If the word "legacy" comes to mind I'd guess that you're thinking about 90s-era video codecs. This article is about the file/container format, which was directl

If the word "legacy" comes to mind I'd guess that you're thinking about 90s-era video codecs. This article is about the file/container format, which was directly adopted as the MPEG-4 file format, which becamse generalized as ISOBMFF (https://en.wikipedia.org/wiki/ISO_base_media_file_format https://en.wikipedia.org/wiki/ISO_base_media_file_format), which won an Emmy in 2021. It's a modern, flexible, extensible format, and so is likely to be around long after we're gone.