fcvvdp

A fast C implementation of the CVVDP metric (arXiv) from the University of Cambridge. More information about how CVVDP works according to this implementation is provided here.

Benchmarks

Benchmarked using poop on Linux, Core i7 13700k. We compare cvvdp (multithreaded) to fcvvdp with & without task threading on 302 frames of 360p video.

poop "cvvdp -r fm360p.y4m -t fm360p_x264.y4m --display standard_fhd" "./fcvvdp -t 1 -m fhd fm360p.y4m fm360p_x264.y4m" "./fcvvdp -t 8 -m fhd fm360p.y4m fm360p_x264.y4m"
Benchmark 1 (3 runs): cvvdp -r fm360p.y4m -t fm360p_x264.y4m --display standard_fhd
  measurement          mean ± σ            min … max           outliers         delta
  wall_time          19.1s  ± 52.5ms    19.0s  … 19.1s           0 ( 0%)        0%
  peak_rss           1.03GB ± 11.1MB    1.02GB … 1.04GB          0 ( 0%)        0%
  cpu_cycles          777G  ± 8.37G      768G  …  784G           0 ( 0%)        0%
  instructions        357G  ± 1.18G      355G  …  358G           0 ( 0%)        0%
  cache_references   2.64G  ± 40.0M     2.60G  … 2.67G           0 ( 0%)        0%
  cache_misses        859M  ± 16.5M      844M  …  877M           0 ( 0%)        0%
  branch_misses      88.8M  ± 2.63M     86.7M  … 91.7M           0 ( 0%)        0%
Benchmark 2 (3 runs): ./fcvvdp -t 1 -m fhd fm360p.y4m fm360p_x264.y4m
  measurement          mean ± σ            min … max           outliers         delta
  wall_time          14.9s  ± 10.3ms    14.9s  … 14.9s           0 ( 0%)        ⚡- 21.7% ±  0.5%
  peak_rss           90.4MB ±  159KB    90.3MB … 90.6MB          0 ( 0%)        ⚡- 91.2% ±  1.7%
  cpu_cycles         79.2G  ± 57.1M     79.1G  … 79.2G           0 ( 0%)        ⚡- 89.8% ±  1.7%
  instructions        246G  ± 32.1M      246G  …  246G           0 ( 0%)        ⚡- 30.9% ±  0.5%
  cache_references   1.29G  ±  138K     1.29G  … 1.29G           0 ( 0%)        ⚡- 51.2% ±  2.4%
  cache_misses        340M  ± 1.94M      339M  …  342M           0 ( 0%)        ⚡- 60.4% ±  3.1%
  branch_misses      9.06M  ± 71.5K     9.01M  … 9.14M           0 ( 0%)        ⚡- 89.8% ±  4.8%
Benchmark 3 (3 runs): ./fcvvdp -t 8 -m fhd fm360p.y4m fm360p_x264.y4m
  measurement          mean ± σ            min … max           outliers         delta
  wall_time          5.94s  ± 36.3ms    5.89s  … 5.96s           0 ( 0%)        ⚡- 68.9% ±  0.5%
  peak_rss           89.7MB ± 75.9KB    89.6MB … 89.7MB          0 ( 0%)        ⚡- 91.3% ±  1.7%
  cpu_cycles          126G  ±  753M      126G  …  127G           0 ( 0%)        ⚡- 83.7% ±  1.7%
  instructions        434G  ± 1.99G      432G  …  436G           0 ( 0%)        💩+ 21.6% ±  1.0%
  cache_references   1.21G  ± 7.24M     1.21G  … 1.22G           0 ( 0%)        ⚡- 54.1% ±  2.5%
  cache_misses        379M  ± 1.92M      378M  …  381M           0 ( 0%)        ⚡- 55.9% ±  3.1%
  branch_misses      13.8M  ±  101K     13.7M  … 13.9M           0 ( 0%)        ⚡- 84.4% ±  4.8%

fcvvdp uses over 91% less memory. With one thread, it is over 28% faster; with multiple threads, fcvvdp is over 221% faster than the reference implementation.

Usage

Compilation requires:

• Optional zlib-rs
• Optional libunwind
• Zig 0.15.x
• macOS, Linux, or Unix-like operating system

Binary

0. Ensure all dependencies are installed
1. Run zig build --release=fast
   • add -Dflto=true for FLTO
   • add -Dlibz-rs=true for zlib-rs
2. Your fcvvdp binary will be in zig-out/bin/

fcvvdp by Halide Compression, LLC | [version]

usage: fcvvdp [options] <reference.(png|y4m)> <distorted.(png|y4m)>

compare two images/videos using the CVVDP perceptual quality metric

options:
  -m, --model <name>
      display model to use (fhd, 4k, hdr_pq, hdr_hlg, hdr_linear,
      hdr_dark, hdr_zoom); default: fhd
  -v, --verbose
      show verbose output with display parameters
  -j, --json
      output result as JSON
  -h, --help
      show this help message

Library

0. Ensure all dependencies are installed
1. Run zig build --release=fast (add -Dflto=true for FLTO)
2. The libcvvdp library will be in zig-out/lib/, alongside cvvdp.h in zig-out/include/.

Library usage is clearly defined in cvvdp.h.

FFmpeg Patch

0. Clone FFmpeg:

git clone https://code.ffmpeg.org/FFmpeg/FFmpeg.git ffmpeg
cd ffmpeg
git checkout n8.0

1. Apply patch (change path to point to your cloned copy of fcvvdp):

git apply ~/fcvvdp/patches/0001-feat-fcvvdp-support.patch

2. Configure & build FFmpeg:

./configure --enable-fcvvdp
make -j$(nproc)

Example usage:

./ffmpeg -i src -i dst -lavfi "fcvvdp" -f null -

For more help, see ./ffmpeg --help filter=fcvvdp.

Credits

fcvvdp is under the Apache 2.0 License. fcvvdp is developed by Halide Compression.

Special thanks to Vship, from which this implementation was derived. Vship is under the MIT license.