Add support for YUYV/YUY2 format

camera/camera_linux.go

@@ -6,9 +6,10 @@ package camera
 import (
 	"fmt"
 	"image"
+	"io"
+	"slices"
 
 	"github.com/korandiz/v4l"
-	"github.com/korandiz/v4l/fmt/mjpeg"
 
 	im "github.com/gen2brain/cam2ip/image"
 )
@@ -17,12 +18,14 @@ import (
 type Camera struct {
 	opts   Options
 	camera *v4l.Device
+	config v4l.DeviceConfig
+	ycbcr  *image.YCbCr
 }
 
 // New returns new Camera for given camera index.
-func New(opts Options) (camera *Camera, err error) {
-	camera = &Camera{}
-	camera.opts = opts
+func New(opts Options) (c *Camera, err error) {
+	c = &Camera{}
+	c.opts = opts
 
 	devices := v4l.FindDevices()
 	if len(devices) < opts.Index+1 {
@@ -31,40 +34,65 @@ func New(opts Options) (camera *Camera, err error) {
 		return
 	}
 
-	camera.camera, err = v4l.Open(devices[opts.Index].Path)
+	c.camera, err = v4l.Open(devices[opts.Index].Path)
 	if err != nil {
 		err = fmt.Errorf("camera: %w", err)
 
 		return
 	}
 
-	if camera.camera == nil {
+	if c.camera == nil {
 		err = fmt.Errorf("camera: can not open camera %d", opts.Index)
 
 		return
 	}
 
-	config, err := camera.camera.GetConfig()
-	if err != nil {
-		err = fmt.Errorf("camera: %w", err)
+	configs, e := c.camera.ListConfigs()
+	if e != nil {
+		err = fmt.Errorf("camera: can not list configs: %w", e)
 
 		return
 	}
 
-	config.Format = mjpeg.FourCC
-	config.Width = int(opts.Width)
-	config.Height = int(opts.Height)
+	formats := make([]uint32, 0)
+	for _, config := range configs {
+		formats = append(formats, config.Format)
+	}
 
-	err = camera.camera.SetConfig(config)
+	c.config, err = c.camera.GetConfig()
 	if err != nil {
-		err = fmt.Errorf("camera: %w", err)
+		err = fmt.Errorf("camera: can not get config: %w", err)
 
 		return
 	}
 
-	err = camera.camera.TurnOn()
+	if slices.Contains(formats, mjpgFourCC) {
+		c.config.Format = mjpgFourCC
+	} else if slices.Contains(formats, yuyvFourCC) {
+		c.config.Format = yuyvFourCC
+	} else {
+		err = fmt.Errorf("camera: unsupported format %d", c.config.Format)
+
+		return
+	}
+
+	c.config.Width = int(opts.Width)
+	c.config.Height = int(opts.Height)
+
+	err = c.camera.SetConfig(c.config)
 	if err != nil {
-		err = fmt.Errorf("camera: %w", err)
+		err = fmt.Errorf("camera: format %d: can not set config: %w", c.config.Format, err)
+
+		return
+	}
+
+	if c.config.Format == yuyvFourCC {
+		c.ycbcr = image.NewYCbCr(image.Rect(0, 0, int(c.opts.Width), int(c.opts.Height)), image.YCbCrSubsampleRatio422)
+	}
+
+	err = c.camera.TurnOn()
+	if err != nil {
+		err = fmt.Errorf("camera: format %d: can not turn on: %w", c.config.Format, err)
 
 		return
 	}
@@ -76,16 +104,35 @@ func New(opts Options) (camera *Camera, err error) {
 func (c *Camera) Read() (img image.Image, err error) {
 	buffer, err := c.camera.Capture()
 	if err != nil {
-		err = fmt.Errorf("camera: can not grab frame: %w", err)
+		err = fmt.Errorf("camera: format %d: can not grab frame: %w", c.config.Format, err)
 
 		return
 	}
 
-	img, err = im.NewDecoder(buffer).Decode()
-	if err != nil {
-		err = fmt.Errorf("camera: %w", err)
+	switch c.config.Format {
+	case yuy2FourCC, yuyvFourCC:
+		data, e := io.ReadAll(buffer)
+		if e != nil {
+			err = fmt.Errorf("camera: format %d: can not read buffer: %w", c.config.Format, e)
 
-		return
+			return
+		}
+
+		e = yuy2ToYCbCr422(data, c.ycbcr)
+		if e != nil {
+			err = fmt.Errorf("camera: format %d: can not retrieve frame: %w", c.config.Format, e)
+
+			return
+		}
+
+		img = c.ycbcr
+	case mjpgFourCC:
+		img, err = im.NewDecoder(buffer).Decode()
+		if err != nil {
+			err = fmt.Errorf("camera: format %d: can not decode frame: %w", c.config.Format, err)
+
+			return
+		}
 	}
 
 	if c.opts.Rotate != 0 {
@@ -97,7 +144,7 @@ func (c *Camera) Read() (img image.Image, err error) {
 	}
 
 	if c.opts.Timestamp {
-		img, err = im.Timestamp(img, "")
+		img, err = im.Timestamp(img, c.opts.TimeFormat)
 	}
 
 	return
@@ -106,7 +153,7 @@ func (c *Camera) Read() (img image.Image, err error) {
 // Close closes camera.
 func (c *Camera) Close() (err error) {
 	if c.camera == nil {
-		err = fmt.Errorf("camera: camera is not opened")
+		err = fmt.Errorf("camera: close: camera is not opened")
 
 		return
 	}