intra formats, and of those all we have used are working OK. Apart from what Marc wrote about stills, titles or sound.