Repository Analysis

vapoursynth/vapoursynth

A video processing framework with simplicity in mind

3.0 Likely human-written View on GitHub

Analysis Overview

This report presents the forensic synthetic code analysis of vapoursynth/vapoursynth, a C++ project with 2,055 GitHub stars. SynthScan v2.0 examined 60,607 lines of code across 130 source files, recording 172 pattern matches distributed across 7 syntactic categories. The overall adjusted score of 3.0 places this repository in the Likely human-written band.

The scanner applied 160+ deterministic lexical heuristics, multi-line block detectors, abstract syntax tree depth profilers, and a cross-file Jaccard similarity matrix to construct a statistically normalised synthetic code estimate. All matches are individually weighted by severity coefficient and contextual multiplier before summation, and the resulting headline score is temporally discounted to account for the repository's development history relative to the commercial emergence of large language model coding tooling (November 2022 onward).

3.0
Adjusted Score
3.0
Raw Score
100%
Time Factor
2026-07-14
Last Push
2.1K
Stars
C++
Language
60.6K
Lines of Code
130
Files
172
Pattern Hits
2026-07-14
Scan Date
0.00
HC Hit Rate

What These Metrics Mean

Adjusted Score
Primary synthetic code indicator. Raw score normalised per 1,000 lines of code and multiplied by the temporal discount factor. This is the definitive comparative metric — use it to rank repositories by AI authorship density.
Raw Score
The unmodified sum of all severity-weighted, context-multiplied pattern match scores before temporal discounting. Reflects the absolute signal strength independent of when the repository was last active.
Time Factor
The temporal discount multiplier (0–100%) applied to the raw score. Repositories last updated before ChatGPT's launch (Nov 2022) receive a 5% factor. Full signal is only assigned to repositories active in the post-adoption era (Jan 2024+).
Pattern Hits
Total count of individual pattern matches across all files and categories. A high hit count with a low score may indicate a very large codebase with isolated AI snippets; a low count with a high score indicates dense, concentrated AI signatures.
HC Hit Rate
High+Critical pattern hits per file, averaged across the repository. This orthogonal signal catches repositories where a few files are densely packed with high-severity AI tells — a strong indicator even when the normalised score appears moderate due to codebase size.
Lines of Code / Files
Total lines and files analysed. The scanner examines 94 file extensions. These denominators are used to normalise the score, enabling fair comparison between repositories of vastly different sizes.

Score History

This chart maps the temporal evolution of the adjusted synthetic code score across successive scan runs. An upward trajectory indicates ongoing incorporation of AI-generated code or expanding LLM-assisted scaffolding; a stable or declining trajectory may reflect active human refactoring, code removal, or the adoption of stricter authorship policies. The dashed secondary line (right axis) independently tracks total raw pattern hit count, which can diverge from the normalised score when codebase size changes significantly between scans.

Severity Breakdown

Classifies detected patterns by their diagnostic confidence and structural impact. CRITICAL patterns (coefficient 10) represent definitive synthetic signatures — hallucinated imports, explicit LLM attribution metadata — virtually never produced by human authors. HIGH (5) indicates strong structural tells such as cross-file repetition or cross-linguistic idioms. MEDIUM (2) covers recognisable conversational padding and AI-specific vocabulary. LOW (1) captures subtle indicators like tautological comments and generic boilerplate that require density to carry independent signal.

CRITICAL 0HIGH 0MEDIUM 1LOW 171

Directory Score Breakdown

This horizontal bar chart decomposes the repository's raw synthetic code score by top-level directory, allowing you to pinpoint precisely which modules or components carry the highest AI authorship density. Directories with disproportionately high scores relative to their size warrant targeted manual review: concentrated AI signatures often trace back to mass-generated configuration layers, auto-ported test suites, LLM-scaffolded boilerplate classes, or entire subsystems authored under heavy copilot assistance. Use this view to prioritise your human code-review effort.

Pattern Findings

The scanner identified 172 distinct pattern matches across 7 syntactic categories. Each entry below represents a discrete location in the source code where the engine recorded a statistically significant AI authorship indicator. Expand any category row to inspect the individual file paths, line numbers, code snippets, and the lexical context (CODE, COMMENT, or STRING) in which each match was detected.

Reading the findings table: The Severity column indicates the diagnostic confidence level (CRITICAL / HIGH / MEDIUM / LOW). The Context column identifies whether the match occurred inside executable code, an inline comment, or a string literal — comment-context matches receive a ×1.5 weight because LLMs systematically over-annotate. The ⚡ bolt icon marks clustered matches: three or more patterns within a 10-line window, each receiving an additional ×1.5 density multiplier as dense clusters constitute far stronger evidence of synthetic authorship than isolated hits.

Over-Commented Block106 hits · 106 pts
SeverityFileLineSnippetContext
LOWinclude/VapourSynth.h21#ifndef VAPOURSYNTH_HCOMMENT
LOWinclude/VapourSynth.h41# define VS_DEPRECATE(REASON)COMMENT
LOWinclude/VapourSynth4.h21#ifndef VAPOURSYNTH4_HCOMMENT
LOWinclude/VapourSynth4.h41#ifdef __cplusplusCOMMENT
LOWinclude/VapourSynth4.h61# define VS_EXTERNAL_API(ret) VS_EXTERN_C __declspec(dllexport) ret VS_CCCOMMENT
LOWinclude/VSHelper.h21#include <malloc.h>COMMENT
LOWinclude/VSHelper.h41#define VS_ALIGNED_FREE(ptr) do { _aligned_free((ptr)); } while (0)COMMENT
LOWinclude/VSHelper4.h21#ifdef _WIN32COMMENT
LOWinclude/VSHelper4.h41#define inline _inlineCOMMENT
LOWinclude/VSScript4.h21#ifndef VSSCRIPT4_HCOMMENT
LOWinclude/cython/vapoursynth.h1/* Generated by Cython 3.0.10 */COMMENT
LOWsdk/invert_example.c1//////////////////////////////////////////COMMENT
LOWsdk/invert_example.c121 // I usually keep the filter data struct on the stack and don't allocate itCOMMENT
LOWsdk/invert_example.c141}COMMENT
LOWdoc/conf.py1#!/usr/bin/env python3COMMENT
LOWdoc/conf.py81# List of patterns, relative to source directory, that match files andCOMMENT
LOWdoc/conf.py101COMMENT
LOWdoc/conf.py121# "<project> v<release> documentation".COMMENT
LOWdoc/conf.py141# These paths are either relative to html_static_pathCOMMENT
LOWdoc/conf.py161# html_domain_indices = TrueCOMMENT
LOWdoc/conf.py181# html_use_opensearch = ''COMMENT
LOWdoc/conf.py201# Grouping the document tree into LaTeX files. List of tuplesCOMMENT
LOWsrc/core/averageframesfilter.cpp21#include <algorithm>COMMENT
LOWsrc/core/float16_helper.h21#ifndef FLOAT16_HELPER_HCOMMENT
LOWsrc/core/version.h21#include "VapourSynth4.h"COMMENT
LOWsrc/core/ter-116n.h21const int character_height = 16;COMMENT
LOWsrc/core/ter-116n.h41#define ___X___X 0x11COMMENT
LOWsrc/core/ter-116n.h61#define __X__X_X 0x25COMMENT
LOWsrc/core/ter-116n.h81#define __XXX__X 0x39COMMENT
LOWsrc/core/ter-116n.h101#define _X__XX_X 0x4DCOMMENT
LOWsrc/core/ter-116n.h121#define _XX____X 0x61COMMENT
LOWsrc/core/ter-116n.h141#define _XXX_X_X 0x75COMMENT
LOWsrc/core/ter-116n.h161#define X___X__X 0x89COMMENT
LOWsrc/core/ter-116n.h181#define X__XXX_X 0x9DCOMMENT
LOWsrc/core/ter-116n.h201#define X_XX___X 0xB1COMMENT
LOWsrc/core/ter-116n.h221#define XX___X_X 0xC5COMMENT
LOWsrc/core/ter-116n.h241#define XX_XX__X 0xD9COMMENT
LOWsrc/core/ter-116n.h261#define XXX_XX_X 0xEDCOMMENT
LOWsrc/core/simplefilters.cpp21#include <cfloat>COMMENT
LOWsrc/core/genericfilters.cpp21COMMENT
LOWsrc/core/audiofilters.cpp21#include <cstdlib>COMMENT
LOWsrc/core/memoryuse.cpp1#include <cassert>COMMENT
LOWsrc/core/vscore.h21#ifndef VSCORE_HCOMMENT
LOWsrc/core/vscore.h41#include <atomic>COMMENT
LOWsrc/core/vscore.cpp21#include "vscore.h"COMMENT
LOWsrc/core/vsthreadpool.cpp21#include "vscore.h"COMMENT
LOWsrc/core/vsresize.cpp21#include <cmath>COMMENT
LOWsrc/core/lutfilters.cpp21#include <cstdlib>COMMENT
LOWsrc/core/boxblurfilter.cpp21#include <memory>COMMENT
LOWsrc/core/filtershared.h21#ifndef FILTERSHARED_HCOMMENT
LOWsrc/core/exprfilter.cpp21#include <algorithm>COMMENT
LOWsrc/core/textfilter.cpp21#include <cstdint>COMMENT
LOWsrc/core/mergefilters.cpp21#include <cstdlib>COMMENT
LOWsrc/core/expr/expr.cpp21#include <algorithm>COMMENT
LOWsrc/core/expr/jitasm.h1// Copyright (c) 2009-2011, Hikaru Inoue, Akihiro Yamasaki,COMMENT
LOWsrc/core/expr/jitasm.h21// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHTCOMMENT
LOWsrc/core/expr/jitasm.h41#if defined(_WIN32)COMMENT
LOWsrc/core/expr/jitasm.h61 #if !defined(__GNUC__) || defined(__SSE__)COMMENT
LOWsrc/core/expr/jitasm.h81#include <string.h>COMMENT
LOWsrc/core/expr/jitasm.h101#if _MSC_VER >= 1400 // VC8 or laterCOMMENT
46 more matches not shown…
Hyper-Verbose Identifiers33 hits · 38 pts
SeverityFileLineSnippetContext
LOWtest/chromaloc_mask_test.py65 def maskedmerge_reveal_chroma_mask(self, mask, n=0, length=1, field_based=False, chromaloc=None, **kwargs):CODE
LOWtest/chromaloc_mask_test.py80 def test_maskedmerge_matches_chromaloc_reference(self):CODE
LOWtest/chromaloc_mask_test.py89 def test_maskedmerge_center_equals_unshifted_downsample(self):CODE
LOWtest/chromaloc_mask_test.py99 def test_maskedmerge_per_frame_dispatch(self):CODE
LOWtest/chromaloc_mask_test.py117 def test_maskedmerge_non_subsampled_ignores_chromaloc(self):CODE
LOWtest/chromaloc_mask_test.py141 def test_maskedmerge_interlaced_matches_chromaloc_reference(self):CODE
LOWtest/chromaloc_mask_test.py152 def test_maskedmerge_interlaced_differs_from_progressive(self):CODE
LOWtest/chromaloc_mask_test.py162 def test_maskedmerge_chromaloc_compatibility(self):CODE
LOWtest/chromaloc_mask_test.py195 def premultiply_reference_chroma(self, alpha, loc, field_based=False):CODE
LOWtest/chromaloc_mask_test.py203 def test_premultiply_matches_reference(self):CODE
LOWtest/chromaloc_mask_test.py213 def test_premultiply_per_frame_dispatch(self):CODE
LOWtest/chromaloc_mask_test.py227 def test_premultiply_interlaced_matches_reference(self):CODE
LOWtest/test.py100 def test_blank_clip_no_variable(self):CODE
LOWtest/test.py111 def test_blank_clip_variable_size(self):CODE
LOWtest/test.py122 def test_blank_clip_variable_format(self):CODE
LOWtest/environment_test.py71 def test_environment_can_retrieve_api(self):CODE
LOWtest/environment_test.py77 def test_environment_can_retrieve_core_ptr(self):CODE
LOWtest/environment_test.py83 def test_environment_use_unsets_environment_on_exit(self):CODE
LOWtest/environment_test.py98 def test_environment_use_restores_environment_on_exit(self):CODE
LOWtest/environment_test.py115 def test_policy_clearing_runs_callbacks(self):CODE
LOWtest/environment_test.py152 def test_environment_destruction_runs_callbacks(self):CODE
LOWtest/environment_test.py192 def test_environment_warns_against_resource_leaks(self):CODE
LOWtest/environment_test.py201 def test_locals_store_data_between_envs(self):CODE
LOWtest/environment_test.py238 def test_locals_differ_from_each_other(self):CODE
LOWtest/environment_test.py254 def test_locals_store_data_between_envs(self):CODE
LOWtest/environment_test.py279 def test_exception_tunneling_and_no_leak(self):CODE
LOWtest/environment_test.py316 def test_environment_invalidation_releases_nodes_and_core(self):CODE
LOWtest/environment_test.py367 def test_environment_waits_for_futures(self):CODE
LOWtest/zimgtest.py34 def test_blank_clip_with_format(self):CODE
LOWsrc/py/_utils.py40def _version_string_to_number(version_string):CODE
LOWsrc/py/_utils.py52def _is_msi_product_installed(upgrade_code, min_version):CODE
LOWsrc/py/_utils.py87def _check_visual_studio_runtime():CODE
LOWsrc/py/_utils.py220def _get_vapoursynth_config_path():CODE
Excessive Try-Catch Wrapping12 hits · 14 pts
SeverityFileLineSnippetContext
LOWsrc/py/_shell.py58 except Exception:CODE
LOWsrc/py/_shell.py65 except Exception:CODE
LOWsrc/py/_shell.py200 except Exception:CODE
LOWsrc/py/_shell.py209 except Exception:CODE
LOWsrc/py/_shell.py219 except Exception:CODE
LOWsrc/py/_utils.py140 except Exception:CODE
LOWsrc/py/_utils.py186 except Exception:CODE
LOWsrc/py/_utils.py209 except Exception:CODE
LOWsrc/py/_utils.py261 except Exception:CODE
LOWsrc/py/_utils.py302 except Exception:CODE
LOWsrc/py/_utils.py318 except Exception:CODE
LOWsrc/py/_utils.py340 except Exception:CODE
Unused Imports11 hits · 11 pts
SeverityFileLineSnippetContext
LOWsrc/py/_shell.py1CODE
LOWsrc/py/__init__.py1CODE
LOWsrc/py/__init__.py2CODE
LOWsrc/py/__init__.py3CODE
LOWsrc/py/__init__.py3CODE
LOWsrc/py/__init__.py3CODE
LOWsrc/py/__init__.py3CODE
LOWsrc/py/__init__.py3CODE
LOWsrc/py/__init__.py3CODE
LOWsrc/py/__init__.py3CODE
LOWsrc/py/__init__.py3CODE
Deep Nesting7 hits · 7 pts
SeverityFileLineSnippetContext
LOWtest/chromaloc_mask_test.py162CODE
LOWtest/zimgtest.py15CODE
LOWtest/zimgtest.py34CODE
LOWtest/expr_compiler/compiler_test.py10CODE
LOWsrc/py/_shell.py19CODE
LOWsrc/py/_utils.py96CODE
LOWsrc/py/_utils.py287CODE
Self-Referential Comments1 hit · 3 pts
SeverityFileLineSnippetContext
MEDIUMdoc/conf.py7# This file is execfile()d with the current directory set to its containing dir.COMMENT
Modern Structural Boilerplate2 hits · 2 pts
SeverityFileLineSnippetContext
LOWsrc/py/_shell.py186def update_shell(path: str) -> None:CODE
LOWsrc/py/__init__.py14__all__ = [CODE