JosiahSiegel/ffmpeg-hardware-acceleration

When to Use This Skill

Activate when GPU acceleration is needed:

• Encoding speed is critical (10-30x faster than CPU)
• Processing large batches of videos
• Real-time encoding for streaming
• Server-side transcoding at scale
• Docker containers with GPU passthrough

GPU encoding trades some quality for massive speed. Use -cq, -qp, or -global_quality for quality control.

Quick Reference

| Platform | Encoder | Decoder | Detect Command | |----------|---------|---------|----------------| | NVIDIA | h264_nvenc, hevc_nvenc, av1_nvenc | h264_cuvid, hevc_cuvid | ffmpeg -encoders \| grep nvenc | | Intel QSV | h264_qsv, hevc_qsv, av1_qsv | h264_qsv, hevc_qsv | ffmpeg -encoders \| grep qsv | | AMD AMF | h264_amf, hevc_amf, av1_amf | N/A (use software) | ffmpeg -encoders \| grep amf | | Apple | h264_videotoolbox, hevc_videotoolbox | h264_videotoolbox | macOS only | | VAAPI | h264_vaapi, hevc_vaapi, av1_vaapi | with -hwaccel vaapi | Linux only | | Vulkan | h264_vulkan, hevc_vulkan, av1_vulkan, ffv1_vulkan | VP9, ProRes RAW (8.0+) | ffmpeg -encoders \| grep vulkan |

Current Latest: FFmpeg 8.0.1 (released 2025-11-20). Check with ffmpeg -version.

Hardware Acceleration Overview

Hardware acceleration uses dedicated GPU/SoC components for video processing:

• NVENC/NVDEC (NVIDIA): dedicated encode/decode engines
• QSV (Intel): Quick Sync Video on Intel CPUs with integrated graphics
• AMF (AMD): Advanced Media Framework for AMD GPUs
• VideoToolbox (Apple): macOS/iOS hardware acceleration
• VAAPI (Linux): Video Acceleration API (Intel, AMD on Linux)
• Vulkan Video (Cross-platform, FFmpeg 7.1+/8.0): compute-shader-based codecs

Performance Comparison (2025 Benchmarks)

| Method | Speed | Quality | Power | Use Case | |--------|-------|---------|-------|----------| | libx264 (CPU) | 1x | Best | High | Quality-critical | | libx265 (CPU) | 0.3x | Best | Very High | Archival | | h264_nvenc | 10-20x | Good | Low | Real-time, streaming | | hevc_nvenc | 8-15x | Good | Low | 4K streaming | | h264_qsv | 8-15x | Good | Very Low | Laptop, efficiency | | h264_amf | 8-15x | Good | Low | AMD systems |

Core Workflow

1. Detect what you have: ffmpeg -hwaccels, ffmpeg -encoders | grep <api>
2. Pick a backend: prefer the vendor-native one (NVENC on NVIDIA, QSV on Intel, AMF on AMD, VideoToolbox on Apple). Use Vulkan for cross-platform portability.
3. Build a full-GPU pipeline where possible:
   • Add -hwaccel <api> and -hwaccel_output_format <api> before -i
   • Use GPU-side filters (scale_cuda, scale_vulkan, vpp_qsv, ...)
   • Use the matching hardware encoder
4. Tune quality: -preset (NVENC p1-p7), -cq/-qp/-global_quality, lookahead, spatial/temporal AQ
5. Verify: benchmark with ffmpeg -benchmark and monitor GPU via nvidia-smi dmon, intel_gpu_top, etc.

Minimal Examples per Backend

# NVIDIA NVENC
ffmpeg -hwaccel cuda -hwaccel_output_format cuda -i input.mp4 \
  -c:v h264_nvenc -preset p4 -b:v 5M output.mp4

# Intel QSV
ffmpeg -hwaccel qsv -hwaccel_output_format qsv -i input.mp4 \
  -c:v h264_qsv -preset medium -b:v 5M output.mp4

# AMD AMF
ffmpeg -i input.mp4 -c:v h264_amf -quality balanced -b:v 5M output.mp4

# Apple VideoToolbox
ffmpeg -i input.mp4 -c:v h264_videotoolbox -b:v 5M output.mp4

# Linux VAAPI
ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 \
  -hwaccel_output_format vaapi -i input.mp4 \
  -c:v h264_vaapi -b:v 5M output.mp4

# Vulkan (cross-platform)
ffmpeg -init_hw_device vulkan -i input.mp4 \
  -c:v h264_vulkan -b:v 5M output.mp4

Full GPU Pipeline Pattern (Critical)

ffmpeg -y -vsync 0 \
  -hwaccel cuda -hwaccel_output_format cuda \
  -i input.mp4 \
  -vf scale_cuda=1280:720 \
  -c:v h264_nvenc -preset p4 -b:v 5M \
  -c:a copy \
  output.mp4

Omitting -hwaccel_output_format can cut throughput by up to 50% because decoded frames silently round-trip through CPU memory. See references/gpu-memory-and-troubleshooting.md for memory flow diagrams and best practices.

Cross-Vendor Filter Quick Map

| Operation | NVIDIA | Intel | AMD/Linux | Cross-platform | |-----------|--------|-------|-----------|----------------| | Scale | scale_cuda, scale_npp | vpp_qsv, scale_qsv | scale_vaapi | scale_vulkan, scale_opencl, libplacebo | | Overlay | overlay_cuda | - | - | overlay_vulkan, overlay_opencl | | Deinterlace | bwdif_cuda | vpp_qsv | deinterlace_vaapi | bwdif_vulkan | | Denoise | bilateral_cuda | - | - | nlmeans_vulkan, nlmeans_opencl | | Chromakey | chromakey_cuda | - | - | colorkey_opencl | | Tonemap (HDR->SDR) | - | - | tonemap_vaapi | libplacebo, tonemap_opencl | | Pad/letterbox | pad_cuda (8.0+) | - | - | pad_opencl |

Use-Case Quick Recipes

Live streaming (low latency)

ffmpeg -hwaccel cuda -hwaccel_output_format cuda -i input \
  -c:v h264_nvenc -preset p3 -tune ll -zerolatency 1 -b:v 6M \
  -f flv rtmp://server/live/stream

VOD (quality target)

ffmpeg -i input.mp4 \
  -c:v hevc_nvenc -preset p6 -tune hq \
  -rc vbr -cq 22 -b:v 0 \
  -rc-lookahead 32 -spatial-aq 1 \
  output.mp4

Batch / parallel encoding

ffmpeg -hwaccel cuda -hwaccel_output_format cuda -i input1.mp4 -c:v h264_nvenc output1.mp4 &
ffmpeg -hwaccel cuda -hwaccel_output_format cuda -i input2.mp4 -c:v h264_nvenc output2.mp4 &
wait

Docker (GPU passthrough)

docker run --gpus all --rm -v $(pwd):/data \
  jrottenberg/ffmpeg:nvidia \
  -hwaccel cuda -hwaccel_output_format cuda \
  -i /data/input.mp4 -c:v h264_nvenc /data/output.mp4

Best Practices

1. Use full GPU pipelines when possible to avoid CPU/GPU memory transfers
2. Match decode and encode hardware for best performance
3. Pick presets deliberately - faster is not always better for quality
4. Enable lookahead and AQ for quality-critical encodes
5. Test on target hardware - quality varies by GPU generation
6. Monitor GPU memory for high-resolution content
7. Consider power efficiency for laptops and servers
8. Update drivers regularly for performance and feature improvements

Reference Map

For deep dives on each backend, see:

• NVIDIA NVENC/NVDEC (presets, CUDA filters, scale_npp, hybrid pipelines, two-pass, multi-GPU, 1:N ABR): references/nvidia-nvenc.md
• Intel QSV (full pipeline, vpp_qsv, lookahead, multi-GPU, VVC decoding): references/intel-qsv.md
• AMD AMF, VAAPI, Apple VideoToolbox (encoders, scaling, VVC VAAPI 8.0+ SCC support): references/amd-amf-vaapi-videotoolbox.md
• Vulkan Video and Vulkan filters (h264/hevc/av1/ffv1, VP9/ProRes RAW decode, scale/overlay/blur/transitions/libplacebo): references/vulkan.md
• OpenCL filters (scale, overlay, colorkey, nlmeans, deshake, unsharp, tonemap): references/opencl-filters.md
• GPU memory management, filter comparison matrix, Docker, troubleshooting: references/gpu-memory-and-troubleshooting.md