[alexis-morain]

Follow-up to #152, from the first real device pass (iPhone 16e, iOS 26.6). Three fixes, each verified on the phone:

1. Launch crash: duplicate plugin registration

The app aborted at startup with Duplicate plugin key: VideoThumbnailPlugin. The project depends on both video_thumbnail (direct git fork) and get_thumbnail_video (transitively through video_trimmer), which is a maintained fork of the same plugin. On Android their registrant keys are distinct FQCNs so the duplication is harmless; on iOS both register the same ObjC class and the engine refuses the second one. Fixed by dropping the direct video_thumbnail dependency and pointing the two call sites at get_thumbnail_video, which video_trimmer forces into the build anyway. Same VideoThumbnail.thumbnailData API, imports only.

2. Save crash: ffmpeg-kit's setFontDirectory and NSNull

Tapping save aborted with -[NSNull allKeys]: unrecognized selector. setFontDirectory(fontPath) without the optional font map sends null across the method channel, which lands in ObjC as NSNull, and ffmpeg-kit iOS calls allKeys on it unchecked. Android tolerates the null, which is why this never surfaced. Fixed by passing an explicit empty map. Worth an upstream report to ffmpeg-kit eventually.

With these two fixes the core loop works on a real iPhone: record (camera outputs HEVC), save with the burned-in date, and VideoToolbox transcodes to H.264 exactly as the runtime encoder selection intends. Reinstalling over an existing install kept every video visible — the container UUID did change between installs, so that path fix is doing its job.

3. main compiles again, and the photo flow gets the same treatment

#150 and #152 crossed in flight: save_photo_button.dart still called StorageUtils.deleteFileWithMediaStore, which #152 had replaced, so flutter analyze failed on main. Since the photo flow is a pre-refactor clone of SaveButton, it now goes through the same seams: AppPaths for output paths (with the missing-profile bounds check), VideoEncoder instead of hardcoded libx264, the empty font map, and the unused MediaStore instance removed.

Still known-broken on iOS, next PR

Subtitles editing and movie generation fail on device (ffmpeg session errors, logs captured). I'm on it — flagging so you know the current state before tagging anything.

flutter analyze clean, 19/19 tests, release build runs on device.

🤖 Generated with Claude Code

[alexis-morain]

Closing the loop on the ffmpeg-kit note in the description: reported upstream as sk3llo/ffmpeg_kit_flutter#167.

Traced the full chain while writing it up. The Dart optional argument defaults to null, the platform channel sends it as a map value, and Flutter's standard codec substitutes kCFNull for null map values (FlutterStandardCodecHelper.cc), so it lands in ObjC as NSNull rather than nil. The plugin's dispatch guards the font directory but never the map, and FFmpegKitConfig then enumerates it with allKeys. A genuine nil would have been harmless there, since a for-in over nil is a no-op, so NSNull is the only fatal case. setFontDirectoryList has the same defect and funnels into the same line. Still present on their main (4.6.2).

Our empty-map workaround is correct and not a papering-over, but this is worth knowing if the dependency ever moves.