问题
I am trying to convert a MPD dash file which has DRM protection in it to a MP4 file. I do have the URL to the DRM license. So, I tried to do this using ffmpeg library, but there is no option to pass the license URL along with ffmpeg command for decryption.
回答1:
DRM is designed and created to stop you from doing it. DRM can have software reader or hardware reader. Hardware reader will not give you neither decryption key, neither decrypted content. Software reader will do it in most obfuscated way possible.
So ffmpeg does not have such option because it is virtually impossible by design of DRM.
However, if you have any relations with content owner, they can share you original encryption key and you will be able to decrypt.
来源：https://stackoverflow.com/questions/54851195/how-to-convert-mpeg-dash-mpd-with-drm-license-to-mp4