diff --git a/Dockerfile b/Dockerfile
index cb70a92..069aa8e 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,6 +4,11 @@ FROM python:3.13.5-slim-bookworm
# set the working directory in the container
WORKDIR /app
+# ffprobe (from ffmpeg) reads each video's duration for the library
+# browser's "how long is this course" display
+RUN apt-get update && apt-get install -y --no-install-recommends ffmpeg \
+ && rm -rf /var/lib/apt/lists/*
+
# copy the dependencies file to the working directory
COPY requirements.txt .
diff --git a/offlineu_core.py b/offlineu_core.py
index edfdbb0..c1851aa 100644
--- a/offlineu_core.py
+++ b/offlineu_core.py
@@ -12,6 +12,7 @@ import re
import sys
import argparse
import io
+import subprocess
import time
import uuid
import zipfile
@@ -886,21 +887,109 @@ def get_all_course_dirs() -> List[Path]:
return cache_get_or_compute('course_dirs', lambda: list(iter_all_courses(get_library_root())))
+def _probe_media_duration_seconds(file_path: Path) -> Optional[float]:
+ """Read a single media file's duration via ffprobe. None if ffprobe is
+ missing, the file isn't readable, or the output can't be parsed."""
+ try:
+ result = subprocess.run(
+ ['ffprobe', '-v', 'error', '-show_entries', 'format=duration',
+ '-of', 'default=noprint_wrappers=1:nokey=1', str(file_path)],
+ capture_output=True, text=True, timeout=15
+ )
+ except (OSError, subprocess.SubprocessError):
+ return None
+ if result.returncode != 0:
+ return None
+ try:
+ return float(result.stdout.strip())
+ except ValueError:
+ return None
+
+
+DURATION_CACHE_FILENAME = '.offlineu_duration_cache.json'
+
+
+def _course_total_duration_seconds(course_dir: Path, media_files: List[Path]) -> Optional[float]:
+ """
+ Total runtime across a course's video/audio files, for the library
+ browser's "how long is this" display. ffprobe only ever runs once per
+ file - results are cached to a small per-course JSON file keyed by
+ (relative path, size, mtime), so a container restart or the library
+ scan's 5-minute cache expiring never re-probes a file that hasn't
+ changed on disk; only a genuinely new or replaced file pays the cost.
+ """
+ if not media_files:
+ return None
+
+ cache_file = course_dir / DURATION_CACHE_FILENAME
+ try:
+ with open(cache_file, 'r') as f:
+ cache = json.load(f)
+ except (FileNotFoundError, json.JSONDecodeError, OSError):
+ cache = {}
+
+ total = 0.0
+ have_any = False
+ changed = False
+ seen_keys = set()
+
+ for media_path in media_files:
+ try:
+ rel_key = str(media_path.relative_to(course_dir))
+ stat = media_path.stat()
+ except OSError:
+ continue
+ seen_keys.add(rel_key)
+
+ cached = cache.get(rel_key)
+ if cached and cached.get('size') == stat.st_size and cached.get('mtime') == stat.st_mtime:
+ duration = cached.get('duration_seconds')
+ else:
+ duration = _probe_media_duration_seconds(media_path)
+ cache[rel_key] = {'size': stat.st_size, 'mtime': stat.st_mtime, 'duration_seconds': duration}
+ changed = True
+
+ if duration:
+ total += duration
+ have_any = True
+
+ # Drop entries for files that no longer exist, so a renamed/deleted
+ # course's cache doesn't grow stale entries forever.
+ stale_keys = set(cache.keys()) - seen_keys
+ if stale_keys:
+ for key in stale_keys:
+ del cache[key]
+ changed = True
+
+ if changed:
+ try:
+ with open(cache_file, 'w') as f:
+ json.dump(cache, f, indent=2)
+ except OSError as e:
+ print(f"Could not save duration cache: {e}")
+
+ return total if have_any else None
+
+
def _course_summary(course_dir: Path) -> Dict[str, Any]:
- """Build the {type, name, path, media_files, hidden, has_thumbnail} shape
- shared by the Library browser, search results, and Recently Added."""
+ """Build the {type, name, path, media_files, hidden, has_thumbnail,
+ duration_display} shape shared by the Library browser, search results,
+ and Recently Added."""
def compute():
- media_count = len([
+ media_files = [
f for f in course_dir.rglob('*')
if f.is_file() and f.suffix.lower() in VIDEO_EXTENSIONS | AUDIO_EXTENSIONS
- ])
+ ]
+ total_duration = _course_total_duration_seconds(course_dir, media_files)
return {
'type': 'course',
'name': course_dir.name,
'path': str(course_dir),
- 'media_files': media_count,
+ 'media_files': len(media_files),
'hidden': False,
- 'has_thumbnail': find_course_thumbnail(str(course_dir)) is not None
+ 'has_thumbnail': find_course_thumbnail(str(course_dir)) is not None,
+ # under a minute isn't a meaningful "how long will this take" signal
+ 'duration_display': format_duration(total_duration) if total_duration and total_duration >= 60 else None,
}
return dict(cache_get_or_compute(f'course_summary:{course_dir}', compute))
diff --git a/templates/course_dashboard.html b/templates/course_dashboard.html
index 25add05..4da1335 100644
--- a/templates/course_dashboard.html
+++ b/templates/course_dashboard.html
@@ -1644,12 +1644,15 @@
const progressBar = pct
? ``
: '';
+ const metaBits = [`${item.media_files} media file${item.media_files === 1 ? '' : 's'}`];
+ if (item.duration_display) metaBits.push(item.duration_display);
+ if (pct) metaBits.push(`${pct}% done`);
return `
${selectableAttrs(item)}
${iconHtml}
${item.name}
-
${item.media_files} media file${item.media_files === 1 ? '' : 's'}${pct ? ` · ${pct}% done` : ''}
+
${metaBits.join(' · ')}
${progressBar}
${progressBadge}
- ${item.media_files} media file${item.media_files === 1 ? '' : 's'}
+ ${item.media_files} media file${item.media_files === 1 ? '' : 's'}${item.duration_display ? ` · ${item.duration_display}` : ''}
${progressBar}