Broadcasting vinyl over my LAN - ALSA2ChromeCast

Previously, on the Terence Eden Adventures:

• I accidentally won a load of vinyl on eBay, and
• I bought the cheapest record player I could find.

The record player has USB output. So I shoved it into a Rock Pi S - an SBC similar to a Raspberry Pi - to broadcast vinyl all over my house via ChromeCast! Here's how.

Detect the audio

Install alsa-utils if they're not already present.

Find your hardware with

 Basharecord -l

One of the outputs should be:

 Bashcard 2: Microphone [USB Microphone], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

In this case, we want Hardware Card 2, Device 0. From now on, we'll refer to this as hw:2,0. Yours may be different.

Record a sample from the input. Make sure the record player is playing music!

 Basharecord  --device="hw:2,0" -d 10 -f dat -t wav test.wav

That will record a 10 second WAV file at the best possible audio resolution. Check that it has worked by playing back the WAV on a different computer.

Install Icecast

Icecast is a terrible bit of software with no sensible user documentation or guide. Install it with:

 Bashsudo apt install icecast2

It should prompt you for some information. And then it will start in the background automagically. If not, run:

 Bash/etc/init.d/icecast2 start

You can edit the default config with:

 Bashsudo nano /etc/icecast2/icecast.xml

Here's a minimal config. This The admin username is admin and all the passwords are password - you probably want to change that! The hostname is set to the IP address of the Pi, 192.168.0.123:

 XML<icecast>
    <hostname>192.168.0.123</hostname>
    <location>Earth</location>
    <admin>icemaster@localhost</admin>
    <limits>
        <clients>100</clients>
        <sources>2</sources>
        <queue-size>524288</queue-size>
        <client-timeout>30</client-timeout>
        <header-timeout>15</header-timeout>
        <source-timeout>10</source-timeout>
        <burst-on-connect>1</burst-on-connect>
        <burst-size>65535</burst-size>
    </limits>
    <authentication>
        <source-password>password</source-password>
        <relay-password>password</relay-password>
        <admin-user>admin</admin-user>
        <admin-password>password</admin-password>
    </authentication>
    <listen-socket>
        <port>8000</port>
    </listen-socket>
    <http-headers>
        <header name="Access-Control-Allow-Origin" value="*"/>
    </http-headers>
    <fileserve>1</fileserve>
    <paths>
        <basedir>/usr/share/icecast2</basedir>
        <logdir>/var/log/icecast2</logdir>
        <webroot>/usr/share/icecast2/web</webroot>
        <adminroot>/usr/share/icecast2/admin</adminroot>
        <alias source="/" destination="/status.xsl"/>
    </paths>
    <logging>
        <accesslog>access.log</accesslog>
        <errorlog>error.log</errorlog>
        <loglevel>3</loglevel>
        <logsize>10000</logsize>
    </logging>
    <security>
        <chroot>0</chroot>
    </security>
</icecast>

To restart after making changes, run:

 Bash/etc/init.d/icecast2 restart

If you visit http://your_server_ip:8000 then you should see a boring interface. You can't do anything with it yet.

Install Ice2

Icecast is a server - but you also need a client to broadcast audio to the server. Annoying that Icecast doesn't come with one. And annoying that there's no tutorial to tell you all this.

 Bashsudo apt install ice2

I followed this tutorial. Basically, create a file called ice.xml with this in it:

 XML<ices>
    <stream>
        <input>
            <module>alsa</module>
            <param name="rate">48000</param>
            <param name="channels">2</param>
            <param name="device">hw:2,0</param>
        </input>
        <metadata>
            <name>@edent's record player</name>
            <genre>Live Vinyl</genre>
            <description>Listen to what's on my record player</description>
            <url>http://192.168.0.123:8000</url>
        </metadata>
        <instance>
            <hostname>192.168.0.123</hostname>
            <port>8000</port>
            <password>password</password>
            <mount>/vinyl.ogg</mount>
            <yp>1</yp>
            <encode>
                <quality>10</quality>
                <samplerate>48000</samplerate>
                <channels>2</channels>
            </encode>
            <downmix>0</downmix>
        </instance>
    </stream>
    <background>1</background>
    <logpath>.</logpath>
    <logfile>ices.log</logfile>
    <logsize>2048</logsize>
    <loglevel>4</loglevel>
    <consolelog>0</consolelog>
</ices>

Now run ices2 ice.xml - it will run in the background.

The admin page of Icecast should now have something like this: You can now play the audio via the HTML5 player on the page - or open the M3U in VLC.

ChromeCast Broadcast

For my home AV set-up, the easiest way to broadcast audio to my amp is to use its built-in ChromeCast Audio.

There are loads of solutions, but the easiest to use was PyChromeCast. Once installed, it can stream audio from IceCast to a ChromeCast. Bit convoluted, but it works!

To discover ChromeCasts on your network, run python3 then enter these commands:

 Python 3import time
import pychromecast
pychromecast.discovery.discover_chromecasts()

You'll get a list of ChromeCasts on your network. Mine showed:

[('192.168.0.789', 4321, UUID('5632e20d-1030-4885-ad3d-496504b7c820'), 'Pioneer VSX-933', 'Pioneer VSX-933 ABC1234')]

We want the ChromeCast's ID - which is the 4 digit int. Back to Python

 Python 3pychromecast.get_chromecasts(4321)

You'll get a bit more debug data:

[Chromecast('192.168.0.789', port=4321, device=DeviceStatus(friendly_name='Pioneer VSX-933 ABC1234', model_name='Pioneer VSX-933', manufacturer='Onkyo And Pioneer', uuid=UUID('5632e20d-1030-4885-ad3d-496504b7c820'), cast_type='cast'))]

This supports cast - good!

Now we can send the audio to the ChromeCast

 Python 3cast = pychromecast.get_chromecasts(4321)[0]
cast.wait()
mc = cast.media_controller
mc.play_media('http://192.168.0.123:8000/vinyl.ogg', 'audio/ogg')

Success! Vinyl ➡️ USB ➡️ ALSA ➡️ IceCast ➡️ Ogg ➡️ Ethernet ➡️ WiFi ➡️ ChromeCast ➡️ Speakers.

Is it worth it?

Depends. Do you like lossy, crackly vinyl, smushed down to OGG, flown across a network, then digitally reprocessed into luscious 5.1 surround sound with a 4.5 second lag?

Meh.