3 commits, 10 days, 191 stars: the "film simulation Win port" pinned in a Bilibili comment
What it is A Chinese-language, unzip-and-run Windows build ("胶片模拟.exe") of SpektraLab, the open-source film simulation app for macOS, with a few interface tweaks.
Why it took off SpektraLab blew up on Bilibili's photography scene but only had a Mac version. This project was the first with a Chinese Windows build, and a tutorial with 16k views pinned it in the comments. The stars rode the hype, and most of the code is inherited from the official Windows branch.
C How you could follow this Don't make another repackage of SpektraLab. Copy the play: next time an open-source tool that's Mac-only or English-only suddenly catches fire in China, ship a Chinese Windows build within a day or two, credit upstream clearly, and get it into the bio or pinned comment of a Bilibili tutorial creator.
- Data (updated daily) · Repo created 2026-10-27 · 200 stars · 7 days +132
GitHub · stars Data 2026-10-30 → 2026-11-08 (10 days, 10 observations). Points before 10-28 come from deeply / archive backfill, not every day has one
At the end of October, SpektraLab, an open-source film simulator that only ran on Mac, suddenly blew up in the Bilibili photography community, with the comments full of "Windows version please." A GitHub account created in October, 27, packaged the official-but-unreleased Windows branch into a fully Chinese-language, install-free "胶片模拟.exe" and uploaded it. Within 10 days it had 191 stars and about 3,400 downloads. This piece covers where the stars came from, why this one stood out among the dozen-plus ports that appeared at the same time, and whether you can still use this playbook.
A 16k-view tutorial with a one-line pinned comment
On Nov 4, Bilibili creator -TimHsu- posted "The god of film emulation? Detailed SpektraLab tutorial (with download)". As of 11-06 it had 16,385 views, 1,011 likes, and 2,568 favorites. Favorites were more than double the likes, which suggests viewers actually planned to come back and install it. The video's pinned comment was a single line:
Win port git address: github.com/trouble123456/Film-Simulation
From that day on, the repo gained a steady 19 to 20 stars per day (GitHub daily records, 11-04 to 11-06). The owner, trouble123456, has only this one repo, has 3 followers, no bio, and hasn't been seen promoting it. The stars mostly came from other people's videos.
What it is
SpektraLab is a film and photo-paper simulator for macOS. You open a RAW file, pick a film stock and a paper, and it models light passing through the film's dye layers and onto the paper across 81 wavelengths, with grain, halation, and edge markings sized to real negatives. Its pitch is the first line of the README: "Spectral, not a LUT"; it's physical simulation, not filter stacking. The engine comes from an earlier Python project, spektrafilm (2,003 stars); SpektraLab turned it into a native app for Apple silicon that renders in about a second. It's free and GPL-licensed.
This repo (description: "Film Simulation — the Windows port of SpektraLab") packages SpektraLab's Windows branch as an exe with a Chinese interface. You unzip and run it, and it adds some interface changes: crop and pan, a "little eye" toggle on each section to turn it off and compare, light/dark themes with accent colors, a CineStill 800T roll, and a collapsible film strip.
The commit history has just 3 commits on 10-27: one init, then two "upload Windows transpiled source" commits. 10-27 shipped v1,10-28, v2,10-30, v3, and there hasn't been an update since.
How well it's growing
| Date | stars | What was happening at the time |
|---|---|---|
| 10-27 | Repo created | v1.0.0 released |
| 10-28 | — | v2.0.0 released; the official Windows installer preview dropped the same day |
| 10-29 | — | Bilibili's first "Windows port" video (遥子同学, 1,3,388 views) |
| 10-30 | 28 | v3.0.0 released, last update |
| 10-31 | 41 | 知非后期课堂 "Win version is now usable!", 12,910 views |
| 11-02 | 86 | 努力的灰's video, 4,531 views |
| 11-03 | 123 | Single-day +37, largest in the observed window |
| 11-04 | 142 | TimHsu tutorial, link in the pinned comment |
| 11-06 | 181 | GitHub page showed 191 the same day |
Sources: GitHub daily records, Bilibili video pages (view counts as of 11-06).
Stars aren't the most telling number. The three Windows builds were downloaded about 3,370 times in total (v1 185, v2 1,057, v3 2,124, GitHub release pages, 11-06), nearly 18 times the star count. Most people coming in were photography enthusiasts who downloaded and used it, not people starring the repo.
Who brought the +37 on 11-03 is not visible from outside. The timing lines up with the videos from 知非后期课堂 and 努力的灰 (inferred). 遥子同学1 wrote in the video description of 10-29 that they "spent some time porting it to Windows." The timing fits, but no link proves they are the trouble123456 account. Unverified.
Why SpektraLab was the one that took off
From Oct 29 to Nov 5, Bilibili had at least 8 SpektraLab videos all saying the same few things: "no need to buy film anymore" and "no filter presets needed." One JCK studio video 11-04 was titled outright "blowing up across the internet." The buzz also shows up upstream: the spektrafilm repo on GitHub went from 1,358 to 1,966 stars between 11-01 and 11-06, and its Mac builds, 1.3.4 and 1.3.5, got roughly 22k downloads combined.
The catch: the Mac version only supports Apple Silicon and macOS 15 or later, and most Chinese photo-editing enthusiasts use Windows. The demand was there; what was missing was a Windows version you could actually download.
Why this one was first among the ports
The crowd that rushed in was huge. Between 10-28 and 11-06, more than a dozen SpektraLab ports and rebrands appeared on GitHub:
| Project | What it does | Stars (11-06) |
|---|---|---|
| JamesQiu2005/SpektraLab (official) | Original Mac + iOS app, with a Windows pre-release build | 1,428 |
| SAINTTaiYi/SpektraLab-Android | Unofficial Android port, created 10-29 | 196 |
| trouble123456/Film-Simulation | Chinese Windows packaged build, created 10-27 | 191 |
| Shayt0ny/Spektra-Studio | "Windows maintenance build," created 10-29 | 83 |
| YZH2006517/SpektraLab-Windows-NANATATA | Windows installer, created 10-28 | 62 |
| evanfan005-bit/SpektraLab-Windows | The repo of the author of the official Windows port | 3 |
There are also Intel Mac builds, a Xiaomi Android version, an iOS version, a browser version, a Photoshop plugin, ComfyUI nodes, and Bilibili uploaders sharing various packages via Quark Drive. The official Windows pre-release portable build alone was downloaded 5,660 times, more than this repo.
It ranked first among the Windows builds for three reasons:
Early. v2 shipped the same day as the official Windows installer pre-release, a day ahead of the official portable build and a day or two ahead of the other unofficial Windows repos.
Chinese-language. The repo description, the program name ("胶片模拟 3.0.exe"), and the entire UI are in Chinese. Searching "胶片模拟 Windows 转译版" puts it at the top. For a hobbyist who doesn't read English READMEs, that's far easier to recognize than the official English pre-release.
Pinned by a big account. This is the one piece of traffic I could directly verify: TimHsu's tutorial linked only this one among the many Windows builds.
Those small UI tweaks made it easier for beginners to get started, but they're not why it took off.
Its problems
The code wasn't written by it. On Oct 30, evanfan005-bit, the author of the official Windows port, opened the first issue, titled "Please add the Windows port's source and contributor notes." He said raw_decoder.cpp and three porting docs in the repo match the snapshot of his Windows branch from Oct 23, and the docs even still contain his local validation path D:/SpektraLab-win/validation/.... He asked the README to state which branch it's based on and to credit the contributor. As of 11-06, the issue is still open.
The person who actually did the Windows port has a repo with 3 stars. Commenters on Bilibili are already asking whether this is "the copied software that doesn't follow the open-source license."
The other two issues are user reports: a flood of cache files filling up the C: drive, and JPEG-XL photos from an iPhone 17 Pro that won't open. Nothing has been fixed since the author stopped updating in 10-30.
Once the official Windows version ships and is signed, the value of these ports drops to zero.
If it were you
The takeaway: the playbook can be copied, but this slot is already taken. "A foreign open-source tool that's Mac-only or English-only suddenly blows up in China, so you ship a Chinese portable Windows build first and get it pinned in the top comment of a tutorial video" really does get stars and downloads cheaply. But this SpektraLab wave already has a dozen ports, and the official Windows build is on the way, so another packaged build now has no point.
Who it suits: developers who can compile someone else's cross-platform branch and package it in Chinese within a day or two, and who know a few tutorial creators on Bilibili, Xiaohongshu photography, design, or video-editing circles, or who make tutorial videos themselves.
Who it doesn't suit: people who want to build a reputation on code they wrote. These stars reflect how fast you moved, not how good the work is, and they're hard to put on a résumé. Also people who don't want to get tangled in open-source attribution disputes.
How to do it:
- Watch for tools that are "upstream open-source, Mac-only or English-only, and suddenly popular in a particular Chinese circle." The signals: the upstream repo gains hundreds of stars a week, three or more videos for the same tool each pass 1,000 views within a few days, and commenters are asking for a Windows or Chinese version.
- Move fast on the first wave, but fix what this one got wrong: state in the first screen of the README which branch it's based on, who the upstream is, and what you changed. Keep fixing the issues users report (cache location, support for new formats) instead of shipping three versions and walking away.
- If you still want to follow SpektraLab, skip the packaged builds and go after the gaps: Chinese film-parameter guides and preset sharing, batch-processing tools, or bridge plugins for Lightroom or Capture One.
How to get users: follow the same path, but be proactive about it: once it's ready, message the creators who are making tutorials for this tool directly and ask them to add it to their description or top comment. Name the repo and program with Chinese feature words (like "胶片模拟") so it's easy to search and to pass along by word of mouth.
When the window is: before the official Windows version ships. The heat went from the first video to a pile of ports in one week, so the window for the next tool like this is probably one to two weeks.
What would signal you misread it: one to two weeks after the official stable release, if this repo's daily star gain drops to single digits and downloads flatline, that shows the port was only a temporary stand-in during the hype. Then this approach is only good for riding one wave and isn't worth building a long-term project around.
Research notes: competitor table, acquisition evidence, full research report
- Competitors
Name Where Launched Scale How it differs from this one JamesQiu2005/SpektraLab (official) Open source 2026-09-11 1,428 stars; Mac DMG 1.3.4/1.3.5 about 22k downloads total; official Windows beta 2 portable build 5,660 downloads The original, most complete, signed and notarized. The Windows version is currently only an English pre-release. This repo is a Chinese repackaging of its Windows branch. SpektraLab iOS iOS 2026 (listed, 1.1.2) Free, scale unverified Official phone version; this repo only covers Windows desktop andreavolpato/spektrafilm Open source 2025-02 2,003 stars, from 11-01 to 11-06 up about 600 Upstream Python engine, high barrier to entry; this repo gives a ready-to-run exe evanfan005-bit/SpektraLab-Windows Open source 2026-10-28 3 star The real author of the official Windows port. This repo's source includes his implementation (issue #1), but he didn't get the traffic YZH2006517/SpektraLab-Windows-NANATATA / Shayt0ny/Spektra-Studio Open source 2026-10-28 / 10-29 62 / 83 star Also a packaged Windows build; this repo wins on Chinese naming, early release, and being pinned by big accounts chaert-s/spektrafilm-ofx Open source 2026-05 362 star DaVinci Resolve plugin aimed at color-grading video; this repo is aimed at RAW photos Dehancer / FilmBox / Genesis / DxO FilmPack Other Years Commercial software Paid, based on LUTs or empirical models; this repo is free and uses a spectral physics model Fujifilm film simulations / X RAW Studio, Lightroom presets Big-company features Since 2004 Big In-camera or preset-based, brand-limited or LUT-dependent; this repo works with RAW from any camera - Where users come from
- Verified Pinned comment on a Bilibili tutorial video: -TimHsu- BV1fDxS6rEvk (11-04,16,385 views, 2,568 favorites), pinned comment reads "win转译版git地址:https://github.com/trouble123456/Film-Simulation"
- 查实 B 站 SpektraLab 热潮(平台事件):10-29 到 11-05 至少 8 条 SpektraLab 视频:知非后期课堂 12,910 播放、努力的灰 4,531、JCK设影室 3,497 等;上游 spektrafilm 6 天 +600 star
- Inferred Possibly a video the author posted on Bilibili: 遥子同学1 posted "SpektraLab胶片模拟器移植Win版" (3,388 views) on 10-29, with the description "I spent some time porting it to Windows," but there's no link proving he is trouble123456
- Verified search / Chinese naming: Jina ranks "Film Simulation Windows port" first; the program is named "Film Simulation 3.0.exe"
trouble123456/Film-Simulation (胶片模拟 · Windows port of SpektraLab) research report
Channel: GitHub · Research date 2026-11-06 · Data card /home/ljr/fanout/why/cards/gh_trouble123456__Film-Simulation.json
One line
A newly registered GitHub account (trouble123456,2026-10-27, with this as its only repo) packaged the Windows version of SpektraLab (a spectral film simulator for macOS) as a Chinese-named "胶片模拟.exe," uploaded as a zip source package, and added small interface tweaks such as cropping, theme color, and a CineStill 800T option. Its stars and downloads weren't earned on their own merits: from late October to early November 2026, SpektraLab suddenly took off on Bilibili, and this repo was one of the "Windows download links" pinned in the comments of those videos.
1. Data
- Stars: created 2026-10-27; our repo tracker (github.repo_day) recorded 10-30 28 → 11-03 123 → 11-06 181; the GitHub API 11-06 shows 191. Over the last 7 days +153, with the single-day peak being +37 on 11-03. Forks 8.
- Release downloads (GitHub API, 2026-11-06): v1.0.0 (10-27) 185, v2.0.0 (10-28) 1,057, v3.0.0 (10-30) 2,124, plus the source zip, about 3,700 total. This number says more about real usage than the star count does.
- Commit history: only 10-27 commits from 3 (Initial commit plus two "upload Windows port source" commits). The last push was 10-30 with v3.0.0, and there have been no updates since.
- 3 issues: #1 asks the official Windows port author evanfan005-bit to add source attribution and contributor notes; #2 reports that it generates a large cache on the C: drive; #3 reports that JPEG-XL files from an iPhone 17 Pro won't open.
II. Competitors (first, who else is doing the same thing)
Upstream and official
| Name | Where | Launched | Scale | How it differs from this repo |
|---|---|---|---|---|
| andreavolpato/spektrafilm | Open source (Python) | 2025-02 | 2,003 stars. From 11-01 to 11-06 it rose from 1,358 to 1,966, riding the same wave (github.repo_day) | The source of everything: the spectral model and 28 measured film and paper profiles all come from it. High barrier, requires Python to install |
| JamesQiu2005/SpektraLab | Open source + macOS + iOS (free on the App Store) | 2026-09-11 | 1,428 stars. Mac DMG downloads: 1.3.4 9,229 times, 1.3.5 13,028 times | The original. The official project itself has a Windows pre-release: the beta.2 portable build has 5,660 downloads and the installer 398 downloads, more than this repo. |
| evanfan005-bit/SpektraLab-Windows | Open source | 2026-10-28 | 3 star | The person who wrote the official Windows port. By his own account in #1, raw_decoder.cpp and several acceptance docs in this repo's source package are identical to his 10-23 branch snapshot. |
SpektraLab ports and re-skins that appeared at the same time (GitHub search, 2026-11-06):
- SAINTTaiYi/SpektraLab-Android: 196 stars, created 10-29, an unofficial Android port growing almost exactly like this repo (11-01 38 → 11-06 184)
- Shayt0ny/Spektra-Studio: 83 stars, created 10-29, "Windows maintenance edition"
- YZH2006517/SpektraLab-Windows-NANATATA: 62 stars, created 10-28, "Windows version · installer on Releases"
- akinal5765-byte/Silverphase (56, macOS), Dear-Ded/Spektralab-X (9, Xiaomi Android), dai327700-source/SpektraLab-Intel-Mac, Minerchu/SpektraLab-iOS, cut-hand/spektra-web (browser version), jerryhubrit/spektrafilmlab-ps (Photoshop plugin), jtydhr88/ComfyUI-Spektrafilm (created 11-05), kveinjay-google/LiteFilm (created 11-06), and a dozen or so more
Earlier ports in the spektrafilm ecosystem: chaert-s/spektrafilm-ofx (362 stars, DaVinci Resolve plugin, boosted by the Reddit r/davinciresolve post "Spektrafilm OFX is here for FREE"), thetechgeekko/Spektrafilm-android (47), turbasvin/spektrafilm-rs (55), the filmsim module in darktable, and the ART editor. A pixls.us thread also covers a "GPU accelerated windows port".
Commercial and big-company options: Dehancer, FilmBox, Genesis (called "the most expensive film emulation plugin ever" on Bilibili), DxO FilmPack, Lightroom film presets and LUTs, FilmLab Desktop, the film simulations built into Fujifilm cameras and X RAW Studio, and Sony's Recipe Lab.
Bottom line: this space isn't short on competitors, it's packed. The Windows version of SpektraLab alone has an official pre-release and at least 4 unofficial packages.
3. Growth levers: where users came from (with evidence)
- Bilibili videos pushed this category of tool into the spotlight, and that's the main driver. Searching the Bilibili API for "SpektraLab" (2026-11-06):
- Yaozi Tongxue1 "SpektraLab film simulator ported to Windows, with several film filters included", 10-29,3,388 views; the same UP 11-01 posted another one, "Ported to Windows, with several photo frames included", 1,059 views, with the description "I spent some time porting it to Windows" and frame and border content inside
- Zhifei Post-Production Class "SpektraLab is here… Windows version now available!", 10-31,12,910 views, with Quark Drive link; 11-03 another tutorial, 4,894 views
- Nuli de Hui, 11-02,4,531; JCK Studio, 11-04,3,497 (claims "viral across the whole web"); FoTo Se-Hushang, 11-05,727 (full Win/Android/Mac bundle on Quark cloud drive)
- -TimHsu-, "The god of film simulation? Detailed SpektraLab tutorial (download included)", 11-04,16,385 views, 1,011 likes, 2,568 favorites. The pinned comment reads: "Win port git address: github.com/trouble123456/Film-Simulation". This is the only piece of evidence that directly shows traffic being routed to this repo.
- "Free + physical spectral simulation, not LUTs" spreads well. Videos keep saying "you don't need to buy film anymore" and "no filters needed," while the Mac version only supports Apple silicon. Most photographers on Bilibili use Windows, so demand for a Windows build already existed. The comments are full of "need the Win version" (BV1yexp6BEdV).
- Search and naming. The repo description is in Chinese, "film simulation", and a Jina search for "film simulation Windows port" ranks it first. The program is also called "film simulation 3.0.exe", which is friendlier to users who don't read English.
- No promotion found on ads, X, Xiaohongshu, Reddit, or HN. x-radar searched SpektraLab over the past 30 days and returned 0. The author account has 3 followers and no bio, and nothing from the author posting about it. Whether 遥子同学1 is the same author in this database is unverified (both say "I ported the Win version" and the timing lines up, but there's no cross-link).
IV. Why it took off
- Rode a platform event: SpektraLab took off in the Chinese photography and post-processing circles around late October. The source, spektrafilm, gained 6 stars in 600 days, and the two Mac versions got 22k downloads. This repo is just one tributary of that wave.
- Caught between "Mac-only" and "lots of Windows users": the stars came before the big-account videos. 10-28 shipped v2,10-30 and then v3, only a little earlier than, or about the same time as, the official Windows pre-release (10-28 installer, 10-29 portable), and it was fully Chinese, needed no install, and had an exe name anyone could read.
- Pinned by a big account: the TimHsu video with 16k views listed this as the only git address for the "win port", and from 11-04 onward it steadily gained +19~20 per day.
- Stars are not product strength: the code is a repackage of the official Windows branch, it hasn't been updated since 10-30, and Bilibili comments already include people asking "is this the copied software that ignores the open-source license?"
5. Differentiation
How it differs from the official Windows pre-release: Chinese UI and Chinese naming ("film simulation"), a no-install zip, extra crop/pan, a per-section "eye" bypass toggle, light/dark themes, accent colors, CineStill 800T film, and a collapsible film strip. It also shipped a day or two ahead of the official beta. These changes do make it easier for Chinese Windows beginners to get started, but they are not the main reason it took off. The main reasons were being "among the first to ship a usable Win version during the hype" and being "linked by a big account." The engine and features are inherited, so there's no moat. There's also a dispute over GPL attribution (issue #1), which is a reputational risk.
VI. Visibility
The word in small circles: a few post-production videos on Bilibili (up to 16k views) and their comment sections. X, Reddit, HN, and the media haven't covered it. Revenue is 0 (free, GPL). But the SpektraLab niche itself is already crowded, with a dozen-plus ports appearing in about a week.
VII. What to take away
- When an overseas open-source project only has a Mac version and suddenly takes off in China, shipping a "Chinese + no install + Windows" build before the official one, then getting the link into the pinned comment or description of Bilibili tutorial accounts, can yield sustained traffic at low cost.
- Using the Chinese functional term directly in the name ("film simulation") makes search and word-of-mouth easier.
- But you have to keep GPL attribution (clearly state the upstream and which branch was inherited), or word of mouth will backfire. Once the official Windows version becomes stable and signed, the value of this kind of port drops to zero quickly.
8. Not sure
- Whether Yaozi Tongxue 1 is trouble123456 in person is unverified
- The stargazers API returns 404, so hourly star timing can't be obtained. The source of the +37 on 11-03 is unverified (possibly the videos from Zhifei Post-Production Class and Nuli de Hui, 11-02, 11-03)
- No spread on Xiaohongshu or Douyin was found
Sources
- GitHub API: repos/trouble123456/Film-Simulation (including releases, issues, commits), JamesQiu2005/SpektraLab (including releases), andreavolpato/spektrafilm, evanfan005-bit/SpektraLab-Windows, search/repositories?q=spektrafilm OR spektralab, all as of 2026-11-06 queries
- Our repo's github.repo_day (2026-10-28 to 11-06)
- Bilibili: BV1fDxS6rEvk (TimHsu, pinned comment), BV1zWxy6REyd, BV1iLxm6ZEz7, BV1314F6dEsU, BV1Q9xX6TEND, BV1ug436JEaV, BV1ttxF65EVS, BV1yexp6BEdV, BV1wmxS6yEfE (api.bilibili.com view and reply endpoints)
- spektralab.app/zh/download/ (official: Mac 1.3.5; iOS 1.1.2 free; Windows 1.3.4 pre-release)
- www.reddit.com/r/davinciresolve/comments/1torpkh/, discuss.pixls.us/t/gpu-accelerated-windows-port/59447
- x-radar search for SpektraLab (30 days): 0 results