FFMPEG in React Native | Video to Audio Trimmer App

Initialize a new React Native project using the CLI with a TypeScript template named Audio Trimmer, then run it on Android and iOS simulators to verify changes.

Design a three-screen flow for a video to audio trimmer app—video select, video convert, and audio trim—navigated with React Navigation in a React Native TypeScript project.

Set up a native stack navigator with react-navigation, configure three screens (video select, video convert, audio trim) under a navigation container, and implement navigation with useNavigation.

Customize the video select header and build a reusable app button in React Native with TypeScript, add on press handling, flexible layout, and future icon support.

Install and configure React Native vector icons for Android and iOS, update Gradle and Info.plist, run pod install, then import and display the cloud upload outline icon.

Install and configure the React Native image crop picker to select video files for conversion, including iOS photo library usage description, Android gradle changes, and cross-platform runs.

Implement Android runtime permissions in a React Native video picker by creating a permission utility, requesting camera and read/write external storage access, and handling permission flow before opening the picker.

Select a video file with the picker and define ffmpeg input and output paths for trimming or conversion. Build the input uri from source url or path.

Fixes type problem in a React Native FFMPEG video to audio trimmer app by defining a root stack param list, screen params, and navigation props to resolve TypeScript warnings.

Build a React Native video-to-audio converter UI with a full-width container, a convert to audio button with a multitrack icon, and setup for ffmpeg commands in the next step.

Learn to set up ffmpeg inside a React Native project with ffmpeg kit. Configure Android SDK 24 and iOS pod, install, and run on Android and iOS for video-audio trimming.

Extract the file name from a URI and sanitize it for FFmpeg by replacing spaces and non alphanumeric characters with underscores, ensuring a unique, cache-based input and output path.

Create a unique file name by combining the base name with date dot now and the extension, and store it in a cache directory to hide work files.

Explore React Native FS to access the file system, copy files into a new directory, install the package, run and test the app on Android and iOS.

Copy a video file into the app cache using react native fs, create a unique cache path, verify its existence, and fetch media information with ffprobe for ffmpeg audio conversion.

Discover how to convert video to audio in a React Native app using the ffmpeg kit, building a command with input and output paths, mp3 audio codec, and quality settings.

Use the ffmpeg kit execute async with complete, log, and statistics callbacks to capture time and duration in milliseconds, calculate progress from the video duration and converted duration.

Calculate video progress by mapping milliseconds to a 0-100% scale with a map range function, handling edge cases, and updating a progress state for a video to audio trim app.

Create a React Native TypeScript progress bar component with a bordered container, a filling progress view, and a percentage label, driven by a percent value to visualize progress.

Install and configure React Native Reanimated in non-expo project with npm, update babel plugins, run pod install, reset cache, and verify on Android and iOS to power progress bar component.

Animate the progress bar for the video to audio trimmer app using React Native Reanimated, creating an animated width with useSharedValue and useAnimatedStyle updated by progress with timing.

Demonstrates achieving precise progress with math.round to hit 100%, then renders audio edit options (convert another, save file, trim) in a React Native video-to-audio trimmer app.

Saving as audio explains implementing a download audio function, using cache/app directories to store the output, managing file info with path and name, and optionally saving to a download folder.

Select a video file, convert it to audio, and save the result; a file saved state reveals the convert another option and returns to the video selection for repeats.

Learn digital audio basics, including sampling and amplitudes, render audio samples in a UI, trim clips with start and end inputs, and prepare data with Web Audio API and FFmpeg.

Extract audio samples from a file using FFmpeg, save them as a txt file in a cache directory, and understand sample size and data points for waveform visualization.

Map audio rms data to 0–30 pixel heights for a trim ui, read and parse a text file, filter rmse lines, and prepare data for rendering vertical waveform lines.

Map rms labels to a 0–30 height scale by building a height-mapping function, deriving min and max rmse, and applying normalization.

Handle NaN in video-to-audio trimmer app by filtering labels to pure numbers and excluding NaN entries. Replace NaN with minimum rmse or silent audio, and return an empty array.

Navigate from video conversion to the audio trim screen, pass and render audio samples, and implement a responsive user interface with a timeline to trim audio based on user input.

Build an audio trim timeline by mapping samples to height-based bars, rendering them in a horizontal scroll view, and styling a rail container for the video to audio trimmer app.

Create an audio trim timeline UI in a React Native app by rendering two color-coded rails—the full audio and the selected trim—and enabling slider-based trimming.

Refactor the audio picks by extracting a reusable pix component, parameterizing data and pixel width, and adjusting margins between peaks for a centered layout.

Add left and right thumbs to the audio trim slider in a React Native FFmpeg app, using absolute positioning and width computed from samples length, peak width, and peak gap.

Render left and right in-out icons with react native vector icons, and implement a reusable thumb component with draggable gestures to trim audio.

Implement a draggable audio trimmer in a React Native app using gesture handler and reanimated, with a gesture handler root view and animated left and right handles clamped to boundaries.

Demonstrates the max thumb gesture in a React Native slider, using a gesture handler and animated view to clamp the maximum thumb position within the slider width.

Clamp left and right slider thumbs to prevent crossing, using minimum and maximum clamps with a 50-pixel margin and combined position checks to respect slider width.

Adjust the trimmer width with an animated view, using min and max positions, and translateX to trim from the left, while layering an inner trimmed area above the slider.

Calculate the trimmed start and end positions on gesture end by normalizing slider values, using min, max, and steps from sample length, with floor rounding for accurate range.

Implement a min max value calculator for a React Native video to audio trimmer using a worklet and run on JavaScript, and expose on change handler returning min and max.

Render the audio trim timeline start and end timestamps in React Native using a timestamp container with two text components, and prepare to pass timestamp start and end props.

Calculate audio timestamps by tracking minimum and maximum samples, convert samples per second to total seconds, and format them as minutes, seconds, and fractions of a second.

Final UI refinements for the audio trimmer: adjust paddings and margins, add an export button with an icon, and fine tune the export control and timeline layout.

Export trimmed audio in a React Native app by passing the audio path and start and end timestamps to ffmpeg, creating an output directory, and handling spaces and file naming.