def get_video_meta(video_path, one=None):
"""
Return a bunch of video information with the fields ('length', 'fps', 'width', 'height',
'duration', 'size')
:param video_path: A path to the video. May be a file path or URL.
:param one: An instance of ONE
:return: A Bunch of video mata data
"""
is_url = isinstance(video_path, str) and video_path.startswith('http')
cap = VideoStreamer(video_path).cap if is_url else cv2.VideoCapture(str(video_path))
assert cap.isOpened(), f'Failed to open video file {video_path}'
# Get basic properties of video
meta = Bunch()
meta.length = int(cap.get(cv2.CAP_PROP_FRAME_COUNT))
meta.fps = int(cap.get(cv2.CAP_PROP_FPS))
meta.width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
meta.height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
meta.duration = timedelta(seconds=meta.length / meta.fps) if meta.fps > 0 else 0
if is_url and one:
eid = one.eid_from_path(video_path)
name = re.match(r'.*(_iblrig_[a-z]+Camera\.raw\.)(?:[\w-]{36}\.)?(mp4)$', video_path)
det, = one.alyx.rest('datasets', 'list', session=eid, name=''.join(name.groups()))
meta.size = det['file_size']
elif is_url and not one:
meta.size = None
else:
meta.size = Path(video_path).stat().st_size
cap.release()
return meta
def get_video_frames_preload(
video_path,
frame_numbers=None,
mask=Ellipsis,
as_list=False,
func=lambda x: x,
):
"""
Obtain numpy array corresponding to a particular video frame in video_path.
Fetching and returning a list is about 33% faster but may be less memory controlled. NB: Any
gain in speed will be lost if subsequently converted to array.
:param video_path: URL or local path to mp4 file
:param frame_numbers: video frames to be returned. If None, return all frames.
:param mask: a logical mask or slice to apply to frames
:param as_list: if true the frames are returned as a list, this is faster but may be less
memory efficient
:param func: Function to be applied to each frame. Applied after masking if applicable.
:return: numpy array corresponding to frame of interest, or list if as_list is True.
Default dimensions are (n, w, h, 3) where n = len(frame_numbers)
Example - Load first 1000 frames, keeping only the first colour channel:
frames = get_video_frames_preload(video_path, range(1000), mask=np.s_[:, :, 0])
"""
is_url = isinstance(video_path, str) and video_path.startswith('http')
cap = VideoStreamer(video_path).cap if is_url else cv2.VideoCapture(
str(video_path))
assert cap.isOpened(), 'Failed to open video'
frame_count = int(cap.get(cv2.CAP_PROP_FRAME_COUNT))
frame_numbers = frame_numbers if frame_numbers is not None else range(
frame_count)
# Setting the index is extremely slow; determine where frame index must be set
# The first index is always explicitly set.
to_set = np.insert(np.diff(frame_numbers), 0, 0) != 1
if as_list:
frame_images = [None] * len(frame_numbers)
else:
ret, frame = cap.read()
frame_images = np.empty(
(len(frame_numbers), *func(frame[mask or ...]).shape), np.uint8)
for ii, i in enumerate(frame_numbers):
sys.stdout.write(f'\rloading frame {ii}/{len(frame_numbers)}')
sys.stdout.flush()
if to_set[ii]:
cap.set(cv2.CAP_PROP_POS_FRAMES, i)
ret, frame = cap.read()
if ret:
frame_images[ii] = func(frame[mask or ...])
else:
print(f'failed to read frame #{i}')
cap.release()
sys.stdout.write('\x1b[2K\r') # Erase current line in stdout
return frame_images
def get_video_length(video_path):
"""
Returns video length
:param video_path: A path to the video
:return:
"""
is_url = isinstance(video_path, str) and video_path.startswith('http')
cap = VideoStreamer(video_path).cap if is_url else cv2.VideoCapture(
str(video_path))
assert cap.isOpened(), f'Failed to open video file {video_path}'
length = int(cap.get(cv2.CAP_PROP_FRAME_COUNT))
cap.release()
return length