This tool forwards audio from an Android 10 device to the computer. It does not require any root access. It works on GNU/Linux, Windows and macOS.
The purpose is to enable audio forwarding while mirroring with scrcpy. However, it can be used independently.
- The Android device requires at least Android 10.
- VLC must be installed on the computer.
Download the latest release:
sndcpy-v1.1.zip
_SHA256: _b045320ddddbc5a237d6d95213c664f03b2f46ef8bbfcef91c2d95644ed42bbcsndcpy-with-adb-windows-v1.1.zip
_SHA256: _0b93c846f574df3f38f53eeee44b1a35b863a49465da8f5cd5b1b69a29305901
On Windows, for simplicity, take the second archive, which also contains
adb
.
Alternatively, you could build the app.
Plug an Android 10 device with USB debugging enabled, and execute:
./sndcpy
If several devices are connected (listed by adb devices
):
./sndcpy <serial> # replace <serial> by the device serial
(omit ./
on Windows)
It will install the app on the device and start forwarding audio.
Press Ctrl
+c
in the terminal to stop (except on Windows, just disconnect the
device or stop capture from the device notifications).
VLC may print this error message once:
main stream error: connection error: Connection refused
It is "expected", just ignore it.
The sound continues to be played on the device. The volume can be adjusted independently on the device and on the computer.
To uninstall the app from the device:
adb uninstall com.rom1v.sndcpy
sndcpy
may only forward audio from apps which do not prevent audio
capture. The rules are detailed in §capture policy:
- By default, apps that target versions up to and including to Android 9.0 do not permit playback capture. To enable it, include
android:allowAudioPlaybackCapture="true"
in the app'smanifest.xml
file.- By default, apps that target Android 10 (API level 29) or higher allow their audio to be captured. To disable playback capture, include
android:allowAudioPlaybackCapture="false"
in the app'smanifest.xml
file.
So some apps might need to be updated to support audio capture.
This is just a proof-of-concept, so it's far from perfect.
For example, jitter may cause VLC to automatically increase its buffering, causing an unacceptable delay:
main input error: ES_OUT_SET_(GROUP_)PCR is called too late (pts_delay increased to 377 ms)
In that case, just restart it.
The scripts sndcpy
and sndcpy.bat
use some default
values which can be overridden by environment variables.
ADB
: the full path to theadb
executableVLC
: the full path to thevlc
executableSNDCPY_APK
: the full path tosndcpy.apk
SNDCPY_PORT
: the local port to forward to communicate with the device