webcam

2026-03-08 22:31:11 -05:00
parent 6c05960400
commit 78a79ea3e1
27 changed files with 1352 additions and 12 deletions
@@ -0,0 +1,161 @@
+//go:build windows
+
+package capture
+
+import (
+	"fmt"
+	"math"
+
+	cam "github.com/Kirizu-Official/windows-camera-go/camera/v1"
+)
+
+type WebcamDeviceInfo struct {
+	Index  int
+	Name   string
+	MaxFPS int
+}
+
+func ListWebcams() ([]WebcamDeviceInfo, error) {
+	webcamMu.Lock()
+	defer webcamMu.Unlock()
+
+	temporaryInit := false
+	if !webcamInitDone {
+		if err := cam.Init(); err != nil {
+			return nil, fmt.Errorf("webcam init failed: %w", err)
+		}
+		webcamInitDone = true
+		temporaryInit = true
+	}
+
+	devices, err := cam.EnumDevice()
+	if err != nil {
+		if temporaryInit && webcamActive == nil {
+			cam.Shutdown()
+			webcamInitDone = false
+		}
+		return nil, fmt.Errorf("webcam enumerate failed: %w", err)
+	}
+
+	out := make([]WebcamDeviceInfo, 0, len(devices))
+	for i, dev := range devices {
+		name := dev.Name
+		if name == "" {
+			name = fmt.Sprintf("Camera %d", i+1)
+		}
+		maxFPS := 30
+		if webcamActive != nil && webcamActive.deviceIndex == i && webcamActive.captureFPS > 0 {
+			maxFPS = int(math.Round(webcamActive.captureFPS))
+		} else if fps, fpsErr := webcamMaxSupportedFPSNoLock(dev.SymbolLink); fpsErr == nil && fps > 0 {
+			maxFPS = fps
+		}
+		out = append(out, WebcamDeviceInfo{Index: i, Name: name, MaxFPS: maxFPS})
+	}
+
+	if temporaryInit && webcamActive == nil {
+		cam.Shutdown()
+		webcamInitDone = false
+	}
+
+	return out, nil
+}
+
+func ClampWebcamFPS(deviceIndex int, requestedFPS int, useMax bool) (int, error) {
+	if requestedFPS < 1 {
+		requestedFPS = 30
+	}
+	if requestedFPS > 120 {
+		requestedFPS = 120
+	}
+
+	maxFPS, err := webcamMaxSupportedFPS(deviceIndex)
+	if err != nil {
+		return requestedFPS, err
+	}
+	if maxFPS <= 0 {
+		return requestedFPS, nil
+	}
+	if useMax || requestedFPS > maxFPS {
+		return maxFPS, nil
+	}
+	return requestedFPS, nil
+}
+
+func webcamMaxSupportedFPS(deviceIndex int) (int, error) {
+	webcamMu.Lock()
+	defer webcamMu.Unlock()
+
+	if webcamActive != nil && webcamActive.deviceIndex == deviceIndex && webcamActive.captureFPS > 0 {
+		return int(math.Round(webcamActive.captureFPS)), nil
+	}
+
+	temporaryInit := false
+	if !webcamInitDone {
+		if err := cam.Init(); err != nil {
+			return 0, fmt.Errorf("webcam init failed: %w", err)
+		}
+		webcamInitDone = true
+		temporaryInit = true
+	}
+
+	devices, err := cam.EnumDevice()
+	if err != nil {
+		if temporaryInit && webcamActive == nil {
+			cam.Shutdown()
+			webcamInitDone = false
+		}
+		return 0, fmt.Errorf("webcam enumerate failed: %w", err)
+	}
+	if len(devices) == 0 {
+		if temporaryInit && webcamActive == nil {
+			cam.Shutdown()
+			webcamInitDone = false
+		}
+		return 0, fmt.Errorf("no webcam devices detected")
+	}
+	if deviceIndex < 0 || deviceIndex >= len(devices) {
+		deviceIndex = 0
+	}
+
+	maxFPS, err := webcamMaxSupportedFPSNoLock(devices[deviceIndex].SymbolLink)
+	if err != nil {
+		if temporaryInit && webcamActive == nil {
+			cam.Shutdown()
+			webcamInitDone = false
+		}
+		return 0, err
+	}
+
+	if temporaryInit && webcamActive == nil {
+		cam.Shutdown()
+		webcamInitDone = false
+	}
+
+	return maxFPS, nil
+}
+
+func webcamMaxSupportedFPSNoLock(symbolLink string) (int, error) {
+	device, err := cam.OpenDevice(symbolLink)
+	if err != nil {
+		return 0, fmt.Errorf("open webcam failed: %w", err)
+	}
+	defer device.CloseDevice()
+
+	formats, err := device.EnumerateCaptureFormats()
+	if err != nil {
+		return 0, fmt.Errorf("enumerate webcam formats failed: %w", err)
+	}
+
+	maxFPS := 0
+	for _, format := range formats {
+		if !isJPEGSubtype(format) && !isH264Subtype(format) {
+			continue
+		}
+		fps := int(math.Round(format.Fps))
+		if fps > maxFPS {
+			maxFPS = fps
+		}
+	}
+
+	return maxFPS, nil
+}