Cinavia is an watermarking and steganography system developed by Verance. In conjunction with the existing AACS DRM, the inclusion of Cinavia watermarking detection support became mandatory for all consumer Blu-ray Disc players in 2012.

Watermark

Cinavia adds an audio watermark embedded in one of the channels of the audio stream using steganography. 

The watermark is inaudible and visually indistinguishable from normal audio:
Normal PCM audio:    ▁▂▃▄▅▆▇██▇▆▅▄▃▂▁
With Cinavia:              ▁▂▃▄▅▆▇██▇▆▅▄▃▂▁  ← same to the eye

In the audio stream, regular dots or bursts at ~18.5 kHz, repeat every 15–30 seconds.
Frequency (Hz)
20,000 ┼──────────────────────────────────
       │
18,500 ┼───────●───────●───────●───────●──  ← **Cinavia watermark**
       │      (on/off modulation)
16,000 ┼──────────────────────────────────
       │
   20 ┼──────────────────────────────────
       → Time (seconds)

Message Codes

When errors occur Cinavia will trigger diffrent messages. There are 4 Message Codes, but only 2 of them will occur on Blu-ray players:

Message Code 1: Playback stopped
“Playback stopped. The content being played is protected by Cinavia™ and is not authorized for playback on this device. For more information, see http://www.cinavia.com. Message Code 1.”

Explanation: The audio track of the video that you are playing contains a Cinavia code indicating it was intended for presentation using professional equipment only (for example, in a theater or hotel) and is not authorized for playback by consumers.

Message Code 3: Audio muted
“Audio outputs temporarily muted. Do not adjust the playback volume. The content being played is protected by Cinavia™ and is not authorized for playback on this device. For more information, see http://www.cinavia.com. Message Code 3.”

Explanation: The audio track of the video that you are playing contains a Cinavia code indicating that it is an unauthorized copy of professionally-produced content. 

Cracking

True removal is challenging because the watermark is steganographically embedded (hidden in the audio signal itself), not a simple encryption layer. No universal "hack" exists that works on all discs without side effects, as watermarks vary per title.

There are several software that will remove Cinavia's audio watermark, notably, DVDFab and Leawo Blu-ray Cinavia Removal. 

Author(s) : Æ Firestone