AgentSkillsCN

static-recomp-av-compare

对比参考音频/视频输出与重新编译后的音频/视频输出，进行对齐、指标计算及阈值设定。适用于验证视觉或音频保真度、计算相似性指标，或生成自动化的音视频对比报告。

SKILL.md
--- frontmatter
name: static-recomp-av-compare
description: Compare reference and recompiled audio/video outputs with alignment, metrics, and thresholds. Use when validating visual or audio fidelity, computing similarity metrics, or generating automated A/V comparison reports.

Static Recomp A/V Compare

Overview

Align and compare reference captures against recompiled outputs using repeatable metrics and clear pass/fail thresholds.

Workflow

  1. •Normalize inputs.
    • •Match resolution, frame rate, and aspect ratio.
    • •Match audio sample rate, channel layout, and length.
  2. •Align timelines.
    • •Use a known sync event (boot logo, sound cue, scene transition).
    • •Apply a fixed offset if one stream starts earlier.
    • •Verify alignment with a short manual check before running full metrics.
  3. •Compute video similarity.
    • •Use SSIM and PSNR for fast regression checks.
    • •Use VMAF when perceptual quality is critical.
  4. •Compute audio similarity.
    • •Compare loudness (EBU R128) and true peak.
    • •Inspect for drift or missing segments.
  5. •Summarize results.
    • •Produce per-scene metrics and overall aggregates.
    • •Flag outliers for manual review.

Automation scripts

  1. •Compare a single scene with scripts/compare_av.py.
  2. •Batch multiple scenes with scripts/batch_compare_av.py and a manifest.
  3. •Convert summary.json to pass/fail with scripts/check_summary.py.

Single scene

bash
python3 "$CODEX_HOME/skills/static-recomp-av-compare/scripts/compare_av.py" \
  --ref ref.mp4 \
  --test recomp.mp4 \
  --out-dir out/scene-01 \
  --label "scene-01" \
  --width 1920 \
  --height 1080 \
  --fps 60 \
  --audio-rate 48000 \
  --offset 0.250 \
  --trim-start 5.0 \
  --duration 30.0

Threshold check

bash
python3 "$CODEX_HOME/skills/static-recomp-av-compare/scripts/check_summary.py" \
  out/scene-01/summary.json \
  --thresholds thresholds/default.json

Batch run

bash
python3 "$CODEX_HOME/skills/static-recomp-av-compare/scripts/batch_compare_av.py" \
  manifests/av-batch.json

Notes:

  • •Requires ffmpeg on PATH. The scripts will use libvmaf if available.
  • •Use --no-vmaf to skip VMAF.
  • •See references/av-batch-manifest.md for manifest schema and example.
  • •A baseline thresholds file is provided at references/default-thresholds.json.

Outputs

  • •Per-scene metrics (SSIM, PSNR, VMAF, loudness).
  • •A summary report with pass/fail thresholds and top mismatches.
  • •Links to aligned captures used for comparison.

References

  • •Batch manifest: references/av-batch-manifest.md
  • •Default thresholds: references/default-thresholds.json

Quality bar

  • •Alignment must be verified before metric runs.
  • •Metrics must be repeatable and tied to explicit thresholds.
  • •Visual or audio mismatches must be paired with evidence artifacts.