使用 Cordova 和 JavaScript 从安卓麦克风获取音频数据（不带 getUserMedia）

Question

I need to obtain frequency/pitch data from the microphone of an android device on the fly using JavaScript.

I have done this for desktop/laptop browsers with getUserMedia and Web Audio API, but these are not supported on the vast majority of Android devices.

I have tried using the cordova-plugin-media-capture however this opens an audio recorder which the user can then save or discard, and after saving you can use cordova-plugin-file to obtain the data as shown here: https://stackoverflow.com/a/32097634/5674976 but I need it not to open the audio recorder, and instead perhaps just a record button, and once it is recording to provide the audio data immediately (so that it can detect the frequency data in real-time).

I have seen recording functionality in place eg WhatsApp, Facebook Messenger etc. and so as a last resort - since I do not know Java - would it be possible to create a plugin using Java for Cordova?

edit: I have also looked at cordova-plugin-media https://github.com/apache/cordova-plugin-media which seems to provide amplitude data and current position data. I'm thinking I could figure out frequency by looking at the amplitude over time, or am I being naive?

Answer 1

I managed to record audio and also analyze the frequency without either getUserMedia or Web Audio API for Android.

Firstly I installed the cordova-plugin-audioinput plugin, which outputs a stream of audio samples (from the microphone), with custom configurations such as buffer size and sample rate. You can then use this data to detect specific frequencies.