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
- Detect what you have:
ffmpeg -hwaccels,ffmpeg -encoders | grep <api> - 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.
- 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
- Add
- Tune quality:
-preset(NVENCp1-p7),-cq/-qp/-global_quality, lookahead, spatial/temporal AQ - Verify: benchmark with
ffmpeg -benchmarkand monitor GPU vianvidia-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
- Use full GPU pipelines when possible to avoid CPU/GPU memory transfers
- Match decode and encode hardware for best performance
- Pick presets deliberately - faster is not always better for quality
- Enable lookahead and AQ for quality-critical encodes
- Test on target hardware - quality varies by GPU generation
- Monitor GPU memory for high-resolution content
- Consider power efficiency for laptops and servers
- 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