m4a, wav audio files appear as black with "Enable Audio" set to "Auto"

[JamesRichards22]

Describe the bug:
When using an audio track of type m4a or wav (maybe others, but not mp3) on a track above a video file, the audio file blocks out the video and appears black.

Steps to reproduce the behavior:

1. Create a new project
2. Drag a video file onto the timeline at track 1
3. Drag a wav file to track 2
4. Drag a m4a file to track 2, after the wav file
5. Put the play head just before the m4a file
6. Click play
   Expected behavior:
   The video plays normally with no interference with the picture.

System Details:

Distributor ID:	Ubuntu
Description:	Ubuntu 25.10
Release:	25.10
Codename:	questing

Loaded modules from: /tmp/.mount_OpenShtfWGp6/usr/bin
Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.
INFO app: ------------------------------------------------
INFO app:             Thu Jan  1 13:07:26 2026            
INFO app:               Starting new session              
INFO app: ------------------------------------------------
INFO app:             OpenShot (version 3.4.0)            
INFO app: ------------------------------------------------
INFO app: openshot-qt version: 3.4.0
INFO app: libopenshot version: 0.5.0
INFO app: platform: Linux-6.17.0-8-generic-x86_64-with-glibc2.4
INFO app: processor: 
INFO app: machine: x86_64
INFO app: python version: 3.8.10
INFO app: qt5 version: 5.12.8
INFO app: pyqt5 version: 5.14.1
INFO app: Frozen version info from build server:
{
    "build_name": "OpenShot-v3.4.0-daily-14916-47b30812-a76e176a",
    "date": "2025-12-18 03:14",
    "libopenshot": {
        "CI_COMMIT_REF_NAME": "develop",
        "CI_COMMIT_SHA": "47b308122f1e55c05392e2d4750ce2ba9fdf04ae",
        "CI_JOB_ID": "46887",
        "CI_PIPELINE_ID": "14891",
        "CI_PROJECT_NAME": "libopenshot",
        "SO": "28",
        "VERSION": "0.5.0"
    },
    "libopenshot-audio": {
        "CI_COMMIT_REF_NAME": "develop",
        "CI_COMMIT_SHA": "a76e176a3b0685cfebdd41ebdc9956eb129517c8",
        "CI_JOB_ID": "46802",
        "CI_PIPELINE_ID": "14866",
        "CI_PROJECT_NAME": "libopenshot-audio",
        "SO": "10",
        "VERSION": "0.5.0"
    },
    "openshot-qt": {
        "CI_COMMIT_REF_NAME": "develop",
        "CI_COMMIT_SHA": "29fbdab8809c0c03364e610d1ce91ba88b1e5771",
        "CI_JOB_ID": "46962",
        "CI_PIPELINE_ID": "14916",
        "CI_PROJECT_NAME": "openshot-qt",
        "SO": null,
        "VERSION": "3.4.0"
    }
}
INFO project_data: Setting profile to HD 720p 30 fps
INFO project_data: Apply default audio playback settings: 44100, 2 channels
INFO app: checking babl_ext_path: /tmp/.mount_OpenShtfWGp6/usr/bin/lib/babl-ext
INFO app: setting BABL_PATH: /tmp/.mount_OpenShtfWGp6/usr/bin/lib/babl-ext
INFO language: Qt Detected Languages: ['en-AU', 'en']
INFO language: LANG Environment Variable: en_AU.UTF-8
INFO language: LOCALE Environment Variable: 
INFO language: OpenShot Preference Language: Default
INFO logger_libopenshot: Connecting to libopenshot with debug port: 5556
INFO ui_util: Initializing UI for MainWindow
INFO thumbnail: Starting thumbnail server listening on ('127.0.0.1', 40649)

[Colorjet3]

Hello @JamesRichards22

I tested this in Windows 11 Pro 25H2 and I am unable to reproduce the issue.

Testing in Ubuntu 25.10 I am able to reproduce the issue with .m4a file only. Both .mp3 and .wav worked fine. The video did not turn black.

I'll submit a bug in the queue for the lead developer to look into this and fix it in a future release.

Obviously, you already know the workaround by moving the audio only files causing this issue to a lower track (below your video files).