SetFrameBuffer returns error

README.md

@@ -32,7 +32,7 @@ FPS() float64
 Codec() string
 AudioCodec() string
 FrameBuffer() []byte
-SetFrameBuffer(buffer []byte)
+SetFrameBuffer(buffer []byte) error
 
 Read() bool
 Close()
@@ -54,7 +54,7 @@ Depth() int
 FPS() float64
 Codec() string
 FrameBuffer() []byte
-SetFrameBuffer(buffer []byte)
+SetFrameBuffer(buffer []byte) error
 
 Read() bool
 Close()

camera.go

@@ -51,10 +51,14 @@ func (camera *Camera) FrameBuffer() []byte {
 	return camera.framebuffer
 }
 
-// Sets the framebuffer to the given byte array. Note that "buffer" must be large enough
-// to store one frame of video data which is width*height*3.
-func (camera *Camera) SetFrameBuffer(buffer []byte) {
+func (camera *Camera) SetFrameBuffer(buffer []byte) error {
+	size := camera.width * camera.height * camera.depth
+	if len(buffer) < size {
+		return fmt.Errorf("buffer size %d is smaller than frame size %d", len(buffer), size)
+	}
+
 	camera.framebuffer = buffer
+	return nil
 }
 
 // Returns the webcam device name.
@@ -200,7 +204,10 @@ func initCamera(camera *Camera) error {
 		return err
 	}
 
-	camera.framebuffer = make([]byte, camera.width*camera.height*camera.depth)
+	if camera.framebuffer == nil {
+		camera.framebuffer = make([]byte, camera.width*camera.height*camera.depth)
+	}
+
 	return nil
 }
 

video.go

@@ -72,10 +72,14 @@ func (video *Video) FrameBuffer() []byte {
 	return video.framebuffer
 }
 
-// Sets the framebuffer to the given byte array. Note that "buffer" must be large enough
-// to store one frame of video data which is width*height*3.
-func (video *Video) SetFrameBuffer(buffer []byte) {
+func (video *Video) SetFrameBuffer(buffer []byte) error {
+	size := video.width * video.height * video.depth
+	if len(buffer) < size {
+		return fmt.Errorf("buffer size %d is smaller than frame size %d", len(buffer), size)
+	}
+
 	video.framebuffer = buffer
+	return nil
 }
 
 // Creates a new Video struct.
@@ -136,7 +140,10 @@ func initVideo(video *Video) error {
 		return err
 	}
 
-	video.framebuffer = make([]byte, video.width*video.height*video.depth)
+	if video.framebuffer == nil {
+		video.framebuffer = make([]byte, video.width*video.height*video.depth)
+	}
+
 	return nil
 }
 

vidio_test.go

@@ -12,6 +12,23 @@ func assertEquals(actual, expected interface{}) {
 	}
 }
 
+func TestSetBuffer(t *testing.T) {
+	video, err := NewVideo("test/koala.mp4")
+	if err != nil {
+		panic(err)
+	}
+	defer video.Close()
+
+	size := video.width*video.height*video.depth + 101
+	video.SetFrameBuffer(make([]uint8, size))
+
+	video.Read()
+
+	assertEquals(len(video.framebuffer), size)
+
+	fmt.Println("Set Buffer Test Passed")
+}
+
 func TestVideoMetaData(t *testing.T) {
 	video, err := NewVideo("test/koala.mp4")
 	if err != nil {