Audio Capture

Client Side API

Since Appium 1.18.0 there is a possibility to record iOS audio stream and save it to a file, which could be then retrieved on the client side. Apple does not provide any API to directly retrieve the audio stream from a Simulator or a real device, but it is possible to redirect that stream to the host machine, where it could be captured.

Server Requirements

Appium version should be 1.18.0 or newer.

It is mandatory that the host machine has FFMPEG installed and available in PATH. On macOS it could be installed via Brew: brew install ffmpeg.

macOS since version 10.15 requires applications that record Microphone audio to be explicitly enabled in System Preferences->Security & Privacy->Privacy->Microphone tab. Make sure either FFMPEG itself or the parent Appium process (e.g. Terminal) is present in that list.

The feature is potentially unsecure, so it must be explicitly allowed on the server side. The feature name is audio_record. See Security for more details.

Simulator Setup

The following steps are necessary to setup iOS Simulator audio capture:

Install Soundflower
Redirect Simulator audio output to Soundflower. From the main Simulator menu select I/O->Audio Output->Soundflower (2ch)
Run ffmpeg -f avfoundation -list_devices true -i "" command in Terminal to get the identifier of the Soundflower (2ch) device. This identifier prefixed with : will be then used as audioInput argument to mobile: startAudioRecording call
Test that your setup works as expected. Run any audio playback in Simulator and execute the following command in Terminal (do not forget to replace the -i argument value with the one you got from the previous step): ffmpeg -t 5 -f avfoundation -i ":1" -c:a aac -b:a 128k -ac 2 -ar 44100 -y ~/Desktop/out.mp4. After 5 seconds there should be out.mp4 file on your Desktop containing the recorded audio stream.

Real Device Setup

The following steps are necessary to setup iOS Real Device audio capture:

Connect your device to the Mac host with a cable
Run open -a /System/Applications/Utilities/Audio\ MIDI\ Setup.app application
Find your phone in the list of devices there and click Enable button next to it
Run ffmpeg -f avfoundation -list_devices true -i "" command in Terminal and find the identifier of your device in the AVFoundation audio devices list. This identifier prefixed with : will be then used as audioInput argument to mobile: startAudioRecording call
Test that your setup works as expected. Run any audio playback on the device and execute the following command in Terminal (do not forget to replace the -i argument value with the value you got from the previous step): ffmpeg -t 5 -f avfoundation -i ":1" -c:a aac -b:a 128k -ac 2 -ar 44100 -y ~/Desktop/out.mp4. After 5 seconds there should be out.mp4 file on your Desktop containing the recorded audio stream.

Apple does not allow phone calls to be redirected this way. You can only record application or system sounds.

Audio Capture

Client Side API

Server Requirements

Simulator Setup

Real Device Setup

Further Reading