Visualization does not work on the new Galaxy devices

[mobilevisuals]

A visualizer can have an internal music player, which means that the app has its own built in player. It can also use the music from external music players( Winamp for instance). Visualization for external players does not work on the new Galaxy devices.

I have played music with external players, while debugging the visualizer apps. The bytes in the updateVisualizerFFT method are always 0 for external players, when a visualizer is created with 0 as an argument.

This results in no visualization, since there is no signal to use for visualization.
It still works for internal players. The bytes in the updateVisualizerFFT are not 0 then, so the app has something to use for visualization, even when the visualizer is created with 0 as an argument.

This is caused by an Android code bug in the Digital Signal Processors, which are included in the new Galaxy and some HTC devices.

Several visualizer apps have this warning message:

"NOTE: To Galaxy S/S2/S3/S4, Galaxy Note 1/2, Galaxy Nexus and HTC Rezound owners: The visualizer will sporadically show a flatline with many music players, due to an Android bug related to the built-in DSP in these phones. This is a problem for all music visualizer apps on these phones, as evidenced by user reviews of other apps. Still looking for a work-around, but we'll probably have to wait for a future version of Android to fix it. If you have this problem, I apologize! Please email me and I will refund you."

Almost all visualizer apps on the market have this problem and can’t visualize from external players on the new Galaxy and some HTC devices.

It seems like it is possible to solve this problem, because external visualization works on the Morphyre Music Visualizer. It is right now the only visualizer on the market, where this works.

[h6ah4i]

Hello. I'm developing and publishing "Music Visualizer" app on Google Play store. My app also have the similar issues, so I know some causes of them.

First, visualizer not working issue is not a single issue. There are several reasons that makes visualizer not working.

1. Galaxy devices (except for S4) and HTC Rezound

Sorry, I don't know about this issue on these phones. I have Galaxy S2 (SC-02C, JP model), but visualizer works well on it. But I got some feedback from Galaxy S3 users that my app doesn't work on it.

2. Galaxy S3, S4, Note 3 and derived models (Snapdragon model only)

Snapdragon based Galaxy S4 have visualizer not working issue. My Galaxy S4 (SC-0E, JP model) corresponds to this case. I investigated this issue and found the reason.

It uses hardware acceleration playback mechanism called "Tunnel Player (Tunnel Playback)" when playing music files. If the tunnel player is used, audio capturing process is bypassed. As a result, visualizer does not work at all.

There are several conditions for the tunnel player to be used.

• Snapdragon platform
• "tunnel.decode = true" system property is set
• Audio playback by MediaPlayer class (*1)
• MP3 or AAC playback only
• Only one instance is permitted (can't create multiple tunnel player instances)

So, workarounds are the follows;

• Use Open SL API instead of MediaPlayer class (*2)
• Use OGG format instead of MP3 or AAC
• Put "tunnel.decode = false" in build.prop file (!!! root required)
• Occupy tunnel player instance by dummy silent MP3/AAC file playback.
  Second MediaPlayer instance will fall back on standard audio playback mechanism.
  (November 20, 2013 added: I found that MediaPlayer.start() is not required on the dummy instance, only MediaPlayer.prepare() call is needed. sample code is here)

NOTE 1) This issue is already reported on Samsung's developer forum. (But it seems not fixed yet...)

• http://developer.samsung.com/forum/board/thread/view.do?boardName=GeneralB&messageId=238465

NOTE 2) Originally, the tunnel player seems to have been introduced by Code Aurora Forum's developer.

• https://www.codeaurora.org/cgit/quic/la//platform/frameworks/base/tree/media/libstagefright/AwesomePlayer.cpp?id=refs/heads/b2g/ics_strawberry

3. Nexus 4, Nexus 5 and Nexus 7 (2013) (maybe Snapdragon based Nexus only)

Nexus series devices are Google's reference model Android devices. So sometimes they support new features earlier than vendor customized models.

The Google has introduced low-latency audio playback feature since Android 4.1. But it has a side-effect, visualizer doesn't work while music playing by Open SL APIs.

However this issue only occurs on certain Nexus devices. Nexus 10 also supports low-latency playback, but it doesn't have the issue. I think the difference came from base platform difference, Nexus 4 and 7 (2013) are using Qualcomm's Snapdragon SOC, on the other hand Nexus 10 uses Samsung's Exynos SOC. (I don't know that Galaxy Nexus has this issue, but it's interesting because the phone using OMAP SOC.)

Workaround is the follow;

• Use MediaPlayer class based player apps (*1)

ref.) http://source.android.com/devices/latency_design.html

4. Some custom ROMs (Old LiquidSmooth, RootBox and VanirAOSP)

Some custom ROMs have bugs on visualizer implementation. I fixed it on LiquidSmooth, RootBox and VanirAOSP ROM, but I'm afraid that there are other custom ROMs still have this bug.

• stagefright: Fix size of metadata key LiquidSmooth-Old/android_frameworks_av#1
• https://github.com/LiquidSmooth/android_frameworks_av/pull/2
• Audio: Fix Visualizer's get/set parameter methods not worked bug Root-Box/frameworks_av#1
• http://vaniraosp.goo.im/#/c/5820/

5. CyanogenMod 10.2 (ADDED on November 18, 2013)

On CyanogenMod 10.2, Visualizer class doesn't work if it created with audio session 0 (= system mixed output).

This issue seems to occur on certain devices only.

[Affected]

• Nexus 7 2013 ("flo")
• Galaxy S Relay G4 ("apexqtmo")

[Not affected]

• Nexus 7 2012 ("grouper")

6. Recent Motorola's phones (Moto X, DROID Mini, ...) (ADDED on November 23, 2013)

Maybe this issue is only occur on JellyBean. After upgrading to KitKat, it seems to be fixed. (A my app user confirmed this, he is using a Moto X phone.)

---

(*1) MediaPlayer class based player apps:

Music Visualizer built-in player, Google Play Music, PlayerPro (without DSP pack), Rocker Player Free, doubleTwist, n7player, Apollo

(*2) Open SL based player apps:

Poweramp, jetAudio, WinAmp, PlayerPro + DSP pack, Rocket Player Premium, GoneMad, Neutron

---

Thanks,
Haruki Hasegawa (h6a h4i)

[mobilevisuals]

It seems like there can be no definite solution to this problem until a new software update is released from Samsung.
How can we make them aware of this problem and encourage them to solve it as soon as possible?

Music visualization always works on the new iOS devices without any issues. Music visualization should work on all the new Android devices according to the specification, but it does not work on a lot of the new high profile devices, like Samsung's S4. This gives Android a bad reputation and makes people want to buy iPhone instead.

[felixpalmer]

I agree that this is vendor issue. Have you tried contacting Samsung directly and seeing if they have a process for reporting such issues, or even a bug tracker (I know Apple has something like that, for example). I'm not in a position to test myself, as I don't have the device in question.

I'm afraid that I'm not that hopeful here, when a manufacturer ships a device that has a bug in its API, there's only so much you can do. Given how long it takes to get a bug fix from reporting stage to actually being pushed out to devices, sadly I don't think this will be fixed soon. Still worth a try though... :(

[abiemann]

My Samsung Galaxy S4, Model SPH-L720, with Android version 4.3, suffers from this problem. Using MediaPlayer to play an MP3 causes the Visualizer to send a steady stream of 0's in the case of onFftDataCapture(), and a steady stream of -128's in the case of onWaveFormDataCapture()

I've tried one of h6ah4i's suggested work arounds: to play a quiet dummy MP3 before playing the actual music MP3. However, I did not see success. I used the 30second and 60second quiet MP3's found here: http://www.xamuel.com/blank-mp3s/

Maybe those MP3's aren't suitable because there wasn't enough data to enage the tunnel player ?

[h6ah4i]

Hello abiemann. I think the Visualizer issue on SPH-L720 is different from tunnel player's side effect. Because the tunnel player is only used on Snapdragon SOC, SPH-L720 is a Samsung's Exynos SOC model... Oops, SPH-L720 is a Snapdragon model.

I downloaded the 1 min length MP3 from your suggested URL, and tried the workaround with using it. The result was good, it seemed to work on my S4 (SC-04E).

Have you tried Poweramp player already? It's the most easy way to identify the cause is a tunnel player's side effect.

[abiemann]

Hi h6ah4i - I did try PowerAmp and with the Visualizer getting data from the mixer i.e. "audioSession=0" does indeed return real amplitude data instead of 0's.

However, my app uses the MediaPlayer and no amplitude data was returned by the Visualizer API on my S4. On other devices like the Nexus 7, and Nexus 4 there's no problem.

When I attempted the work-around with the quiet MP3, I simply created two MediaPlayer objects: one played the quiet MP3 first (looping was enabled), the second MediaPlayer then played the real music - but again I received no amplitude data from the mixer :-(

[h6ah4i]

@abiemann I made a sample code that shows how to avoid tunnel player. Can you try this?

https://github.com/h6ah4i/tunnel_player_workaround

[mobilevisuals]

I want to test your sample app, to see if it fixes the problem. I only need the APK file to test, I don't need the source and the other files. Can you upload the APK file? abiemann, have you tested the file?

I think that this bug is devastating for the music visualizer business. There is no point in making music visualizers if they can't work on the most popular devices. I am not going to make any more music visualizers until this is fixed. It simply results in too many refunds and complaints from users.

This bug also makes people want to buy iPhone instead, since music visualizing works without problems there.

[mobilevisuals]

Maybe we should contact the Code Aurora project, since they are responsible for this bug?

[abiemann]

Sorry about that long delay - and thank you h6ah4i for your effort !
I've just deployed the "tunnel player workaround" to my Samsung Galaxy S4 (Model SPH-L720, Android 4.3, Hardware version L720.08) and after pressing "play" and selecting a music track, I do see a red waveform on the display that matches the beat of the music ! It looks like the work-around is functional.

[felixpalmer]

@abiemann, great to hear you've found a workaround for the tunnel player. Do you think you could perhaps integrate the same workaround into this project and submit it as a Pull Request, so others can benefit? Thanks

[mobilevisuals]

I have tested on my S4 Mini. The visualization works the first time the project is installed from Eclipse. I test with the music players "Sound picker" and "Choose music track". I close "Tunnel player workaround" and then start it by clicking on the app icon. The visualization also works now for both of the music players.

I restart the S4 Mini and open "Tunnel player workaround". The visualization does not work now, it only shows a flatline.

abiemann, do you get the same problem when you restart your S4?

h6ah4i, is it possible to make the visualization work then the device is restarted? It seems like the restart messes up something.

[h6ah4i]

@mobilevisuals I think it's impossible to make the workaround more reliable. No way to obtain whether the MediaPlayer instance backend is a tunnel player...

[mobilevisuals]

h6ah4i; Do you get the same problem when you restart your S4?

[mobilevisuals]

Felix: Have you tested this on your mobile? Do you get the same problem when you restart it? I want to know if this only happens on the S4 Mini, which is a very compact device. This makes it limited in some ways, it doesn't have the full capacity as the S4.