Question about connecting to Calibre via USB

[kaufman]

I'm not sure if this is a setup question or a wishlist question.

Version 2.0 contains the following fix:

> Add support for MTP devices (Android phones/tablets) on OS X

Does that mean that there is some way to connect CC and Calibre with the USB connection?

If not now, is this a possibility for the future? Note that this would be nice to have, but if its a lot of work, then its probably not enough of an improvement to be worth your trouble.

[DoctorOhh]

I would like this option too.

[chaley]

This is on the wishlist, but it is rather hard to do for two reasons. The first is that the file names and paths used by MTP could easily be different from those used by CC. Any book outside CC's set of folders must be ignored. Second is getting the metadata for the books. In theory the file .metadata.calibre contains everything we need, but I have seen many cases where it was corrupted and the thumbnail is usually miniscule.

Regardless, with the above caveats it is worth doing, and I will look at raising its priority in my brain.

[a_daley]

More than 7 of my customers who I have convinced to purchase CC have asked me how to configure CC to use it via USB (which doesn't yet exist)....

[chaley]

To say again, the problem here is that there is absolutely no guarantee that the user will store books in CC's folders. Any book not in the proper CC folder must be ignored. I am very concerned that this behavior will create no end of support problems because people won't understand why it doesn't "just work". And it won't "just work".

The above notwithstanding, I am willing to look at this, but to do so I need help. I don't have a device with an SD card, so I have no idea whether calibre can send to sd cards, and if so, what is in the metadata.calibre file. Could some brave soul with an sdcard-equipped device tell me:

1. How does calibre's MTP driver distinguish between main memory and a card?
2. Assuming that there are books on the SD card, does calibre put a metadata.calibre file on the sdcard? Where? In the root?
3. Assuming that there are books in main memory, is there also a metadata.calibre file in main memory? Where? In the root? (That is where I see it on my devices.)

It would be most helpful if you can send me copies of the metadata.calibre files.

Note: if and when this function arrives, it will require an explicit choice to run it, similar to the "Find missing books" in CC today. The processing is complex and time consuming, so it can't be run automatically. Any new or changed book will require modifying the database, which will run at the same speed as metadata upgrades received over wifi.

Finally, I am curious about why people want this feature? It is purely an expectation of better performance, in that copying books over USB is faster? If so, does this advantage go away because of CC's import and the time taken to update metadata? It isn't obvious to me that a combination of sending over a cable and then importing into CC will be faster than simply sending to CC to begin with.

[DoctorOhh]

The only reason I was interested was because calibre has been crashing often on me during sending books to my device and this would have been another troubleshooting point. Add to that the rare time I would like to transfer a book when I'm at work, but any cloud solution you might implement would handle that. So I really have no reason and could easily do without it.

It sounds like a can of worms you don't need to open.

[kaufman]

Originally Posted by chaley

Finally, I am curious about why people want this feature? It is purely an expectation of better performance, in that copying books over USB is faster? If so, does this advantage go away because of CC's import and the time taken to update metadata? It isn't obvious to me that a combination of sending over a cable and then importing into CC will be faster than simply sending to CC to begin with.

The only reasons I wanted this was:

1) I assumed that copying books via USB would be faster than copying them via Wifi

2) Sometimes when I try to connect via Wifi it fails because my phone is plugged into the computer. Then I get a message that says that something else is already connected to calibre.

If Calibre isn't going to make a direct connection to CC, than I would never use this. I would continue to use the Wifi connection, because the results are viewable in real time, the end result is more deterministic, and you would still need the Wifi connection for some actions (ie deleting books).

[PeterT]

Even if you connect via USB, if there is another device (ie a phone) connected via USB to calibre, the new connection will be rejected.

Only a single device can be attached at one time to calibre.

[kaufman]

That's not a problem. I was trying to solve the problem that exists when my phone is connected via USB and I am trying to sync my Calibre library on the same phone via a wireless connection.

[chaley]

Originally Posted by kaufman

That's not a problem. I was trying to solve the problem that exists when my phone is connected via USB and I am trying to sync my Calibre library on the same phone via a wireless connection.

If it is being recognized as an MTP device then blacklist it. If it is being recognized as an android device, disable that plugin.

[eschwartz]

Sounds to me like this is just another iteration of "CC and the cloud: discussion".

[kaufman]

Originally Posted by chaley

If it is being recognized as an MTP device then blacklist it.

So, I plugged my phone in with Calibre running and it asked me it I wanted to control it. I said no, and then I went into preferences->sharing->Ignored devices and confirmed that it was listed. I then quit everything and disconnected my phone from the computer. I then reconnected and started up Calibre and CC. I then tried to make a wireless connection. I still get the same error: "The Connection failed because some other device is connected to Calibre". If I then disconnect my phone, it connect to Calibre without a problem.

Any thoughts/ideas would be appreciated.

[chaley]

Originally Posted by kaufman

So, I plugged my phone in with Calibre running and it asked me it I wanted to control it. I said no, and then I went into preferences->sharing->Ignored devices and confirmed that it was listed. I then quit everything and disconnected my phone from the computer. I then reconnected and started up Calibre and CC. I then tried to make a wireless connection. I still get the same error: "The Connection failed because some other device is connected to Calibre". If I then disconnect my phone, it connect to Calibre without a problem.

Any thoughts/ideas would be appreciated.

Does calibre think it is connected to something, shown in the status line and if you try "Debug device connection" (Preferences / Misc / Debug device connection)? Your phone might be capable of connecting as an MTP device and as an android disk device.

I can say with certainty that for my devices (Galaxy Nexus, Nexus 7, Kindle File HD, HTC Sensation), if I blacklist the devices and disable the Android plugin then I have no trouble connecting via wifi even when the device is connected by cable. I do see a message in calibre's debug log saying that the device is blacklisted, except for the HTC that doesn't support MTP.

[kaufman]

Originally Posted by chaley

Does calibre think it is connected to something, shown in the status line and if you try "Debug device connection" (Preferences / Misc / Debug device connection)? Your phone might be capable of connecting as an MTP device and as an android disk device.

It doesn't show anything in the status line, and if I click on the debug device connection, it says:

Looking for devices of type: MTP_DEVICE
MTP devices connected:
USBDevice(busnum=160, devnum=6, vendor_id=0x04e8, product_id=0x6860, bcd=0x0400, manufacturer=SAMSUNG, product=SAMSUNG_Android, serial=75e2b2d9)

Trying to open: USBDevice(busnum=160, devnum=6, vendor_id=0x04e8, product_id=0x6860, bcd=0x0400, manufacturer=SAMSUNG, product=SAMSUNG_Android, serial=75e2b2d9)
Opening device failed:
Traceback (most recent call last):
File "site-packages/calibre/devices/mtp/unix/driver.py", line 147, in debug_managed_device_detection
File "site-packages/calibre/devices/mtp/driver.py", line 123, in open
File "site-packages/calibre/devices/mtp/base.py", line 24, in synchronizer
File "site-packages/calibre/devices/mtp/unix/driver.py", line 216, in open
OpenFailed: Failed to open USBDevice(busnum=160, devnum=6, vendor_id=0x04e8, product_id=0x6860, bcd=0x0400, manufacturer=SAMSUNG, product=SAMSUNG_Android, serial=75e2b2d9): Error: Unable to open MTP device with busnum=160 and devnum=6, tried 1 such devices

Is there some way to just disable MTP connections completely?

[eschwartz]

Disable the MTP device driver.