DRM related Stream descriptor fields

skip_encryption=0|1:  Optional. Defaults to 0 if not specified. If it is set to 1, no encryption of the stream will be made. drm_label:Optional value for custom DRM label, which defines the encryption key applied to the stream. Typically values include AUDIO, SD, HD, UHD1, UHD2. For raw key, it should be a label defined in –keys. If not provided, the DRM label is derived from stream type (video, audio), resolutions, etc. Note that it is case sensitive.