# AsciiCam

Real-time ASCII video from your webcam in the terminal - pure C99, no heavy runtime dependencies.

<img src="assets/demo.gif" width="325">

### Edge detection + threshold plugin

<img src="assets/demo-edgedetection.gif" width="325">

---

## Features

| Feature                   | Details                                                                               |
| ------------------------- | ------------------------------------------------------------------------------------- |
| **YUYV to grayscale**     | SSE2 SIMD (`yuyv_to_gray_simd`) - 16 pixels per iteration on x86_64, NEON on ARM64    |
| **YUYV to RGB**           | Fixed‑point BT.601 conversion for truecolor output                                    |
| **Multiple render modes** | Braille (`⠿`), Blocks (`█ ░`), ASCII ramp, Half‑block, Dots - switch live with `m`/`M` |
| **Edge detection**        | Sobel, Sobel with direction, Laplacian - toggle with `x`/`X`                          |
| **Hot‑reloadable charsets**| Load `.txt` ramps from a directory, switch with `n`/`N`, monitor with inotify          |
| **Pseudo‑3D depth pop**   | Parallax effect based on brightness - adjust with `+`/`-`/`v`                         |
| **Floyd‑Steinberg dither**| Error‑diffusion to reduce banding                                                     |
| **ANSI truecolor**        | `\033[38;2;R;G;Bm` per‑cell coloring                                                  |
| **Hot‑reload plugin system**| `inotify` + `dlopen` - rebuild a filter `.so`, it reloads live                       |
| **FPS‑capped render loop**| `CLOCK_MONOTONIC` + `nanosleep` frame pacing                                         |
| **Producer/consumer threads**| Double‑buffered capture + render (stubbed in main loop, active in `thread_sharing.c`) |
| **Cross‑platform**        | Linux (V4L2, nolibc) and macOS (AVFoundation, system libc)                           |


Linux: requires `gcc`, `linux/videodev2.h` (kernel headers), `libdl`, `libpthread`.
macOS: requires `Clang` and `AVFoundation` frameworks (linked automatically).

No other external dependencies.

---

## Build

```bash
git clone https://github.com/Harshit-Dhanwalkar/AsciiCam.git
cd AsciiCam/C/
make
```

Requires: `gcc`, `linux/videodev2.h` (kernel headers), `libdl`, `libpthread`.
No other external dependencies.

```
build/webcam_ascii --help
```

---

## Run

```bash
# Basic (grayscale, 80×40, /dev/video0)
./build/webcam_ascii

# Truecolor output
./build/webcam_ascii -C

# With all three plugins
./build/webcam_ascii -p build/invert.so -p build/threshold.so -p build/edge_detect.so

# Edge detection mode, custom resolution
./build/webcam_ascii -e -w 320 -h 240 -W 120 -H 50

# Dithering + inverted charset
./build/webcam_ascii -D -i
```

---

## Plugin system

Plugins are shared objects (`.so`).

```bash
gcc -O2 -fPIC -shared -Iinclude filters/my_filter.c -o build/my_filter.so
./build/webcam_ascii -p build/my_filter.so
```

**Hot-reload:** the binary watches the `.so` with `inotify`. Recompile it while the viewer is running and it reloads automatically within $\approx$100 ms.

**Runtime controls:**
| Key | Action |
|---|---|
| `↑` / `↓` | select plugin |
| `[` / `]` | param $\pm$1 |
| `{` / `}` | param $\pm$10 |
| `r` | reset param to 128 |
| `q` | quit |

---

## TODO

- [x] Adjustable capture resolution
- [x] Producer/consumer thread split (double-buffered)
- [x] Brightness / contrast adjustment
- [x] Invert brightness to charset mapping
- [x] ANSI truecolor output
- [x] Floyd-Steinberg dithering
- [x] Sobel edge detection
- [x] SIMD YUYV to grayscale (SSE2)
- [x] Hot-reload plugin system
- [x] nolibc - zero libc calls
- [x] Custom charset via config file
- [ ] Record to `.mp4` / `.gif`
- [ ] Inter-frame delta compression
- [ ] LUT cache optimization
- [ ] Replace `pthread` with raw `futex` syscalls
- [ ] Replace `dlopen` with a minimal ELF loader
- [ ] Custom threading library using `clone()` + `futex` to eliminate `-lpthread` (`pthread` functions) dependency
- [ ] Implement an ELF loader (or statically link plugins) to eliminate `-ldl` (`dlopen`/`dlsym`/`dlclose` which are part of `libdl.so` also `glibc`) dependency
- [x] MacOS support
  - [ ] Color support for MacOS
- [ ] Windows support

## Fixes
- [x] [Issue #2](https://github.com/Harshit-Dhanwalkar/AsciiCam/issues/2) MacOS support
  - [x] Rewrite `capture.c` for MacOS port using [AVFoundation](https://developer.apple.com/library/archive/documentation/AudioVideo/Conceptual/AVFoundationPG/Articles/04_MediaCapture.html). ([Stackoverflow : how do I set up a video input using the AVFoundation framework](https://stackoverflow.com/questions/32053460/how-do-i-set-up-a-video-input-using-the-avfoundation-framework))

---

Project is under [PolyForm Noncommercial License BY-NC](LICENCE).
For commercial use contact *harshitpd1729@gmail.com*.