If you have any other thoughts please share them with me
I see what you are doing now. Because you are sharing files from the PC to the laptop, converted to ogg format, using Playlists as the selection method, one or more ogg files could already exist on the laptop due to use in a prior Playlist. Hence one solution is to use exactly the same folder structure on both the PC and laptop to avoid duplicates, as the PC would try to write the new off files to exactly the same place, and depending on the method used, either not transfer the new ogg file, or at a minimum just overwrite existing file.
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A.
First, the method I described above would still work.
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B.
Second,
if the Handheld Sync function did work with the expressions we discussed, you would still need to edit the Playlists created to point them to the correct disk drive, even though they would have the correct folder structure in them. At least, with the setup you described, assuming that both the PC and laptop have just a C:\ drive, or you are using the C:\ drive in both cases to store your music, and that now you have established the library on the laptop, you won't be copying the library from the PC again in the future. Basically, you will be running two separate libraries permanently. Here is why.
As you would be transferring files from the C:\ drive on the PC to a mapped drive you have called Z:\, all the Playlists would point to the Z:\ drive, but they would actually be on the C:\ drive of the laptop. When you tried to use them on the laptop, none of the files would be found. So you would have to edit the playlists and Replace Z:\ with C:\ preferably before opening MC on the laptop so that the Playlists aren't imported with the incorrect data. If they were, you would have to specifically re-import them after the editing. Not a big issue, but a bit of a nuisance.
I can think of a few ways to avoid the extra step.
1. One that I thought would not work but actually does is sharing the C: drive on the laptop and then mapping it to Z: as a Network Drive, also on the laptop, so that Windows refers to the C: drive as both C: and Z: on the laptop. That seems pretty easy. On the PC you would then also map a network drive called Z: to the C: drive on the laptop for file transfers. While you probably wouldn't need to, you probably should do a mass change in your laptop MC Library to change the location of files from C: to Z: using the RM&CF function, but it might work without doing that, just reading Z: from the Playlists and finding the ogg files via that mapped drive just fine. It might get a little confusing though.
2. Another way to fix the Playlist drive designation issue would be to split the laptop drive into two partitions, C: for all programs an whatever you currently have on the PC, and let's call it M: for all your media (ogg) files. You would then move all you existing ogg files to the M: drive just using Windows Explorer, and then do a mass change in your laptop MC Library to change the location of files from C: to M: using the RM&CF function. In this case, when working on the PC you would map drive M: to the laptop drive M:. All Playlists would then contain M: as the drive to find the ogg files, and that is where they would be found. This method has the disadvantage of splitting one large drive on the laptop into two of course, which means that you would have to guess the correct size, but there are tools available these days to resize partitions without losing data, if you needed to do that in the future.
3. Another way would be to start using URIs within the MC Library on your laptop, so that both the PC and the laptop refered to files on the C: drive using the same URI, and therefore so would the Playlists created by the Handheld Sync process... I think. I can't really test this one as my network doesn't want to play nicely just at the moment.
But anyway, let's assume that you create a Share on your laptop called "\\LAPTOP\Music". Then you create a Device in MC on the PC that points to that Share. MC requires a Share to be visible in the dialogue that creates a Device, so your network needs to be playing ball and displaying that share on the PC. You can't just type the Share into the dialogue, unfortunately. So Network Discovery needs to be working properly and active. Now when you transfer files using the Handheld Sync fucntion, and when it creates Playlists, they will refer to the URI/Share on the Laptop, "\\LAPTOP\Music", as the root location. Hence, the Playlists should work, and the ogg files will be copied to the correct place. Again, you may not need to update the existing records in the MC Library on the laptop, but it may work better if you do. Some people use URI's in their library all the time, and it works fine. Again, you do a mass change in your laptop MC Library to change the location of files from C: to \\LAPTOP\Music using the RM&CF function.
Ah wait. I forgot that when using Handheld Sync to sync to a hard drive location, you can now create custom Playlists and specify relative paths in the Playlist. So the drive naming issue becomes moot. Silly me, to not think of that until I had written all the above. I'll leave it there as a thought exercise.
24.0.28 (5/15/2018)
5. NEW: Added an option to choose the playlist format when syncing to Handhelds.[/color]
Actually, that change may have added custom playlists for Devices such as Android phones, rather than for Hard Drive locations. I forget which way around it was now. It is in a thread around here somewhere... =======================
C.
Here is another thought though;
You don't have to use the exact same folder structure on the laptop as you do on the PC, as long as the folder structure on the laptop is consistent every time you use the Handheld Sync function to copy ogg files and Playlists from the PC to the laptop. That way, if an ogg file exists on the laptop when you run a Handheld Sync, MC will know about it, and won't transfer it over again, unless your settings say it should.
You can just use rules in the Handheld Sync function that are based on known reliable tags in the MC Library, such as [Album], [Album Artist (auto)], and maybe [Disc #] if you want to include that in the laptop library. Even using the default basic Device Audio Path of "[Album Artist (auto)]\[Album]\" would result in consistent and repeatable folder structures on the laptop, so "no" duplicates.
The catch is that you have 150K tracks, and your tags may not all be perfect, so that if you change the tags that are used in rules on your PC, you may still get some duplicates of ogg files on the laptop. But probably not many.
One big advantage of this method is that it would work with the Handheld Sync functionality right now, as it doesn't rely on the expressions we discussed. Of course in order to use this method you would have to update the file locations of existing files on the laptop, so that they were consistent with the rules you decide to use in the Handheld Sync functionality. Again, the RM&CF function can do that for you quite easily.
You would still need to deal with the drive naming issue,
or use custom Playlists with relative paths.=======================
How is that? Enough to think about?