chapters: improve ExtractChapterFramesTask

Author: zubeydecivelek

cds/modules/flows/tasks.py

@@ -28,6 +28,7 @@
 import shutil
 import signal
 import tempfile
+from io import BytesIO
 
 import jsonpatch
 import requests
@@ -57,7 +58,7 @@
 
 from cds.modules.flows.models import FlowTaskMetadata
 from cds.modules.flows.models import FlowTaskStatus as FlowTaskStatus
-
+from cds.modules.records.api import CDSVideosFilesIterator
 from ..ffmpeg import ff_frames, ff_probe_all
 from ..opencast.api import OpenCast
 from ..opencast.error import RequestError
@@ -746,8 +747,13 @@ class ExtractChapterFramesTask(AVCTask):
     name = "file_video_extract_chapter_frames"
 
     @staticmethod
-    def clean(version_id, *args, **kwargs):
-        """Delete generated chapter frame ObjectVersion slaves."""
+    def clean(version_id, valid_chapter_seconds=None, *args, **kwargs):
+        """Delete generated chapter frame ObjectVersion slaves.
+        
+        - If valid_chapter_seconds is given, keep them.
+        - If not, remove all chapter frames.
+        """
+        valid_chapter_seconds = valid_chapter_seconds or []
         # remove all objects version "slave" with type "frame" that are chapter frames
         tag_alias_1 = aliased(ObjectVersionTag)
         tag_alias_2 = aliased(ObjectVersionTag)
@@ -764,8 +770,18 @@ def clean(version_id, *args, **kwargs):
         )
 
         for slave in slaves:
+            ts_val = next(t.value for t in slave.tags if t.key == "timestamp")
+            if ts_val in valid_chapter_seconds:
+                continue
             dispose_object_version(slave)
 
+        # If no valid chapter seconds, remove the chapters.vtt file
+        if not valid_chapter_seconds:
+            master_obj = ObjectVersion.query.get(version_id)                  
+            vtt_objs = ObjectVersion.get_versions(master_obj.bucket_id, "chapters.vtt")
+            for vtt_obj in vtt_objs:
+                dispose_object_version(vtt_obj)
+
     def run(self, *args, **kwargs):
         """Extract frames only at chapter timestamps from video description.
 
@@ -808,10 +824,6 @@ def run(self, *args, **kwargs):
 
             # Parse chapters from description
             chapters = parse_video_chapters(description)
-            
-            if not chapters:
-                self.log("No chapters found in description - task completed")
-                return {"chapter_frames_extracted": 0, "status": "no_chapters"}
 
             self.log("Found {0} chapters in description".format(len(chapters)))
 
@@ -822,7 +834,7 @@ def run(self, *args, **kwargs):
                 raise ValueError("Video duration is 0 - cannot extract frames")
 
             # Check which timestamps already have frames
-            existing_timestamps = self._get_existing_frame_timestamps()
+            existing_timestamps = self._get_existing_chapter_frame_timestamps(deposit_video)
 
             def progress_updater(current_chapter):
                 """Progress reporter."""
@@ -835,7 +847,7 @@ def progress_updater(current_chapter):
                 )
                 self.log(meta["message"])
 
-            frames = self._create_chapter_frames(
+            frames, chapter_seconds = self._create_chapter_frames(
                 chapters=chapters,
                 duration=duration,
                 object_=self.object_version,
@@ -844,6 +856,12 @@ def progress_updater(current_chapter):
                 progress_updater=progress_updater,
             )
 
+            # Clean unused chapters
+            self.clean(version_id=self.object_version_id, valid_chapter_seconds=chapter_seconds)
+
+            # Create or update WebVTT file for chapters
+            self._build_chapter_vtt(chapters, duration)
+
             # Sync deposit and record files
             sync_records_with_deposit_files(self.deposit_id)
 
@@ -865,32 +883,17 @@ def progress_updater(current_chapter):
         self.log("Finished task {0}".format(kwargs["task_id"]))
         return "Created {0} chapter frames.".format(total_frames)
 
-    def _get_existing_frame_timestamps(self):
-        """Get set of existing frame timestamps to avoid duplicates."""
-        tag_alias_1 = aliased(ObjectVersionTag)
-        tag_alias_2 = aliased(ObjectVersionTag)
-        tag_alias_3 = aliased(ObjectVersionTag)
+    def _get_existing_chapter_frame_timestamps(self, deposit):
+        """Get timestamps of existing chapter frames."""
+        master_file = CDSVideosFilesIterator.get_master_video_file(deposit)
+        frames = CDSVideosFilesIterator.get_video_frames(master_file)
 
-        existing = (
-            ObjectVersion.query.join(tag_alias_1, ObjectVersion.tags)
-            .join(tag_alias_2, ObjectVersion.tags)
-            .join(tag_alias_3, ObjectVersion.tags)
-            .filter(tag_alias_1.key == "master", tag_alias_1.value == self.object_version_id)
-            .filter(tag_alias_2.key == "context_type", tag_alias_2.value == "frame")
-            .filter(tag_alias_3.key == "timestamp")
-            .all()
-        )
-        
-        existing_timestamps = set()
-        for obj in existing:
-            for tag in obj.tags:
-                if tag.key == "timestamp":
-                    try:
-                        existing_timestamps.add(float(tag.value))
-                    except ValueError:
-                        continue
-        
-        return existing_timestamps
+        existing = set()
+        for f in frames:
+            tags = f.get("tags", {})
+            if tags.get("is_chapter_frame") == "true":
+                existing.add(float(tags.get("timestamp")))
+        return existing
 
     @classmethod
     def _create_chapter_frames(
@@ -904,6 +907,7 @@ def _create_chapter_frames(
     ):
         """Create frames for chapters that don't already exist at those timestamps."""
         created_frames = []
+        valid_chapter_seconds = []
         current_chapter = 0
 
         with move_file_into_local(object_, delete=True) as url:
@@ -920,6 +924,10 @@ def _create_chapter_frames(
                 if chapter_seconds > duration:
                     continue
 
+                # For 0:00 chapters, use a small offset to avoid extraction issues
+                chapter_seconds = max(chapter_seconds, 0.1) if chapter_seconds == 0 else chapter_seconds
+                valid_chapter_seconds.append(to_string(chapter_seconds))
+                
                 # Skip if frame already exists at this timestamp (with some tolerance)
                 timestamp_exists = any(
                     abs(existing_ts - chapter_seconds) < 0.1 
@@ -931,9 +939,6 @@ def _create_chapter_frames(
                 frame_filename = "chapter-{0}.jpg".format(int(chapter_seconds))
                 frame_path = os.path.join(output_dir, frame_filename)
 
-                # For 0:00 chapters, use a small offset to avoid extraction issues
-                chapter_seconds = max(chapter_seconds, 0.1) if chapter_seconds == 0 else chapter_seconds
-                
                 try:
                     # Extract single frame at chapter timestamp using ff_frames
                     ff_frames(
@@ -970,7 +975,41 @@ def _create_chapter_frames(
                     )
                     continue
 
-        return created_frames
+        return created_frames, valid_chapter_seconds
+
+    def _build_chapter_vtt(self, chapters, duration):
+        """Build WebVTT content string from chapters list."""
+        if not chapters:
+            return
+        vtt = "WEBVTT\n\n"
+        for i, c in enumerate(sorted(chapters, key=lambda x: x["seconds"])):
+            start = c["seconds"]
+            end = chapters[i+1]["seconds"] if i+1 < len(chapters) else duration
+            start_str = "{:02}:{:02}:{:02}.000".format(
+                int(start // 3600),
+                int((start % 3600) // 60),
+                int(start % 60)
+            )
+            end_str = "{:02}:{:02}:{:02}.000".format(
+                int(end // 3600),
+                int((end % 3600) // 60),
+                int(end % 60)
+            )
+            vtt += f"{i+1}\n{start_str} --> {end_str}\n{c['title']}\n\n"
+        
+        vtt_bytes = vtt.encode("utf-8")
+        vtt_key = "chapters.vtt"
+
+        obj = ObjectVersion.create(
+            bucket=self.object_version.bucket,
+            key=vtt_key,
+            stream=BytesIO(vtt_bytes),
+            size=len(vtt_bytes),
+        )
+        ObjectVersionTag.create(obj, "media_type", "chapters")
+        ObjectVersionTag.create(obj, "context_type", "chapters")
+        ObjectVersionTag.create(obj, "content_type", "vtt")
+        self.log("Created chapters.vtt")
 
 
 class TranscodeVideoTask(AVCTask):

cds/modules/previewer/api.py

@@ -128,6 +128,18 @@ def vr(self):
         """Get video's VR flag."""
         return self.record.get("vr")
 
+    @property
+    def chapters_uri(self):
+        """Get the chapters.vtt file link if available."""
+        try:
+            return [
+                f["links"]["self"]
+                for f in self.record["_files"]
+                if f.get("context_type") == "chapters" and f.get("content_type") == "vtt"
+            ][0]
+        except IndexError:
+            return None
+
 
 class CDSPreviewDepositFile(PreviewFile):
     """Preview deposit files implementation."""

cds/modules/previewer/extensions/video.py

@@ -65,12 +65,6 @@ def preview(self, file, embed_config=None):
             else ""
         )
 
-        description = record.get('description', '')
-        if description:
-            record['chapters'] = parse_video_chapters(description)
-        else:
-            record['chapters'] = []
-
         return render_template(
             self.template,
             file=file,

cds/modules/previewer/templates/cds_previewer/macros/player.html

@@ -54,7 +54,7 @@
 
       window.top.player = player;
 
-    // --- Chapters helpers ---
+    // --- helpers ---
     function durationToSeconds(durationStr) {
       if (!durationStr) return null;
       const parts = durationStr.split(':').map(Number); // [HH, MM, SS] or [MM, SS]
@@ -66,55 +66,8 @@
       }
       return null;
     }
-    function formatVttTime(total) {
-      const h = Math.floor(total / 3600);
-      const m = Math.floor((total % 3600) / 60);
-      const s = Math.floor(total % 60);
-      return String(h).padStart(2,'0') + ':' + String(m).padStart(2,'0') + ':' + String(s).padStart(2,'0') + '.000';
-    }
-    function buildChaptersVttFromArray(chaptersArr, videoDurationStr) {
-      if (!chaptersArr || !chaptersArr.length) return null;
-
-      chaptersArr.sort((a,b) => a.seconds - b.seconds);
-      const videoDuration = durationToSeconds(videoDurationStr);
-      if (videoDuration !== null && videoDuration <= 0) return null;
-      let vtt = 'WEBVTT\n\n';
-      for (let i = 0; i < chaptersArr.length; i++) {
-        const c = chaptersArr[i];
-        const start = c.seconds;
-        const end = (i + 1 < chaptersArr.length)
-                      ? chaptersArr[i+1].seconds
-                      : (videoDuration || start + 1);
-
-        vtt += `${i+1}\n${formatVttTime(start)} --> ${formatVttTime(end)}\n${c.title}\n\n`;
-      }
-      return vtt;
-    }
 
-    // Build textTracks
-    var textTracksArr = [];
-    // Chapters
-    var chaptersArr = {{ (record.chapters if record and record.chapters else []) | tojson }};
-    var videoDurationStr = {{ (record.duration if record and record.duration else "") | tojson }};
-    var vttStr = buildChaptersVttFromArray(chaptersArr, videoDurationStr);
-    if (vttStr) {
-      var chapUrl = URL.createObjectURL(new Blob([vttStr], { type: 'text/vtt' }));
-      textTracksArr.push({ kind: 'chapters', src: chapUrl, label: 'Chapters' });
-    }
-    {% if not embed_config.subtitlesOff %}
-    textTracksArr.push({ kind: 'metadata', src: '{{ obj.thumbnails_uri }}', label: 'thumbnails', default: true });
-    {% for uri, lang in obj.subtitles %}
-    textTracksArr.push({
-      kind: 'subtitles',
-      src: '{{ uri }}',
-      label: '{{ lang }}',
-      srclang: '{{ lang }}'
-      {% if embed_config.subtitles and embed_config.subtitles == lang %}, default: true{% endif %}
-    });
-    {% endfor %}
-    {% endif %}
-
-    // Set source with textTracks
+    // Preload
     player.source = {
       sources: [
         {
@@ -128,11 +81,42 @@
             src: '{{ obj.uri }}',
             type: 'video/mp4'
           {% endif %}
-        }
+        },
+      ],
+      textTracks: [
+        {
+          kind: 'metadata',
+          src: '{{ obj.thumbnails_uri }}',
+          label: 'thumbnails',
+          default: true,
+        },
+
+        // Add chapters.vtt if available
+        {% if obj.chapters_uri %}
+        {
+          kind: 'chapters',
+          src: '{{ obj.chapters_uri }}',
+          label: 'Chapters',
+        },
+        {% endif %}
+
+        // Add subtitles
+        {% if not embed_config.subtitlesOff %}
+        {% for uri, lang in obj.subtitles %}
+        {
+          kind: 'subtitles',
+          src: '{{ uri }}',
+          label: '{{ lang }}',
+          srclang: '{{ lang }}',
+          {% if embed_config.subtitles and embed_config.subtitles == lang %}
+          default: true,
+          {% endif %}
+        },
+        {% endfor %}
+        {% endif %}
       ],
-      textTracks: textTracksArr,
       poster: '{{ obj.poster_uri }}',
-        {% if obj.vr %}
+      {% if obj.vr %}
         vr: {
           360: true,
         },

cds/modules/records/static/templates/cds_records/video/detail.html

@@ -26,7 +26,7 @@
             <div class="cds-detail-title cds-detail-video-title">
               <h3 class="bt bw-1 pt-10 mb-0">
                 <i class="fa fa-video-camera"></i> In this video
-                <div class="pull-right"><i class="fa fa-close transcription-close" ng-click="toggleInThisVideo()"></i></div>
+                <div class="pull-right"><i class="fa fa-close transcription-close" ng-click="closeInThisVideoSection()"></i></div>
               </h3>
             </div>
             <!-- Tabs -->
@@ -312,7 +312,7 @@ <h4>{{translation.title.title}}</h4>
             <div style="display: flex; align-items: center; justify-content: space-between; margin-bottom: 10px;">
               <h3><strong>Chapters</strong></h3>
               <button class="btn btn-sm btn-default transcription-button" ng-click="toggleInThisVideo('chapters')">
-                {{ showInThisVideoSection ? 'Show Less' : 'View All' }}
+                View All
               </button>
             </div>
 
@@ -369,7 +369,7 @@ <h3><strong>Transcriptions</strong></h3>
               <div class="transcription-button-wrapper pt-10">
                 <button class="btn btn-sm btn-default transcription-button"
                         ng-click="toggleInThisVideo('transcript')">
-                  {{ showInThisVideoSection ? 'Hide Transcriptions' : 'Show Transcriptions' }}
+                  Show Transcriptions
                 </button>
               </div>
             </div>

cds/modules/theme/assets/bootstrap3/js/cds_records/cdsRecord.js

@@ -117,8 +117,12 @@ function cdsRecordController($scope, $sce, $http, $timeout, $filter) {
     $scope.seekTo(timecode);
   };
 
+  $scope.closeInThisVideoSection = function () {
+    $scope.showInThisVideoSection = false;
+  };
+
   $scope.toggleInThisVideo = function (tab) {
-    $scope.showInThisVideoSection = !$scope.showInThisVideoSection;
+    $scope.showInThisVideoSection = true;
     $scope.activeTab = tab;
 
     // Jump to Transcriptions section