FFmpegProcessor.crop() returns asset with correct dimensions.

eseifert · Aug 6, 2018 · addaf8c · addaf8c
1 parent a3c4cbd
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Showing 2 changed files with 30 additions and 1 deletion.
diff --git a/madam/ffmpeg.py b/madam/ffmpeg.py
@@ -427,7 +427,24 @@ def crop(self, asset, x, y, width, height):
         if min_x == asset.width or min_y == asset.height or max_x <= min_x or max_y <= min_y:
             raise OperatorError('Invalid cropping area: <x=%r, y=%r, width=%r, height=%r>' % (x, y, width, height))
 
-        return None
+        width = max_x - min_x
+        height = max_y - min_y
+
+        result = io.BytesIO()
+        with _FFmpegContext(asset.essence, result) as ctx:
+            command = ['ffmpeg', '-v', 'error',
+                       '-i', ctx.input_path, '-codec', 'copy',
+                       '-f:v', 'crop=w=%d:h=%d:x=%d:y=%d' % (width, height, x, y),
+                       '-f', encoder_name, '-y', ctx.output_path]
+
+            try:
+                subprocess_run(command, stderr=subprocess.PIPE, check=True)
+            except CalledProcessError as ffmpeg_error:
+                error_message = ffmpeg_error.stderr.decode('utf-8')
+                raise OperatorError('Could not convert video asset: %s' % error_message)
+
+        return Asset(essence=result, mime_type=mime_type,
+                     width=width, height=height)
 
 
 class FFmpegMetadataProcessor(MetadataProcessor):

diff --git a/tests/test_video.py b/tests/test_video.py
@@ -237,6 +237,18 @@ def test_crop_with_original_dimensions_returns_identical_asset(self, processor,
 
         assert cropped_asset is video_asset
 
+    def test_crop_returns_asset_with_correct_dimensions(self, processor, video_asset):
+        crop_width = video_asset.width // 2
+        crop_height = video_asset.height // 2
+        crop_x = (video_asset.width - crop_width) // 2
+        crop_y = (video_asset.height - crop_height) // 2
+        crop_operator = processor.crop(x=crop_x, y=crop_y, width=crop_width, height=crop_height)
+
+        cropped_asset = crop_operator(video_asset)
+
+        assert cropped_asset.width == crop_width
+        assert cropped_asset.height == crop_height
+
     @pytest.mark.parametrize('x, y, width, height', [
         (-DEFAULT_WIDTH, -DEFAULT_HEIGHT, DEFAULT_WIDTH, DEFAULT_HEIGHT),
         (DEFAULT_WIDTH, DEFAULT_HEIGHT, DEFAULT_WIDTH, DEFAULT_HEIGHT),