wip yuv_rgb refactor

frigate/util.py

@@ -149,85 +149,94 @@ def get_yuv_crop(frame_shape, crop):
     return y, u1, u2, v1, v2
 
 
+def yuv_crop_and_resize(frame, region, height=None):
+    # Crops and resizes a YUV frame while maintaining aspect ratio
+    # https://stackoverflow.com/a/57022634
+    height = frame.shape[0] // 3 * 2
+    width = frame.shape[1]
+
+    # get the crop box if the region extends beyond the frame
+    crop_x1 = max(0, region[0])
+    crop_y1 = max(0, region[1])
+    # ensure these are a multiple of 4
+    crop_x2 = min(width, region[2])
+    crop_y2 = min(height, region[3])
+    crop_box = (crop_x1, crop_y1, crop_x2, crop_y2)
+
+    y, u1, u2, v1, v2 = get_yuv_crop(frame.shape, crop_box)
+
+    # if the region starts outside the frame, indent the start point in the cropped frame
+    y_channel_x_offset = abs(min(0, region[0]))
+    y_channel_y_offset = abs(min(0, region[1]))
+
+    uv_channel_x_offset = y_channel_x_offset // 2
+    uv_channel_y_offset = y_channel_y_offset // 4
+
+    # create the yuv region frame
+    # make sure the size is a multiple of 4
+    # TODO: this should be based on the size after resize now
+    size = (region[3] - region[1]) // 4 * 4
+    yuv_cropped_frame = np.zeros((size + size // 2, size), np.uint8)
+    # fill in black
+    yuv_cropped_frame[:] = 128
+    yuv_cropped_frame[0:size, 0:size] = 16
+
+    # copy the y channel
+    yuv_cropped_frame[
+        y_channel_y_offset : y_channel_y_offset + y[3] - y[1],
+        y_channel_x_offset : y_channel_x_offset + y[2] - y[0],
+    ] = frame[y[1] : y[3], y[0] : y[2]]
+
+    uv_crop_width = u1[2] - u1[0]
+    uv_crop_height = u1[3] - u1[1]
+
+    # copy u1
+    yuv_cropped_frame[
+        size + uv_channel_y_offset : size + uv_channel_y_offset + uv_crop_height,
+        0 + uv_channel_x_offset : 0 + uv_channel_x_offset + uv_crop_width,
+    ] = frame[u1[1] : u1[3], u1[0] : u1[2]]
+
+    # copy u2
+    yuv_cropped_frame[
+        size + uv_channel_y_offset : size + uv_channel_y_offset + uv_crop_height,
+        size // 2
+        + uv_channel_x_offset : size // 2
+        + uv_channel_x_offset
+        + uv_crop_width,
+    ] = frame[u2[1] : u2[3], u2[0] : u2[2]]
+
+    # copy v1
+    yuv_cropped_frame[
+        size
+        + size // 4
+        + uv_channel_y_offset : size
+        + size // 4
+        + uv_channel_y_offset
+        + uv_crop_height,
+        0 + uv_channel_x_offset : 0 + uv_channel_x_offset + uv_crop_width,
+    ] = frame[v1[1] : v1[3], v1[0] : v1[2]]
+
+    # copy v2
+    yuv_cropped_frame[
+        size
+        + size // 4
+        + uv_channel_y_offset : size
+        + size // 4
+        + uv_channel_y_offset
+        + uv_crop_height,
+        size // 2
+        + uv_channel_x_offset : size // 2
+        + uv_channel_x_offset
+        + uv_crop_width,
+    ] = frame[v2[1] : v2[3], v2[0] : v2[2]]
+
+    return yuv_cropped_frame
+
+
 def yuv_region_2_rgb(frame, region):
     try:
-        height = frame.shape[0] // 3 * 2
-        width = frame.shape[1]
-
-        # get the crop box if the region extends beyond the frame
-        crop_x1 = max(0, region[0])
-        crop_y1 = max(0, region[1])
-        # ensure these are a multiple of 4
-        crop_x2 = min(width, region[2])
-        crop_y2 = min(height, region[3])
-        crop_box = (crop_x1, crop_y1, crop_x2, crop_y2)
-
-        y, u1, u2, v1, v2 = get_yuv_crop(frame.shape, crop_box)
-
-        # if the region starts outside the frame, indent the start point in the cropped frame
-        y_channel_x_offset = abs(min(0, region[0]))
-        y_channel_y_offset = abs(min(0, region[1]))
-
-        uv_channel_x_offset = y_channel_x_offset // 2
-        uv_channel_y_offset = y_channel_y_offset // 4
-
-        # create the yuv region frame
-        # make sure the size is a multiple of 4
-        size = (region[3] - region[1]) // 4 * 4
-        yuv_cropped_frame = np.zeros((size + size // 2, size), np.uint8)
-        # fill in black
-        yuv_cropped_frame[:] = 128
-        yuv_cropped_frame[0:size, 0:size] = 16
-
-        # copy the y channel
-        yuv_cropped_frame[
-            y_channel_y_offset : y_channel_y_offset + y[3] - y[1],
-            y_channel_x_offset : y_channel_x_offset + y[2] - y[0],
-        ] = frame[y[1] : y[3], y[0] : y[2]]
-
-        uv_crop_width = u1[2] - u1[0]
-        uv_crop_height = u1[3] - u1[1]
-
-        # copy u1
-        yuv_cropped_frame[
-            size + uv_channel_y_offset : size + uv_channel_y_offset + uv_crop_height,
-            0 + uv_channel_x_offset : 0 + uv_channel_x_offset + uv_crop_width,
-        ] = frame[u1[1] : u1[3], u1[0] : u1[2]]
-
-        # copy u2
-        yuv_cropped_frame[
-            size + uv_channel_y_offset : size + uv_channel_y_offset + uv_crop_height,
-            size // 2
-            + uv_channel_x_offset : size // 2
-            + uv_channel_x_offset
-            + uv_crop_width,
-        ] = frame[u2[1] : u2[3], u2[0] : u2[2]]
-
-        # copy v1
-        yuv_cropped_frame[
-            size
-            + size // 4
-            + uv_channel_y_offset : size
-            + size // 4
-            + uv_channel_y_offset
-            + uv_crop_height,
-            0 + uv_channel_x_offset : 0 + uv_channel_x_offset + uv_crop_width,
-        ] = frame[v1[1] : v1[3], v1[0] : v1[2]]
-
-        # copy v2
-        yuv_cropped_frame[
-            size
-            + size // 4
-            + uv_channel_y_offset : size
-            + size // 4
-            + uv_channel_y_offset
-            + uv_crop_height,
-            size // 2
-            + uv_channel_x_offset : size // 2
-            + uv_channel_x_offset
-            + uv_crop_width,
-        ] = frame[v2[1] : v2[3], v2[0] : v2[2]]
-
+        # TODO: does this copy the numpy array?
+        yuv_cropped_frame = yuv_crop_and_resize(frame, region)
         return cv2.cvtColor(yuv_cropped_frame, cv2.COLOR_YUV2RGB_I420)
     except:
         print(f"frame.shape: {frame.shape}")