# stream_send_cli

Captures MJPEG from a V4L2 device and streams it to a receiver over TCP as `VIDEO_FRAME` protocol messages. Prints per-stream throughput statistics. Pair with [`stream_recv_cli`](stream_recv_cli.md) to test an end-to-end stream without running a full node.

---

## Build

From the repository root:

```sh
make cli
```

The binary is placed in `build/cli/`.

---

## Usage

```sh
./stream_send_cli [--device PATH] [--host HOST] [--port PORT] [--stream-id N]
```

| Option | Default | Description |
|---|---|---|
| `--device PATH` | `/dev/video0` | V4L2 capture device |
| `--host HOST` | `127.0.0.1` | Receiver hostname or IP |
| `--port PORT` | `7700` | Receiver TCP port |
| `--stream-id N` | `1` | Stream ID embedded in each `VIDEO_FRAME` message |

### Example

```sh
# Terminal 1 — start a receiver
./stream_recv_cli --port 7700

# Terminal 2 — start the sender
./stream_send_cli --device /dev/video0 --host 127.0.0.1 --port 7700 --stream-id 1
```

### Statistics output

Printed to stderr every 0.5 seconds:

```
stream 1: 30.2 fps  18.4 Mbps
```

---

## Notes

- The tool opens the device and selects the highest-FPS MJPEG mode automatically.
- Frames are sent as-is (raw MJPEG from the kernel) wrapped in `VIDEO_FRAME` messages — no re-encoding.
- The connection is outbound: `stream_send_cli` connects to the receiver, not the other way around. This mirrors the node's START_INGEST behaviour.

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## Relationship to the Video Routing System

`stream_send_cli` tests the source end of the ingest pipeline: V4L2 capture → transport send → `VIDEO_FRAME` messages. The node's ingest module performs the same operation, but driven by `START_INGEST` commands over the control channel.

See also: [`stream_recv_cli.md`](stream_recv_cli.md) for the receive side; [`v4l2_view_cli.md`](v4l2_view_cli.md) for local-only viewing.