First few seconds of video sent from iPhone are frozen

• I have searched open and closed issues for duplicates
• I am submitting a bug report for existing functionality that does not work as intended
• I have read https://github.com/signalapp/Signal-Android/wiki/Submitting-useful-bug-reports
• This isn't a feature request or a discussion topic

Bug description

I encounter this bug just about every time I receive a video from someone using Signal on an iPhone.

When they send a video and I play it, the video is frozen for the first few seconds, but I can still hear the audio. Then, the video starts playing and the rest of the video is usually fine.

Steps to reproduce

• receive a video from an iPhone user
• play it
• notice that for the first few seconds, the video is frozen

Actual result: The first few seconds of the received video is frozen.

Expected result: The video should never freeze.

Device info

Device: OnePlus 7 Pro
Android version: 10
Signal version: 4.64.0

Link to debug log

https://debuglogs.org/b7251a40e0c47c2bc54945d852f8b6d84b05902234003e009fb9328d75e0cd55

EDIT: New debug log: https://debuglogs.org/74b0919baa28649f5b36770939ac2912efedd4131c1fa552bcc88d1886a67324

Start by reproducing the issue with a video received from an iPhone on the reported Android setup, then inspect the linked debug logs for playback details. Compare the initial video rendering with its audio playback and verify that the complete video displays normally from the first frame.