What is the difference FMOD_OUTPUTTYPE_OPENSL to (FMOD_OUTPUTTYPE_AUDIOTRACK in Android

FMOD Engine
1

hi,

when i setOutput FMOD_OUTPUTTYPE_OPENSL or FMOD_OUTPUTTYPE_AUDIOTRACK
i get 512 buffer size and 2 buffers with 240000 sample rate.
on bluetooth i get shutring sound over FMOD_OUTPUTTYPE_OPENSL , supposed to be low latency?.

i want to know what fmod does to the audio system when i use each of them and why i have delay over bluetooth when im using android 8.0 on my nexus 6p where my device latency is only 8-10ms with the loopback App writing by google engineers(drrickorang).

Thanks,
tal

2

AudioTrack is the default audio output for devices running Android 2.2 or earlier:
https://developer.android.com/reference/android/media/AudioTrack.html

OpenSL is the default, for most but not all, devices running Android 2.3 or later:
https://developer.android.com/ndk/guides/audio/opensl-for-android.html

We do attempt to determine what would run best on the device, but the results can vary dramatically depending on device hardware.

Pairing with a BlueTooth speaker or headset will incur significant extra latency, 120ms in some tests. This is currently unavoidable due to the OS taking extra buffering beyond developer control.

If you are using an app that has much lower latency with bluetooth, let us know what it is and where we can find it and we will investigate.

3

hi,

im using this app :

from the play store…

or you can find the source code in github:

another thing, in call im not having a bluetooth latency over voice,
so maybe its not the phone latency is fault.

check it out and let me know…

thanks,

tal

4

For best results we recommend to use AudioTrack with the default buffer settings for bluetooth audio.

The OpenSL Low Latency mode is only available on certain hardware and software configurations, using bluetooth will automatically disable this mode.