Worked on the opencv/opencv repository to enhance the stability of Video I/O workflows on iOS, focusing on resolving a crash in the VideoWriter destructor. Addressed a SIGSEGV issue by replacing the deprecated synchronous finishWriting method with the asynchronous finishWritingWithCompletionHandler, using dispatch_semaphore to ensure safe resource release. This approach improved concurrency management and aligned the codebase with modern AVFoundation APIs. The work, implemented in Objective-C, reduced race conditions and eliminated a common crash path, resulting in more reliable video export processes. These changes contributed to fewer crash reports and increased confidence for developers and users working with video processing on iOS.