A video processing framework with simplicity in mind
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).
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.
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.
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.
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.
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | include/VapourSynth.h | 21 | #ifndef VAPOURSYNTH_H | COMMENT |
| LOW | include/VapourSynth.h | 41 | # define VS_DEPRECATE(REASON) | COMMENT |
| LOW | include/VapourSynth4.h | 21 | #ifndef VAPOURSYNTH4_H | COMMENT |
| LOW | include/VapourSynth4.h | 41 | #ifdef __cplusplus | COMMENT |
| LOW | include/VapourSynth4.h | 61 | # define VS_EXTERNAL_API(ret) VS_EXTERN_C __declspec(dllexport) ret VS_CC | COMMENT |
| LOW | include/VSHelper.h | 21 | #include <malloc.h> | COMMENT |
| LOW | include/VSHelper.h | 41 | #define VS_ALIGNED_FREE(ptr) do { _aligned_free((ptr)); } while (0) | COMMENT |
| LOW | include/VSHelper4.h | 21 | #ifdef _WIN32 | COMMENT |
| LOW | include/VSHelper4.h | 41 | #define inline _inline | COMMENT |
| LOW | include/VSScript4.h | 21 | #ifndef VSSCRIPT4_H | COMMENT |
| LOW | include/cython/vapoursynth.h | 1 | /* Generated by Cython 3.0.10 */ | COMMENT |
| LOW | sdk/invert_example.c | 1 | ////////////////////////////////////////// | COMMENT |
| LOW | sdk/invert_example.c | 121 | // I usually keep the filter data struct on the stack and don't allocate it | COMMENT |
| LOW | sdk/invert_example.c | 141 | } | COMMENT |
| LOW | doc/conf.py | 1 | #!/usr/bin/env python3 | COMMENT |
| LOW | doc/conf.py | 81 | # List of patterns, relative to source directory, that match files and | COMMENT |
| LOW | doc/conf.py | 101 | COMMENT | |
| LOW | doc/conf.py | 121 | # "<project> v<release> documentation". | COMMENT |
| LOW | doc/conf.py | 141 | # These paths are either relative to html_static_path | COMMENT |
| LOW | doc/conf.py | 161 | # html_domain_indices = True | COMMENT |
| LOW | doc/conf.py | 181 | # html_use_opensearch = '' | COMMENT |
| LOW | doc/conf.py | 201 | # Grouping the document tree into LaTeX files. List of tuples | COMMENT |
| LOW | src/core/averageframesfilter.cpp | 21 | #include <algorithm> | COMMENT |
| LOW | src/core/float16_helper.h | 21 | #ifndef FLOAT16_HELPER_H | COMMENT |
| LOW | src/core/version.h | 21 | #include "VapourSynth4.h" | COMMENT |
| LOW | src/core/ter-116n.h | 21 | const int character_height = 16; | COMMENT |
| LOW | src/core/ter-116n.h | 41 | #define ___X___X 0x11 | COMMENT |
| LOW | src/core/ter-116n.h | 61 | #define __X__X_X 0x25 | COMMENT |
| LOW | src/core/ter-116n.h | 81 | #define __XXX__X 0x39 | COMMENT |
| LOW | src/core/ter-116n.h | 101 | #define _X__XX_X 0x4D | COMMENT |
| LOW | src/core/ter-116n.h | 121 | #define _XX____X 0x61 | COMMENT |
| LOW | src/core/ter-116n.h | 141 | #define _XXX_X_X 0x75 | COMMENT |
| LOW | src/core/ter-116n.h | 161 | #define X___X__X 0x89 | COMMENT |
| LOW | src/core/ter-116n.h | 181 | #define X__XXX_X 0x9D | COMMENT |
| LOW | src/core/ter-116n.h | 201 | #define X_XX___X 0xB1 | COMMENT |
| LOW | src/core/ter-116n.h | 221 | #define XX___X_X 0xC5 | COMMENT |
| LOW | src/core/ter-116n.h | 241 | #define XX_XX__X 0xD9 | COMMENT |
| LOW | src/core/ter-116n.h | 261 | #define XXX_XX_X 0xED | COMMENT |
| LOW | src/core/simplefilters.cpp | 21 | #include <cfloat> | COMMENT |
| LOW | src/core/genericfilters.cpp | 21 | COMMENT | |
| LOW | src/core/audiofilters.cpp | 21 | #include <cstdlib> | COMMENT |
| LOW | src/core/memoryuse.cpp | 1 | #include <cassert> | COMMENT |
| LOW | src/core/vscore.h | 21 | #ifndef VSCORE_H | COMMENT |
| LOW | src/core/vscore.h | 41 | #include <atomic> | COMMENT |
| LOW | src/core/vscore.cpp | 21 | #include "vscore.h" | COMMENT |
| LOW | src/core/vsthreadpool.cpp | 21 | #include "vscore.h" | COMMENT |
| LOW | src/core/vsresize.cpp | 21 | #include <cmath> | COMMENT |
| LOW | src/core/lutfilters.cpp | 21 | #include <cstdlib> | COMMENT |
| LOW | src/core/boxblurfilter.cpp | 21 | #include <memory> | COMMENT |
| LOW | src/core/filtershared.h | 21 | #ifndef FILTERSHARED_H | COMMENT |
| LOW | src/core/exprfilter.cpp | 21 | #include <algorithm> | COMMENT |
| LOW | src/core/textfilter.cpp | 21 | #include <cstdint> | COMMENT |
| LOW | src/core/mergefilters.cpp | 21 | #include <cstdlib> | COMMENT |
| LOW | src/core/expr/expr.cpp | 21 | #include <algorithm> | COMMENT |
| LOW | src/core/expr/jitasm.h | 1 | // Copyright (c) 2009-2011, Hikaru Inoue, Akihiro Yamasaki, | COMMENT |
| LOW | src/core/expr/jitasm.h | 21 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | COMMENT |
| LOW | src/core/expr/jitasm.h | 41 | #if defined(_WIN32) | COMMENT |
| LOW | src/core/expr/jitasm.h | 61 | #if !defined(__GNUC__) || defined(__SSE__) | COMMENT |
| LOW | src/core/expr/jitasm.h | 81 | #include <string.h> | COMMENT |
| LOW | src/core/expr/jitasm.h | 101 | #if _MSC_VER >= 1400 // VC8 or later | COMMENT |
| 46 more matches not shown… | ||||
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | test/chromaloc_mask_test.py | 65 | def maskedmerge_reveal_chroma_mask(self, mask, n=0, length=1, field_based=False, chromaloc=None, **kwargs): | CODE |
| LOW⚡ | test/chromaloc_mask_test.py | 80 | def test_maskedmerge_matches_chromaloc_reference(self): | CODE |
| LOW⚡ | test/chromaloc_mask_test.py | 89 | def test_maskedmerge_center_equals_unshifted_downsample(self): | CODE |
| LOW⚡ | test/chromaloc_mask_test.py | 99 | def test_maskedmerge_per_frame_dispatch(self): | CODE |
| LOW | test/chromaloc_mask_test.py | 117 | def test_maskedmerge_non_subsampled_ignores_chromaloc(self): | CODE |
| LOW | test/chromaloc_mask_test.py | 141 | def test_maskedmerge_interlaced_matches_chromaloc_reference(self): | CODE |
| LOW | test/chromaloc_mask_test.py | 152 | def test_maskedmerge_interlaced_differs_from_progressive(self): | CODE |
| LOW | test/chromaloc_mask_test.py | 162 | def test_maskedmerge_chromaloc_compatibility(self): | CODE |
| LOW⚡ | test/chromaloc_mask_test.py | 195 | def premultiply_reference_chroma(self, alpha, loc, field_based=False): | CODE |
| LOW⚡ | test/chromaloc_mask_test.py | 203 | def test_premultiply_matches_reference(self): | CODE |
| LOW⚡ | test/chromaloc_mask_test.py | 213 | def test_premultiply_per_frame_dispatch(self): | CODE |
| LOW | test/chromaloc_mask_test.py | 227 | def test_premultiply_interlaced_matches_reference(self): | CODE |
| LOW | test/test.py | 100 | def test_blank_clip_no_variable(self): | CODE |
| LOW | test/test.py | 111 | def test_blank_clip_variable_size(self): | CODE |
| LOW | test/test.py | 122 | def test_blank_clip_variable_format(self): | CODE |
| LOW⚡ | test/environment_test.py | 71 | def test_environment_can_retrieve_api(self): | CODE |
| LOW⚡ | test/environment_test.py | 77 | def test_environment_can_retrieve_core_ptr(self): | CODE |
| LOW⚡ | test/environment_test.py | 83 | def test_environment_use_unsets_environment_on_exit(self): | CODE |
| LOW | test/environment_test.py | 98 | def test_environment_use_restores_environment_on_exit(self): | CODE |
| LOW | test/environment_test.py | 115 | def test_policy_clearing_runs_callbacks(self): | CODE |
| LOW | test/environment_test.py | 152 | def test_environment_destruction_runs_callbacks(self): | CODE |
| LOW | test/environment_test.py | 192 | def test_environment_warns_against_resource_leaks(self): | CODE |
| LOW | test/environment_test.py | 201 | def test_locals_store_data_between_envs(self): | CODE |
| LOW | test/environment_test.py | 238 | def test_locals_differ_from_each_other(self): | CODE |
| LOW | test/environment_test.py | 254 | def test_locals_store_data_between_envs(self): | CODE |
| LOW | test/environment_test.py | 279 | def test_exception_tunneling_and_no_leak(self): | CODE |
| LOW | test/environment_test.py | 316 | def test_environment_invalidation_releases_nodes_and_core(self): | CODE |
| LOW | test/environment_test.py | 367 | def test_environment_waits_for_futures(self): | CODE |
| LOW | test/zimgtest.py | 34 | def test_blank_clip_with_format(self): | CODE |
| LOW | src/py/_utils.py | 40 | def _version_string_to_number(version_string): | CODE |
| LOW | src/py/_utils.py | 52 | def _is_msi_product_installed(upgrade_code, min_version): | CODE |
| LOW | src/py/_utils.py | 87 | def _check_visual_studio_runtime(): | CODE |
| LOW | src/py/_utils.py | 220 | def _get_vapoursynth_config_path(): | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | src/py/_shell.py | 58 | except Exception: | CODE |
| LOW | src/py/_shell.py | 65 | except Exception: | CODE |
| LOW⚡ | src/py/_shell.py | 200 | except Exception: | CODE |
| LOW⚡ | src/py/_shell.py | 209 | except Exception: | CODE |
| LOW⚡ | src/py/_shell.py | 219 | except Exception: | CODE |
| LOW | src/py/_utils.py | 140 | except Exception: | CODE |
| LOW | src/py/_utils.py | 186 | except Exception: | CODE |
| LOW | src/py/_utils.py | 209 | except Exception: | CODE |
| LOW | src/py/_utils.py | 261 | except Exception: | CODE |
| LOW | src/py/_utils.py | 302 | except Exception: | CODE |
| LOW | src/py/_utils.py | 318 | except Exception: | CODE |
| LOW | src/py/_utils.py | 340 | except Exception: | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | src/py/_shell.py | 1 | CODE | |
| LOW | src/py/__init__.py | 1 | CODE | |
| LOW | src/py/__init__.py | 2 | CODE | |
| LOW | src/py/__init__.py | 3 | CODE | |
| LOW | src/py/__init__.py | 3 | CODE | |
| LOW | src/py/__init__.py | 3 | CODE | |
| LOW | src/py/__init__.py | 3 | CODE | |
| LOW | src/py/__init__.py | 3 | CODE | |
| LOW | src/py/__init__.py | 3 | CODE | |
| LOW | src/py/__init__.py | 3 | CODE | |
| LOW | src/py/__init__.py | 3 | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | test/chromaloc_mask_test.py | 162 | CODE | |
| LOW | test/zimgtest.py | 15 | CODE | |
| LOW | test/zimgtest.py | 34 | CODE | |
| LOW | test/expr_compiler/compiler_test.py | 10 | CODE | |
| LOW | src/py/_shell.py | 19 | CODE | |
| LOW | src/py/_utils.py | 96 | CODE | |
| LOW | src/py/_utils.py | 287 | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | doc/conf.py | 7 | # This file is execfile()d with the current directory set to its containing dir. | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | src/py/_shell.py | 186 | def update_shell(path: str) -> None: | CODE |
| LOW | src/py/__init__.py | 14 | __all__ = [ | CODE |