Remove video download and instead move it to repo (#3116)

Makes it appease fbcode internal tests

Author: fmassa

test/assets/videos/hmdb51_Turnk_r_Pippi_Michel_cartwheel_f_cm_np2_le_med_6.avi

@@ -3,7 +3,6 @@
 import sys
 import tempfile
 import torch
-import torchvision.datasets.utils as utils
 import torchvision.io as io
 from torchvision import get_video_backend
 import unittest
@@ -148,20 +147,12 @@ def test_read_partial_video_bframes(self):
                 self.assertTrue((data[5:8].float() - lv.float()).abs().max() < self.TOLERANCE)
 
     def test_read_packed_b_frames_divx_file(self):
-        with get_tmp_dir() as temp_dir:
-            name = "hmdb51_Turnk_r_Pippi_Michel_cartwheel_f_cm_np2_le_med_6.avi"
-            f_name = os.path.join(temp_dir, name)
-            url = "https://download.pytorch.org/vision_tests/io/" + name
-            try:
-                utils.download_url(url, temp_dir)
-                pts, fps = io.read_video_timestamps(f_name)
-
-                self.assertEqual(pts, sorted(pts))
-                self.assertEqual(fps, 30)
-            except URLError:
-                msg = "could not download test file '{}'".format(url)
-                warnings.warn(msg, RuntimeWarning)
-                raise unittest.SkipTest(msg)
+        name = "hmdb51_Turnk_r_Pippi_Michel_cartwheel_f_cm_np2_le_med_6.avi"
+        f_name = os.path.join(VIDEO_DIR, name)
+        pts, fps = io.read_video_timestamps(f_name)
+
+        self.assertEqual(pts, sorted(pts))
+        self.assertEqual(fps, 30)
 
     def test_read_timestamps_from_packet(self):
         with temp_video(10, 300, 300, 5, video_codec='mpeg4') as (f_name, data):