• Status Closed
  • Percent Complete
  • Task Type Patches
  • Category Settings
  • Assigned To No-one
  • Operating System iPod 5G
  • Severity Low
  • Priority Very Low
  • Reported Version Daily build (which?)
  • Due in Version Undecided
  • Due Date Undecided
  • Votes
  • Private
Attached to Project: Rockbox
Opened by safetydan - 2007-07-15
Last edited by safetydan - 2007-11-24

FS#7440 - Remove (non-functional) hardware equalizer on iPod

The attached patch removes the hardware equalizer menu from the iPod Video settings. It does keep the low-shelf and high-shelf filter settings but moves those to a bass and treble cutoff setting in the sound settings menu. Also, the bass and treble settings in the sound settings menu are replaced with the hardware eq equivalents.

Unfortunately I haven’t tested this on target as I don’t have an iPod Video to use.

Closed by  safetydan
2007-11-24 07:58
Reason for closing:  Accepted
Additional comments about closing:   Warning: Undefined array key "typography" in /home/rockbox/flyspray/plugins/dokuwiki/inc/parserutils.php on line 371 Warning: Undefined array key "camelcase" in /home/rockbox/flyspray/plugins/dokuwiki/inc/parserutils.php on line 407


Whoops. Didn’t #ifdef a few things properly.

New version. Should actually let you set the treble and bass cutoffs.

New version. Disables the volume prescaler so volume doesn’t go up when you up the bass/treble setting. Cutoff settings don’t seem to work though.

Fix a warning. Correct the range of values for the cutoff setting. Only set the 0×100 flag on EQ1. Still no idea if the cutoff setting works or survives restarts.


I don’t know if I like this.

The hardware equalizer and the bass/treble settings produce different results!

The bass/treble settings on the sound menu does have bugs, but using the hardware equalizer clips the sound, making bass sound really fuzzy and crap!

And no, I’m not confusing this with the “software equalizer”.

I prefer to use the bass/treble settings on the sound menu (even though the sound volume actually increases while using them) rather than linking them to the poorly designed hardware. unless there can be confirmation that the bad quality sound achieved using the hardware equalizer is not passed on to the settings in the ‘bass/treble settings’.

If not, then I fully support this patch, as it possibly fixes the volume problem I filed on  FS#7427 

Had a look at the driver code, and the bass and treble controls don’t actually do anything (apart from the volume adjustment, which is a side-effect). Don’t ask me why this hasn’t been fixed before now, but with this patch it will at least be fixed. I don’t really think this codec chip has any bass/treble controls apart from the HW EQ.
Any EQ will clip your sound if your volume isn’t low enough, and this one is no exception. The SW EQ is actually worse at this unless you don’t use the precut, at least the hardware EQ won’t clip your sound unless you have the volume close to 0 dB.

I knew that the sound will clip if it’s too loud. I didn’t know, however, that the current bass/treble settings did nothing but a volume increase! No wonder I didn’t hear any clipping, hey :P ?

Someone should really finish this and commit it.

I would…but I don’t have the time or experience

And I don’t have an Ipod Video. However, if no one seems to turn up today, I’ll see if I can just cook up a patch and have someone test it.

Basic resync of the patch. I’ll work on getting the cutoff options being numeric rather than stings in a bit.

Updated patch with numeric settings.

I’ve finally got around to testing this.

Firstly, I’m aware that the cut-off frequencies quoted in the datasheet are unlikely to be accurate at different samplerates, but I don’t like the use of “0”, “1”, “2” and “3”. I’m sure we’ll get lots of complaints/queries about that. But I also can’t think of anything better…

There does seem to be a problem with the patch though - if I change the bass gain, then go to the bass cutoff screen and change the bass cutoff, then the bass gain is reset to 0. Going back to the bass gain shows the previous value selected, but it’s no longer applied.

The same problem appears to happen with the treble.

The attached patch should fix the base/bass issue in the settings list and also change the cutoff settings values from 0..3 to 1..4. Still not great, but a little better.

I was unable to reproduce the issues with the gain resetting in the simulator.

Now with non-broken english.lang

Please resync. I’m getting an error on apps/settings_list.c

Back in sync with r15772.

This version of the patch uses shadow registers. However I’m not certain I’ve got the mask values correct.

This version should have correct mask values. I’ve verified that the bit patterns are correct for all values.


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