[BUG] VAAPI hardware encoding fails on Intel J4125 CPU (Synology DS920+)

Start by reproducing the issue with the provided Synology Docker configuration and device mappings, then inspect the logs around Unified VAAPI Encoder and Parsed_scale_vaapi_1. Done means the J4125 initializes VAAPI H.264 hardware encoding successfully and the stream reports a hardware encoder instead of falling back to CPU.

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

VAAPI hardware encoding fails to initialize on an Intel J4125 (Synology DS920+) despite the GPU being detected correctly.

Selkies detects /dev/dri/renderD128 and begins initializing the VAAPI encoder, but fails with:

[Parsed_scale_vaapi_1] Failed to create processing pipeline config: 12 (the requested VAProfile is not supported).
[x11] Failed to init VAAPI: Failed to config filter graph. Falling back to CPU.

The stream then falls back to CPU encoding, resulting in approximately 10-20 FPS at 1920x1080 and making video playback (e.g. YouTube) unusably slow.

Additional troubleshooting performed: I confirmed that /dev/dri/renderD128 is accessible inside the container, the abc user is a member of the render/video group, iHD_drv_video.so is present, and LIBVA_DRIVER_NAME=iHD is set. Selkies successfully detects the Intel GPU before failing during VAAPI filter graph initialization.

Expected Behavior

The Intel Quick Sync GPU (Intel UHD 600 / J4125) should initialize successfully using VAAPI and hardware H.264 encoding instead of falling back to CPU encoding.

Steps To Reproduce

1. Run on a Synology DS920+ (Intel Celeron J4125 / Intel UHD 600).
2. Pass through:
   /dev/dri/card0
   /dev/dri/renderD128
3. Start the latest linuxserver/firefox container.
4. Connect to the browser.
5. Observe the container log showing:

[x11] AUTO_GPU enabled. Selected: /dev/dri/renderD128
[x11] Initializing Unified VAAPI Encoder...
[Parsed_scale_vaapi_1] Failed to create processing pipeline config: 12 (the requested VAProfile is not supported).
[Parsed_scale_vaapi_1] Failed to configure output pad on Parsed_scale_vaapi_1
[x11] Failed to init VAAPI: Failed to config filter graph. Falling back to CPU.

The stream then reports:

[x11] Stream settings active -> Encoder: CPU

Environment

OS: Synology DSM 7.2.2-72806 Update 2

How docker service was installed:
Synology Container Manager (Docker)

CPU architecture:
x86_64

CPU:
Intel Celeron J4125

CPU architecture

x86-64

Docker creation

services:
  firefox:
    image: lscr.io/linuxserver/firefox:latest
    container_name: firefox
    security_opt:
      - seccomp:unconfined
    devices:
      - /dev/dri/renderD128:/dev/dri/renderD128
      - /dev/dri/card0:/dev/dri/card0
    environment:
      - PUID=1026
      - PGID=100
      - TZ=Australia/Melbourne
      - HTTP_PROXY=http://localhost:8888
      - HTTPS_PROXY=https://localhost:8888
      - DRINODE=/dev/dri/renderD128
      - DRI_NODE=/dev/dri/renderD128
      - AUTO_GPU=true
      - PIXELFLUX_WAYLAND=true
      - LIBVA_DRIVER_NAME=iHD
      - SELKIES_ENCODER=x264enc
    volumes:
      - /volume3/docker/firefox:/config
    shm_size: "2gb"
    network_mode: "container:gluetun"
    restart: unless-stopped

Container logs

Relevant section of the log:

[x11] AUTO_GPU enabled. Selected: /dev/dri/renderD128
[x11] Initializing Unified VAAPI Encoder...
[h264_vaapi] Slice count rounded up due to driver constraints.
[Parsed_scale_vaapi_1] Failed to create processing pipeline config: 12 (the requested VAProfile is not supported).
[Parsed_scale_vaapi_1] Failed to configure output pad on Parsed_scale_vaapi_1
[x11] Failed to init VAAPI: Failed to config filter graph. Falling back to CPU.
[x11] Stream settings active -> Encoder: CPU