NVIDIA NVENC

Alchemist uses NVENC when NVIDIA is available and selected. Set Settings → Hardware → Preferred Vendor to nvidia if you want to pin it instead of using auto detection.

Supported generations

Generation	Example cards	H.264	HEVC	AV1	Notes
Pascal	GTX 10-series	Yes	Yes	No	2 concurrent encode streams on consumer cards
Turing	GTX 16 / RTX 20	Yes	Yes	No	Better quality than Pascal
Ampere	RTX 30	Yes	Yes	Yes	First NVENC generation with AV1
Ada Lovelace	RTX 40	Yes	Yes	Yes	Dual AV1 encoders on supported SKUs

Docker

Install nvidia-container-toolkit on the host first.

distribution=$(. /etc/os-release; echo $ID$VERSION_ID)
curl -fsSL https://nvidia.github.io/libnvidia-container/gpgkey | \
  sudo gpg --dearmor -o /usr/share/keyrings/nvidia-container-toolkit-keyring.gpg
curl -s -L "https://nvidia.github.io/libnvidia-container/$distribution/libnvidia-container.list" | \
  sed 's#deb https://#deb [signed-by=/usr/share/keyrings/nvidia-container-toolkit-keyring.gpg] https://#g' | \
  sudo tee /etc/apt/sources.list.d/nvidia-container-toolkit.list
sudo apt update
sudo apt install -y nvidia-container-toolkit
sudo systemctl restart docker

Docker Compose

services:
  alchemist:
    image: ghcr.io/bybrooklyn/alchemist:latest
    ports:
      - "3000:3000"
    volumes:
      - ~/.config/alchemist:/app/config
      - ~/.config/alchemist:/app/data
      - /path/to/media:/media
    environment:
      - ALCHEMIST_CONFIG_PATH=/app/config/config.toml
      - ALCHEMIST_DB_PATH=/app/data/alchemist.db
    deploy:
      resources:
        reservations:
          devices:
            - driver: nvidia
              count: 1
              capabilities: [gpu]
    restart: unless-stopped

docker run

docker run -d \
  --name alchemist \
  --gpus all \
  -p 3000:3000 \
  -v ~/.config/alchemist:/app/config \
  -v ~/.config/alchemist:/app/data \
  -v /path/to/media:/media \
  -e ALCHEMIST_CONFIG_PATH=/app/config/config.toml \
  -e ALCHEMIST_DB_PATH=/app/data/alchemist.db \
  --restart unless-stopped \
  ghcr.io/bybrooklyn/alchemist:latest

Binary installs

Verify the driver first:

nvidia-smi

Then verify FFmpeg exposes NVENC:

ffmpeg -encoders | grep nvenc

Expected encoders:

• h264_nvenc
• hevc_nvenc
• av1_nvenc on RTX 30/40 class hardware

In Alchemist

Set Settings → Hardware → Preferred Vendor → nvidia. Leave Device Path empty. NVENC is detected from the driver and /dev/nvidiactl.

Troubleshooting

Problem	Cause	Fix
No encoder found	FFmpeg lacks NVENC or the driver is missing	Run `ffmpeg -encoders
Container cannot see GPU	NVIDIA runtime/toolkit not installed or --gpus all missing	Reinstall nvidia-container-toolkit, restart Docker, and test with docker run --rm --gpus all nvidia/cuda:12.0.0-base-ubuntu22.04 nvidia-smi
Driver version mismatch	Host driver and container runtime stack disagree	Update the NVIDIA driver and toolkit together, then restart Docker