def get_frame_ts_table(video):
vr = VideoReader(video, ctx=cpu(0))
return [int(vr.get_frame_timestamp(i)[1] * 1000) for i in range(len(vr))]
def run_data_worker(idx, args, data_queue, safe_gap=10000, nframes=10):
assert args.interval * nframes < safe_gap
videos = [i for i in os.listdir(args.data_dir) if i.endswith('.mp4')]
videos = [os.path.join(args.data_dir, i) for i in videos]
sub_videos = []
for i, v in enumerate(videos):
if i % args.num_data_threads == idx:
sub_videos.append(v)
for video in sub_videos:
txt = glob.glob(video + '_*.txt')[0]
annos = read_anno_txt(txt)
vr = VideoReader(video, ctx=cpu(idx))
vid = os.path.basename(video)
frame_ts_table = [
int(vr.get_frame_timestamp(i)[1] * 1000) for i in range(len(vr))
]
frame_ids = []
t = fid = aid = 0 # three trace pointers
# O(N+M), N=len(intervals), M=len(vr)
while aid < len(annos) and \
t < max(args.interval // 2, annos[aid]['Time'] - safe_gap):
# Extract negative example
# NOTE: for simplicity, this implementation the segment
# from last positive anno to the video end
while fid < len(vr) and frame_ts_table[fid] < t:
fid += 1
if len(frame_ids) < nframes:
frame_ids.append(fid)
else:
frame_ids.pop(0)
frame_ids.append(fid)
if len(frame_ids) == nframes:
frames = [
cv2.resize(img[:, :, ::-1], (640, 360))
for img in list(vr.get_batch(frame_ids).asnumpy())
]
data_queue.put((frames, 0, vid, t))
t += args.interval
if t >= annos[aid]['Time'] - safe_gap:
# Extract positive example
frame_ids.clear()
for i in range(nframes - 1, -1, -1):
# i = 9, 8, ..., 0 when nframes = 10
t = annos[aid]['Time'] - args.interval * i
while frame_ts_table[fid] < t:
fid += 1
frame_ids.append(fid)
frames = [
cv2.resize(img[:, :, ::-1], (640, 360))
for img in list(vr.get_batch(frame_ids).asnumpy())
]
data_queue.put((frames, 1, vid, t))
frame_ids.clear()
t = annos[aid]['Time'] + safe_gap
while aid < len(annos) and t >= annos[aid]['Time'] - safe_gap:
aid += 1
def video_legal(video_path, remove_illegal=True):
# 检查切出来的视频是否可读
try:
cv_wrong = False
cap = cv2.VideoCapture(str(video_path))
flag, f = cap.read()
if not flag:
cv_wrong = True
cap.release()
if cv_wrong:
# opencv检测出视频不正常，删掉
print("opencv remove", video_path, flush=True)
if remove_illegal:
os.remove(str(video_path))
return False
vr = VideoReader(str(video_path))
last_timestamp = [-100, -100]
video_wrong = False if (len(vr) > 1
and len(vr.get_key_indices()) > 1) else True
if video_wrong:
print("len vr {} and len(vr.get_key_indices()) {}".format(
len(vr), len(vr.get_key_indices())),
video_path,
flush=True)
if remove_illegal:
os.remove(str(video_path))
return False
for i in range(len(vr)):
# 解决卡住
tmp = vr.get_frame_timestamp(i)
if last_timestamp[0] == tmp[0] and last_timestamp[1] <= tmp[1]:
print("last_timestamp",
i,
video_path,
last_timestamp[0],
tmp[0],
last_timestamp[1],
tmp[1],
flush=True)
video_wrong = True
break
last_timestamp = tmp
if video_wrong:
print("timestamp error", video_path, flush=True)
if remove_illegal:
os.remove(str(video_path))
return False
for i in range(len(vr)):
# 解决decord._ffi.base.DECORDError: [18:09:55] /io/decord/src/video/ffmpeg -loglevel quiet/threaded_decoder.cc:288: [18:08:29] /io/decord/src/video/ffmpeg -loglevel quiet/threaded_decoder.cc:216: Check failed: avcodec_send_packet(dec_ctx_.get(), pkt.get()) >= 0 (-1094995529 vs. 0) Thread worker: Error sending packet.
try:
_t = vr[i]
except Exception as e:
print("DECORDError", e, i, video_path, flush=True)
if remove_illegal:
os.remove(str(video_path))
return False
except:
print("remove video format exception", video_path, flush=True)
if remove_illegal:
os.remove(str(video_path))
return False
return True
