Playback of 1080i content with DRM




Hi all.

I’ve recently taken part in the development of a small media service, that includes a full implementation of:

  • Bitmovin Player
  • BuyDRM MultiDRM
  • Wowza Media Server

During the testing phase of this infrastructure and software configuration, we encountered a rather interesting issue regarding the playback of 1080i (interlaced video) content.
We have observed the following:

  1. 1080i content is playable on all tested platforms with DRM disabled.
  2. 1080i content is only playable on Android devices with DRM enabled.

EDIT: This is only true for Widevine DRM (see replies)

Our test setup:

  • Latest Edge & Chrome browsers on Windows 10
  • Playready and Widevine DRMs
  • Android mobile devices with versions 10-13
  • Dash & HLS playback was tested

The playback of DRM protected content on Windows 10 does not explicitly fail. The player begins to buffer, loading chunks and initializing the DRM system, however a “waiting for key” message is repeatedly logged to the browser console (debug logging enabled) by the Bitmovin player.
After a few minutes of buffering the player begins to play audio, but no video (black screen).

This issue only reproduces on Windows 10, but we believe this issue is somehow related to the DRM implementation, so all modern versions of Windows are probably affected. Browsers use a software based DRM system for content protection, while Android devices might be capable of providing more robust (or at least differently implemented) solutions.

We are unsure if this is an issue with Bitmovin player itself. We have tested other players and the issues has reproduced (dash.js). This means we are most likely dealing with either a limitation of the software based DRM solution in the Browser or bug in it. However, we were advised by Bitmovin support to write to this community page about this to allow for a public discussion and sharing of information regarding this issue. We agreed as this issue has been hardly discussed publicly on the internet.

Our solution to this issue was to transcode our large catalogue of 1080i content to 1080p, which was luckily not that costly thanks to AWS Elemental MediaConvert.
Regardless of that I want to invite you all to discuss this issue and especially to find the true root cause of this undocumented (?) behavior / bug.

- Eemil from Singularity Designs

Thanks for reaching out.
Can you confirm that you are using Playready on Edge and Widevine on Android?
Are you using a real device or a simulator (browserstack etc). DRM don’t work on simulators, usually.

If you are using the right DRM technology on a real device, then Waiting for Key, could mean that none of the keys returned by your DRM server match the content you are trying to play.

Please let me know in case you have any questions and please feel free to share your streams here or in a support ticket.

We tested on real Android devices on Chromium based browsers that used Widevine.
However, we are not sure if Playready has these issues on desktop. We will test this specific case to make sure and come back to you with the results later.

We don’t think this is related to key delivery, as the exact same test was ran on Android and PC. None of the backend components were modified between tests. The network traffic exchanged during all the tests we did seemed similar.

Additionally, audio is also using content protection and plays after some sort of timeout. Wouldn’t this mean that the correct keys are being provided to the player, but it fails to play video for some other reason? Again, no errors or warnings are logged even with debugging enabled.

We might be able to publish our tests, but some internal discussions must happen before we do so.

We have come to the conclusion that 1080i with DRM enabled works fine with PlayReady DRM on desktop, but not with Widevine. This was tested on the Edge browser on real hardware by selecting which DRM to use.