How can I query for the active codec and bandwidth being played in a mixed-codec, multi-period manifest?

[willdharris]

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?

N/A

What version of Shaka Player are you using? 4.9.0 and main

What browser and OS are you using? Chrome Version 125.0.6422.113 (Official Build) (arm64) macOS Ventura 13.6

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My question is related to Shaka's period flattening and representation matching. During playback, when a variant has multiple codecs that it could change between, is there a way to query for the true codec and bandwidth being played?

• I have a DAI manifest (DASH, static, multi-period) with representations of different video codecs per period.
• When Shaka flattens the periods, it matches representations from each period and creates a single outputStream.
• The single outputStream could include multiple different codecs and bandwidths that could be played.
• That outputStream eventually becomes a variant track with a single video codec and bandwidth value.
• The alternate, matched representations that the variant could be playing are obfuscated.

During playback, is there a way to access the obfuscated representations during the periods in which they are being played?

Example

• My manifest has 3 periods: pre-roll-1-ad-1, pre-roll-1-ad-2, 0.
• Periods pre-roll-1-ad-1 and pre-roll-1-ad-2 only have hev and avc representations, they do not have dvhe representations.
• Period 0 has dvhe representations.
• I want to play the Dolby Vision version of the content, so I configure the player with preferredVideoCodes = ['dvhe'].
• Since the pre-roll periods do not contain dvhe representations, I see hev representations from the pre-roll periods have been matched to the dvhe outputStreams as the alternate representations.
• During playback of the pre-rolls, if I query for the active variant track player.getVariantTracks().find((track) => track.active), I will see that a dvhe codec variant is playing. I know that is not accurate because the manifest does not have dvhe representations in the pre-roll periods. If I inspect the network for the segments being download and buffered, I can confirm that it's the hev segments being played.

In the case of the above screenshot, depending on the presentation time, this variant labeled with a dvhe codec could be playing an hev codec with a bandwidth of 4.2mb or it could be playing the actual dvhe codec with a bandwidth of 5.8mb. Is there a way to access the true codec and bandwidths being played?