AVI to MJPEG 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.

MJPEG (Motion JPEG) is a video compression format in which each frame is independently compressed as a separate JPEG image. Unlike interframe codecs that exploit temporal redundancy between successive frames, MJPEG treats every frame as a standalone photograph, applying the discrete cosine transform compression familiar from still image JPEG encoding. This approach dates back to 1992, coinciding with the establishment of the JPEG standard itself, and was widely adopted as one of the earliest practical methods for compressing digital video. The intraframe-only nature of MJPEG carries several practical benefits: any frame can be accessed and edited independently without decoding neighboring frames, making it exceptionally well-suited for video editing and applications requiring frame-accurate random access. MJPEG is commonly used in IP cameras, security surveillance systems, medical imaging, and industrial machine vision, where individual frame integrity and low processing latency outweigh the higher bandwidth requirements compared to modern interframe codecs. The format achieves typical compression ratios of 10:1 to 20:1 while maintaining good visual quality, though at significantly higher bit rates than temporal compression methods for equivalent quality. MJPEG streams can be delivered over HTTP, making them straightforward to implement in web-based monitoring applications, and the simplicity of the codec ensures reliable decoding even on resource-constrained embedded hardware.