expo-video-compress

An Expo native module that processes videos recorded on device:

1. Trims leading dead frames — Many device cameras produce videos where the first frame's presentation timestamp (PTS) is not at 0. This module detects that offset and trims the beginning so the first valid frame starts at t=0.
2. Converts H.264 to H.265/HEVC (Android only) — If the source video is not already HEVC-encoded, it re-encodes to H.265 for smaller file sizes. iOS devices record in HEVC natively so no conversion is needed.
3. HDR tone-mapping (Android only) — HDR videos are tone-mapped to SDR using OpenGL.

API

trimVideo(videoPath: string): Promise<VideoCompressResult>

Processes a video and returns metadata about what was done.

Parameters:

• videoPath — A local file:// URI pointing to the source video.

Returns a VideoCompressResult:

type VideoCompressResult = {
  uri: string;                 // file:// URI of the processed (or original) video
  trimmedStartSeconds: number; // seconds trimmed from the beginning (0 if no trim was needed)
  convertedToHevc: boolean;    // true if the video was re-encoded from H.264 to H.265
};

If no processing is needed (first frame is already at t=0 and codec is already HEVC), the original videoPath is returned as uri with trimmedStartSeconds: 0 and convertedToHevc: false.

Errors include trimmedStartSeconds and convertedToHevc in the error message when those values are known at the point of failure.

Usage

import ExpoVideoCompress from 'expo-video-compress';

const result = await ExpoVideoCompress.trimVideo(videoUri);
console.log(result.uri);                 // "file:///path/to/processed.mp4"
console.log(result.trimmedStartSeconds); // e.g. 0.033
console.log(result.convertedToHevc);     // true on Android if source was H.264

Installation

Managed Expo projects

npx expo install expo-video-compress

Bare React Native projects

Ensure you have installed and configured the expo package first.

npm install expo-video-compress

Then run npx pod-install for iOS.

Platform support

| Feature | iOS | Android | Web | |---|---|---|---| | Trim leading frames | Yes | Yes | No | | H.264 to H.265 | No (not needed) | Yes | No | | HDR tone-mapping | No | Yes | No |

Minimum versions: iOS 15.1, Android SDK 33.