Multikey protected Dash video doesn't work

[pi-andrei]

Issue description

ExoPlayer is unable to play DASH video with multiple content protection keys and fails with error:

com.google.android.exoplayer2.demo E/ExoPlayerImplInternal: Renderer error.
com.google.android.exoplayer2.ExoPlaybackException
    at com.google.android.exoplayer2.mediacodec.MediaCodecRenderer.feedInputBuffer(MediaCodecRenderer.java:750)
    at com.google.android.exoplayer2.mediacodec.MediaCodecRenderer.render(MediaCodecRenderer.java:553)
    at com.google.android.exoplayer2.ExoPlayerImplInternal.doSomeWork(ExoPlayerImplInternal.java:560)
    at com.google.android.exoplayer2.ExoPlayerImplInternal.handleMessage(ExoPlayerImplInternal.java:306)
    at android.os.Handler.dispatchMessage(Handler.java:98)
    at android.os.Looper.loop(Looper.java:154)
    at android.os.HandlerThread.run(HandlerThread.java:61)
Caused by: android.media.MediaCodec$CryptoException: Error decrypting data: requested key has not been loaded
    at android.media.MediaCodec.native_queueSecureInputBuffer(Native Method)
    at android.media.MediaCodec.queueSecureInputBuffer(MediaCodec.java:2480)
    at com.google.android.exoplayer2.mediacodec.MediaCodecRenderer.feedInputBuffer(MediaCodecRenderer.java:741)
    at com.google.android.exoplayer2.mediacodec.MediaCodecRenderer.render(MediaCodecRenderer.java:553) 
    at com.google.android.exoplayer2.ExoPlayerImplInternal.doSomeWork(ExoPlayerImplInternal.java:560) 
    at com.google.android.exoplayer2.ExoPlayerImplInternal.handleMessage(ExoPlayerImplInternal.java:306) 
    at android.os.Handler.dispatchMessage(Handler.java:98) 
    at android.os.Looper.loop(Looper.java:154) 
    at android.os.HandlerThread.run(HandlerThread.java:61) 

I saw one related topic in issue tracker: #1824 However it is closed with no actions done. There was a discussion about other ways to implement it and how to interpret DASH specs, but time has passed, and there is more clear explanation in newer spec what should client (player) do (See http://dashif.org/wp-content/uploads/2017/09/DASH-IF-IOP-v4.1-clean.pdf chapter 7.7.9. Client Interactions with DRM Systems):

Clients SHALL explicitly request all required media keys signaled by default KIDs and SHALL NOT assume that requesting one key from this set will implicitly make others available.

Multi-key is important in situation with different quality levels, because we need to apply different protection policies to different types of content. E.g. client needs a high security in-seat airline-owned device to play 4K video, but he may need medium security for 1080p and below that on any device. Using different keys is the technical mechanism that enables DRM system to enforce such different rules.

Reproduction steps

1. In the ExoPlayer demo app version 2.6.1 add next content to the media.exolist.json

{
        "name": "v7-MultiDRM-MultiKey 1080p",
        "uri": "https://media.axprod.net/TestVectors/v7-MultiDRM-MultiKey/Manifest_1080p.mpd",
        "drm_scheme": "widevine",
        "drm_license_url": "https://drm-widevine-licensing.axtest.net/AcquireLicense",
        "drm_key_request_properties": {
          "X-AxDRM-Message": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.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.uF6YlKAREOmbniAeYiH070HSJhV0YS7zSKjlCtiDR5Y"
        }
}

2. Try to play added media.

Link to test content

https://media.axprod.net/TestVectors/v7-MultiDRM-MultiKey/Manifest_1080p.mpd

Version of ExoPlayer being used

ExoPlayer 2.6.1

Device(s) and version(s) of Android being used

Not device specific. For bugreport used Nexus 9 with Android 7.1.1

A full bug report captured from the device

Bugreport sent by email

[ojw28]

• Note that for the specific case where audio and video are encrypted with separate keys, you can enable support by setting multiSession = true when instantiating DefaultDrmSessionManager.
• Enabling multiSession = true probably works for content where different representations within an adaptation set (e.g. HD vs SD video) as well, however I think adaptation wont be seamless. Ensuring it is, and that playback proceeds correctly, is what's being tracked by this issue.

[pi-andrei]

Thanks for reply, multiple keys obtaining now works indeed.

[ojw28]

The remaining work here is now tracked by #4133.