Release Frame Extractor v1.2.0 · nokarin-dev/FrameExtractor

Added

Core

Preset System - Save, browse, and apply named extraction presets (FPS, format, quality, scale, time range, prefix). Built-in presets included: High Quality PNG, Fast Preview, Web Optimized, 4K Lossless
Settings Persistence - All extraction settings (FPS, format, quality, scale, time range, prefix, "open folder on done") are now saved between sessions and automatically restored on next launch
Frame & Size Estimator - Live frame count and estimated output size shown below settings when a source and output folder are selected
Keyboard shortcut Ctrl+P - Opens the Presets panel
Close confirmation dialog - Closing the window while extraction is in progress now shows a confirmation dialog ("Keep Running" / "Close Anyway") instead of immediately terminating the process
Batch extraction - define multiple time ranges (each with its own frame prefix) and extract all of them in a single run. A new StartBatchExtraction event drives the ExtractionBloc, which reports per-job progress (e.g. "Job 2/5: extracting…") and saves a separate history record for every completed job.
Extraction history - every successful extraction is automatically saved to AppPrefs (max 50 records). The new History screen (title bar button or Ctrl+H) shows video name, frame count, elapsed time, fps, format, and the output path, with one-click "Open folder" and "Copy path" actions.
Video metadata card - after selecting a local video the app runs ffmpeg (desktop) or FFprobeKit (Android) to read duration, resolution, fps, and codec, then renders a thumbnail alongside these details below the source card. The thumbnail is cached in the system temp directory so subsequent opens are instant.
Frame preview screen - tap the thumbnail (or the preview button) to open a full-screen scrubber that renders the frame at any timestamp before committing to a full extraction. Uses ffmpeg -vframes 1 under the hood; the preview is cached per-path-and-timestamp.
Drag & drop video files (desktop) - drag any supported video file directly onto the app window using the desktop_drop package. Unsupported extensions show a toast error.
Keyboard shortcut Ctrl+H - shortcut for history panel, added to the Settings keyboard shortcuts list.
Long-press hint overlay - a subtle dark pill in the bottom-right corner of the preview image reminds users that long-pressing copies the timestamp.
Ctrl+B keyboard shortcut - shortcut for batch panel, listed in the Settings shortcuts panel.

Bloc / Events

StartBatchExtraction event - list of ExtractionParams, each run in sequence; first failure aborts the batch.
SavePreset and DeletePreset events now have working handlers in ExtractionBloc (previously defined in extraction_event.dart but silently ignored because no on<SavePreset> / on<DeletePreset> handlers were registered).
LogLevel enum (debug, info, warn, error) on AppendLog - debug-level lines are stored in the log buffer but tagged [DEBUG] so they are visually grouped; future work can filter them out of the panel.

Services

FFmpegService.getVideoMetadata(String videoPath) - new abstract method implemented in both FFmpegServiceDesktop (ffmpeg) and FFmpegServiceMobile (FFprobeKit).
FFmpegService.extractPreviewFrame({required String videoPath, required String timestamp}) - renders a single JPEG to the temp directory; cached by path + timestamp.

Models

VideoMetadata - new model: duration, width, height, fps, codec, thumbnailPath. Helpers: resolutionLabel, durationFormatted.
ExtractionRecord - new model for history: full JSON serialization round-trips via listFromJson / listToJson. Fields: id, videoPath, outputDirectory,frameCount, completedAt, elapsed, format, fps. Helper: videoName.
ExtractionSuccess now carries frameCount (previously always 0), which is used when persisting the history record.
ExtractionInProgress now carries batchIndex and batchTotal for batch progress UI. Helper getter isBatch.

Validation

Time range validation - Start/End time fields now validate in real-time: incorrect format (non-HH:MM:SS), start ≥ end, and range < 0.1s are flagged with inline error messages. Fields turn red and extraction is blocked until fixed
Pre-extraction validation - ExtractionParams now has a validate() method and isValid getter. Both FFmpeg services validate params before running and emit a clear error if validation fails
Illegal character check in frame name prefix (rejects < > : " / \ | ? *)
Recent video file validation - Recent video entries are now checked for existence on disk at startup; stale entries are automatically removed from the list

ExtractionParams improvements

estimatedFrameCount getter - calculates frames from time range × FPS
estimatedSizeBytes and estimatedSizeFormatted getters - rough per-format size estimate
ExtractionParams.validated() factory - throws ArgumentError with all error details if params are invalid
== and hashCode overrides for safe comparison
Descriptive toString()

Preset Model

New ExtractionPreset model with full JSON serialization/deserialization
ExtractionPreset.defaults - 4 built-in read-only presets
isDefault flag - built-in presets cannot be deleted by the user

AppPrefs

lastFps, lastFormat, lastQuality, lastScale, lastStartTime, lastEndTime, lastPrefix, openFolderOnDone - persisted extraction settings
customPresets, allPresets, savePreset(), deletePreset(), clearCustomPresets() - full preset CRUD
addHistoryRecord(), history getter, clearHistory() - history CRUD backed by prefHistory key.

AppConstants

prefLastFps, prefLastFormat, prefLastQuality, prefLastScale, prefLastStartTime, prefLastEndTime, prefLastPrefix, prefOpenFolderOnDone, prefPresets - new preference keys
- ffmpegThreads constant (defaults to 0 = auto)
maxCustomPresets limit (20)
Expanded supportedVideoExtensions: added ts, 3gp
maxFps raised from 60 → 120
minScale lowered from 0.25 → 0.1, maxScale raised from 2.0 → 4.0
maxHistoryRecords constant (50).
prefHistory preference key.

User Interface

Presets panel accessible via new title bar button (bookmarks icon) or Ctrl+P
- Lists all presets with name, settings summary, Apply and Delete buttons
- Built-in presets show a lock icon and cannot be deleted
Save as Preset button inside Advanced settings panel
Estimate row below settings card: shows ~N frames and ~X MB live as user adjusts FPS, format, quality, and time range
Pulse animation for progress indicator now correctly starts/stops based on actual extraction state (was always running before)
Full path tooltip on Video File and Output Folder rows - hovering shows the complete file/directory path, not just the truncated filename
History screen - full-screen list of past extractions. Each tile shows video name, date, frame count, elapsed time, fps, format, and output path. "Clear all" with confirmation dialog. Works on desktop and Android (folder-open disabled on mobile).
VideoMetadataCard widget - thumbnail + resolution + duration + codec + fps chips. Tapping opens FramePreviewScreen.
FramePreviewScreen - scrubber slider (0–3600 s), timestamp label, refresh button, pinch-to-zoom via InteractiveViewer. Loading spinner and "could not extract" error state.
Set as Start / Set as End - two buttons in the preview control bar let the user set the extraction start or end time directly from the scrubbed frame, updating _startTimeCtrl / _endTimeCtrl in the home screen without leaving the preview screen.
Retry on error - if a frame cannot be extracted (e.g. timestamp beyond the actual end), an error state with a Retry button is shown instead of a blank screen.
Save log button added next to "Copy all". On desktop it writes to the Downloads folder (falls back to Documents); on Android it writes to the app Documents directory. Filename format: frameextractor_log_YYYY-MM-DDTHH-MM-SS.txt. The button is visually disabled (dimmed) when there are no log lines.
History button (clock icon) in title bar; Ctrl+H shortcut.
ProgressSection now shows a "Job N of M" indicator during batch runs and renders a BATCH phase label.
Time field error state: red border, red icon, red label, red tinted background, inline error text below field
Presets keyboard shortcut Ctrl+P row added to Settings panel
Update badge label changed from generic "out-of-date" to the specific version string (e.g. "v1.2.0 available")

Fixed

Core

SavePreset / DeletePreset silently dropped - the bloc now has on<SavePreset> and on<DeletePreset> handlers that call AppPrefs.savePreset() / AppPrefs.deletePreset(). Previously, dispatching these events did nothing.
LogMixin dead code removed from extraction_state.dart - the mixin was defined but never mixed into any state class. Log state is correctly managed on the bloc itself as _logs.
_parseSeconds duplicated in home_screen.dart and extraction_params.dart - both copies are replaced by a single top-level parseTimeString(String t) function exported from extraction_params.dart. The UI import is show parseTimeString to keep the namespace clean.
isClosed guards missing inside _copyFramesToUserDir - every await in the copy loop and SAF path is now preceded by an if (isClosed) return guard, preventing state emissions after the bloc is disposed.
[DEBUG] log strings in user-visible panel - bloc internal diagnostic lines are now emitted via AppendLog(line, level: LogLevel.debug) and stored with a [DEBUG] prefix. They appear in the log buffer (for export) but are visually distinguished from user-facing [INFO] / [WARN] / [ERR] lines.

YouTube Service

Cancel flag not reset - YouTubeService._cancelled was never reset to false before starting a new download, causing the first download after a cancellation to immediately return null. Fixed via new resetCancelFlag() method called by ExtractionBloc before each download
YouTubeService recreated on every fetch - _fetchYtInfo() was instantiating a new YouTubeService() on each button press. It now reuses the instance owned by ExtractionBloc, avoiding redundant allocations and potential state inconsistency

FFmpeg Services

FFmpegServiceMobile blocking UI thread - replaced FFmpegKit.execute() with FFmpegKit.executeAsync() + polling loop, preventing jank during long extractions on mobile
Scale filter quality - resolution scaling now uses flags=lanczos for better downscale quality
Progress emit throttle reduced from 500ms → 300ms for more responsive progress updates
ffmpeg_service_base.dart: estimateExtractionImpl now uses a more realistic speed estimate for PNG (67% of JPG speed)

User Interface

_LiveThemeChild polling loop removed - the 100ms polling timer that detected theme changes by repeated AppTheme.of() calls is eliminated. Dialogs and sheets now read theme directly from the InheritedWidget (AppTheme.of()), which rebuilds automatically on change with zero overhead
_AppThemeNotifier static singleton removed - the leaked ChangeNotifier singleton that was never disposed is fully removed. Theme propagation now relies exclusively on Flutter's InheritedWidget mechanism
BlocBuilder rebuild scope reduced - the main Column is no longer wrapped in a single BlocBuilder. Each section (source card, output card, settings, progress, action buttons) now has its own narrowly-scoped BlocBuilder with buildWhen guards, so progress updates only rebuild the progress card instead of the entire screen
Pulse animation no longer synced inside BlocBuilder builder - starting/stopping _pulseCtrl is now handled in BlocListener (side-effect handler) instead of the BlocBuilder rebuild cycle, preventing potential animation restart glitches
ExtractionParams construction cached - estimate values (_cachedEstimatedFrames, _cachedEstimatedSize) are computed once via _refreshEstimates() when inputs change (slider, format chip, time field), instead of rebuilding ExtractionParams on every build() call
_buildAdvancedToggle opacity corrected - was always applying the disabled opacity value regardless of the disabled flag. Now only applies reduced opacity when the toggle is actually disabled

Changed

Architecture

buildVfFilter() and qualityToQv() moved to FFmpegService base class (shared between desktop and mobile instead of duplicated)
ExtractionBloc._onStartYouTubeExtraction now calls youTubeService.resetCancelFlag() before download
ExtractionBloc persists settings to AppPrefs after each successful extraction start via _persistSettings()
HomeScreen._loadPrefs() now restores all persisted extraction settings on init, and filters stale recent video entries asynchronously
_validateTimeRange() wired to _onTimeChanged() listener which also triggers _refreshEstimates(), keeping estimate display in sync with time field edits
HomeScreen split into focused files under presentation/screens/sections/: source_section.dart, output_section.dart, settings_section.dart, advanced_section.dart, progress_section.dart. The root home_screen.dart is now a thin orchestrator.
Shared UI primitives extracted to presentation/widgets/: app_card.dart, app_divider.dart, clear_row.dart, compact_field.dart, disabled_overlay.dart, file_row.dart, gloss_chip.dart, slider_row.dart, small_btn.dart, time_field.dart, video_metadata_card.dart.
isGlass and isDark are no longer prop-drilled through every widget constructor. All extracted widgets call AppTheme.of(context) directly, relying on Flutter's InheritedWidget mechanism.
ExtractionBloc._persistSettings refactored to accept ExtractionParams instead of seven individual parameters.