FrameNth Exporter (Multi-GPU)

Export every Nth frame from a video at max speed with GPU decode and smart parallelism. Perfect for prepping drone and 360 footage for photogrammetry or Gaussian splatting. Keeps original dimensions. Filenames like myclip_[0001].jpeg.

Why

• Drone and 360 rigs produce huge files.
• Photogrammetry and splat trainers often need sparse, evenly sampled frames.
• This app slices timelines across multiple GPUs, spills to RAM if VRAM gets tight.

Features

• Multi-GPU NVDEC with per-device checkboxes
• Parallel chunking across selected GPUs
• VRAM-safe spill to RAM with auto CPU fallback on OOM
• JPEG 4:4:4 q=1 by default. PNG option for true lossless
• Constant naming: [basename]_[####].jpeg
• Original resolution preserved

Ideal for

• Agisoft Metashape, RealityCapture, COLMAP
• Gaussian splats pipelines (gsplat, SIBR, PostShot, custom trainers)
• Aerial and 360 capture workflows

Quick start

1. Download and run the EXE. Check you have FFmpeg and FFprobe installed and in the PATH directory

2. Select:

   • Input video
   • Output folder
   • Every Nth frame
   • GPUs to use
   • Optional VRAM-safe mode
   • Choose JPEG or PNG

3. Click Export. Files are written as yourfile_[0001].jpeg etc.

If you need to install FFmpeg yourself

Windows CMD only (elevated):

winget install -e --id FFmpeg.FFmpeg --accept-source-agreements --accept-package-agreements
ffmpeg -version
ffprobe -version

If ffmpeg is not found, add its bin to PATH for this session:

set "PATH=C:\Program Files\ffmpeg\bin;%PATH%"

Chocolatey alternative:

powershell -NoProfile -ExecutionPolicy Bypass -Command "Set-ExecutionPolicy Bypass -Scope Process -Force; [System.Net.ServicePointManager]::SecurityProtocol=3072; iex ((New-Object System.Net.WebClient).DownloadString('https://community.chocolatey.org/install.ps1'))"
choco install -y ffmpeg

Build from source

python -m pip install PySide6 pyinstaller
pyinstaller --onefile --windowed --name FrameNthExporter frame_nth_exporter_multi_gpu.py

Notes for image formats

• JPEG has no true zero compression. This app uses q=1 and 4:4:4 for minimal loss.
• Choose PNG for lossless if your pipeline demands it.

Performance tips

• Start with 2 chunks per GPU. Increase if disks are fast NVMe.
• For variable frame rate sources, use 1 chunk per GPU for mathematically exact selection.
• Output to a fast local drive. Network shares bottleneck quickly.

Troubleshooting

• OOM or stutters: enable VRAM-safe mode. The app reduces in-flight frames and spills to RAM. It will auto retry chunks on CPU if needed.
• No GPU listed: update NVIDIA driver. The app falls back to CPU if NVDEC is unavailable.
• Wrong file numbering when slicing tiny clips: reduce chunks.