Demonizer – when your voice becomes the demon’s voice

An interactive voice transformation web app built by CodeWave for Warner Bros.’ The Conjuring 2 campaign.

About the Client

Warner Bros. is one of the world’s leading entertainment companies, producing and distributing movies, TV shows, and digital media. For the premiere of The Conjuring 2, the studio wanted an online campaign that would let fans become part of the horror experience.

Key Insights

Web app created for the online promotion of The Conjuring 2 by Warner Bros.

Real-time voice recording and transformation integrated into the official movie trailer.

Built in record time to support a global marketing campaign.

The Challenge

As with many creative marketing projects, the biggest challenge was time and the constantly evolving scope. New ideas and changes were being introduced daily - from additional translation requirements to integrating the application with external tools. The system also needed to handle a high number of concurrent users during the movie’s promotional peak and process media files quickly and reliably.

The Solution

Our team developed a web application that let users record their own voices and hear them transformed into the voice of a demon inside the official movie trailer. The app handled:

recording and storing user audio
real-time voice transformation and mixing using SoX and ffmpeg
final video generation with the modified sound layered over the trailer

The application was deployed on AWS to ensure stability and scalability during the international campaign launch.

Technology

JavaScript

for the interactive web application

Asterisk

for prank calls

SoX

ffmpeg for voice altering and final video mixing

AWS

for compute and file storage

The Results

The project achieved a successful global rollout during the movie’s premiere campaign, attracting thousands of user-generated recordings within just a few days. It received highly positive feedback from both the creative agency and Warner Bros. marketing team, who praised the platform’s technical reliability and creative execution. Fun fact: The original idea included real prank calls to friends - your “demon voice” would actually call them. Unfortunately, the legal department decided the world wasn’t quite ready for that level of horror.

The Summary

The Demonizer project proved that combining creative marketing ideas with strong technical execution can make a movie campaign truly memorable. It showcased CodeWave’s ability to handle complex multimedia processing and deliver stable, high-performing applications under tight deadlines.

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Let’s create a success story together.

contact

Poland: CodeWave sp. z o.o. Opolska 13, 52-010 Wrocław, Poland
+48 539 019 430, hello@codewave.eu
US: CodeWave LLC 16192 Coastal Hwy, Lewes, DE 19958, United States
+1 (631) 909 5771, hello@codewave.eu