I have a service which uses azure media service v3 sdk to upload(and transform)video files. At the moment I am working with some solution for video virus scanning. Have a question As they are re-encoding video files to host on their streaming service does it negate the requirement to scan these files? Thanks
Reencoding video pulls apart the source video by decoding the original audio and video 'in the clear' and then reencoding it. This would limit the attack vectors since the MP4 header would be rewritten, the video and audio are not the original, and a limited amount of metadata gets copied from the old header.
For a virus attack it is less common to hide something in an actual video file and instead just disguise the video as something executable with no video in the file. For example, a .exe file made to appear as a video would not survive the reencoding process since it is not an actual video file. This does not mitigate all risk, but it does mitigate a lot of it.