Media Transfer Protocol

Taken from Wikipedia:
http://en.wikipedia.org/wiki/Media_Transfer_Protocol

In the world of clix it means that the user can use the player with software such as Windows Media Player and Music Services such as URGE, Rhapsody, Napster, etc.

The clix 1st Generation was strictly an MTP device although the user could drag and drop through Windows Explorer.

The clix 2nd Generation will have a user selectable Transfer Protocol choice in the settings menu to switch between MTP or MSC.

I like to think of MTP as an analogy to a network protocol. Unlike MSC, where a device attached to the PC acts like a removable storage device, MTP uses a series of commands to communicate with the device. The device recieves these commands and executes an action. Sort of like two computers connected via a network connection like say TelNet, SMB, etc.

Pretty much like in a network setting you have a "host" and a "client" (or it is easier to think of it that way). The protocol was derived from the PTP protocol, used in the cameras for transfering digital photos. There are a number of advantages for having this way of communicating with digital players and the PC and (as with anything) there are some disadvantages.

Of the most technical advantages is the fact that this means of communication is (at least in theory) capable of having completely different filesystems. For instance, if the device had a filesystem for which there's no available driver for any other OS, the device would still be able to connect and transfer data. A different filesystem also gives opportunity for a better utilization of the player, database structure, metadata fetching, etc. In contrast MSC devices are pretty much all formatted in the now ubiquitous FAT(16/32) filesystem. There's nothing wrong with this, but there are inherent defficiencies of the FAT filesystem (like its tendency for corruption, lack of support for journaling, etc). With MTP the host computer does not have to know which filesystem the player connected has.

One of the disadvantages, though is that the player is left to do "all the work", this is in fact a two edged blade. The computer simply first (through MTP) instructs for file transfer and awaits confirmation, the player receives the commands, checks for free space and notifies, then the files are transfered. There is also the possibility for the device to act as an external storage device, however, instead of giving total control over to the host computer, the same mechanics apply, and all communication is made through the series of commands. In a way here's where the network analogy better applies, as the device may have two separate areas for system files and those media files, but the user in the end only sees the media files section on its local storage, like a network share, where users from other computers can explore the share as part of their own computers, but not the whole remote system. The same analogy applies.

Given its characteristics, MTP will be the preferred transport protocol for media devices, just like PTP is still in use by many cameras. And as with many cameras out there, it should be possible to swtich back and forth the connection method with the computer. Also MTP is a requirement for modern DRM schemes such as the Janus DRM for subscription content. Alas, for obvious reasons, when switching from one method to another a format of the device is usually required.