Audio only, no video with new player backend (Flatpak, Intel HD 620, Zorin OS 18.1)

[11dash11]

Environment

OS: Zorin OS 18.1 (based on Ubuntu 24.04)

Architecture: amd64

GPU: Intel HD Graphics 620 (Kaby Lake)

Shotcut: 26.6.25 (Flatpak from Flathub: org.shotcut.Shotcut)

OpenGL: Mesa Intel(R) HD Graphics 620, Mesa 25.2.8

Vulkan: working (vulkaninfo sees Intel HD 620)

VAAPI: working (vainfo):

VA-API version: 1.20 (libva 2.12.0)
Driver: Intel iHD driver for Intel(R) Gen Graphics - 24.1.0
Profiles include MPEG2, H.264 (Main/High/Constrained Baseline), HEVC Main/Main10, VP8, VP9, etc.
Summary

With the default/new Shotcut video player backend, opening an MP4 file plays audio only with no video visible in the preview.
If I enable Settings → Player → “Use old video player”, the same file plays with both audio and video correctly.

Steps to reproduce

Install Shotcut via Flatpak from Flathub: org.shotcut.Shotcut (version 26.6.25).
Ensure Settings → Player → “Use old video player” is OFF (i.e., using the new player backend).
Open an MP4 video (plays fine in VLC on the same system).
Press Play.
Expected result

Video preview shows the video while audio plays.
Actual result

Audio plays.
Video preview area stays black (no video frames rendered).
Additional information

The issue started after updating to Zorin OS 18.1; the same Shotcut Flatpak worked about a week earlier.

Host graphics stack looks healthy:

glxinfo -B shows direct rendering: Yes, Intel HD 620, OpenGL 4.6, Mesa 25.2.8.
vulkaninfo initializes successfully and lists Intel HD 620 as GPU 0.
VAAPI was initially failing with vaInitialize failed, but is now fixed by:

Installing intel-media-va-driver-non-free (i386 + amd64).
Creating a symlink:
sudo ln -s /usr/lib/x86_64-linux-gnu/dri /usr/lib/dri
vainfo now works and lists multiple decode/encode profiles.
Running Shotcut via Flatpak:

bash

flatpak run org.shotcut.Shotcut
shows only minor warnings (e.g., libDeckLinkAPI.so: cannot open shared object file: No such file or directory and some mp3float overread messages), but nothing obvious about the video pipeline.

Workaround

Enabling Settings → Player → “Use old video player” restores normal behavior (audio + video) with the same files and on the same system.
Request

Please investigate why the new player backend in the Flatpak fails to render video on Intel HD 620 / Zorin OS 18.1, despite a working OpenGL/Vulkan/VAAPI stack on the host.
If you need more logs, I can provide additional debug output or try specific environment variables or builds.

[ddennedy]

It works on my systems, so I am unable to fix it for you. I do not have a system with Intel HD 620, only a discrete Intel Arc GPU. This is exactly why Settings> Player > Use Old Video Output exists in the first place. Someone with the problem needs to address it. What you can do to help is: With Use Old Video Output turned off, start the app, open a video file, choose View > Application Log, and paste or upload it to here.

[11dash11]

@ddennedy Thank you for your reply. I appreciate it and I understand. I'm not a tech fundi or programmer. I'm just an enthusiastic power user who has switched to Linux about three years ago. So, I understand and I will do my best to provide you with information. See below two files for your perusal; Both trimmed to Info/Warning-level lines (Debug lines stripped) for a fast maintainer read. if you want the full raw files instead, let me know.

1. Shotcut_App_Log_4_New_backend_2026-07-06.txt (Use Old Video Output OFF — the one requested):
   [Info ]

   Starting Shotcut version 26.6.25
   [Info ] Linux version "6.10"
   [Info ] number of logical cores = 4
   [Info ] locale = QLocale::system()/* C, Default, Default */
   [Info ] install dir = "/app/bin"
   [Info ] graphics backend = OpenGL
   [Info ] ShotcutSettings::log language "C"
   [Info ] ShotcutSettings::log deinterlacer "onefield"
   [Info ] ShotcutSettings::log external monitor ""
   [Info ] ShotcutSettings::log GPU processing false
   [Info ] ShotcutSettings::log interpolation "bilinear"
   [Info ] ShotcutSettings::log video mode ""
   [Info ] ShotcutSettings::log realtime true
   [Info ] ShotcutSettings::log audio channels 2
   [Info ] ShotcutSettings::log audio driver "pulseaudio"
   [Info ] MainWindow::MainWindow device pixel ratio = 1
   [Info ] Mlt::Controller::resetLocale decimal point .
   [Warning] [consumer 0x557b88ae9190] The DeckLink drivers not installed.
   [Info ] Util::isMemoryLow available RAM = 9440472 KB
   [Info ] MainWindow::open "/home/jay77/Videos/Kooha/Kooha-2026-05-17-15-26-18.mp4"
   [Info ] [producer avformat] "/home/jay77/Videos/Kooha/Kooha-2026-05-17-15-26-18.mp4" hwaccel vaapi av_hwdevice_ctx_create() success
   [Info ] [producer avformat-novalidate] "/home/jay77/Videos/Kooha/Kooha-2026-05-17-15-26-18.mp4" hwaccel vaapi av_hwdevice_ctx_create() success
   [Info ] MainWindow::open "/home/jay77/Videos/Kooha/Kooha-2026-05-17-15-26-18.mp4"
   [Info ] MainWindow::showStatusMessage "You are running the latest version of Shotcut."
   [Info ] [consumer sdl2_audio] Audio Opened: driver=pulseaudio channels=2 frequency=48000

2. Shotcut_App_Log_4_Old_backend_2026-07-06.txt (Use Old Video Output ON — for comparison):
   [Info ]

   Starting Shotcut version 26.6.25
   [Info ] Linux version "6.10"
   [Info ] number of logical cores = 4
   [Info ] locale = QLocale::system()/* C, Default, Default */
   [Info ] install dir = "/app/bin"
   [Info ] graphics backend = OpenGL
   [Info ] ShotcutSettings::log language "C"
   [Info ] ShotcutSettings::log deinterlacer "onefield"
   [Info ] ShotcutSettings::log external monitor ""
   [Info ] ShotcutSettings::log GPU processing false
   [Info ] ShotcutSettings::log interpolation "bilinear"
   [Info ] ShotcutSettings::log video mode ""
   [Info ] ShotcutSettings::log realtime true
   [Info ] ShotcutSettings::log audio channels 2
   [Info ] ShotcutSettings::log audio driver "pulseaudio"
   [Info ] MainWindow::MainWindow device pixel ratio = 1
   [Info ] Mlt::Controller::resetLocale decimal point .
   [Warning] [consumer 0x5b3e9792af60] The DeckLink drivers not installed.
   [Info ] OpenGLVideoWidget::initialize OpenGL vendor "Intel"
   [Info ] OpenGLVideoWidget::initialize OpenGL renderer "Mesa Intel(R) HD Graphics 620 (KBL GT2)"
   [Info ] OpenGLVideoWidget::initialize OpenGL threaded? true
   [Info ] OpenGLVideoWidget::initialize OpenGL ES? false
   [Info ] OpenGLVideoWidget::initialize OpenGL maximum texture size = 16384
   [Info ] OpenGLVideoWidget::initialize OpenGL maximum viewport size = 16384 x 16384
   [Info ] Util::isMemoryLow available RAM = 9219532 KB
   [Info ] MainWindow::open "/home/jay77/Videos/Kooha/Kooha-2026-05-17-15-26-18.mp4"
   [Info ] [producer avformat] "/home/jay77/Videos/Kooha/Kooha-2026-05-17-15-26-18.mp4" hwaccel vaapi av_hwdevice_ctx_create() success
   [Info ] [producer avformat-novalidate] "/home/jay77/Videos/Kooha/Kooha-2026-05-17-15-26-18.mp4" hwaccel vaapi av_hwdevice_ctx_create() success
   [Info ] MainWindow::open "/home/jay77/Videos/Kooha/Kooha-2026-05-17-15-26-18.mp4"
   [Info ] MainWindow::showStatusMessage "You are running the latest version of Shotcut."
   [Info ] [consumer sdl2_audio] Audio Opened: driver=pulseaudio channels=2 frequency=48000