Stream Audio from RAR Without Saving to Disk

Extracting audio files from a RAR archive directly into memory without saving them to your hard drive or SSD is entirely possible using the standard unrar utility. By directing the extracted audio stream straight to standard output (stdout), you can pipe the binary data directly into media players or audio processing tools in real time. This guide covers how this process works, the exact commands required, and practical playback examples.

How In-Memory Extraction Works

By default, unrar extracts compressed files directly to a destination directory on your physical storage. However, unrar provides a print command (p) that directs the extracted file data to the terminal's standard output instead of creating a file on disk.

When you combine the print command with switches to suppress status messages and banners, the resulting output is a clean, raw binary stream of the audio file. This stream can be piped immediately into any media software that accepts input from standard input (stdin).

The Command Syntax

To extract an audio file to standard output cleanly, use the following syntax:

unrar p -inul archive.rar "song.mp3"

Here is a breakdown of the essential flags:

  • p: Prints the extracted file to stdout instead of saving it to disk.
  • -inul: Disables all informational messages, headers, and copyright notices. Without this switch, console text will mix into your audio stream, corrupting the file and preventing playback.
  • archive.rar: The path to your target RAR archive.
  • "song.mp3": The specific file name inside the archive. Specifying the file name ensures only the intended track is streamed.

Streaming Directly to Media Players

You can pipe the decompressed output directly into command-line media players without generating any temporary files on disk.

Using MPV

MPV natively supports reading from standard input using a hyphen (-):

unrar p -inul music_archive.rar "track01.flac" | mpv -

Using VLC

VLC can read from standard input using the fd://0 (file descriptor 0) argument:

unrar p -inul music_archive.rar "track01.mp3" | vlc fd://0

Using FFplay

FFplay (part of FFmpeg) also uses the hyphen syntax to accept piped audio:

unrar p -inul music_archive.rar "track01.wav" | ffplay -nodisp -autoexit -

Handling Encrypted Archives

If the RAR archive is password-protected, you must supply the password on the command line to prevent interactive prompts from breaking the pipeline:

unrar p -inul -p"YourPassword" archive.rar "track01.mp3" | mpv -

Limitations to Consider

  • Seeking Restrictions: Because the audio is streamed via a standard unidirectional pipe, seeking forward or backward may be restricted or unavailable in the media player, depending on the format and the player's buffering capabilities.
  • Single Track Output: Streaming works best on a per-file basis. Attempting to output an entire multi-track album into a single pipe will merge multiple discrete audio streams into one continuous data flow, which can confuse decoders.