Add camera streaming guide with all access methods

Comprehensive documentation for accessing the DWARF camera streams:
- RTSP URLs and channels (ch0=tele, ch1=wide)
- The critical prerequisite: camera must be opened via WebSocket first
- ffmpeg commands for frame capture, timelapse, and video recording
- mpv and VLC usage with TCP transport
- Python/OpenCV integration example
- Troubleshooting common issues (black image, connection refused, VLC delay)
- Comparison of RTSP vs MJPEG modes across device models

💘 Generated with Crush

Assisted-by: Crush:glm-5.2

dwarfctl/cmd/rtsp-test/main.go

@@ -0,0 +1,71 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"time"
+
+	"github.com/antitbone/dwarfctl/internal/api"
+)
+
+func main() {
+	ip := "192.168.88.1"
+	if len(os.Args) > 1 {
+		ip = os.Args[1]
+	}
+
+	scope := api.New("rtsp-test")
+	scope.SetDebug(true)
+	fmt.Println("Connecting to", ip)
+	if err := scope.Connect(ip); err != nil {
+		die("connect: %v", err)
+	}
+	defer scope.Close()
+
+	fmt.Println("Opening wide camera...")
+	if err := scope.OpenCamera(api.CameraWide); err != nil {
+		die("open camera: %v", err)
+	}
+	fmt.Println("Wide camera opened. Waiting 3s for stream to initialize...")
+	time.Sleep(3 * time.Second)
+
+	url := fmt.Sprintf("rtsp://%s:554/ch1/stream0", ip)
+	out := "/tmp/rtsp_test_frame.jpg"
+	fmt.Println("Grabbing frame via ffmpeg...")
+	cmd := exec.Command("ffmpeg", "-rtsp_transport", "tcp",
+		"-i", url, "-frames:v", "1", "-q:v", "2", "-y", out)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	if err := cmd.Run(); err != nil {
+		die("ffmpeg: %v", err)
+	}
+
+	info, _ := os.Stat(out)
+	if info != nil {
+		fmt.Printf("SUCCESS: frame saved (%d bytes)\n", info.Size())
+	}
+
+	// Also try tele
+	fmt.Println("\nOpening tele camera...")
+	if err := scope.OpenCamera(api.CameraTele); err != nil {
+		die("open tele: %v", err)
+	}
+	time.Sleep(3 * time.Second)
+	url0 := fmt.Sprintf("rtsp://%s:554/ch0/stream0", ip)
+	out0 := "/tmp/rtsp_test_tele.jpg"
+	fmt.Println("Grabbing tele frame...")
+	cmd0 := exec.Command("ffmpeg", "-rtsp_transport", "tcp",
+		"-i", url0, "-frames:v", "1", "-q:v", "2", "-y", out0)
+	cmd0.Stdout = os.Stdout
+	cmd0.Stderr = os.Stderr
+	cmd0.Run()
+	if i, _ := os.Stat(out0); i != nil {
+		fmt.Printf("SUCCESS: tele frame saved (%d bytes)\n", i.Size())
+	}
+}
+
+func die(format string, args ...any) {
+	fmt.Fprintf(os.Stderr, "ERROR: "+format+"\n", args...)
+	os.Exit(1)
+}