Merge branch 'cache' of https://github.com/Marishka17/cvat into origin/cache
commit
0f7f14a1ef
@ -0,0 +1,76 @@
|
||||
import av
|
||||
|
||||
class PrepareInfo:
|
||||
|
||||
def __init__(self, source_path, meta_path):
|
||||
self.source_path = source_path
|
||||
self.meta_path = meta_path
|
||||
|
||||
def _open_video_container(self, sourse_path, mode, options=None):
|
||||
return av.open(sourse_path, mode=mode, options=options)
|
||||
|
||||
def _close_video_container(self, container):
|
||||
container.close()
|
||||
|
||||
def _get_video_stream(self, container):
|
||||
video_stream = next(stream for stream in container.streams if stream.type == 'video')
|
||||
video_stream.thread_type = 'AUTO'
|
||||
return video_stream
|
||||
|
||||
#@get_execution_time
|
||||
def save_meta_info(self):
|
||||
container = self._open_video_container(self.source_path, mode='r')
|
||||
video_stream = self._get_video_stream(container)
|
||||
|
||||
with open(self.meta_path, 'w') as file:
|
||||
frame_number = 0
|
||||
|
||||
for packet in container.demux(video_stream):
|
||||
for frame in packet.decode():
|
||||
frame_number += 1
|
||||
if frame.key_frame:
|
||||
file.write('{} {}\n'.format(frame_number, frame.pts))
|
||||
|
||||
self._close_video_container(container)
|
||||
return frame_number# == task_size
|
||||
|
||||
def get_nearest_left_key_frame(self, start_chunk_frame_number):
|
||||
start_decode_frame_number = 0
|
||||
start_decode_timestamp = 0
|
||||
|
||||
with open(self.meta_path, 'r') as file:
|
||||
for line in file:
|
||||
frame_number, timestamp = line.strip().split(' ')
|
||||
|
||||
#TODO: исправить если вдруг ключевой кадр окажется не первым
|
||||
if int(frame_number) <= start_chunk_frame_number:
|
||||
start_decode_frame_number = frame_number
|
||||
start_decode_timestamp = timestamp
|
||||
else:
|
||||
break
|
||||
|
||||
return int(start_decode_frame_number), int(start_decode_timestamp)
|
||||
|
||||
def decode_needed_frames(self, chunk_number, chunk_size):
|
||||
start_chunk_frame_number = (chunk_number - 1) * chunk_size + 1
|
||||
end_chunk_frame_number = start_chunk_frame_number + chunk_size #- 1
|
||||
start_decode_frame_number, start_decode_timestamp = self.get_nearest_left_key_frame(start_chunk_frame_number)
|
||||
extra_frames = start_chunk_frame_number - start_decode_frame_number
|
||||
|
||||
container = self._open_video_container(self.source_path, mode='r')
|
||||
video_stream = self._get_video_stream(container)
|
||||
container.seek(offset=start_decode_timestamp, stream=video_stream)
|
||||
|
||||
frame_number = start_decode_frame_number - 1
|
||||
for packet in container.demux(video_stream):
|
||||
for frame in packet.decode():
|
||||
frame_number += 1
|
||||
if frame_number < start_chunk_frame_number:
|
||||
continue
|
||||
elif frame_number < end_chunk_frame_number:
|
||||
yield frame
|
||||
else:
|
||||
self._close_video_container(container)
|
||||
return
|
||||
|
||||
self._close_video_container(container)
|
||||
Loading…
Reference in New Issue