We were previously using the container format of the media being
played as the mimeType generating key requests, but this is not
always correct. As an example, where a manifest contains webm streams
but specifies initialization data using cenc:pssh elements in the
manifest, the media has a webm mimeType, but the DRM initialization
data has an mp4 mimeType.
- Keys should not expire during normal playbacks of correctly configured content.
- Attempting to refresh on expiration causes a race condition, that may result
in either failure or brief re-buffer, for the 30s license test video.
- This change provides deterministic behavior, which is to always fail.
- Rather than returning a map, return a DrmInitData object,
with mapped and non-mapped implementations.
- Include a suitable mimeType to pass to the MediaDrm. Previously
we were incorrectly passing the mimeType of the samples,
where-as MediaDrm expects the container mimeType. Note that
it doesn't matter whether the mimeType starts with "video" or
"audio", hence using video mimeTypes everywhere.
