What does location sync do?

[twentw]

Can someone explain what location sync does? I can't seem to find an explanation anywhere.

[MeSue]

After reading on one device, it takes you to where you left off on another device. So you can switch back and forth between devices and always pick up your place.

[vikarti]

http://blog.marvinapp.com/post/61407...ion-sync-works

[Suzibingo]

Can someone tell me what I'm doing wrong? Location sync isn't getting me anywhere near where I left off on my device. If I read on my iPad, press sync when I'm done, pick up my iPod later to read, it will put me back a few chapters and not close to my current reading location. Dropbox is enabled on both devices. Any suggestions?

[Faterson]

A few chapters back? That definitely should not be occurring. Imprecision has in some cases been observed in the range of several page flips, at most (discussed here), but location sync should definitely put you in the same chapter, because that's how it's designed to work.

I suggest that you do not sync your location by manually pressing the sync button (because that can cause confusion: see here).

Please try syncing your position on the 1st device simply by backgrounding Marvin (by returning to your device's home screen). Then, pick up your 2nd device, press the sync button and perform the sync. I believe you should get a much better result. Please allow a couple of minutes to pass (at least initially for the first test, to make sure) before picking up the 2nd device.

[Suzibingo]

I tried your suggestion and backgrounded Marvin but when I tried to sync to my other device, it told me I was already at the farthest location in the book. I also backed out of the book and went to the library, waited 15 minutes before trying to sync on my other device but received the same message. Anything else to try?

[Faterson]

Oh, it's not necessary to wait for 15 minutes. I think 2 or 3 minutes, at most, should be enough. Normally, seconds should be enough, if you're on a WiFi network. You could open a desktop computer/notebook of yours and as soon as you see the sync file arrive in Dropbox there, you can try opening the book on the 2nd device. (Which reminds me of another feature request.)

Please, make another sync test, but before you do so, go to your 2nd device and flip to the beginning of the book. That way, you will be certain to avoid that "You are already at the furthest location" message there -- if syncing is working for you at all. I think you may have been in the correct place from your previous sync attempts, which is why the test failed to show if sync is working for you or not.

[vikarti]

Originally Posted by Faterson

A few chapters back? That definitely should not be occurring. Imprecision has in some cases been observed in the range of several page flips, at most (discussed here), but location sync should definitely put you in the same chapter, because that's how it's designed to work.

One possible issue here is that Chapter-as-user-see ('Chapter 1' in text) is not same as Marvin sees.
You could try to get big text from somewhere, make epub out of it using Apple Pages and you will see 'chapters' of hundeds of Kbs. If THIS is a problem here, which is unlikely,epub-epub conversion in calibre with split section set to lower number could help.

[Faterson]

Even under that scenario of abnormally long sections, the sync putting the reader "a few chapters back" would be very unexpected. (Unless the individual chapters were extremely brief, like a couple of pages per chapter.)

[kguil]

@Suzibingo, is it possible that when you finished reading (you closed the book or put your device to sleep) you weren't connected to the internet?

[Suzibingo]

I was on chapter 12 on my first device. I just tried Faterson's suggestion of moving the second device to the beginning of the book. I backgrounded Marvin, watched Dropbox for the sync record, and when i synced on my second device, it took me to chapter 11. Better!

[Faterson]

With most books in Marvin, a section = a chapter, and Marvin uses chapters/sections as the basic unit when attempting to synchronise... So it practically always gets the chapter right, at the very least.

Looks like vikarti was correct and that the structure of your particular e-book is non-standard, in that a single section of your book contains several chapters, making it all the more difficult for Marvin to synchronise locations precisely.

Generally, the longer a section/chapter is, the harder it will be for Marvin to synchronise locations precisely. A number of possible improvement suggestions, including ADE-style pages (in background), have been discussed in the GitHub threads referred to above; I'm sure Kris will come up with something to increase the precision.

[Suzibingo]

Thanks for your help, Faterson! I'm just happy to have the app available for my iPod. :-)

[DaleDe]

Actually one way to sync is to remember the filename (usually a chapter) and then the bytecount to the top of the page as displayed. This should get you to the correct place always.

Dale

[Faterson]

Originally Posted by DaleDe

Actually one way to sync is to remember the filename (usually a chapter) and then the bytecount to the top of the page as displayed.

The trouble is when that file is extremely long, like dozens of iPad screens long. Unfortunately, there are many mangled e-books like that out there.

Marvin currently uses filename+percentage inside the file, which should be pretty much the same as byte-count. For brief or moderately long chapters (sections = files), the sync results seem to be pretty precise. It's those extra-large sections=files that are troublesome; they may contain several chapters per section/file... It's a mistake on the part of the e-book publisher, but regular Marvin users will be unable to fix it manually.