diff --git a/Crawler/Kinetics/download.py b/Crawler/Kinetics/download.py
index c8b2cdc..bb840f0 100755
--- a/Crawler/Kinetics/download.py
+++ b/Crawler/Kinetics/download.py
@@ -4,12 +4,22 @@
 import os
 import shutil
 import subprocess
+from typing import Dict, List, Set
 import uuid
 from collections import OrderedDict
+from pathlib import Path
 
 from joblib import delayed
 from joblib import Parallel
 import pandas as pd
+from functools import partial
+
+import random
+def generate_key():
+    STR_KEY_GEN = 'ABCDEFGHIJKLMNOPQRSTUVWXYzabcdefghijklmnopqrstuvwxyz'
+    return ''.join(random.choice(STR_KEY_GEN) for _ in range(20))
+
+erf = "errorlog" + generate_key()
 
 
 def create_video_folders(dataset, output_dir, tmp_dir):
@@ -52,7 +62,7 @@ def construct_video_filename(row, label_to_dir, trim_format='%06d'):
 def download_clip(video_identifier, output_filename,
                   start_time, end_time,
                   tmp_dir='/tmp/kinetics',
-                  num_attempts=5,
+                  num_attempts=2,
                   url_base='https://www.youtube.com/watch?v='):
     """Download a video from youtube if exists and is not blocked.
 
@@ -76,63 +86,89 @@ def download_clip(video_identifier, output_filename,
     status = False
     # Construct command line for getting the direct video link.
     tmp_filename = os.path.join(tmp_dir,
-                                '%s.%%(ext)s' % uuid.uuid4())
-    command = ['youtube-dl',
-               '--quiet', '--no-warnings',
-               '-f', 'mp4',
-               '-o', '"%s"' % tmp_filename,
-               '"%s"' % (url_base + video_identifier)]
-    command = ' '.join(command)
-    attempts = 0
-    while True:
-        try:
-            output = subprocess.check_output(command, shell=True,
-                                             stderr=subprocess.STDOUT)
-        except subprocess.CalledProcessError as err:
-            attempts += 1
-            if attempts == num_attempts:
-                return status, err.output
-        else:
-            break
-
-    tmp_filename = glob.glob('%s*' % tmp_filename.split('.')[0])[0]
-    # Construct command to trim the videos (ffmpeg required).
-    command = ['ffmpeg',
-               '-i', '"%s"' % tmp_filename,
-               '-ss', str(start_time),
-               '-t', str(end_time - start_time),
-               '-c:v', 'libx264', '-c:a', 'copy',
-               '-threads', '1',
-               '-loglevel', 'panic',
-               '"%s"' % output_filename]
-    command = ' '.join(command)
-    try:
-        output = subprocess.check_output(command, shell=True,
-                                         stderr=subprocess.STDOUT)
-    except subprocess.CalledProcessError as err:
-        return status, err.output
+                                f'{video_identifier}.mp4')
+        
+    if not os.path.exists(output_filename):
+
+        command = f'youtube-dl -f mp4 --quiet --no-warnings -o {tmp_filename} "{url_base + video_identifier}" && ffmpeg -i {tmp_filename} -ss {str(start_time)} -t {str(end_time - start_time)} -threads 1 -c:v libx264 -c:a copy -loglevel error "{output_filename}" -f mp4 -y'
+
+        attempts = 0
+        while True:
+            try:
+                output = subprocess.check_output(command, shell=True,
+                                                stderr=subprocess.STDOUT)
+            except subprocess.CalledProcessError as err:
+                attempts += 1
+                if attempts == num_attempts:
+                    return status, f"{str(err.output)[:500]}"
+            else:
+                break
 
     # Check if the video was successfully saved.
     status = os.path.exists(output_filename)
-    os.remove(tmp_filename)
+    try:
+        os.remove(tmp_filename)
+    except:
+        pass
     return status, 'Downloaded'
 
 
-def download_clip_wrapper(row, label_to_dir, trim_format, tmp_dir):
+def download_clip_wrapper(row, label_to_dir, trim_format, tmp_dir, existing_files:Dict[str,Path]={}):
     """Wrapper for parallel processing purposes."""
     output_filename = construct_video_filename(row, label_to_dir,
                                                trim_format)
     clip_id = os.path.basename(output_filename).split('.mp4')[0]
     if os.path.exists(output_filename):
         status = tuple([clip_id, True, 'Exists'])
+        print(status)
+        return status
+    if clip_id in existing_files:
+        shutil.copyfile(src=existing_files[clip_id],dst=output_filename)
+        status = tuple([clip_id, True, 'Copied'])
+        print(status)
         return status
 
     downloaded, log = download_clip(row['video-id'], output_filename,
                                     row['start-time'], row['end-time'],
                                     tmp_dir=tmp_dir)
     status = tuple([clip_id, downloaded, log])
+    print(status)
     return status
 
+def redownload_clip_wrapper(row, label_to_dir, trim_format, tmp_dir):
+    """Wrapper for parallel processing purposes."""
+    output_filename = construct_video_filename(row, label_to_dir,
+                                               trim_format)
+    clip_id = os.path.basename(output_filename).split('.mp4')[0]
+    if os.path.exists(output_filename):
+        
+        check_for_errors_in_file = f'ffmpeg -v error -i "{output_filename}" -f null - 2>{erf} && cat {erf}'
+        try:
+            output = subprocess.check_output(check_for_errors_in_file, shell=True, stderr=subprocess.STDOUT)
+            if not output:
+                status = tuple([clip_id, True, 'Exists'])
+                print(status)
+                return status
+        except subprocess.CalledProcessError as err:
+            print(err)
+        
+        print(f"Removing corrupted file: {output_filename}")
+        try:
+            os.remove(output_filename)
+        except:
+            pass
+        downloaded, log = download_clip(row['video-id'], output_filename,
+                                        row['start-time'], row['end-time'],
+                                        tmp_dir=tmp_dir)
+        status = tuple([clip_id, downloaded, log])
+        print(status)
+        return status
+    else:
+        # Was never able to download clip
+        status = tuple([clip_id, True, "Could not download"])
+        print(status)
+        return status
+
 
 def parse_kinetics_annotations(input_csv, ignore_is_cc=False):
     """Returns a parsed DataFrame.
@@ -164,33 +200,40 @@ def parse_kinetics_annotations(input_csv, ignore_is_cc=False):
 
 def main(input_csv, output_dir,
          trim_format='%06d', num_jobs=24, tmp_dir='/tmp/kinetics',
-         drop_duplicates=False):
+         drop_duplicates=False, download_mode="download", source_dir="", reverse=False):
 
     # Reading and parsing Kinetics.
     dataset = parse_kinetics_annotations(input_csv)
-    # if os.path.isfile(drop_duplicates):
-    #     print('Attempt to remove duplicates')
-    #     old_dataset = parse_kinetics_annotations(drop_duplicates,
-    #                                              ignore_is_cc=True)
-    #     df = pd.concat([dataset, old_dataset], axis=0, ignore_index=True)
-    #     df.drop_duplicates(inplace=True, keep=False)
-    #     print(dataset.shape, old_dataset.shape)
-    #     dataset = df
-    #     print(dataset.shape)
+    if reverse:
+        dataset.reindex(index=dataset.index[::-1])
+    
+    # Make catalogue of existing files
+    source_dir = Path(source_dir)
+    if source_dir.is_dir():
+        print("Looking through source dir")
+        existing_files = {str(p.stem): p for p in source_dir.rglob("*.mp4")} if source_dir.is_dir() else {}
+        print("Done looking")
+    else:
+        existing_files = {}
 
     # Creates folders where videos will be saved later.
     label_to_dir = create_video_folders(dataset, output_dir, tmp_dir)
 
+    run = {
+        "download": partial(download_clip_wrapper, existing_files=existing_files), 
+        "redownload": redownload_clip_wrapper
+    }[download_mode]
+
     # Download all clips.
     if num_jobs == 1:
         status_lst = []
         for i, row in dataset.iterrows():
-            status_lst.append(download_clip_wrapper(row, label_to_dir,
-                                                    trim_format, tmp_dir))
+            status_lst.append(run(row, label_to_dir, trim_format, tmp_dir))
     else:
-        status_lst = Parallel(n_jobs=num_jobs)(delayed(download_clip_wrapper)(
-            row, label_to_dir,
-            trim_format, tmp_dir) for i, row in dataset.iterrows())
+        status_lst = Parallel(n_jobs=num_jobs)(
+            delayed(run)(row, label_to_dir, trim_format, tmp_dir) 
+            for i, row in dataset.iterrows()
+        )
 
     # Clean tmp dir.
     shutil.rmtree(tmp_dir)
@@ -212,9 +255,11 @@ def main(input_csv, output_dir,
                    help=('This will be the format for the '
                          'filename of trimmed videos: '
                          'videoid_%0xd(start_time)_%0xd(end_time).mp4'))
-    p.add_argument('-n', '--num-jobs', type=int, default=24)
+    p.add_argument('-n', '--num-jobs', type=int, default=1)
     p.add_argument('-t', '--tmp-dir', type=str, default='/tmp/kinetics')
     p.add_argument('--drop-duplicates', type=str, default='non-existent',
                    help='Unavailable at the moment')
-                   # help='CSV file of the previous version of Kinetics.')
+    p.add_argument('-m', '--download_mode', type=str, default='download', choices=["download", "redownload"])
+    p.add_argument('-s', '--source-dir', type=str, default='', help="Directory in which to look for files before download.")
+    p.add_argument('-r', '--reverse', action="store_true", help="Reverse direction of download.")
     main(**vars(p.parse_args()))
diff --git a/Crawler/Kinetics/environment.yml b/Crawler/Kinetics/environment.yml
index cc6eadb..3285a56 100755
--- a/Crawler/Kinetics/environment.yml
+++ b/Crawler/Kinetics/environment.yml
@@ -1,28 +1,37 @@
 name: kinetics
-channels: !!python/tuple
-- !!python/unicode
-  'defaults'
+channels:
+  - anaconda
+  - menpo
+  - conda-forge
+  - defaults
 dependencies:
-- joblib=0.9.4=py27_0
-- menpo::ffmpeg=3.1.3=0
-- mkl=2017.0.1=0
-- numpy=1.12.1=py27_0
-- openssl=1.0.2k=1
-- pandas=0.19.2=np112py27_1
-- pip=9.0.1=py27_1
-- python=2.7.13=0
-- python-dateutil=2.6.0=py27_0
-- pytz=2017.2=py27_0
-- readline=6.2=2
-- setuptools=27.2.0=py27_0
-- six=1.10.0=py27_0
-- sqlite=3.13.0=0
-- tk=8.5.18=0
-- wheel=0.29.0=py27_0
-- zlib=1.2.8=3
-- pip:
-  - decorator==4.0.11
-  - olefile==0.44
-  - youtube-dl==2017.6.5
-prefix: /home/cabaf/.conda/envs/kinetics
+  - ca-certificates=2020.1.1
+  - certifi=2020.4.5.1
+  - ffmpeg=2.8.6
+  - libcxx=10.0.0
+  - libedit=3.1.20181209
+  - libffi=3.3
+  - ncurses=6.2
+  - openssl=1.1.1g
+  - pip=20.0.2
+  - python=3.7.7
+  - readline=8.0
+  - setuptools=46.4.0
+  - sqlite=3.31.1
+  - tk=8.6.8
+  - wheel=0.34.2
+  - xz=5.2.5
+  - zlib=1.2.11
+  - pip:
+    - decorator==4.4.2
+    - intel-openmp==2019.0
+    - joblib==0.15.1
+    - mkl==2019.0
+    - numpy==1.18.4
+    - olefile==0.46
+    - pandas==1.0.3
+    - python-dateutil==2.8.1
+    - pytz==2020.1
+    - six==1.14.0
+    - youtube-dl==2020.5.8