Media compression and transformation native module for React Native. Named after the Fairchild 670 audio compressor.
Currently iOS only. Early-stage but functional — contributions welcome!
This is a utility library for compression, cropping, rotation and other such operations on audio-visual media.
Currently, it accomplishes compression, rotation and square cropping via a single function (compressVideo) and its options, but the plan is to add more functions and operations to the library as needed.
The idea is that libraries for uses such as these should provide specific, composeable operations to avoid burdening libraries such as react-native-camera with functionality that would be better be developed separately.
Add the following line to your package.json (coming soon to npm!):
"fairchild": "git+https://github.com/thsig/fairchild.git"Then, similarly to react-native-camera — add the Fairchild XCode project from node_modules/fairchild to XCode, then add libFairchild.a to the Link Library With Binaries step under Build Settings for the main project.
Fairchild is Promise-based, so it's easy to chain it with other operations.
Here's an example of using Fairchild in conjunction with react-native-camera to compress video files before persisting them to the server:
var compressionOptions = {
resolution: '720p',
bitRate: 5 * 1000 * 1024,
cropSquare: true,
orientation: 'portrait'
};
this.refs.camera.capture()
.then((uri) => Fairchild.compressVideo(uri, compressionOptions))
.then(((compressed) => this.persistVideo(compressed.compressedUri))); // e.g. upload file to serverinputFilePath should be a (string) path to the video file on the local device, such as those generated by react-native-camera.
Returns a promise which resolves to an object of the form:
{
outputFileUri, // path to the compressed/processed file
inputFileSizeBytes, // these other three are just diagnostic/informational output
outputFileSizeBytes,
compressionRatio
}The following settings are currently supported in outputOptions:
When false, deletes the file at inputFilePath after the output file has been written. When true, does not delete it.
Default: Same as source. The desired output filetype.
Default: Inferred from path prefix. Indicates whether the file at inputFilePath is to be treated as a bundled asset (e.g. included in the XCode project). Should be false for most real-world use cases.
The desired output resolution. In future versions, more fine-grained control over the output resolution will be implemented.
By default, the height and width of the output file are scaled according to the ratio
(number of output pixels) / (input height * input width),
where the number of output pixels is 1920 * 1080, 1280 * 720 or 640 * 480, respectively.
The other case is when cropSquare is set to true. In that case, the ratio becomes
(number of output pixels) / (w * w),
where w = min(input height, input width).
When true, the output file is cropped to a square aspect ratio such that its width and height are equal to min(height, width), starting the crop from the top left corner of the original file.
When cropSquare = true, sets the vertical offset of the top-left corner of the crop square to cropSquareVerticalOffset * height. Useful for cropping when the visible area of the camera in the UI is partially obscured by an overlay, to ensure that the output video is cropped in a way consistent with what the user saw during recording.
Default: Same as source file. Indicates the average bitrate to be used for the output file.
The target orientation of the output file.