Demonizer, a voice transformation app for Warner Bros.’ The Conjuring 2
The web app processed users’ voice recordings and transformed them into demonic audio, creating an interactive experience directly in the browser.
About the client
Warner Bros. is one of the world’s leading entertainment companies, producing and distributing movies, TV shows, and digital media. They launched The Conjuring 2 with a digital campaign designed to bring fans directly into the film’s horror world. The experience needed to work in the browser, transform users’ voices and give them something they could immediately share with others.
Key insights
Web app created for the online promotion of The Conjuring 2 by Warner Bros.
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
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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