I'm trying to write a program that will use torchvision.io.VideoReader to extract a number of still images from a set of video files. This program is expected to run on Google Colab. Unfortunately, even though torchvision 0.18.0 is available on Colab's runtime, when I try to create a VideoReader object I get an AttributeError raised with the message 'ImportError' object has no attribute 'open'.
Full code of my Colab notebook:
import torch
import torchvision
import os
from google.colab import drive
driveLoc = '/content/drive'
if os.path.exists(driveLoc):
print ("Drive already mounted")
else:
print ("Mounting drive")
drive.mount(driveLoc)
vpath = driveLoc + "/MyDrive/videos"
datafiles = os.listdir(vpath)
for f in datafiles:
if not os.path.isfile(vpath+"/"+f):
continue
print (f)
video = torchvision.io.VideoReader(vpath+"/"+f, "video")
print (video.get_metadata())
Full traceback:
AttributeError Traceback (most recent call last)
<ipython-input-7-1051bd84b049> in <cell line: 16>()
19 print (f)
20
---> 21 video = torchvision.io.VideoReader(vpath+"/"+f, "video")
22 print (video.get_metadata())
23
/usr/local/lib/python3.10/dist-packages/torchvision/io/video_reader.py in __init__(self, src, stream, num_threads)
157
158 elif self.backend == "pyav":
--> 159 self.container = av.open(src, metadata_errors="ignore")
160 # TODO: load metadata
161 stream_type = stream.split(":")[0]
AttributeError: 'ImportError' object has no attribute 'open'
Just running this on the default Colab runtime, with no extra packages installed. I presume I need to install something else, but the error gives me no clue as to what...
This error is caused by not having a sufficiently recent version of PyAV installed on the system when you import torchvision. Adding !pip install av==11.0.0 at the top of the file solved the issue for me; fixing the version at 11.0.0 was necessary to avoid this problem.