def find_text_in_video(frame_iterator, find_text_in_frame_func, stability_threshold=5):
base_frame = []
pending_blobs = []
past_blobs = []
frame_queue = deque(maxlen=stability_threshold) # general buffer
rewinding_queue = deque()
frame_iterator = iter(frame_iterator)
def next_frame():
while True:
if len(rewinding_queue) > 0: yield rewinding_queue.popleft()
else: yield frame_iterator.next()
def rewind(nframe):
assert(nframe <= len(frame_queue))
for _ in xrange(len(frame_queue)-nframe): frame_queue.popleft()
rewinding_queue.extend(frame_queue)
for sec, frame in next_frame():
frame_queue.append((sec,frame))
yield 'new_frame', (sec,frame)
if len(base_frame) == 0:
base_frame = [frame]
continue
for blob in past_blobs[:]:
if len(blob.get('removed_changed_frac',[])) >= stability_threshold:
# if np.median(blob['removed_changed_frac']) < 0.4: # erasure seems stable
fracs = np.array(blob['removed_changed_frac'])
# second largest unchanged fraction is < 0.4, so lots seem to have been changed...
if fracs[fracs.argsort()[-2:][0]] < 0.4:
print blob['sec'], np.median(blob['removed_changed_frac'])
try:
past_blobs.remove(blob)
yield 'erased_blob', blob
except Exception, e:
print e
print int(blob['sec']),blob['left_corner']
# todo rewind?
# print 'frame reset at', blob['removed_at_sec']
base_frame = [blob['removed_at_frame']] # reset base frame
else: # probably not actual erasure
del blob['removed_at_sec'], blob['removed_at_frame'], blob['removed_changed_frac']
for blob in past_blobs:
b = blob.get('blob_bw', img_proc_utils.otsu_thresholded(blob['blob']))
x, y = blob['left_corner']
current_blob = (img_proc_utils.otsu_thresholded(frame[x:x+b.shape[0],y:y+b.shape[1]]).astype(np.bool))
frac = img_proc_utils.unchanged_fraction(b, current_blob, white_overweight=1/2.)
if 'removed_at_sec' in blob: # pending erasure
blob['removed_changed_frac'].append(frac)
elif frac < 0.4:
blob['removed_at_sec'] = int(sec)
blob['removed_at_frame'] = frame
blob['removed_changed_frac'] = [frac]
# which pending blob is stable and thus a real text change?
for blob in (b for b in pending_blobs if len(b['unchange_frac']) == stability_threshold):
if np.median(blob['unchange_frac'])>0.7: # seems stable between frames
other_blobs = [b for b in pending_blobs if len(b['unchange_frac']) < stability_threshold
and img_proc_utils.shared_fraction(blob, b) > 0.4]
largest_blob = max([blob]+other_blobs, key=lambda x: np.count_nonzero(img_proc_utils.threshold_otsu(x['blob'])>0))
base_frame = [largest_blob['frame']] # reset base frame
for b in other_blobs:
pending_blobs.remove(b);
past_blobs.append(largest_blob)
largest_blob['n_sameblobs'] = [b['proba'] for b in [blob]+other_blobs]
yield 'new_blob', largest_blob
pending_blobs.remove(blob)
# compute the change frac with subsequent frames
for blob in (b for b in pending_blobs if len(b['unchange_frac']) < stability_threshold):
b = blob.get('blob_bw', img_proc_utils.otsu_thresholded(blob['blob']))
x, y = blob['left_corner']
frac = img_proc_utils.unchanged_fraction(b, img_proc_utils.otsu_thresholded(frame[x:x+b.shape[0],y:y+b.shape[1]]), white_overweight=2)
blob['unchange_frac'].append(frac)
# calculate new blobs
text_blobs = find_text_in_frame_func(frame, base_frame)
for blob in text_blobs:
#print blob
blob.update({'frame': frame, 'sec': int(sec), 'unchange_frac':[]})
pending_blobs += text_blobs
def stream_frames(stream, pafy_video = None):
r = StrictRedis('localhost')
try:
r.incr('counter') # keep track of how many processes are running
demo_diff = 0
video_length = pafy_video.length if pafy_video else (5412-demo_diff if 'rubakov1' in stream else 5000)
if pafy_video:
yield server_event_msg({'video_length': pafy_video.length,
'video_title': pafy_video.title,
'video_desc': pafy_video.description,
'video_author': pafy_video.author,
'video_url': pafy_video.url},
'onstart')
else:
if 'rubakov1' in stream:
demo_diff = 4*60 # the demo video is four min in
yield server_event_msg({"video_author": "Galileo Galilei",
"video_length": 5412-demo_diff,
"video_title": "Early Universe - V. Rubakov - lecture 1/9",
"video_url": "https://www.youtube.com/watch?v=XsqtPhra2f0",
"video_desc": "GGI lectures on the theory of fundamental interactions, January 2015\nhttp://heidi.pd.infn.it/html/GGI/index.php"},
'onstart')
else:
yield server_event_msg({'video_length': 5000,'video_title': stream }, 'onstart')
hist = defaultdict(float)
it = utils.find_text_in_video(
utils.get_frames_from_stream(stream,3),
lambda frame,base_frames: utils.find_text_in_frame(frame, base_frames, proba_threshold=0.5))
for dtype, data in it:
if dtype == 'new_frame':
yield server_event_msg({'sec': int(data[0])},'onprogress')
elif dtype == 'new_blob':
yield server_event_msg({'img': utils.img_to_base64_bytes(data['blob']), #utils.img_to_base64_bytes(255-np.nan_to_num(abs(blob))),
'sec': int(data['sec']+demo_diff),
'proba': round(data['proba'],2),
'left_corner': data['left_corner'],
'size': data['blob'].shape,
'n_sameblobs': data['n_sameblobs'],
# 'frame': utils.img_to_base64_bytes(data['frame'])
})
if 'blob_bw' not in data: data['blob_bw'] = img_proc_utils.otsu_thresholded(data['blob'])
hist[(int(data['sec']+demo_diff)/60)] += np.count_nonzero(data['blob_bw'][data['blob_bw']>0])
# print hist, {'hist': [{'x': k, 'y': v} for k,v in hist.iteritems()]}
# yield server_event_msg({'hist': [{'x': k, 'y': int(v/10.)} for k,v in hist.iteritems()]}, 'onhist')
yield server_event_msg({'hist': [{'x': i, 'y': hist.get(i,0)} for i in xrange(video_length/60)]}, 'onhist')
elif dtype == "erased_blob":
yield server_event_msg({'sec': int(data['sec']+demo_diff),
'removed_sec': int(data['removed_at_sec']+demo_diff),
'left_corner': data['left_corner']},
'onerasure')
hist[(int(data['removed_at_sec']+demo_diff)/60)] -= np.count_nonzero(data['blob_bw'][data['blob_bw']>0])
yield server_event_msg({'hist': [{'x': i, 'y': hist.get(i,0)} for i in xrange(video_length/60)]}, 'onhist')
yield server_event_msg({'end':True}, 'onend')
raise StopIteration
finally:
r.decr('counter')