"B128" is frequently used in product codes for electronic storage or security hardware:

In video compression, "128" is a common reference to bitrate:

The most likely professional or technical origin for a file named "b128" or similar is the standard.

: In developer communities (like GitHub or Stack Overflow), "b" often stands for "batch," suggesting this file could be the 128th item in a batch-processed video script. Summary of Possibilities Potential Origin Description Broadcasting A test video normalized to the EBU R128 loudness standard. Consumer Electronics A video saved on or formatted for a 128 GB storage device. Development A test file used in FFmpeg or batch-processing scripts. Provide more context to help narrow it down.