Merge pull request #53 from neon-jungle/tracks

Tracks

CHANGELOG.rst

 CHANGELOG
 =========
 
+2.10.0
+------
+
+- Added ability to use custom models for Videos + Transcodes
+- Added a way to add VTT files to videos and render them
+
 2.9.0
 -----
 

README.rst

@@ -139,6 +139,11 @@ Same as Wagtail Images, a custom model can be used to replace the built in Video
             )
 
 
+Video text tracks:
+~~~~~~~~~~~~~~~~~~
+
+To enable the uploading and displaying of VTT tracks (e.g. subtitles, captions) you'll need to add ``wagtail.contrib.modeladmin`` to your installed apps.
+Once added, there will be an new area in the admin for attaching VTT files to videos with associaled metadata.
 
 Future features
 ---------------

settings.py

@@ -12,3 +12,4 @@ INSTALLED_APPS += [
 ]
 
 WAGTAILVIDEOS_VIDEO_MODEL = 'app.CustomVideoModel'
+WAGTAIL_USAGE_COUNT_ENABLED = True

setup.py

@@ -21,6 +21,7 @@ setup(
         'wagtail>=2.4',
         'Django>=1.11',
         'django-enumchoicefield>=1.1.0',
+        'bcp47==0.0.4',
     ],
     extras_require={
         'testing': [

tests/app/migrations/0001_initial.py

-# Generated by Django 2.2.17 on 2021-01-28 00:22
+# Generated by Django 2.2.17 on 2021-01-29 05:03
 
 from django.conf import settings
 from django.db import migrations, models
@@ -17,9 +17,8 @@ class Migration(migrations.Migration):
     initial = True
 
     dependencies = [
-        ('taggit', '0003_taggeditem_add_unique_index'),
         migrations.swappable_dependency(settings.AUTH_USER_MODEL),
-        ('wagtailvideos', '0010_video_ordering'),
+        ('taggit', '0003_taggeditem_add_unique_index'),
         ('wagtailcore', '0059_apply_collection_ordering'),
     ]
 
@@ -50,7 +49,7 @@ class Migration(migrations.Migration):
             fields=[
                 ('page_ptr', models.OneToOneField(auto_created=True, on_delete=django.db.models.deletion.CASCADE, parent_link=True, primary_key=True, serialize=False, to='wagtailcore.Page')),
                 ('video_streamfield', wagtail.core.fields.StreamField([('video', wagtailvideos.blocks.VideoChooserBlock())], blank=True)),
-                ('video_field', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='+', to='wagtailvideos.Video')),
+                ('video_field', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='+', to='app.CustomVideoModel')),
             ],
             options={
                 'abstract': False,

tests/app/models.py

@@ -6,6 +6,7 @@ from wagtail.admin.edit_handlers import StreamFieldPanel
 from wagtailvideos.edit_handlers import VideoChooserPanel
 from wagtailvideos.blocks import VideoChooserBlock
 from wagtailvideos.models import AbstractVideo, AbstractVideoTranscode
+from modelcluster.fields import ParentalKey
 
 
 class CustomVideoModel(AbstractVideo):
@@ -32,7 +33,7 @@ class CustomVideoTranscode(AbstractVideoTranscode):
 
 class TestPage(Page):
     video_field = models.ForeignKey(
-        'wagtailvideos.Video', related_name='+', null=True, blank=True, on_delete=models.SET_NULL)
+        CustomVideoModel, related_name='+', null=True, blank=True, on_delete=models.SET_NULL)
 
     video_streamfield = StreamField([
         ('video', VideoChooserBlock())

tests/app/settings.py

@@ -16,6 +16,7 @@ INSTALLED_APPS = [
     'wagtail.snippets',
     'wagtail.images',
     'wagtail.documents',
+    'wagtail.contrib.modeladmin',
 
     'django.contrib.admin',
     'django.contrib.auth',

tests/small.vtt

+WEBVTT
+
+00:00:03.000 --> 00:00:04.000
+Weapon of mass destruction
\ No newline at end of file

tests/test_admin_views.py

@@ -235,9 +235,6 @@ class TestVideoEditView(TestCase, WagtailTestUtils):
             'title': "Edited",
         })
 
-        # Should redirect back to index
-        self.assertRedirects(response, reverse('wagtailvideos:index'))
-
         # Check that the video was edited
         video = Video.objects.get(id=self.video.id)
         self.assertEqual(video.title, "Edited")
@@ -254,9 +251,6 @@ class TestVideoEditView(TestCase, WagtailTestUtils):
             'file': SimpleUploadedFile('new.mp4', new_file.read(), "video/mp4"),
         })
 
-        # Should redirect back to index
-        self.assertRedirects(response, reverse('wagtailvideos:index'))
-
         # Check that the video file size changed (assume it changed to the correct value)
         video = Video.objects.get(id=self.video.id)
         self.assertNotEqual(video.file_size, 100000)
@@ -476,6 +470,7 @@ class TestMultipleVideoUploader(TestCase, WagtailTestUtils):
     """
     This tests the multiple video upload views located in wagtailvideos/views/multiple.py
     """
+
     def setUp(self):
         self.login()
 

tests/test_template_tag.py

@@ -2,9 +2,9 @@ from __future__ import unicode_literals
 
 from django.template import Context, Template, TemplateSyntaxError
 from django.test import TestCase
-from tests.utils import create_test_video_file
+from tests.utils import create_test_video_file, create_test_vtt_file
 
-from wagtailvideos.models import Video
+from wagtailvideos.models import Video, TrackListing, VideoTrack
 
 
 class TestVideoTag(TestCase):
@@ -33,3 +33,14 @@ class TestVideoTag(TestCase):
             self.render_video_tag(None)
         except TemplateSyntaxError as e:
             self.assertEqual(str(e), 'video tag requires a Video object as the first parameter')
+
+    def test_render_tracks(self):
+        listing = TrackListing.objects.create(video=self.video)
+        track = VideoTrack.objects.create(
+            listing=listing,
+            file=create_test_vtt_file(),
+            label='Test subtitles',
+            kind='subtitles',
+            language='en',
+        )
+        self.assertInHTML(track.track_tag(), self.render_video_tag(self.video))

tests/utils.py

-from __future__ import unicode_literals
-
 import os
 
 import tests
@@ -9,3 +7,8 @@ from django.core.files import File
 def create_test_video_file():
     video_file = open(os.path.join(tests.__path__[0], 'small.mp4'), 'rb')
     return File(video_file, name='small.mp4')
+
+
+def create_test_vtt_file():
+    vtt_file = open(os.path.join(tests.__path__[0], 'small.vtt'), 'rb')
+    return File(vtt_file, name='small.vtt')

wagtailvideos/__init__.py

@@ -4,6 +4,11 @@ from django.core.exceptions import ImproperlyConfigured
 default_app_config = 'wagtailvideos.apps.WagtailVideosApp'
 
 
+def is_modeladmin_installed():
+    from django.apps import apps
+    return apps.is_installed('wagtail.contrib.modeladmin')
+
+
 def get_video_model_string():
     return getattr(settings, 'WAGTAILVIDEOS_VIDEO_MODEL', 'wagtailvideos.Video')
 

wagtailvideos/apps.py

@@ -23,4 +23,6 @@ class WagtailVideosApp(AppConfig):
     verbose_name = 'Wagtail Videos'
 
     def ready(self):
+        from wagtailvideos.signals import register_signal_handlers
+        register_signal_handlers()
         register(ffmpeg_check)

wagtailvideos/forms.py

@@ -41,7 +41,6 @@ def get_video_form(model):
         # cause dubious results when multiple collections exist (e.g adding the
         # document to the root collection where the user may not have permission) -
         # and when only one collection exists, it will get hidden anyway.
-        print('collection not found')
         fields = list(fields) + ['collection']
 
     return modelform_factory(

wagtailvideos/models.py

@@ -6,28 +6,27 @@ import shutil
 import subprocess
 import tempfile
 import threading
-from contextlib import contextmanager
 from distutils.version import LooseVersion
 
+import bcp47
 import wagtail
 from django.conf import settings
 from django.core.exceptions import SuspiciousFileOperation
 from django.core.files.base import ContentFile
-from django.core.files.temp import NamedTemporaryFile
 from django.db import models
-from django.db.models.signals import post_save, pre_delete
-from django.dispatch.dispatcher import receiver
 from django.forms.utils import flatatt
 from django.urls import reverse
 from django.utils.safestring import mark_safe
 from django.utils.translation import ugettext_lazy as _
 from enumchoicefield import ChoiceEnum, EnumChoiceField
+from modelcluster.fields import ParentalKey
+from modelcluster.models import ClusterableModel
 from taggit.managers import TaggableManager
-from wagtail.core.models import CollectionMember
+from wagtail.core.models import CollectionMember, Orderable
 from wagtail.search import index
 from wagtail.search.queryset import SearchableQuerySetMixin
 
-from wagtailvideos import ffmpeg
+from wagtailvideos import get_video_model_string
 
 if LooseVersion(wagtail.__version__) >= LooseVersion('2.7'):
     from wagtail.admin.models import get_object_usage
@@ -180,13 +179,6 @@ class AbstractVideo(CollectionMember, index.Indexed, models.Model):
     def get_transcode_model(cls):
         return cls.transcodes.rel.related_model
 
-    def get_transcode(self, media_format):
-        Transcode = self.get_transcode_model()
-        try:
-            return self.transcodes.get(media_format=media_format)
-        except Transcode.DoesNotExist:
-            return self.do_transcode(media_format)
-
     def video_tag(self, attrs=None):
         if attrs is None:
             attrs = {}
@@ -205,14 +197,19 @@ class AbstractVideo(CollectionMember, index.Indexed, models.Model):
                        .format(self.url, mime.guess_type(self.url)[0]))
 
         sources.append("<p>Sorry, your browser doesn't support playback for this video</p>")
+
+        tracks = []
+        if hasattr(self, 'track_listing'):
+            tracks = [t.track_tag() for t in self.track_listing.tracks.all()]
+
         return mark_safe(
-            "<video {0}>\n{1}\n</video>".format(flatatt(attrs), "\n".join(sources)))
+            "<video {0}>\n{1}\n{2}\n</video>".format(flatatt(attrs), "\n".join(sources), "\n".join(tracks)))
 
     def do_transcode(self, media_format, quality):
         transcode, created = self.transcodes.get_or_create(
             media_format=media_format,
         )
-        if transcode.processing is False:
+        if created or transcode.processing is False:
             transcode.processing = True
             transcode.error_messages = ''
             transcode.quality = quality
@@ -292,61 +289,6 @@ class TranscodingThread(threading.Thread):
             shutil.rmtree(output_dir, ignore_errors=True)
 
 
-@contextmanager
-def get_local_file(file):
-    """
-    Get a local version of the file, downloading it from the remote storage if
-    required. The returned value should be used as a context manager to
-    ensure any temporary files are cleaned up afterwards.
-    """
-    try:
-        with open(file.path):
-            yield file.path
-    except NotImplementedError:
-        _, ext = os.path.splitext(file.name)
-        with NamedTemporaryFile(prefix='wagtailvideo-', suffix=ext) as tmp:
-            try:
-                file.open('rb')
-                for chunk in file.chunks():
-                    tmp.write(chunk)
-            finally:
-                file.close()
-            tmp.flush()
-            yield tmp.name
-
-
-# Delete files when model is deleted
-@receiver(pre_delete, sender=Video)
-def video_delete(sender, instance, **kwargs):
-    instance.thumbnail.delete(False)
-    instance.file.delete(False)
-
-
-# Fields that need the actual video file to create
-@receiver(post_save, sender=Video)
-def video_saved(sender, instance, **kwargs):
-    if not ffmpeg.installed():
-        return
-
-    if hasattr(instance, '_from_signal'):
-        return
-
-    has_changed = instance._initial_file is not instance.file
-    filled_out = instance.thumbnail is not None and instance.duration is not None
-    if has_changed or not filled_out:
-        with get_local_file(instance.file) as file_path:
-            if has_changed or instance.thumbnail is None:
-                instance.thumbnail = ffmpeg.get_thumbnail(file_path)
-
-            if has_changed or instance.duration is None:
-                instance.duration = ffmpeg.get_duration(file_path)
-
-    instance.file_size = instance.file.size
-    instance._from_signal = True
-    instance.save()
-    del instance._from_signal
-
-
 class AbstractVideoTranscode(models.Model):
     media_format = EnumChoiceField(MediaFormats)
     quality = EnumChoiceField(VideoQuality, default=VideoQuality.default)
@@ -377,7 +319,59 @@ class VideoTranscode(AbstractVideoTranscode):
         )
 
 
-# Delete files when model is deleted
-@receiver(pre_delete, sender=VideoTranscode)
-def transcode_delete(sender, instance, **kwargs):
-    instance.file.delete(False)
+class TrackListing(ClusterableModel):
+    video = models.OneToOneField(
+        get_video_model_string(), on_delete=models.CASCADE,
+        related_name='track_listing')
+
+    def __str__(self):
+        return self.video.title
+
+
+class VideoTrack(Orderable):
+    listing = ParentalKey(TrackListing, related_name='tracks', on_delete=models.CASCADE)
+    # TODO move to TextChoices once django < 3 is dropped
+    track_kinds = [
+        ('subtitles', 'Subtitles'),
+        ('captions', 'Captions'),
+        ('descriptions', 'Descriptions'),
+        ('chapters', 'Chapters'),
+        ('metadata', 'Metadata'),
+    ]
+
+    file = models.FileField(
+        verbose_name=_('file'),
+        upload_to=get_upload_to
+    )
+    kind = models.CharField(max_length=50, choices=track_kinds, default=track_kinds[0][0])
+    label = models.CharField(
+        max_length=255, blank=True,
+        help_text='A user-readable title of the text track.')
+    language = models.CharField(
+        max_length=50,
+        choices=[(v, k) for k, v in bcp47.languages.items()],
+        default='en', blank=True, help_text='Required if type is "Subtitle"', unique=True)
+
+    def track_tag(self):
+        attrs = {
+            'kind': self.kind,
+            'src': self.url,
+        }
+        if self.label:
+            attrs['label'] = self.label
+        if self.language:
+            attrs['srclang'] = self.language
+
+        return "<track {0}{1}>".format(flatatt(attrs), ' default' if self.sort_order == 0 else '')
+
+    def __str__(self):
+        return "{0} - {1}".format(self.label or self.get_kind_display(), self.get_language_display())
+
+    @property
+    def url(self):
+        return self.file.url
+
+    def get_upload_to(self, filename):
+        folder_name = 'video_tracks'
+        filename = self.file.field.storage.get_valid_name(filename)
+        return os.path.join(folder_name, filename)

wagtailvideos/signals.py

+import os
+from contextlib import contextmanager
+
+from django.core.files.temp import NamedTemporaryFile
+from django.db import transaction
+from django.db.models.signals import post_delete, post_save
+
+from wagtailvideos import ffmpeg, get_video_model
+from wagtailvideos.models import VideoTrack
+
+
+@contextmanager
+def get_local_file(file):
+    """
+    Get a local version of the file, downloading it from the remote storage if
+    required. The returned value should be used as a context manager to
+    ensure any temporary files are cleaned up afterwards.
+    """
+    try:
+        with open(file.path):
+            yield file.path
+    except NotImplementedError:
+        _, ext = os.path.splitext(file.name)
+        with NamedTemporaryFile(prefix='wagtailvideo-', suffix=ext) as tmp:
+            try:
+                file.open('rb')
+                for chunk in file.chunks():
+                    tmp.write(chunk)
+            finally:
+                file.close()
+            tmp.flush()
+            yield tmp.name
+
+
+def post_delete_file_cleanup(instance, **kwargs):
+    # Pass false so FileField doesn't save the model.
+    transaction.on_commit(lambda: instance.file.delete(False))
+    if hasattr(instance, 'thumbnail'):
+        # Delete the thumbnail for videos too
+        transaction.on_commit(lambda: instance.thumbnail.delete(False))
+
+
+# Fields that need the actual video file to create using ffmpeg
+def video_post_save(instance, **kwargs):
+    if not ffmpeg.installed():
+        return
+
+    if hasattr(instance, '_from_signal'):
+        # Sender was us, don't run post save
+        return
+
+    has_changed = instance._initial_file is not instance.file
+    filled_out = instance.thumbnail is not None and instance.duration is not None
+    if has_changed or not filled_out:
+        with get_local_file(instance.file) as file_path:
+            if has_changed or instance.thumbnail is None:
+                instance.thumbnail = ffmpeg.get_thumbnail(file_path)
+
+            if has_changed or instance.duration is None:
+                instance.duration = ffmpeg.get_duration(file_path)
+
+    instance.file_size = instance.file.size
+    instance._from_signal = True
+    instance.save()
+    del instance._from_signal
+
+
+def register_signal_handlers():
+    Video = get_video_model()
+    VideoTranscode = Video.get_transcode_model()
+
+    post_save.connect(video_post_save, sender=Video)
+    post_delete.connect(post_delete_file_cleanup, sender=Video)
+    post_delete.connect(post_delete_file_cleanup, sender=VideoTranscode)
+    post_delete.connect(post_delete_file_cleanup, sender=VideoTrack)

wagtailvideos/templates/wagtailvideos/videos/edit.html

@@ -28,7 +28,7 @@
 {% include "wagtailadmin/shared/header.html" with title=editing_str subtitle=video.title icon="media" %}
 
 <div class="row row-flush nice-padding">
-    <div class="col5">
+    <div class="col6">
         <form action="{% url 'wagtailvideos:edit' video.id %}" method="POST" enctype="multipart/form-data">
             {% csrf_token %}
             <ul class="fields">
@@ -48,13 +48,39 @@
             </ul>
         </form>
     </div>
-    <div class="col5 divider-after">
-        <h2 class="label no-float u-text-transform-uppercase">{% trans "Video preview" %}</h2> {% video video controls style=max-width:100% %}
+    <div class="col6">
+        <div class='row'>
+            <div class='col10 divider-after'>
+                {% video video controls style=max-width:100%;width:100%;height:auto; %}
+            </div>
+            <div class='col2'>
+                <dl style='margin-top: 0'>
+                    {% if video.thumbnail %}
+                    <dt>{% trans "Thumbnail" %}</dt>
+                    <dd><img src="{{ video.thumbnail.url }}" /></dd>
+                    {% endif %}
+                    <dt>{% trans "Filesize" %}</dt>
+                    <dd>{% if filesize %}{{ filesize|filesizeformat }}{% else %}{% trans "File not found" %}{% endif %}</dd>
+                    {% if video.duration %}
+                    <dt>{% trans "Duration" %}</dt>
+                    <dd>{{ video.formatted_duration }}</dd>
+                    {% endif %}
+                    {% usage_count_enabled as uc_enabled %}
+                    {% if uc_enabled %}
+                        <dt>{% trans "Usage" %}</dt>
+                        <dd>
+                            <a href="{{ video.usage_url }}">{% blocktrans count usage_count=video.get_usage.count %}Used {{ usage_count }} time{% plural %}Used {{ usage_count }} times{% endblocktrans %}</a>
+                        </dd>
+                    {% endif %}
+                </dl>
+            </div>
+        </div>
+        <div class="row" style='margin-top: 2em;'>
         {% if can_transcode %}
-            <h3 class="label no-float u-text-transform-uppercase">Transcodes</h3>
+            <h2 class="u-text-transform-uppercase">Transcodes</h2>
             <p>If you wish to generate HTML5 compliant transcodes use the form below. This may take a while depending on the length of the video.</p>
             {% if transcodes %}
-            <h3 class="label no-float u-text-transform-uppercase">Available Transcodes</h3>
+            <h3 class="u-text-transform-uppercase">Available Transcodes</h3>
             <ul>
                 {% for transcode in transcodes %}
                 <li>
@@ -68,7 +94,7 @@
                 {% endfor %}
             </ul>
             {% endif %}
-            <h3 class="label no-float u-text-transform-uppercase">Create transcode</h3>
+            <h3 class="u-text-transform-uppercase">Create transcode</h3>
             <form action="{% url 'wagtailvideos:create_transcode' video.id %}" method="POST">
                 <ul class="fields">
                     {% csrf_token %}
@@ -83,27 +109,21 @@
             <br/><br/>
             <span class='transcode-error'>Ffmpeg is not found on your server. Please install if you wish to transcode videos into an HTML5 video compliant format.</span>
         {% endif %}
-    </div>
-    <div class="col2 ">
-        <dl>
-            {% if video.thumbnail %}
-            <dt>{% trans "Thumbnail" %}</dt>
-            <dd><img src="{{ video.thumbnail.url }}" /></dd>
-            {% endif %}
-            <dt>{% trans "Filesize" %}</dt>
-            <dd>{% if filesize %}{{ filesize|filesizeformat }}{% else %}{% trans "File not found" %}{% endif %}</dd>
-            {% if video.duration %}
-            <dt>{% trans "Duration" %}</dt>
-            <dd>{{ video.formatted_duration }}</dd>
-            {% usage_count_enabled as uc_enabled %}
-            {% if uc_enabled %}
-                <dt>{% trans "Usage" %}</dt>
-                <dd>
-                    <a href="{{ video.usage_url }}">{% blocktrans count usage_count=video.get_usage.count %}Used {{ usage_count }} time{% plural %}Used {{ usage_count }} times{% endblocktrans %}</a>
-                </dd>
+        {% if tracks_action_url %}
+            <h2 class="u-text-transform-uppercase">Tracks</h2>
+            <p>You can add/edit subtitles or accessibility captions for this video. For information about the filetype that should be used see the mozilla docs on <a href="https://developer.mozilla.org/en-US/docs/Web/API/WebVTT_API">WebVTT</a></p>
+                {% if video.track_listing %}
+                <ul>
+                {% for track in video.track_listing.tracks.all %}
+                    <li>{{ track }}</li>
+                {% endfor %}
+                </ul>
+                <a class='button' href="{{ tracks_action_url }}">Edit</a>
+                {% else %}
+                <a class='button' href="{{ tracks_action_url }}">Add tracks</a>
                 {% endif %}
         {% endif %}
-        </dl>
+        </div>
     </div>
 </div>
 {% endblock %}

wagtailvideos/templates/wagtailvideos/videos/usage.html

 {% extends "wagtailadmin/base.html" %}
 {% load i18n %}
-{% block titletag %}{% blocktrans with title=image.title %}Usage of {{ title }}{% endblocktrans %}{% endblock %}
+{% block titletag %}{% blocktrans with title=video.title %}Usage of {{ title }}{% endblocktrans %}{% endblock %}
 {% block content %}
     {% trans "Usage of" as usage_str %}
-    {% include "wagtailadmin/shared/header.html" with title=usage_str subtitle=image.title %}
+    {% include "wagtailadmin/shared/header.html" with title=usage_str subtitle=video.title %}
 
     <div class="nice-padding">
         <table class="listing">

wagtailvideos/views/videos.py

+from wagtail.contrib.modeladmin.helpers import AdminURLHelper
 from distutils.version import LooseVersion
 
 import wagtail
 from django.core.paginator import Paginator
-from django.http import HttpResponseNotAllowed
 from django.shortcuts import get_object_or_404, redirect, render
 from django.urls import reverse
 from django.utils.translation import ugettext as _
+from django.views.decorators.http import require_POST
 from django.views.decorators.vary import vary_on_headers
 from wagtail.admin import messages
 from wagtail.admin.forms.search import SearchForm
 from wagtail.core.models import Collection
 from wagtail.search.backends import get_search_backends
 
-from wagtailvideos import ffmpeg, get_video_model
+from wagtailvideos import ffmpeg, get_video_model, is_modeladmin_installed
 from wagtailvideos.forms import VideoTranscodeAdminForm, get_video_form
 from wagtailvideos.permissions import permission_policy
+from wagtailvideos.models import TrackListing
 
 if LooseVersion(wagtail.__version__) >= LooseVersion('2.7'):
     from wagtail.admin.auth import PermissionPolicyChecker
@@ -104,10 +106,7 @@ def edit(request, video_id):
             for backend in get_search_backends():
                 backend.add(video)
 
-            messages.success(request, _("Video '{0}' updated.").format(video.title), buttons=[
-                messages.button(reverse('wagtailvideos:edit', args=(video.id,)), _('Edit again'))
-            ])
-            return redirect('wagtailvideos:index')
+            messages.success(request, _("Video '{0}' updated.").format(video.title))
         else:
             messages.error(request, _("The video could not be saved due to errors."))
     else:
@@ -120,6 +119,14 @@ def edit(request, video_id):
         ).format(video.title), buttons=[
             messages.button(reverse('wagtailvideos:delete', args=(video.id,)), _('Delete'))
         ])
+    if is_modeladmin_installed():
+        url_helper = AdminURLHelper(TrackListing)
+        if hasattr(video, 'track_listing'):
+            action_url = url_helper.get_action_url('edit', instance_pk=video.track_listing.pk)
+        else:
+            action_url = url_helper.create_url
+    else:
+        action_url = ''
 
     return render(request, "wagtailvideos/videos/edit.html", {
         'video': video,
@@ -128,13 +135,13 @@ def edit(request, video_id):
         'can_transcode': ffmpeg.installed(),
         'transcodes': video.transcodes.all(),
         'transcode_form': VideoTranscodeAdminForm(video=video),
+        'tracks_action_url': action_url,
         'user_can_delete': permission_policy.user_has_permission_for_instance(request.user, 'delete', video)
     })
 
 
+@require_POST
 def create_transcode(request, video_id):
-    if request.method != 'POST':
-        return HttpResponseNotAllowed(['POST'])
     video = get_object_or_404(get_video_model(), id=video_id)
     transcode_form = VideoTranscodeAdminForm(data=request.POST, video=video)
 
@@ -189,13 +196,13 @@ def add(request):
     })
 
 
-def usage(request, image_id):
-    image = get_object_or_404(get_video_model(), id=image_id)
+def usage(request, video_id):
+    video = get_object_or_404(get_video_model(), id=video_id)
 
-    paginator = Paginator(image.get_usage(), per_page=12)
+    paginator = Paginator(video.get_usage(), per_page=12)
     page = paginator.get_page(request.GET.get('p'))
 
     return render(request, "wagtailvideos/videos/usage.html", {
-        'image': image,
+        'video': video,
         'used_by': page
     })