I am not sure what do you mean by connecting the drive to the laptop and viewing the files from the DVD player, how will the DVD player will see the laptop and the drive?
You have said elsewhere that your laptop is presenting media files to your network already, via UPnP. I forget the gui steps, but this is media player network sharing stuff - services are UPnP, SSDP, and windows media network sharing, IIRC.
Once set this way, the DVD player will see the files off your laptop in exactly the same manner it sees them off the router. Including once you plug your usb drive in. (I have always assumed this is not your preferred place for the USB drive as the laptop likely moves around within your residence, and it's a PITA to drag the USB drive with you.)
A corresponding test ... with the usb drive connected to the router, does the win 7 laptop media player see the same files as the dvd player when the laptop media player app looks to the router for files? More files? Less?
If I connect the USB drive to the router and enable web access, going to http://<router ip address>:8181 on the laptop, yes I am able to see all file types that the DVD player cannot but no folder names, just list of files but I cannot play them from the web access page.
That's OK - what you just PROVED is that the router is able to present those files to the world as media files. You've proved it knows those file types to be media files - therefore the DVD player should be seeing them. (I am assuming to the router's mind, presentation via web access and via UPnP, are the same things.)
When Shareport Web Access is accessed, the DVD player does not see other files or folder.
I'm confused with this - Shareport, Web Access, and DVD player are 3 distinct things that don't overlap. Shareport is windows file sharing via the router (Shareport isn't even necessary for this, it's a windows utility tapping into the native capability of the router). Web Access is the router presenting files via internet browser. DVD Player needs UPnP availability (which the router does natively.) Sort of like using wood, plastic, or steel, to build something. Still gets built, just different materials.
In fact when I was testing today and started the router the first time, onlt one folder was visible showing 2 files (out of 20). When I restarted the router, 2 folders were visible and more files as well, but not all files in these folders were visible. Really confusing.
Presumably your USB drive has a light on it to indicate when it's being accessed. When you first turn on the router, does that light blink very rapidly for some period of time? That would be the router indexing it. Does it eventually settle down? (May take some time, even an hour or more?, for that to happen.)
The file types the DVD can read and play: MP4, MKV, AVI, WMV. The same file types are not visible in the same folder and in other folders that are completely invisible. I don't think the file type has anything to do with it.
It does if my speculation is correct - if the router doesn't agree that those file types are media files, it won't present them to the DVD player. One way to tell, given your message - are there folders where you see files of one type, but not another? e.g. You see the .avi files, but not the .mkv files? The only explanation I can think of for missing folders though is that the router has not yet indexed them. Which doesn't seem to apply if they display in web access.
Hope this helps, again I think it is related to the router and nothing else. I am reluctant to contact D-Link support as I feel this issue will not be solved by them, it is most probably related to the router design or firmware.
It does help - Furry and I are speculating, and your excellent efforts chase down the accuracy of those speculations.
I sure get the reluctance to contact D-Link support, however, what it will buy you is assurance of the specifics of how things are supposed to work. At least then you'll know what you should see, as opposed to the guessing we're all doing, here.
This is starting to feel like a DVD player issue, not a router issue - if the win 7 laptop can see the files off the router via upnp, but the dvd player cannot, it's a dvd player (UPnP) issue. Recognizing that DVD access via router/UPnP and via local direct usb or net connection is akin to building with plastic vs wood. (Different sharing / file access mechanisms / program code.)
The one other thing I can think of ... when you have the drive connected to the laptop next, perhaps as one of the tests in the first paragraph ... run a chkdsk on the drive. right-click, properties, tools, <something> or other. Just in case the file system indices are corrupt. Then, after moving the drive back to the router leave it overnight. See if the DVD player shows you all the things you expect, the next day.
Good luck with this all. Sorry you're going through it all / things aren't more clear / obvious. I get the hope was that things would 'just work'. Sorry it's not.