Take video screenshots after 50% of frames instead of 60secs of video by default, to support thumbnailing shorter videos

Author: tykling

src/bma_client_lib/bma_client.py

@@ -202,22 +202,18 @@ def _handle_thumbnail_source_job(self, job: ThumbnailSourceJob, fileinfo: dict[s
         # unsupported filetype
         raise JobNotSupportedError(job=job)
 
-    def _get_video_screenshot(self, job: ThumbnailSourceJob, seconds: int = 60) -> Image.Image:
-        """Get a screenshot a certain number of seconds into the video."""
+    def _get_video_screenshot(self, job: ThumbnailSourceJob, percent: int = 50) -> Image.Image:
+        """Get a screenshot a certain percent of frames into the video."""
         path = self.path / job.source_url[1:]
-        cam = cv2.VideoCapture(path)
-        fps = int(cam.get(cv2.CAP_PROP_FPS))
-        currentframe = 0
-        while True:
-            ret, frame = cam.read()
-            if ret:
-                if currentframe > 0 and currentframe % (fps * seconds) == 0:
-                    # take screenshot
-                    break
-                currentframe += 1
-            else:
-                raise JobNotSupportedError(job=job)
-        cam.release()
+        cap = cv2.VideoCapture(path)
+        frames = int(cap.get(cv2.CAP_PROP_FRAME_COUNT))
+        ss_frame = int((frames / 100) * percent)
+        logger.debug(f"Getting video screenshot from frame {ss_frame} out of total {frames} frames in video {path} for job {job}")
+        cap.set(cv2.CAP_PROP_POS_FRAMES, ss_frame-1)
+        ret, frame = cap.read()
+        if not ret:
+            raise JobNotSupportedError(job=job)
+        cap.release()
         cv2.destroyAllWindows()
         return frame  # type: ignore[no-any-return]