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Dash-Industry-Forum / dash.js

A reference client implementation for the playback of MPEG DASH via Javascript and compliant browsers.
http://reference.dashif.org/dash.js/nightly/samples/dash-if-reference-player/index.html
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Support seamless period switch from non DRM periods to DRM periods #4137

Closed minhui-foxtel closed 2 months ago

minhui-foxtel commented 1 year ago

Is your feature request related to a problem? Please describe.

I noticed that seamless period switch from non DRM periods to DRM periods was disabled due to buffer errors that is mentioned in the original PR https://github.com/Dash-Industry-Forum/dash.js/pull/3413.

Reinitialize source buffers when switching from non DRM periods to DRM periods for the first time. Otherwise we encounter buffer errors.

However, seamless period switch is still possible in this case from my recent testing. I'm not sure that something changed or not in the past two years. Maybe just because we implemented a ProtectionController by ourselves, we uses MediaPlayer.attachProtectionController.

Describe the solution you'd like

https://github.com/Dash-Industry-Forum/dash.js/blob/a1cc5b2cd615e08e2d212da7b15884c54a9d646a/src/streaming/controllers/StreamController.js#L620-L629 Is it possible/proper to add a new setting to bypass previousStream.isProtectionCompatible(nextStream)?

I did see that there was still a playback issue when replace previousStream.isProtectionCompatible(nextStream) to true in DASH-IF sample, but not sure if it's just buffer errors that mentioned before.

Additional context

We're using dash.js@4.3.0, I'm sure no changes about this in latest dash.js.

dsilhavy commented 1 year ago

I still see this problem in Chrome Version 111.0.5563.64 on MacOSx.

A MEDIA_ERR_DECODE occured: Resetting the MediaSource

We need to reset the MSE for the first transition between non encrypted to encrypted content. One possible workaround would be to append the encrypted init segment of an upcoming encrypted period before starting the playback of the non-encrypted period. For now, I don't think a settings flag to disable isProtectionCompatible makes much sense.

Which platform are you testing on?

minhui-foxtel commented 1 year ago

I mainly checked this on Chrome based platform, from my Mac Chrome 110.0.5481.177 to old version of Chromes from TV, e.g. Chrome/88.0.4324.182 from a Hisense TV. Indeed I can still see this problem in some devices, but it works well in most of devices I tested. I have no confidence to talk too much EME/DRM stuff, just FYI 😄

bwallberg commented 1 year ago

This does work in shaka so it should at the very least be possible.

dsilhavy commented 1 year ago

@bwallberg Do you know how they implemented it? Are they appending an encrypted init segment before playback of mixed content (DRM and non DRM)?

bwallberg commented 1 year ago

@dsilhavy unfortunately not. Not yet anyway.

dsilhavy commented 7 months ago

Related issue #4396

dsilhavy commented 2 months ago

Closing this issue as we have a more detailed description in #4396