In a previous post I wrote about the google cast audio, and how to cast audio from Linux. Now, I would like to write how to cast your audio from Mac OS X.

Casting from Mac OS X to a Google cast device

As I didn’t find any satisfactory solution for this, I decided to write mkchromecast. This is an application written in Python, that uses two backends to stream audio to your google cast devices: node or python flask + ffmpeg. Moreover, you can modify the bitrates, sample rates and audio coding formats (the latter one is available provided that you use ffmpeg). To communicate to the google cast devices it uses pychromecast.

To install it, just clone from github:

git clone

Then, you have to install the dependencies:

pip install -r requirements.txt

You will also need soundflower. These are the minimal requirements to stream to your google cast using the node backend (mp3 audio format by default). If you would like to use ffmpeg check the instructions here.

I am also working in providing a system tray menu, which in fact works decently right now. I have written it using the Qt5 python bindings.

List of supported encoders

When using ffmpeg, the following audio coding formats are available:

Audio coding format Description Notes
mp3 MPEG Audio Layer III (default) Lossy compression format (default bitrate: 192k)
ogg Ogg Vorbis Lossy compression format (default bitrate: 192k)
aac Advanced Audio Coding (AAC) Lossy compression format (default bitrate: 192k)
wav Waveform Audio File Format Lossless format (HQ sound)
flac Free Lossless Audio Codec Lossless format (HQ sound)

To use mkchromecast it is very easy. Just get into the cloned directory and execute the program as follows:


Note: you can use mkchromecast with Python3 if you want to.

Some examples

Using aac with a selected bitrate of 256k:

python --encoder-backend ffmpeg -c aac -b 256

Using flac with the system tray:

python --encoder-backend ffmpeg -c flac -t

For more help:

python -h

Complete instructions and information can be found at: