The following links show how to get the iRiver iFP-799 working as a USB Mass Storage (UMS) device. This should allow you to connect it to your Linux box and then talk to it directly as a device.
Upgrading iFP (iriver) players' firmware:
http://www.iriveramerica.com/support..._firmware.aspx
How to use UMS Firmware:
http://www.iriveramerica.com/support/ums.aspx
iFP-790/795/799 Firmware V1.28(UMS):
http://www.iriver.com/html/support/d...pSearchString=
How to upgrade firmware on UMS version:
http://www.iriver.com/html/support/f...iew.asp?idx=47
How to upgrade firmware (more general):
http://www.iriver.com/html/support/f...ew.asp?idx=252
LinuxQuestions.org member DreameR-X also sent me the following note which should answer any additional questions. Yes, I know some of the links are repeats, but I am keeping this note as-is for completeness' sake. I didn't have to go with the Korean version, but I am using the EU version, because it seemed currently slightly newer (v 1.29 vs. v 1.28 for U.S.).
Well, I didn't get the iRiver to work with Linux right out of the box. I had to change it to a UMS storage device by firmware-flashing it with iRiver's UMS firmware (they have a how-to on the site).
I have the latest UMS firmware, which is from Korea. The only difference is that when you turn it on or off, the message is in Korean....otherwise everything else is in English...but they do have a US UMS firmware (it's just not "the latest")
Basically, what it does, is convert your iRiver to a USB Mass Storage Device (and Linux can detect this). The disadvantage is that you can now only record line-in recordings at 96kbs max (not 320 as I believe you used to). The reason for this is that iRiver states that at above 96kbs they were receiving problems (and this max didn't bother me at all).
The advantage is that now you can transfer any documents back and forth drag-and-drop style without having to worry about the copyright protection.
--Here are the links for the UMS--
Latest Download Thread: (seems to be down)
http://www.misticriver.net/boards/showthread.php?t=9020
Official Download: (Says backlight won't work...but mine does)
http://www.iriver.com/html/support/d...pSearchString=
Firmware Upgrade:
http://www.iriveramerica.com/support..._firmware.aspx
UMS Conversion:
http://www.iriveramerica.com/support/ums.aspx
Another Issue Some Guy Had (But I didn't have this):
http://www.misticriver.net/boards/showthread.php?t=553
Now, if you're thinking "Yea, I already have UMS dummy," then you need to setup your /etc/fstab.
This is what mine looks like:
/dev/cdrom /mnt/cdrom iso9660 user,noauto,ro 0 0
/dev/sda /mnt/media vfat user,noauto,umask=000 0 0
/dev/sda1 /mnt/usbstick vfat user,noauto,umask=000 0 0
The one that works for the iRiver for me is the /dev/sda one (the sda1 is for my SanDisk USB drive).
Hope that helps!