
Posted by Don Turner – Android Developer Relations Engineer
This text takes a take a look at what’s modified within the Android ecosystem for audio builders not too long ago, the audio latency of common Android gadgets, and discusses Android’s suitability for real-time audio apps.
What’s modified?
Over the previous 4 years we have now taken numerous actions which have improved audio latency.
Latency discount
These actions, coupled with a renewed focus from machine producers on audio latency, have led to vital enhancements within the machine ecosystem. The typical latency of the preferred Android telephones has dropped to underneath 40ms, which is properly throughout the vary required for real-time functions.
machine recognition supply: appbrain.com
Better consistency
Digging into the information we will see that in 2017 there was a major distinction between the very best and lowest values (222ms).
machine recognition supply: appbrain.com
Evaluate that to the information for 2021. The vary has lowered by an element of 8 to only 28ms, offering a much more constant audio expertise. That is extra spectacular when you think about that there at the moment are a number of OEMs on the most-popular record, in comparison with solely a single producer in 2017. As well as, lots of the gadgets on the record aren’t high-end flagship fashions.
machine recognition supply: appbrain.com
Faucet-to-tone latency
So far I have been referring to round-trip audio latency. Spherical-trip latency entails three elements within the audio chain: audio enter, audio processing and audio output.
Many real-time audio apps generate audio from display screen faucet occasions moderately than counting on enter audio. These sorts of apps are delicate to “tap-to-tone” latency – the time taken from tapping on the display screen to listening to a sound. The latency launched by tapping the touch screen is anywhere from 10-35ms, with 20ms being pretty typical on trendy Android gadgets.
To estimate tap-to-tone latency given round-trip latency, you may subtract the audio enter latency (usually 5ms), and add the contact latency (usually 20ms). In different phrases, add 15ms to the round-trip latency. Given the numbers above, this implies the typical tap-to-tone latency of the preferred android telephones can be properly underneath that required for many real-time audio functions.
Trying to the long run
Regardless of the numerous reductions in audio latency throughout the Android ecosystem our work is nowhere close to full. 20ms round-tip latency is required for Android professional audio apps, and 10ms stays the long run objective. And right now some much less common gadgets nonetheless have excessive audio latency. Nonetheless, in case you have been holding again on creating an Android app due to audio latency, it is likely to be time to rethink.
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Information sources and instruments
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