[BUG] "Muxer error" when converting videos

[Vtech8]

Prerequisites

• I have checked that there are no open issues that are the same or very similar to mine, and I understand that my issue will be closed if it is a duplicate
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Issue Description (required)

When I try to compress videos recorded natively on the phone (FullHD, h265 and h264, 30 or 60fps) the compression process doesn't start at all or stops after short time. Sometimes the app displays gray screen with 0 MB and progress bar at 0. Sometimes the compression starts, halts randomly and the app returns to settings window with "Error: Muxer error" text at the bottom of the window.
The problem seems to be random. After several tries it is possible to successfully compress a video. Compressing 8min video took 20 tries. Compressing 1min video took 3 tries.
I've tested version 1.3.0 and 1.3.1 with the same results.
The issue seems to be only with the videos recorded by the phone itself. Videos from other devices compress without problems.
Video settings selected in the settings window doesn't seem to matter.
I've tested clips recorded using h265 and h264 codecs (there is a codec selection in the phone's camera settings) but the result is the same.

I still think the app is great. Probably my old phone is weird.

Expected Behaviour (required)

Successful compression of the video.

Device Info (required)

• Device Manufacturer* (e.g. Samsung): Huawei
• Device Model* (e.g. Galaxy S10): P30pro
• Android Version* (e.g. 12): 10
• Compressor Version* (e.g. 1.1.0): 1.3.1
• Where did you get Compressor from?* (GitHub Releases, IzzyOnDroid/F-Droid, Google Play Store): GitHub
• Device Chipset (e.g. Exynos 9820): Kirin 980
• Device Model Number (e.g. SM-G973F): VOG-L29

App Version: 1.3.1
Device: HUAWEI VOG-L29 (Android 10)
Supported Encoders: video/avc, video/hevc

Screenshots (required)

Logcat

[JoshAtticus]

Hi @Vtech8! Thanks for the detailed report. Huawei's Android 10 drivers can be a bit strict with media encoding.

The error Muxer error usually means the app successfully encoded the video frames, but failed to 'package' them into the final file, often due to a conflict between the Audio and Video timestamps in the original recording.

Could you try one specific test for me?

• Open Advanced Options.
• Enable "Remove Audio".

Try to compress one of the native camera videos that usually fails.

• If this works, it confirms the issue is with the Audio Track format from the Huawei camera. I can fix this by forcing a specific AAC re-encoding profile.
• If this fails, it confirms the issue is with the Video Timestamps (Variable Frame Rate) or the Huawei Hardware Encoder itself.

Regarding logs, since you are on GitHub, do you have a PC? If you can connect your phone via ADB and run this command in terminal/PowerShell right after the error happens, it would pinpoint the crash immediately:

adb logcat -s "Compressor" "AndroidRuntime" "Transformer" "Muxer"

This will show exactly why the Muxer decided to quit!

[JoshAtticus]

Hi @Vtech8, I haven't heard back from you yet so I'll move your issue to low priority for now. Once you've completed the test steps (and gotten a logcat if possible), I'll move it back.