Multiple DRM license requests

[mikeszutu]

Have you read the Tutorials?
Yes

Have you read the FAQ and checked for duplicate open issues?
Yes

If the question is related to FairPlay, have you read the tutorial?
No

What version of Shaka Player are you using?
4.13.5

What browser and OS are you using?
Chrome 133.0.6943.55 / Mac 15.3.1

Please ask your question
I'm noticing an issue where if we have a key rotation of 5 mins, we're making multiple DRM license requests on initial launch of the app. I've tried limiting using:
drm.retryParameters: {
maxAttempts: 2
}
but continues to make 12 additional requests + the usual 2 but playback is fine.

Update: Upon looking at our manifest we've set 7 periods and I believe each period is making 2 drm calls which equals to 14.

Is this typically normal or am I missing something here?

[mmsreedhar]

We also have same issue. Is it possible to parse PERIOD in MPD depending on the current playback position? If anyone has any suggestions please help.

[avelad]

@joeyparrish ?

[shaka-bot]

@mikeszutu Does this answer all your questions? If so, would you please close the issue?

[mmsreedhar]

Still waiting for an answer.

[joeyparrish]

2 requests is relatively normal. If you set the server certificate in advance, it doesn't have to request one to create the DRM session, and that goes down to 1 request.

But these are the number of requests per unique PSSH. From the player's point of view, we don't know what is in a PSSH. The structure varies by DRM vendor, and we don't always get to know how they are encoded.

Widevine PSSHs have a "content ID" field in their opaque structure, which is used to identify a whole set of keys that belong together. If you have multiple PSSHs that all refer to the same VOD content ID, you only need to generate one DRM session and request one license.

But the player doesn't know that. It doesn't parse PSSHs deeply. And sadly, there is no standard API in the browser to figure out which PSSHs are needed for different DRM sessions and which are duplicates you could throw away.

So if you're seeing 2 requests x 7 periods = 14 requests, that's probably 7 certificate requests and 7 license requests in 7 different DRM sessions (one per period). I'm guessing the PSSHs differ (byte-for-byte) across periods.

Does that sound right?

[mikeszutu]

I was tested with a DASH manifest with 7 periods arising from a 30min long length and 5-min key rotation period, one pssh box per period per relevant adaptation set (video and audio, one for each), and I saw only 2 requests issued.
Does the client request based on the number of PSSH blocks in the active playing Period, or should it be requesting for all of the Periods and all encountered PSSH boxes across the entire manifest?

[sojadhav]

Hi @joeyparrish, @avelad

We are also seeing multiple widevine License requests

Our setup is like following :

AUDIO, SD, HD, UHD1, UHD2 tracks are having different encryption/decryption keys & different pssh box, Our license server adds decryption keys for all tracks in single License response

So first License Response has decryption keys for all track_types, still we see multiple license requests in following cases

• When playback starts, One for AUDIO track & 2nd one for SD track
• We see license request when track switch happens e.g SD --> HD

Is this expected ?

Please check the following & let me know if my understanding is correct

• Shaka player will initiate new license request if it finds new unique pssh box

Please let me know

Thanks

[sojadhav]

Hi @joeyparrish

Just following up on the above message — I was wondering if there have been any updates or if you had a chance to look into it. Please let me know if there's anything I can clarify or help with.

Thanks again for your time