Adding new calls and examples for capture pipeline

device/device.go

@@ -80,9 +80,7 @@ func Open(path string, options ...Option) (*Device, error) {
 	}
 
 	// ensures IOType is set, only MemMap supported now
-	//if reflect.ValueOf(dev.config.ioType).IsZero() {
 	dev.config.ioType = v4l2.IOTypeMMAP
-	//}
 
 	// reset crop, only if cropping supported
 	if cropcap, err := v4l2.GetCropCapability(dev.fd, dev.bufType); err == nil {
@@ -425,19 +423,3 @@ func (d *Device) startStreamLoop(ctx context.Context) error {
 
 	return nil
 }
-
-// prepareCaptureBuffer prepares a frame buffer for stream capture
-func (d *Device) prepareCaptureBuffer(fd uintptr, ioType v4l2.IOType, bufType v4l2.BufType) (v4l2.Buffer, error) {
-	bufInfo, err := v4l2.DequeueBuffer(fd, ioType, bufType)
-	if err != nil {
-		return v4l2.Buffer{}, fmt.Errorf("capture buffer info: dequeue: %w", err)
-	}
-
-	// requeue/clear used buffer, prepare for next read
-	if _, err := v4l2.QueueBuffer(fd, ioType, bufType, bufInfo.Index); err != nil {
-		return v4l2.Buffer{}, fmt.Errorf("capture buffer info: queue: %w", err)
-	}
-
-	// return captured buffer info
-	return bufInfo, nil
-}

examples/ccapture/README.md

@@ -0,0 +1,30 @@
+# V4L2 video capture example in C
+
+This an example in C showing a minimally required steps to capture video using V4L2. This is can be used to run tests on devices and compare results with the Go4VL code.
+
+## Build and run
+On a Linux machine, run the following:
+
+```
+gcc -o capture capture.c
+```
+
+Run the program using:
+
+```
+./capture
+```
+
+Or, run `--help` to see available flags:
+
+```
+./capture --help
+```
+
+## Debugging with `strace`
+
+To view the ioctl calls made when running the capture program:
+
+```
+strace -o trace.log -e trace=ioctl  ./capture
+```