# MXL Multiviewer

Small Vulkan/SDL3 multiviewer for test feeds and MXL SDK video flows.

## Dependencies

Install:

- CMake 3.20+
- C++20 compiler
- Vulkan loader and headers
- Vulkan driver for the target GPU
- SDL3 development package with `pkg-config` support
- `glslangValidator`

On Ubuntu/Debian-like systems the packages are usually similar to:

```bash
sudo apt install cmake g++ pkg-config libvulkan-dev vulkan-tools glslang-tools libsdl3-dev
```

Check that the discrete GPU is visible:

```bash
vulkaninfo --summary
```

## Build Without MXL SDK

This builds synthetic feeds, SMPTE bars, and no-signal mode:

```bash
cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build -j
```

Run a synthetic v210 test grid:

```bash
./build/mxl_multiviewer --perf --grid 4x4 v210 v210 v210 v210 v210 v210 v210 v210 v210
```

## Build With MXL SDK

Set `MXL_SDK_ROOT` to the SDK checkout/root that contains `lib/include` and `build/Linux-Clang-Release/lib`:

```bash
cmake -S . -B build-sdk \
  -DCMAKE_BUILD_TYPE=Release \
  -DMXL_MULTIVIEWER_ENABLE_MXL_SDK=ON \
  -DMXL_SDK_ROOT=/path/to/mxl-sdk

cmake --build build-sdk -j
```

Run with an existing feed config:

```bash
./build-sdk/mxl_multiviewer --perf --grid 4x4 --config /tmp/feeds_config.json
```

Useful probe flags:

```bash
--v210-upload-worker
--adaptive-feed-texture
--v210-staging-memory default|cached|device-local
```

Example:

```bash
./build-sdk/mxl_multiviewer \
  --adaptive-feed-texture \
  --v210-upload-worker \
  --perf \
  --grid 4x4 \
  --config /tmp/feeds_config.json
```

## Notes

- Run from the repository root or keep the `shaders/` directory next to the executable path expected by the app.
- If SDL opens on the wrong GPU/session, try running from the desktop session attached to the discrete GPU and confirm with `vulkaninfo --summary`.
- `v210_test` is a CPU-side conversion sanity check:

```bash
./build/v210_test
```