: It contains the metadata (like the "moov atom") required to initialize your device's video and audio decoders.
: Interestingly, this file usually contains no actual video data ; it simply tells the player how to handle the video segments that follow.
In the world of streaming, videos are not delivered as one giant file. Instead, they are broken into thousands of tiny pieces called . The dashinit file (often a fragmented MP4) is the very first piece your video player requests.
: Without this "handshake" file, the player wouldn't know how to interpret the subsequent chunks of video it receives. How MPEG-DASH Works
Large platforms like YouTube and Netflix use this technology to ensure you don't experience buffering. Using generated dashinit mp4 for progressive download #406