{
  "schema": 1,
  "purpose": "Bounded timing consistency audit; not a hidden-message extraction.",
  "audio": {
    "path": "audio-48khz-mono.wav",
    "sample_rate_hz": 48000
  },
  "midi": {
    "path": "mutopia-contrapunctusI.mid",
    "last_note_seconds": 156.0,
    "voice_tracks": [
      1,
      2,
      3,
      4
    ]
  },
  "partial_chroma_alignment": {
    "best": {
      "semitone_shift": 0,
      "mean_chroma_cosine": 0.5822194735052558,
      "time_scale": 1.139999999999996,
      "offset_seconds": 0.0,
      "selected_frame_coverage": 0.9518716577540107
    },
    "by_transposition": [
      {
        "semitone_shift": 0,
        "mean_chroma_cosine": 0.5822194735052558,
        "time_scale": 1.139999999999996,
        "offset_seconds": 0.0,
        "selected_frame_coverage": 0.9518716577540107
      },
      {
        "semitone_shift": 7,
        "mean_chroma_cosine": 0.5307639948812656,
        "time_scale": 1.139999999999996,
        "offset_seconds": 0.0,
        "selected_frame_coverage": 0.9518716577540107
      },
      {
        "semitone_shift": 4,
        "mean_chroma_cosine": 0.4907045891201561,
        "time_scale": 1.139999999999996,
        "offset_seconds": 0.0,
        "selected_frame_coverage": 0.9518716577540107
      },
      {
        "semitone_shift": 11,
        "mean_chroma_cosine": 0.4720044829484952,
        "time_scale": 1.134999999999996,
        "offset_seconds": -0.625,
        "selected_frame_coverage": 0.9518716577540107
      },
      {
        "semitone_shift": 2,
        "mean_chroma_cosine": 0.4517887018997701,
        "time_scale": 1.1424999999999959,
        "offset_seconds": 1.0,
        "selected_frame_coverage": 0.9518716577540107
      },
      {
        "semitone_shift": 8,
        "mean_chroma_cosine": 0.44896646375890414,
        "time_scale": 0.9524999999999999,
        "offset_seconds": -0.375,
        "selected_frame_coverage": 1.0
      },
      {
        "semitone_shift": 3,
        "mean_chroma_cosine": 0.44847173636580473,
        "time_scale": 1.1274999999999962,
        "offset_seconds": -1.125,
        "selected_frame_coverage": 0.9545454545454546
      },
      {
        "semitone_shift": 1,
        "mean_chroma_cosine": 0.44831626918897705,
        "time_scale": 1.139999999999996,
        "offset_seconds": 0.125,
        "selected_frame_coverage": 0.9518716577540107
      },
      {
        "semitone_shift": 9,
        "mean_chroma_cosine": 0.44518958183729634,
        "time_scale": 0.9524999999999999,
        "offset_seconds": 1.125,
        "selected_frame_coverage": 0.9919786096256684
      },
      {
        "semitone_shift": 6,
        "mean_chroma_cosine": 0.43897000090052374,
        "time_scale": 0.9749999999999994,
        "offset_seconds": 1.875,
        "selected_frame_coverage": 0.9866310160427807
      },
      {
        "semitone_shift": 5,
        "mean_chroma_cosine": 0.42600838531234864,
        "time_scale": 0.992499999999999,
        "offset_seconds": 2.0,
        "selected_frame_coverage": 0.9866310160427807
      },
      {
        "semitone_shift": 10,
        "mean_chroma_cosine": 0.42596685672765994,
        "time_scale": 0.9824999999999993,
        "offset_seconds": 0.625,
        "selected_frame_coverage": 0.9946524064171123
      }
    ]
  },
  "audio_exact_zero_runs_over_half_second": [
    {
      "start_video_seconds": 122.28835416666666,
      "end_video_seconds": 123.5473125,
      "duration_seconds": 1.2589583333333334,
      "samples": 60430
    },
    {
      "start_video_seconds": 124.03058333333334,
      "end_video_seconds": 125.4275,
      "duration_seconds": 1.3969166666666666,
      "samples": 67052
    },
    {
      "start_video_seconds": 143.08929166666667,
      "end_video_seconds": 148.5845,
      "duration_seconds": 5.495208333333333,
      "samples": 263770
    }
  ],
  "score_full_ensemble_rests": [
    {
      "start_score_seconds": 139.5,
      "end_score_seconds": 141.0,
      "duration_seconds": 1.5
    },
    {
      "start_score_seconds": 141.5,
      "end_score_seconds": 143.0,
      "duration_seconds": 1.5
    }
  ],
  "mapped_interior_zero_runs": [
    {
      "start_video_seconds": 122.28835416666666,
      "end_video_seconds": 123.5473125,
      "duration_seconds": 1.2589583333333334,
      "samples": 60430,
      "mapped_start_score_seconds": 139.4087237499995,
      "mapped_end_score_seconds": 140.8439362499995,
      "mapped_duration_seconds": 1.4352125000000058,
      "reference_rest_start_seconds": 139.5,
      "reference_rest_end_seconds": 141.0,
      "start_residual_seconds": -0.09127625000050443,
      "end_residual_seconds": -0.15606375000049866
    },
    {
      "start_video_seconds": 124.03058333333334,
      "end_video_seconds": 125.4275,
      "duration_seconds": 1.3969166666666666,
      "samples": 67052,
      "mapped_start_score_seconds": 141.3948649999995,
      "mapped_end_score_seconds": 142.98734999999948,
      "mapped_duration_seconds": 1.5924849999999822,
      "reference_rest_start_seconds": 141.5,
      "reference_rest_end_seconds": 143.0,
      "start_residual_seconds": -0.10513500000050158,
      "end_residual_seconds": -0.012650000000519412
    }
  ],
  "expected_video_score_end_seconds": 136.84210526315837,
  "interpretation": "Under the independently selected partial chroma alignment, the two literal-zero audio gaps align closely with the reference score's only two full-ensemble rests. This supports the uploader-labelled musical identification and means the gaps are not, by themselves, a binary-message result. The post-score render tail is preserved but not decoded.",
  "derived": [
    "timing-audit.png"
  ]
}