A 90s cable box for a folder of video files.
Point it at a directory and it deals the files across N always-on channels, each a looping playlist whose position is a pure function of wall-clock time. You don't pick what to watch, you flip channels: snow, a hiss, a lock-in wobble, and you're on whatever is playing right now. Channel 0 is a Prevue-style channel with a scrolling grid, a preview box and hold music; G opens the same grid as an interactive guide.
Tuning is instant. Every channel owns a demuxer + decoder pipeline that background workers keep primed at the keyframe just before "now", so a channel change is a pointer swap plus one frame. Rust + FFmpeg. On Windows video decodes through D3D11VA and is presented with a Direct3D 11 shader; on Linux it decodes in software and is presented through wgpu (Vulkan, OpenGL fallback). The CRT pass is optional on both.
- Snow between channels. Picture and sound go to static the instant a key is pressed and stay there until the new channel has a frame, then the picture rolls once and the horizontal hold hunts for half a second before it locks.
- Tube warm-up. On launch the raster opens from a white-hot line over a PLEASE STAND BY card while the library is indexed (the window is up at once, even on a slow network share); Esc collapses it back.
- TV-set OSD. Big green channel number top right, in the VCR OSD Mono font, aliased with a
drop shadow. Typed digits show as
3-until they commit. - Cable-box banner. Channel number, network, what's on, what's next, time left, a progress bar and the clock, on a translucent bevelled bar. Comes up on every tune, or on Enter.
- Volume and MUTE. Twenty green segments. MUTE blinks in the corner while it's on.
- Recall. Backspace jumps to the previous channel.
- Prevue channel. Channel 0 is a blue Prevue grid with alternating rows, a clock and date, a preview box that rotates through the channels, and a ticker along the bottom. It scrolls on its own and isn't interactive, like the real thing: arrows change channel, Enter watches the preview.
- Interactive guide. G opens the same grid with a cursor. Up/Down move it (the preview box and its audio follow), Left/Right jump ten, Enter tunes, G closes. Hold music only plays on the Prevue channel.
- CRT pass. Phosphor triads, scanlines, interference, barrel curvature, vignette, rounded bezel. Toggle with C; curvature, scanline depth, noise and vignette are tunable in the menu.
- Channels dress their picture. Every channel is assigned a network from your logo folders
(fixed per channel number); networks without a PNG, or every channel when you have no logo
folder at all, get a drawn station bug and a made-up call sign. About half show a translucent logo bug in a corner, a quarter run a
small clock, a fifth run a lower-third news crawl with headlines from
assets/headlines.txt. - Commercial breaks. Point
commercial_dirat a folder of ad clips and every ~5 minutes of program time a break of a few ads plays (same breaks after restarts). Ads never show as now/next. - Station idents. A bumper from
<idents folder>\<Network>\plays between programs, matched to the channel's network folder when one exists. The guide and banner skip idents when saying what's on. - WeatherStar 3000. The last channel is ws3kp (bundled, MIT) in a WebView2 child window, pointed at your ZIP code. No server or install: the page is served from disk and fetches forecasts from the National Weather Service. Snow, then the forecast.
- Set up menu (S). Black VCR-style menu: CRT tube and its four knobs, overscan/underscan,
aspect (FIT / 4:3 / 16:9 / STRETCH), HUD colour, logos, clocks, ticker, idents, snow, hold
music, 24-hour clock, and a WEATHER ZIP row you type digits into. Saved to
tuner_settings.jsonnext to the exe.
| Key | Action |
|---|---|
| Up / Down | Channel +1 / -1 (interactive guide: move cursor) |
| Left / Right | Channel +10 / -10 (interactive guide: cursor +10 / -10) |
| 0-9 | Direct tune; commits after the last digit or 1.5 s. 0 is the Prevue channel |
| Enter | Info banner; Prevue channel: watch the preview; interactive guide: tune the cursor row |
| Backspace / R | Recall last channel |
| + / - | Volume |
| M | Mute |
| G | Interactive guide (again to close) |
| I | Info banner |
| S | Set up menu (Up/Down row, Left/Right change, digits + Enter on WEATHER ZIP) |
| C | CRT pass |
| Page Up / Down, Media Next / Previous | Channel +1 / -1 (same as Up / Down) |
| Media Play/Pause | Info banner |
| F11 / Alt+Enter | Fullscreen (remembered) |
| H / F1 | Remote legend |
| Esc | Power off |
Volume and mute keys on a keyboard are left to the OS (they change the system volume); use + / - for the TV's own volume bar.
Any controller the OS sees (Xbox, PlayStation, generic; Windows and Linux) works as a remote:
| Button | Action |
|---|---|
| D-pad | Up / Down channel, Left / Right +-10 (hold to surf); moves the cursor in the guide and menu |
| A / Cross | Enter (info banner, tune the guide cursor, change a menu value) |
| B / Circle | Back: closes the menu, legend or guide, otherwise Recall |
| Y / Triangle | Interactive guide |
| X / Square | Info banner |
| Start | Set up menu |
| Select / Share | Remote legend |
| LB / RB | Volume - / + (hold to repeat) |
| Left / right stick click | CRT tube / Mute |
Double-click tuner.exe (or "Save & launch" in tuner-setup.exe) and it runs from
tuner_settings.json and tuner_lineup.json with no console window. Command-line flags override
the settings and keep the console for logs:
tuner [<dir>] [--channels N] [--music DIR] [--crt] [--sw] [--start N] [--bench N] [--shot MS]
| Flag | Meaning |
|---|---|
<dir> |
Folder of video files (default: content_dir from settings). Probed once, cached in tuner_index_v2.json |
--channels N |
Number of channels to deal the files across (default: channels from settings) |
--music DIR |
Folder of audio files for the guide's hold music (default: music_dir from settings) |
--crt |
Start with the CRT pass on |
--sw |
Software decode instead of hardware (D3D11VA on Windows; Linux is always software) |
--start N |
Channel to start on (default 1) |
--bench N |
Automated random tunes at key-repeat speed, then print latency stats and exit |
--shot MS |
Dump one frame to bench_last.ppm after MS milliseconds and exit |
gen_content.sh [N] [DUR] renders N test channels (colour bars with a channel number and clock)
into content/ with ffmpeg, for trying it without a library.
A windowed editor for everything below, with folder-browse dialogs, plus a channel lineup
table: give any channel number a name, a logo from your logo folders, its own source folders
(played shuffled or A→Z), and dressing overrides (bug corner, clock, ticker, which ident folder).
Channels you don't list are dealt from the content library as usual. "Save & launch" starts the
tuner. It writes tuner_settings.json and tuner_lineup.json next to the exes.
On a first run (no tuner_settings.json yet) tuner.exe opens this tool as a step-by-step wizard
(tuner-setup.exe --wizard); the Wizard button brings it back any time.
Written next to the exe on first run; everything in the set up menu lives here, plus paths the menu doesn't edit:
| Key | Meaning |
|---|---|
logo_dirs |
;-separated folders of PNG network logos. The file stem is the network name (MTV (US).png is MTV) |
bumper_dir |
Folder tree of idents, one subfolder per network. Subfolders without a logo still become networks |
commercials |
Commercial breaks on/off (also in the menu; needs a restart) |
commercial_dir |
Folder (subfolders included) of ad clips; empty = no commercials |
commercial_break_secs |
Program time between breaks, default 300 |
commercials_per_break |
Ads per break, default 3 |
weather |
WeatherStar channel on/off (after the last regular channel) |
weather_url |
Empty = the bundled page; set it to show some other page on that channel instead |
fullscreen |
Start fullscreen (F11 / Alt+Enter toggles and saves it) |
weather_zip |
Set from the menu; looked up via zippopotam.us into weather_lat/weather_lon/weather_location |
The weather channel needs only the WebView2 runtime (ships with Edge) and a US ZIP code. Program names come from file tags, else a tidied file name (release tags, resolutions and hashes removed), else the folder name.
Esc or closing the window prints tune-latency percentiles (keypress to first presented frame).
Unzip tuner-<version>-win64.zip anywhere and double-click TUNER.exe: on first run it opens the
set up wizard to pick your video folder and the optional extras. TUNER Setup.exe reopens the
editor. Both are small launchers for bin\tuner.exe and bin\tuner-setup.exe, which sit in
bin\ with the FFmpeg DLLs; settings are written there too (or under %LOCALAPPDATA%\tuner if
that folder is read-only). Requirements: Windows
10 or later and a Direct3D 11 GPU. Linux: tuner-<version>-linux-x86_64.tar.gz, needs the distro's
FFmpeg shared libraries and Vulkan or OpenGL drivers. On Windows the WebView2 runtime (ships with
Edge) is used by tuner-setup.exe and the weather channel.
If something goes wrong at startup the tuner shows a dialog and writes tuner_crash.log next to
the exe. A second double-click while it's running does nothing (single instance).
dist.ps1 builds that zip from a checkout.
Windows is the primary target (Direct3D 11 presenter, D3D11VA zero-copy decode). Linux builds use a wgpu presenter (Vulkan, OpenGL fallback) with software decode; see below.
- Rust stable
- FFmpeg 6.x shared build (e.g. BtbN
ffmpeg-n6.1-win64-gpl-shared), path inFFMPEG_DIR - LLVM/libclang for
ffmpeg-next's bindgen, path inLIBCLANG_PATH
Copy .cargo/config.windows.toml to .cargo/config.toml and edit the two paths for your machine (the copy is
gitignored; Linux builds must not have it, they use pkg-config). build.rs copies the
FFmpeg DLLs next to the exe so cargo run --release works without touching PATH.
cargo build --release
.\target\release\tuner.exe D:\videos --channels 40 --crt
Three binaries come out: tuner.exe, tuner-setup.exe, and launcher.exe (the stub dist.ps1
copies to the top of the zip as TUNER.exe / TUNER Setup.exe).
Pushing a v* tag (for example v1.2.0) runs .github/workflows/release.yml, which builds the
Windows zip and the Linux tarball and attaches both to a draft GitHub Release for review.
The tuner itself builds and runs on Linux with the wgpu renderer. Not there yet: the WeatherStar
channel and tuner-setup (both need WebView2), hardware decode (VAAPI), and idle-drag handling
is simply not needed. Edit tuner_settings.json / tuner_lineup.json by hand (the tuner writes
defaults on first run next to the binary, or under ~/.config/tuner).
Debian / Ubuntu prerequisites:
sudo apt install build-essential pkg-config clang libclang-dev libavcodec-dev libavformat-dev libavutil-dev libswresample-dev libswscale-dev libavdevice-dev libavfilter-dev libasound2-dev libvulkan-dev mesa-vulkan-drivers libxkbcommon-dev libwayland-dev libx11-dev libudev-dev
curl https://sh.rustup.rs -sSf | sh
./build-linux.sh # or: cargo build --release (sets LIBCLANG_PATH for you)
./target/release/tuner /path/to/videos --channels 40
Built and run on Ubuntu 22.04 (FFmpeg 4.4) through WSLg; FFmpeg 4.4 through 7.x are supported.
On Windows the same renderer can be forced for testing with cargo build --release --features wgpu-render.
- Schedule. Files are shuffled deterministically and dealt round-robin into channels. Each
channel is a loop of its files;
(now + ch * 997) mod loop_lengthsays what's on and how far in. Restart the app and every channel is where it would have been. - Priming. Worker threads keep every idle channel's pipeline seeked to the keyframe before "now" with that frame already decoded. The two neighbours of the current channel are kept fully caught up (video and audio at the schedule point) so Up/Down is frame-exact with sound queued.
- Tune. The UI thread puts snow up and sends one message. The decode thread hands its pipeline back to the slot, takes the target's, ships the primed frame. No file I/O or decoder setup on the hot path; a cold open only happens if a worker hadn't reached that channel yet.
- Presenting. One HLSL pass does NV12/yuv420p to RGB, letterboxing, snow, the tube warm-up and lock-in wobble, and composites a CPU-drawn ARGB overlay (OSD, banner, guide). The CRT pass renders that composite through a second shader. Present is tearing-enabled and never blocks.
- Audio. One cpal output stream fed from a ring; the callback mixes white noise in proportion to the on-screen snow and applies the volume/mute gain.
- Networks and idents. Logo PNGs are decoded once and box-filtered to size on first use.
Idents are probed like library files and appended with a
bumperflag; the schedule builder inserts one after every program, so "now/next" walks past them. - Weather. The weather channel has an empty schedule; tuning it parks the decode thread and
shows the WebView2 control (a child HWND, so it paints above the D3D11 swapchain and outside the
CRT pass). The page is
assets/ws3kp, mapped into WebView2 as a virtual host, so nothing runs besides the tuner; seeassets/ws3kp/VENDORED.md.
Font: VCR OSD Mono by Riciery Leal.
GPL-3.0-or-later. See LICENSE and NOTICES.md.