VRKA Android

Native Android media downloader and passive web stream discovery.

Download APK (v5.0.2) • Screenshots • Architecture • Build Guide • Signing Protocol • Security

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Origin

Note

VRKA Android is the Android companion of the desktop media downloader VRKA by MaverickRox.

• Desktop Source Repository: https://github.com/MaverickRox/VRKA
• Android Port Repository: https://github.com/MaverickRox/VRKA-Android

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Overview

VRKA Android is built with Jetpack Compose and Kotlin Coroutines. Normal downloads and Browser Fallback transfers use yt-dlp; GeckoView provides browser navigation and media discovery, while FFmpeg handles local post-processing and validation. uBlock Origin is used as a browser privacy filter.

Designed for local, on-device processing without an application analytics service, featuring an AMOLED-optimized Liquid Glass interface.

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Screenshots

Download Interface Format, resolution & codec selection	Task Queue Persistent queue with optional concurrency	Download History Archived tasks & media files
Light Mode Adaptive high-contrast light theme

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Features

• Direct Extraction & Download: Powered by yt-dlp and FFmpeg (arm64-v8a), supporting video/audio stream extraction where provided by the source, resolution selection (Best, 4K, 1440p, 1080p, 720p, etc.), 60 FPS preference, subtitle embedding, and audio extraction (MP3 with 128–320 kbps selectable bitrate, Opus with prefer native stream-copy remuxing and fallback transcode, and uncompressed 16-bit PCM WAV).
• Subtitle Scope: Subtitle download and embedding options apply to normal yt-dlp jobs. Browser Fallback does not currently fetch subtitles.
• Custom HTTP Headers & Injection Protection: Network customization with dedicated Referer and Origin parameters and user-defined HTTP headers validated against RFC 7230 token specifications and CRLF injection rejection.
• Sensitive Header Redaction: Multi-tier data protection masking sensitive authorization tokens, cookies, and secret headers ([REDACTED]) across logs, crash diagnostics, on-device stores, and UI cards.
• Dynamic Font Preference: User-toggleable application typography supporting the signature monospace VRKA Font (Space Mono) and clean System Font (Roboto / device default) with persistent DataStore configuration.
• Download Location Modes: Clear destination control supporting "Use selected" (defaulting to Downloads/VRKA with persistent directory permissions) or "Ask every time" (modal confirmation before queuing).
• Background Orchestration: Foreground DownloadService with JobStore persistence, notification progress tracking, cancellation, and optional persisted parallel job execution (2–4 workers; sequential by default).
• Passive Browser Fallback: An embedded Mozilla GeckoView session automatically activates when direct extraction encounters anti-bot challenges or client-side player scripts.
• Integrated Content Filtering: Bundled uBlock Origin WebExtension filters network requests to suppress intrusive ads and tracking scripts during fallback stream observation.
• Browser Fallback Discovery: The VRKA media-detector WebExtension observes browser requests and page media elements, including direct media, HLS and DASH candidates. Candidate discovery is followed by yt-dlp probing and the standard yt-dlp transfer.
• Local On-Device Diagnostics: On-device diagnostic failure logging in Settings with stage attribution, terminal trace viewer, secret-sanitized reporting, and one-tap clipboard export.
• In-App Component Updates: The app checks and updates the active yt-dlp and uBlock Origin components. Installed versions come from the running yt-dlp runtime or the installed/bundled extension; “Up to date” is shown only after a successful remote check.
• In-App Application Self-Update: Secure in-app update checker querying GitHub Releases with a 24-hour automatic gate, manual checks from Settings, strict stable three-part semantic versions, exact APK asset verification (VRKA-Android-vX.Y.Z.apk), HTTPS redirect validation, and package/version/code/signing-certificate verification before FileProvider installation.
• Browser Session Clearing: Settings clears GeckoView cookies, DOM storage, auth sessions, site data, caches and in-memory discovered candidates. It does not cancel an active fallback.
• H.264 Compatibility Mode: Optional, off by default. If a downloaded video is not H.264, FFmpeg converts the local staged file, validates the result and preserves supported audio/subtitle streams.
• Custom yt-dlp Commands: Named argument templates for normal jobs. Templates are argv lists, not shell commands; VRKA controls output staging. Eligible failures can still enter Browser Fallback, whose standard yt-dlp request ignores the selected template.
• Liquid Glass Design System: Floating capsule navigation with hardware-accelerated RenderEffect backdrop blur across AMOLED Black and Light modes.

In-App Application Self-Update

VRKA Android includes an in-app update checker for updates from official GitHub releases:

• GitHub Releases Integration: Periodically checks the official repository (/repos/MaverickRox/VRKA-Android/releases/latest) for new releases.
• 24-Hour Automatic Gate: Automatic startup checks run at most once every 24 hours to reduce network traffic.
• Manual Check Bypass: The [Check for Updates] button in Settings bypasses the 24-hour interval to check immediately.
• Non-Blocking Startup: Checks run in the background without slowing down app startup.
• Canonical Stable Releases: Accepts stable three-part tags such as v5.0.2, compares numeric version segments, and requires the exact matching asset VRKA-Android-v5.0.2.apk.
• HTTPS-Only Networking & Host Validation: Streams metadata and APK files over HTTPS from approved GitHub release hosts, rejecting user-info, nonstandard ports, and unapproved hosts.
• Redirect Validation: Validates every redirect target and limits redirect hops to at most 5.
• Install Verification: Requires the APK to remain in the private update cache and verifies package identity, filename/version agreement, non-downgrade version code, and the installed signing certificate before launching Android's installer.
• FileProvider Installation: APKs are saved to private app cache and handed off to Android's PackageInstaller via FileProvider.
• Persistent Downloads: Downloads run through WorkManager so they continue even if the app is backgrounded.

In-App Component Updates

VRKA Android independently manages and updates its core media and filtering components:

• yt-dlp: The installed runtime version is queried when available and updated using the app's updater. No historical version is presented as the active version when it cannot be queried.
• uBlock Origin: Bundled as a Firefox XPI (uBlock0@raymondhill.net) in assets/extensions/ublock.xpi; it is installed and enabled for Browser Fallback sessions. The Settings version row reports the detected runtime/package/update version rather than an embedded historical label.
• Persistent Background Execution: Component updates use WorkManager to survive Activity recreation and backgrounding.
• Concurrency & Spam Protection: Only one update operation runs per component at a time. Rapid button taps are de-duplicated without freezing the UI.

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Architecture

┌────────────────────────────────────────────────────────┐
│                   Jetpack Compose UI                   │
│   (HomeScreen, JobsScreen, HistoryScreen, Settings)   │
└──────────────────────────┬─────────────────────────────┘
                           │
┌───────────────────┐
│ Compose UI / Queue│
└─────────┬─────────┘
          ▼
┌──────────────────────┐     ┌─────────────────────────────┐
│ VrkaDownloadManager  │────▶│ yt-dlp normal acquisition   │
└──────────┬───────────┘     └──────────────┬──────────────┘
           │ eligible failure                │
           ▼                                 │
┌────────────────────────────┐               │
│ GeckoView + detector bridge│               │
│ candidate store / ranker   │               │
└──────────────┬─────────────┘               │
               └──── selected candidate ────┘
                              ▼
                 ┌────────────────────────┐
                 │ FFmpeg local processing│
                 │ validation / publish   │
                 └────────────────────────┘

Architectural Highlights

1. UI Layer: Built with Jetpack Compose and design tokens (VrkaTokens), featuring floating capsule navigation with adaptive backdrop blur across AMOLED Dark and Light modes.
2. Download Pipeline: VrkaDownloadManager invokes yt-dlp through the ordinary request factory. An eligible failure can enter Browser Fallback. A failed custom-template attempt follows the same eligibility check.
3. Browser Fallback: GeckoView navigates in a task-scoped private session. The media-detector WebExtension and GeckoMediaBridge feed the candidate store/ranker. yt-dlp probes the selected candidate and performs the transfer using its standard request path; custom template arguments and custom request headers are not carried into that handoff. FFmpeg is used only for local processing and validation.
4. Components and Updates: yt-dlp and uBlock Origin are the active update-managed components. GeckoView's dependency version is declared once in the Gradle build and displayed from generated BuildConfig.

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Requirements

• Device Architecture: arm64-v8a
• Minimum OS: Android 8.0 (API Level 26)
• Target OS: Android 16 (API Level 36)
• Java Development Kit: JDK 17 or newer supported by the configured Gradle version (Android Studio JBR is suitable)
• Android SDK: Build-Tools 36.1+

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Build Instructions

Prerequisites

Set JAVA_HOME to your JDK 17+ path:

$env:JAVA_HOME = "C:\Program Files\Android\Android Studio\jbr"

Running Offline Unit Tests

.\gradlew.bat testDebugUnitTest --offline

Assembling Debug APK

.\gradlew.bat assembleDebug --offline

Output artifact: app/build/outputs/apk/debug/app-debug.apk

Assembling Release APK

Production release builds require explicit signing credentials. The build system strictly rejects release builds without credentials and will never silently fall back to debug signing.

1. Configure your release signing properties (outside Git) in ~/.vrka-android-signing/signing.properties or via the VRKA_SIGNING_PROPERTIES environment variable:

storeFile=/absolute/path/to/vrka-release.p12
storePassword=YOUR_KEYSTORE_PASSWORD
keyAlias=YOUR_KEY_ALIAS
keyPassword=YOUR_KEY_PASSWORD

2. Build the release APK:

$env:VRKA_SIGNING_PROPERTIES = "C:\Users\username\.vrka-android-signing\signing.properties"
.\gradlew.bat assembleRelease --offline

The compiled release artifact will be located at:

app/build/outputs/apk/release/app-release.apk

The official v5.0.2 release APK is production-signed. Check RELEASE_EVIDENCE.md for its exact path, SHA-256, package metadata and signing certificate.

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Release Signing

The release build type requires explicit signing credentials and never silently falls back to a debug key. Verify the v5.0.2 artifact's certificate and SHA-256 against RELEASE_EVIDENCE.md or official release checksums before installation.

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Installation

1. Download the official VRKA-Android-v5.0.2.apk from GitHub Releases.
2. Verify the SHA-256 hash against SHA256SUMS:

   (Get-FileHash .\VRKA-Android-v5.0.2.apk -Algorithm SHA256).Hash

   Expected: 136707980C34EA4242AB3B183571BC24C063A3DDB22BDB0A1CF56258345B9D54. The same value is recorded in SHA256SUMS and the official release page.
3. Install on your Android device:

   adb install -r .\VRKA-Android-v5.0.2.apk

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Third-Party Notices & Attribution

VRKA Android integrates the following open-source software:

• yt-dlp: The Unlicense (yt-dlp/yt-dlp)
• Mozilla GeckoView: Mozilla Public License 2.0 (GeckoView)
• uBlock Origin: GNU General Public License v3.0 (gorhill/uBlock)
• FFmpeg: LGPL / GPL licensed components
• Space Mono Font: SIL Open Font License 1.1

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License

VRKA Android is free software licensed under the GNU General Public License v3.0. See the LICENSE file for details.