Vbrfix; Applications; Alpine Cd Changer Emulator - Rockbox Archos Jukebox Studio 5000 User Manual

C 7. P
HAPTER LUGINS
7.3.4. VBRfix
This function scans a VBR (Variable Bitrate) MP3 file and updates/creates the Xing VBR
header. The Xing header contains information about the VBR stream used to calculate
average bit rate, time information and to more accurately fwd/rew in the stream. This
function is especially useful when the playback of a file skips, fwd/rew does not work
correctly or the time display is incorrect.
Note: VBRfix can only run when music is turned off (since it uses the same memory as
the player) and can take a while to complete if run on big files.

7.4. Applications

7.4.1. Alpine CD changer emulator

This plugin emulates an Alpine CD changer. It allows to plug the Archos to a com-
patible head unit and control the playback from there, too. Currently implemented is
track change, shuffle, seek, but no disk change. The plugin is a TSR, meaning it silently
operates in the background once started. It will keep doing so until a new plugin is
started. Alpine also did M-Bus as OEM for other brands (Honda, Acura, Volvo, BMW,
etc.) Nowadays Alpine uses a different protocol, called Ai-Net, not supported by this
plugin. (As well as all other protocols, please do not ask for such!)
The cable
Hookup to Archos works by connecting the headphone output including the remote
pin (you need a 4-ring 3.5 mm plug for that) to the changer jack of the radio. M-Bus
radios have a DIN-style circular jack with 8 pins (7 in a
center). A standard 5-pin DIN plug is OK for this, since we don't use the other (power)
pins.
As OEM, they shuffled the pins around a bit, better check first if it's not genuine
Alpine. The bus pin is pulled high to 12 volts with a
low. Because it's open collector, this is not harmful to the Archos.
ASCII art of the 4-pin headphone plug:
/ \
\_/ left -> Alpine pin 5
|_| right -> Alpine pin 4
|_| remote -> Alpine pin 1
|_| ground -> Alpine pin 2 + 3
The remote pin can be programmed bidirectional, that's the reason this works. Very
luckily the M-Bus uses a single wire communication and the two radios I tried are
happy with the 3.3 Volt level the Arcos can deliver. So the connection is a simple cable!
For all protocols requiring more lines, an external controller would be necessary.
Note: Archos FMs don't have the remote pin internally connected, but one unit that
was opened was internally prepared for it, a matter of closing a bridge.
T R
HE OCKBOX MANUAL
270 degree circle, one in the
2kOhm resistor, pulses driven
A S
RCHOS TUDIO
42
/P
LAYER