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Won't Fix

Votes

0

Found in [Package]

4.1.1

Issue ID

1292500

Regression

No

[iOS] [AR Foundation] Video and Audio get out of sync over time

Package: ARFoundation

-

Reproduction steps:
1. Open the project in "MWE.zip"
2. Open SampleScene and build for iOS
3. Deploy the project to an iOS device
4. Locate the video of a person talking in 3D space
5. Move the Camera around, inspect the person talking and listen to the sound

Expected result: Audio and Video is in sync
Actual result: Audio and Video is out of sync by more than a second

Reproducible with: 4.0.2 (2019.4.14f1), 4.1.1 (2019.4.17f1, 2020.1.17f1, 2020.2.0f1, 2021.1.0a9)
Could not test with: 2018.4.30f1, because I could not resolve the errors related to packages

Devices tested:
Reproducible:
VLNQA00310 iPad Pro 12.9 1st gen (iOS 13.4.1)
Not reproducible (IMPORTANT: read note 3):
VLNQA00335, Samsung Galaxy S20+ 5G (SM-G986B), Android 10, CPU: Exynos 990, GPU: Mali-G77
VLNQA00015, Samsung Galaxy Note8 (SM-N950W), Android 8.0.0, CPU: Snapdragon 835 MSM8998, GPU: Adreno (TM) 540

Notes:
1. The issue may occur more quickly if moving the camera a lot
2. Over time the video and audio become more and more out of sync
3. On android the video is not 360 degrees

  1. Resolution Note:

    This problem reproduces, even if we eliminate all AR aspects of the repro project, and just play the video full-screen in a simple project on an iPhone 7. From the Unity profiler, I can see that some frames take 60-90ms to decode in a job. The original video is VP8, which means it is likely being decoded in software on iOS. If the video is transcoded to a lower-resolution VP8 video (i.e. half resolution), then it plays back correctly.

Comments (1)

  1. Donna_Anderson

    Jan 23, 2022 09:06

    Video and audio get out of sync over time in inshot video editor. I had the same problem. Do NOT use preview as affirmation of A/V Sync. Go by your wave forms and Markers. See my bug report also. In my case it was 6 frames off. I just did a video with my iphone 8 instead of my go-pro and once again preview audio was slightly out of sync, but my wave-forms line up. Now move your audio file to the new placement of the play head and export it in inshot pro apk here apklifezone.com Exported with perfect audio sync in Pro-Res 4:2. Then I use handbrake to get that down to a more manageable size.

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