Playback doesn't start on DRMized streams

[nicoweilelemental]

Environment

• The MPD passes the DASH-IF Conformance Tool on https://conformance.dashif.org/
• The stream has correct Access-Control-Allow-Origin headers (CORS)
• There are no network errors such as 404s in the browser console when trying to play the stream
• The issue observed is not mentioned on https://github.com/Dash-Industry-Forum/dash.js/wiki/FAQ
• The issue occurs in the latest reference client on http://reference.dashif.org/dash.js/ and not just on my page

• Link to playable MPD files:

https://d24rwxnt7vw9qb.cloudfront.net/out/v1/2fc23947945841b9b1be9768f9c13e75/index.mpd (one key for both audio and video tracks, key rotation activated)

https://d24rwxnt7vw9qb.cloudfront.net/out/v1/6e16c26536564c2f9dbc5f725a820cff/index.mpd (one key for video and one key for audio, no key rotation)

Streams are using both Widevive and Playready, multi-period but all periods are encrypted (no mix of clear + encrypted)

• Dash.js version: 4.0.1
• Browser name/version: Chrome 91
• OS name/version: win10

Steps to reproduce

1. Please provide clear steps to reproduce your problem
   Load one of the two streams with Widevine parameters:
   License URL : https://lic.staging.drmtoday.com/license-proxy-widevine/cenc/
   Request header key: x-dt-custom-data
   Request header value: ewogICAgInVzZXJJZCI6ICJhd3MtZWxlbWVudGFsOjpzcGVrZS10ZXN0aW5nIiwKICAgICJzZXNzaW9uSWQiOiAidGVzdHNlc3Npb24xMjMiLAogICAgIm1lcmNoYW50IjogImF3cy1lbGVtZW50YWwiCn0=

2. If the bug is intermittent, give a rough frequency if possible
   Permanent problem

Observed behavior

The DRM license requests are succesful but the playback doesn't start. Another DRM partner reported they have the same problem with dash.js v4 and that they didn't have it with v3.

Console output (second stream URL)

emeLogger.RequestMediaKeySystemAccessCall {timestamp: "15:1:41:639", title: "RequestMediaKeySystemAccessCall", target: Navigator, returned: Promise, keySystem: "com.widevine.alpha", …}
VM16:418 emeLogger.PromiseResult {timestamp: "15:1:41:639", title: "RequestMediaKeySystemAccessCall Promise Result", status: "resolved", args: Array(2), result: e…r.MediaKeySystemAccess}
VM16:418 emeLogger.GetConfigurationCall {timestamp: "15:1:41:640", title: "GetConfigurationCall", target: e…r.MediaKeySystemAccess, returned: {…}}
Debug.js:169 [4668314][ProtectionController] DRM: KeySystem Access Granted (com.widevine.alpha)!  Selecting key system..
[...].
[4668551][ProtectionModel_21Jan2015] DRM: Session created.  SessionID = 50CF9E69577CC7C2181EA7FB5DCD3CF0  
[4668583][ProtectionModel_21Jan2015] DRM: Session created.  SessionID = 686A0055992CAA23727CED2A6DC4454E 
emeLogger.MessageEvent {title: "MessageEvent", event: MediaKeyMessageEvent, timestamp: "17:17:50:468", target: e…r.MediaKeySession, message: Uint8Array(2), …}
Debug.js:169 [4668584][ProtectionController] DRM: onKeyMessage 
Debug.js:169 [4668648][BufferController][video] Waiting for more buffer before starting playback 
Debug.js:169 [4668761][StreamProcessor][audio] OnFragmentLoadingCompleted for stream id 3584702 and media type audio - Url: https://d24rwxnt7vw9qb.cloudfront.net/out/v1/6e16c26536564c2f9dbc5f725a820cff/index_audio_6_0_3584713.mp4?m=1618852834  
Debug.js:169 [4668763][BufferController][audio] Got enough buffer to start 
Debug.js:169 [4668763][BufferController][audio] Buffered range: 8016011.966667 - 8016013.972, currentTime =  8016012.9735 
Debug.js:169 [4668763][ScheduleController][audio] Appended bytes for audio and stream id 3584702 
VM16:418 emeLogger.EncryptedEvent {title: "EncryptedEvent", event: MediaEncryptedEvent, timestamp: "17:17:50:647", target: e…r.HTMLMediaElement, initData: Uint8Array(975), …}
Debug.js:169 [4668766][ProtectionController] DRM: onNeedKey 
Debug.js:169 [4668767][ProtectionController] DRM: Ignoring initData because we have already seen it! 
Debug.js:169 [4668779][ScheduleController][audio] Media segment needed for audio and stream id 3584702 
Debug.js:169 [4668779][StreamProcessor][audio] Next fragment request url for stream id 3584702 and media type audio is https://d24rwxnt7vw9qb.cloudfront.net/out/v1/6e16c26536564c2f9dbc5f725a820cff/index_audio_6_0_3584714.mp4?m=1618852834 
VM16:418 emeLogger.UpdateCall {timestamp: "15:1:42:190", title: "UpdateCall", target: e…r.MediaKeySession, returned: Promise, response: Uint8Array(1304), …}
VM16:418 emeLogger.PromiseResult {timestamp: "15:1:42:234", title: "UpdateCall Promise Result", status: "rejected", args: Array(1), result: TypeError: Failed to execute 'update' on 'MediaKeySession': Rejected with system code (13)}
VM16:418 emeLogger.UpdateCall {timestamp: "15:1:42:236", title: "UpdateCall", target: e…r.MediaKeySession, returned: Promise, response: Uint8Array(1304), …}
VM16:418 emeLogger.PromiseResult {timestamp: "15:1:42:264", title: "UpdateCall Promise Result", status: "rejected", args: Array(1), result: TypeError: Failed to execute 'update' on 'MediaKeySession': Rejected with system code (13)}
Debug.js:169 [4668968][StreamProcessor][video] OnFragmentLoadingCompleted for stream id 3584702 and media type video - Url: https://d24rwxnt7vw9qb.cloudfront.net/out/v1/6e16c26536564c2f9dbc5f725a820cff/index_video_4_0_3584713.mp4?m=1618852834  
VM16:418 emeLogger.EncryptedEvent {title: "EncryptedEvent", event: MediaEncryptedEvent, timestamp: "17:17:50:858", target: e…r.HTMLMediaElement, initData: Uint8Array(975), …}

Expected behavior

The playback should start, as verified in the castLabs player:

https://players.castlabs.com/presto/6.1.9/#/player/config?cfg=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%3D%3D

https://players.castlabs.com/presto/6.1.9/#/player/config?cfg=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%3D

[dsilhavy]

@nicoweilelemental I checked this and it does not work for me in dash.js 3.2.2 and 4.0.0. Also not working in Shaka. Both, dash.js and Shaka fail with:

Failed to execute 'update' on 'MediaKeySession': Rejected with system code (13)

when calling session.update(message) after the successful license request.

One thing I need to check is why dash.js does not dispatch that error to the reference UI.

[dsilhavy]

It looks like DRMToday returns the Widevine license in a JSON object rather than in arraybuffer format. We do have an implementation for that which can be called the following way:

{
  "name": "Elemental DRM Today",
  "url": "https://d24rwxnt7vw9qb.cloudfront.net/out/v1/2fc23947945841b9b1be9768f9c13e75/index.mpd",
  "protData": {
    "com.widevine.alpha": {
      "drmtoday": true,
      "serverURL": "https://lic.staging.drmtoday.com/license-proxy-widevine/cenc/",
      "httpRequestHeaders": {
        "x-dt-custom-data": "ewogICAgInVzZXJJZCI6ICJhd3MtZWxlbWVudGFsOjpzcGVrZS10ZXN0aW5nIiwKICAgICJzZXNzaW9uSWQiOiAidGVzdHNlc3Npb24xMjMiLAogICAgIm1lcmNoYW50IjogImF3cy1lbGVtZW50YWwiCn0="
      },
      "httpTimeout": 5000
    }
  }
}

By adding "drmtoday": true we will use the CastLabs DRMToday License Server implementation and treat the payload of the DRM server different than we usually do. Setting this flag the playback works for me.

I will add a checkbox for that in the reference UI

[dsilhavy]

There is a new checkbox in the options section: "DRM Today". If this is checked we will handle the license response accordingly. With that, playback works fine for me.

[nicoweilelemental]

So cool, thanks Daniel! Should the checkbox rather be a generic radiobutton called "License response expexted as json" or "License response expected as arraybuffer"?

[dsilhavy]

@nicoweilelemental I agree, that might be worth adding in the future. For now I would like to keep it as it is since the DRMToday implementation we have in place handles Playready and Widevine responses differently. So it is not just the response type but also how the license message is parsed.

[nicoweilelemental]

@dsilhavy no worries, I see the streams playing now, so it's all good. Thanks!