ekuiter / virtual-choir

Singing together in times of Corona

Virtual Choir

Coordinates voice recordings and synchronized mixes in virtual choirs.

XAMPP setup instructions

This works out of the box with XAMPP (AllowEncodedSlashes On) by accessing http://[::1]/ in the browser (make sure ffmpeg, mysql, and mysqldump are installed).

AWS setup instructions

This will set up a virtual choir on AWS EC2 with a Let's Encrypt certificate. A custom domain is required because MediaDevices.getUserMedia() only works with HTTPS.

• git clone https://github.com/ekuiter/virtual-choir.git && cd virtual-choir
• npm install && npm run build
• Rename config.template.json to config.json and update the songs you want to sing, their starting offsets, and voice registers for stereo balancing.
• For each song, supply an MP3 file (and optionally, MSCZ, PDF, and MusicXML files) in the app/songs directory. Such files can generated with MuseScore or bemuse).
• Generate an app/.htpasswd file with some login credentials.
• Create an AWS account and a user with AdministratorAccess in the IAM console.
• Install EB CLI.
• eb init --platform "PHP 7.3 running on 64bit Amazon Linux" --region "eu-central-1"
• eb create virtual-choir --single --database --database.engine "mysql" --database.username "<username>" --database.password "<password>" --envvars "CERT_DOMAIN=<custom-domain>"
• Take note of the CNAME field in eb status.
• eb ssh -c "wget https://dl.eff.org/certbot-auto; chmod a+x certbot-auto; sudo ./certbot-auto certonly --debug --manual --preferred-challenges dns --email <your-email-address> --domains <custom-domain>"
• You may need to press y and Enter after installing dependencies. Then agree to the terms and IP logging.
• Take note of the TXT field, create according CNAME and TXT DNS records for your custom domain, wait a few seconds to minutes for the DNS update, and press Enter.
• Restart Apache with eb deploy.
• For subsequent deploys, you can migrate existing data with npm run build && curl -L --user <user>:<password> https://<custom-domain>/php/app.php?backup --output backup.zip && eb deploy && curl -F "restore=@backup.zip" --user <user>:<password> https://<custom-domain>/php/app.php?backup.

Benchmarking

Use ApacheBench to simulate n users with c concurrent requests:

# use C:\xampp\apache\bin\abs.exe on Windows
ab -n 100 -c 50 -A <user>:<password> https://<custom-domain>/

To simulate recordings, use a hex editor to insert an OGG file into ab.txt (this can fail on Windows, in which case you should use wsl with apache2-utils):

ab -n 100 -c 50 -A <user>:<password> -p ab.txt -T "multipart/form-data; boundary=1234567890" https://<custom-domain>/php/app.php