jellyfin/Docs/tonemapping.md

Understanding Tonemapping in Jellyfin

What is Tonemapping?

Tonemapping converts HDR (High Dynamic Range) videos to look good on non-HDR screens. Think of it like your eyes adjusting when you walk from bright sunlight into a dimmer room - it helps balance bright and dark areas to make everything visible.

Why Do I Need It?

If you have HDR content (like 4K HDR movies) but watch them on a non-HDR screen, without tonemapping:

• Bright areas might look washed out
• Dark areas might be too dark to see
• Colors might appear wrong or faded

Available Algorithms

hable

• Best for: Modern GPUs (NVIDIA RTX, AMD RX 6000+, Intel ARC)
• What it does: Makes HDR content look natural, similar to how your eyes adjust
• Good for: Movies and shows, especially ones with both bright and dark scenes
• Example: In a night scene with street lights, you'll see both the dark alleys and the bright lights clearly

bt2390

• Best for: Integrated graphics (Intel iGPU, AMD APU) and older GPUs
• What it does: Follows TV industry standards for HDR conversion
• Good for: Broadcast content and professional productions
• Example: Makes your content look similar to how it would appear on a standard TV

Other Options

reinhard

• Pros: Fast and simple, uses less processing power
• Cons: Can make dark scenes too dark
• Best for: Older hardware or when performance is a priority

mobius

• Pros: Keeps bright areas detailed
• Cons: Can make the overall image look flat
• Best for: Content with lots of bright scenes

Which Should I Choose?

1. For Modern GPUs:

   • NVIDIA RTX Series: Use hable - excellent performance with good quality
   • AMD RX 6000/7000: Use hable - works well with modern AMD cards
   • Intel ARC: Use hable - optimized for ARC architecture

2. For Integrated Graphics:

   • AMD Ryzen APU: Use bt2390 or try hable on newer models
   • Intel iGPU: Use bt2390 (or hable on 11th gen or newer)

3. For Older GPUs:

   • NVIDIA GTX Series: Start with bt2390, try reinhard if needed
   • AMD RX 5000 or older: Use bt2390 or reinhard
   • CPU's or Older integrated graphics: Use reinhard for best performance

Quick Tips

• If videos look too dark: Try switching from bt2390 to hable
• If playback is stuttering: Try reinhard for better performance
• For best results: Enable hardware acceleration and use appropriate drivers:
  • NVIDIA: Latest drivers with NVENC support
  • AMD: Mesa or AMDGPU-PRO with VA-API
  • Intel: Latest drivers with QuickSync support

CPU-Only Transcoding

If you're not using hardware acceleration (GPU/iGPU):

1. Performance Impact: Tonemapping is very CPU-intensive without hardware acceleration
2. Recommended Settings:
   • Use reinhard algorithm - it's the most CPU-efficient
   • Consider pre-converting HDR content to SDR if possible
   • Limit concurrent transcoding sessions
3. CPU Requirements:
   • Modern CPU (6+ cores recommended)
   • Expect high CPU usage during HDR transcoding
   • Multiple simultaneous HDR transcodes may not be possible

Note: If you have a modern Intel CPU with integrated graphics (iGPU), enabling hardware acceleration is strongly recommended, even if you don't have a dedicated GPU.