AVI to SPH Converter

AVI (Audio Video Interleave) is one of the oldest and most recognized multimedia container formats, introduced by Microsoft in November 1992 as part of its Video for Windows technology. Built on the Resource Interchange File Format (RIFF) structure, AVI interleaves audio and video data in alternating chunks, allowing synchronized playback without requiring sophisticated stream management. The format is codec-agnostic, meaning it can hold video compressed with virtually any codec, from early Cinepak and Indeo to modern DivX, Xvid, and H.264 streams. This flexibility contributed to widespread adoption across personal computers throughout the 1990s and 2000s. One notable characteristic is a straightforward internal structure that makes AVI files relatively easy to edit and process at the binary level compared to more complex modern containers. AVI also supports multiple audio streams, enabling multilingual content within a single file. However, the original specification has limitations, including a 2 GB file size ceiling in older implementations and no native support for variable frame rates or advanced subtitle formats. The OpenDML extensions (AVI 2.0) addressed the size limitation by allowing files to exceed the original boundary. Despite being decades old, AVI remains one of the most universally recognized multimedia formats and is still widely supported by media players and editing tools across all major operating systems.