koel/docs/usage/streaming.md

Streaming Music

Streaming Methods

Koel supports three streaming methods which can be configured via the STREAMING_METHOD setting in .env file:

• php: Uses native PHP file reading. This is the default method.
• x-accel-redirect: Only applicable if your webserver is nginx. Uses nginx's X-Accel module, designed for serving larger contents directly to the end user. Refer to nginx.conf.example for a sample nginx configuration file.
• x-sendfile: Only applicable if your webserver is Apache (with or without a proxy server like nginx). Uses Apache's mod_xsendfile module. You'll need to install and configure the module manually. A sample configuration is as following:

  LoadModule xsendfile_module   libexec/apache2/mod_xsendfile.so
  
  # These configuration can be put in the VirtualHost directive as well
  <IfModule mod_xsendfile.c>
    XSendFile on
    XSendFilePath /mnt/media
  </IfModule>
  

  Note that although its home page denotes "Apache2/Apache2.2," the module itself is known to work with later versions of Apache as well.

:::tip Tip If you're using Koel mobile app and can't play the songs, try switching the streaming method to x-accel-redirect or x-sendfile instead of php. :::

:::warning Notice Koel always uses the native PHP method if you're transcoding or streaming from a cloud storage. :::

Transcoding FLAC

Koel supports transcoding FLAC to mp3 on the fly when streaming music. This behavior can be controlled via a TRANSCODE_FLAC setting in .env file:

• false: Disable FLAC transcoding. Koel will stream FLAC files as-is, producing the lossless audio quality. This is the default behavior.
• true: Enable FLAC transcoding. Koel will transcode FLAC to mp3 on the fly. You'll need to have FFmpeg installed on your server and set its executable path via the FFMPEG_PATH setting in the .env file. The transcoding quality can also be controlled via OUTPUT_BIT_RATE (defaults to 128).