ExoPlayer uses Android’s MediaDrm API to support DRM protected playbacks.
The minimum Android versions required for different supported DRM schemes, along
with the streaming formats for which they’re supported, are:
| DRM scheme | Android version number | Android API level | Supported formats |
|---|---|---|---|
| Widevine “cenc” | 4.4 | 19 | DASH, HLS (FMP4 only) |
| Widevine “cbcs”, “cbc1” and “cens” | 7.1 | 25 | DASH, HLS (FMP4 only) |
| ClearKey | 5.0 | 21 | DASH |
| PlayReady SL2000 | AndroidTV | AndroidTV | DASH, SmoothStreaming, HLS (FMP4 only) |
In order to play DRM protected content with ExoPlayer, your app must inject a
DrmSessionManager when instantiating MediaSources. The MediaSource
factories provide methods that allow this.
The library provides a default implementation of DrmSessionManager, called
DefaultDrmSessionManager, that’s suitable for most use cases. PlayerActivity
in the main demo app demonstrates how a DefaultDrmSessionManager can be
created and injected when instantiating MediaSources.
For some use cases additional configuration may be necessary, as outlined in the sections below.
Key rotation
To play streams with rotating keys, set the multiSession builder parameter to
true when instantiating DefaultDrmSessionManager.
Known issue #4133 - There may be a slight pause in playback when key rotation occurs.
Known issue #3561 - On API level 22 and below, the output surface may flicker when key rotation occurs.
Multi-key content
Multi-key content consists of multiple streams, where some streams use different keys than others. Multi-key content can be played in one of two ways, depending on how the license server is configured.
Case 1: License server responds with all keys for the content
In this case, the license server is configured so that when it receives a request for one key, it responds with all keys for the content. This case is handled by ExoPlayer without the need for any special configuration. Adaptation between streams (e.g. SD and HD video) is seamless even if they use different keys.
Where possible, we recommend configuring your license server to behave in this way. It’s the most efficient and robust way to support playback of multikey content, because it doesn’t require the client to make multiple license requests to access the different streams.
Case 2: License server responds with requested key only
In this case, the license server is configured to respond with only the key
specified in the request. Multi-key content can be played with this license
server configuration by setting the multiSession builder parameter to true
when instantiating DefaultDrmSessionManager.
We do not recommend configuring your license server to behave in this way. It requires extra license requests to play multi-key content, which is less efficient and robust than the alternative described above.
Known issue #4133 - When using this license server configuration, there may be a slight pause in playback when adapting between streams that use different keys.
Offline keys
An offline key set can be loaded into DefaultDrmSessionManager by setting the
offlineLicenseKeySetId in DefaultDrmSessionManager.setMode, which allows
playback using the keys stored in the offline key set with the specified id.
Known issue #3872 - Only one offline key set can be specified per playback. As a result, offline playback of multi-key content is currently supported only when the license server is configured as described in Case 1 above.
DRM sessions for clear content
Use of placeholder DrmSessions allows ExoPlayer to use the same decoders for
clear content as are used when playing encrypted content. When media contains
both clear and encrypted sections, you may want to use placeholder DrmSessions
to avoid re-creation of decoders when transitions between clear and encrypted
sections occur. Use of placeholder DrmSessions can be enabled for
DefaultDrmSessionManager with the builder’s setUseDrmSessionsForClearContent
method.