1285832 - Media Playback via Widevine Stutters, Jitters

Status: RESOLVED DUPLICATE of bug 1266938

(Core :: Audio/Video: Playback, defect, P1)

Description

[Bryce Seager van Dyk [:bryce] (he/him) - Not reading bugmail]

Playback of encrypted media when using the Widevine CDM can result in a jittery or stuttery effect. Specifically it appears frames are being presented in an incorrect order. This can be seen when seeking in video, before the video 'catches up' after the seek there is a jitter in the frames presented. This seems to be worse in debug builds. I've noticed this particularly when debugging WebM, but am not certain it is a WebM specific issue -- I have also seen problems with mp4 h264 media.

In the worst case scenarios, that I believe I've only seen with WebM, play back get permanently stuck in a 'jittery' state.

This issue can be reproed using the Shaka player demo, with the Sintel Widevine media.

Comment 1

[Bryce Seager van Dyk [:bryce] (he/him) - Not reading bugmail]

Attachment: MediaFormatReader NSPR_LOG output from Sintel Playback with Jitter

Comment 2

[Bryce Seager van Dyk [:bryce] (he/him) - Not reading bugmail]

Attachment: Python script to parse MediaFormatReader logs and look for out of order samples

Comment 3

[Bryce Seager van Dyk [:bryce] (he/him) - Not reading bugmail]

Attached a log of Sintel playback that contains jitter near the end of playback. Also attached a python script to parse the logs and the look for out of order samples. Right now hard coded to load 'log.txt'. Running the script on the log created above suggests that the samples are being fed into the decoder in the correct order, but the samples returning form the decoded for video are out of order at times.

Comment 5

[Bryce Seager van Dyk [:bryce] (he/him) - Not reading bugmail]

Resolving as a dupe, will continue working on this in the lower bug number.