FS#4937 - Ipod Video constant ticking and scrollwheel noise bug

Attached to Project: Rockbox
Opened by Brian (pinkzeppelin) - Tuesday, 28 March 2006, 06:35 GMT
Last edited by Steve Bavin (pondlife) - Sunday, 29 October 2006, 13:55 GMT
Task Type Bugs
Category Music playback
Status Closed
Assigned To No-one
Operating System All players
Severity Low
Priority Normal
Reported Version
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Votes 0
Private No


After booting into rockbox on an Ipod Video, a constant rhythmic ticking noise occurs in the right channel. At lower volumes, it is much harder to hear without sensitive headphones in a quiet environment, but can be heard by less sensitive phones at higher volumes. The scrollwheel creates audible clicking at higher volume levels as well.

Very easy to reproduce - boot up rockbox, open a file for playback, pause the file, crank the volume up to the max (so those using less sensitive headphones can hear). Not only is the scroll wheel movement easily audible at this volume, but the constant ticking is also much easier to hear, especially when going to the "menu" settings screen.

Neither of these two problems occur when booting into the original apple firmware.
This task depends upon

Closed by  Daniel Stenberg (bagder)
Saturday, 19 May 2007, 15:14 GMT
Reason for closing:  Later
Additional comments about closing:  Moved to the new KNOWN_ISSUES files since this is unlikely to be fixed in a forseeable time.
Comment by Brandon Low (lostlogic) - Thursday, 30 March 2006, 15:16 GMT
As we discussed on IRC, I believe this to be related to our slow I2C implementation, and occurs when the battery status and/or realtime clock are updated (the battery is read at up-to 2.5hz and the clock at up-to 1hz). Nothing is going to change with it until someone spends a lot of time analyzing the portalplayer's I2C control registers, or finds a datasheet for the damned thing.
Comment by Brandon Low (lostlogic) - Thursday, 30 March 2006, 15:18 GMT
Also, since you have RMAA, can you detect the volume change clicks at higher volume levels when music is playing? I believe they should now only happen when music is idle, as I've activated the DAC's zero-cross detection for volume changes.
Comment by Steve Bavin (pondlife) - Tuesday, 24 October 2006, 09:39 GMT
Is any iPod Video user still seeing this problem?
Comment by Brandon Low (lostlogic) - Tuesday, 24 October 2006, 15:55 GMT
Yes, it is still audible.