933916 - FM radio sound is mono not stereo

Status: RESOLVED DUPLICATE of bug 852497

(Firefox OS Graveyard :: Gaia::FMRadio, defect)

Description

[Michelle Luna]

Enable FM radio on LG commercial device and listen for evidence of stereo. Sound is ok, but is only mono as reported by a customer with the LG device.

I spoke to mwu about this and he confirmed there is not stereo sound. He said he didn't see code that would let us specify stereo vs. mono, that it would be related to how the audio is routed. So, I include Naoki here to have a look.

Comment 1

[Naoki Hirata :nhirata (please use needinfo instead of cc)]

I don't see any code that would specify stereo versus mono either.

on 1.3 and 1.2 Leo I hear stereo.  I'll have to check the 1.1 Leo version.

In the meantime, can you try checking to see if a different headset would give stereo?  It may be the pin configuration on the headset.

en.wikipedia.org/wiki/Phone_connector_(audio)#Mono_and_stereo_compatibility
http://en.wikipedia.org/wiki/Phone_connector_%28audio%29#Design

Comment 2

[Naoki Hirata :nhirata (please use needinfo instead of cc)]

Further discussion with mwu, I got clarity in regards to this...

It may be mono going out both left and right channel instead of stereo outputs for the radio.
I need to retest.

Comment 3

[Naoki Hirata :nhirata (please use needinfo instead of cc)]

Confirmed; I'm hearing mono through both left/right channels.

Music app is outputting left channel, right channel correctly in stereo.
Video app is outputting left channel, right channel correctly in stereo.

CC'ing the leo team as it's not in our code to specify mono/stereo within the gecko/gaia... it may be gonk or below...  Not sure.

Comment 4

[Michael Wu [:mwu]]

I found that we weren't configuring stereo mode. It was fixed as part of https://bugzilla.mozilla.org/show_bug.cgi?id=852497 , but we can fix just the stereo issue for 1.2 if we can get approval. This assumes that the analog path is also properly configured for stereo.

Comment 5

[Michael Wu [:mwu]]

Attachment: Enable stereo mode

This is a patch for 1.2 to just enable stereo FM.

Comment 6

[Michael Wu [:mwu]]

Comment on attachment 832426 [details] [diff] [review]
Enable stereo mode

This is really an approval request for the 1.2/gecko26 branch, but I couldn't find anything closer.

[Approval Request Comment]
Bug caused by (feature/regressing bug #): None
User impact if declined: FM radio continues to play in mono.
Testing completed (on m-c, etc.): Landed, tested on Buri device
Risk to taking this patch (and alternatives if risky): Minimal. This has been tested on the target devices and appears to work fine. It allows the device to play in stereo if it can.
String or IDL/UUID changes made by this patch: None

Comment 7

[Michael Wu [:mwu]]

Comment on attachment 832426 [details] [diff] [review]
Enable stereo mode

Ryan says I'm doing it wrong.

Comment 8

[Michael Wu [:mwu]]

koi blocking appears to be the closest thing we have at the moment.

Comment 9

[Michael Wu [:mwu]]

Stereo appears to work on both Buri and Leo with this fixed. Clearing POVB.

Comment 10

[bhavana bajaj [:bajaj]]

(In reply to Michelle Luna from comment #0)
> Enable FM radio on LG commercial device and listen for evidence of stereo.
> Sound is ok, but is only mono as reported by a customer with the LG device.
> 
> I spoke to mwu about this and he confirmed there is not stereo sound. He
> said he didn't see code that would let us specify stereo vs. mono, that it
> would be related to how the audio is routed. So, I include Naoki here to
> have a look.

Can you confirm what version was this was regression on ? 1.1?

Comment 11

[Michael Wu [:mwu]]

This isn't a regression. We never turned on stereo to begin with. However, turning it back on is simple and low risk.

Comment 12

[bhavana bajaj [:bajaj]]

Although this might be a simple pref change we might be introducing a whole new code path with this change. So unless stereo is absolutely required and promised for 1.2, I am leaning this ride's the trains and gets resolved in upcoming releases.

Comment 13

[Michael Wu [:mwu]]

The code path shouldn't change significantly - this mostly flips a bit on the hardware side.

Comment 14

[bhavana bajaj [:bajaj]]

(In reply to Michael Wu [:mwu] from comment #13)
> The code path shouldn't change significantly - this mostly flips a bit on
> the hardware side.

Understood, but this sounds like a new feature support and a request that we would not take at this point in the 1.2 cycle.

Comment 15

[Michael Wu [:mwu]]

Fair enough. Duping to the bug that will ultimately fix this.