def __call__(self, video: FieldFile):
# Get the MIME type string of this video.
videoContentType = magic.from_buffer(video.read(), mime=True)
# Point the cursor to the beginning of the file.
video.seek(0)
if videoContentType not in self.allowedContentTypes:
raise ValidationError(
'The file type %(contentType)s is not supported.',
params={'contentType': videoContentType})
def get_preview(file: FieldFile) -> bytes:
"""
Retrieves frame from the middle of video as preview image
"""
temp_filename = os.path.join(tempfile.gettempdir(), str(uuid.uuid4()))
with open(temp_filename, "wb") as _file:
file.seek(0)
_file.write(file.read())
capture = cv2.VideoCapture(temp_filename)
frame_count = int(capture.get(cv2.CAP_PROP_FRAME_COUNT))
capture.set(cv2.CAP_PROP_POS_FRAMES, round(frame_count / 2))
capture.grab()
retval, img = capture.retrieve(0)
image_bytes = cv2.imencode("temp/preview.jpg", img)[1].tobytes()
capture.release()
os.remove(temp_filename)
return image_bytes
