Synopsis

If you hate working with AVAssetWriters and AVAssetWriterInputs and AVAssetWriterInputPixelBufferAdapters as much as I do, and all you want to do is create a damn movie file from a collection of images without writing 300 lines of code then maybe you won't hate using NWImageSequencer - a small Swift (4.0) framework which lets you do exactly that in only a few lines of code.

Code Example

Basic Usage

The following steps create a movie in your local directory.

let images:[UIImage] //<--your array of images
let options = NWImageSequencerOptions(outputSize: CGSize(720,720), secondsPerImage: 2.5)

NWImageSequencer.createLocalMovieWithImages(images, options: options,
            onSuccess: { (movieUrl) -> Void in
                print("movie successfully created at \(movieUrl)")
            }, 
            onError: { (error) -> Void in
                print("error occured creating movie \(error)")
            }, 
            onProgress: { (progress) -> Void in
                print("progress creating movie reported at \(progress)")
            })

NWImageSequencer also has helper functions to save the movie created in the local directory to an album the photo roll using the Photos framework. The success block returns a PHAsset instance that can be used to fetch the saved video

NWImageSequencer.saveMovieAtUrl(movieUrl, toAlbumNamed: "Example", 
                               onSaveSuccess: { (asset) -> Void in
                                    print("Sucessfully saved video asset: \(asset)")
                               }, 
                               onError: { (error) -> Void in
                                    print("Error saving video: \(error)")
                               })

Configuration

the NWImageSequencerOptions object is where you configure the options for the generated movie.

let options =  NWImageSequencerOptions(
	   outputSize:CGSize //width and height of exported movie (required)
	   secondsPerImage:Float //time in seconds each image is displayed (default = 1)
	   localPath:String //specify local path in app directory to save movie (optional)
	   fileType:String //file format of generated movie (default = AVFileTypeQuickTimeMovie)
)

##Tips

• When passing in images of various sizes, NWImageSequencer always fits the movie to the largest width and height found in the images array. For best results you will probably want to stick with images of the same size and ensure that the outputSize always matches the aspect ratio of the source images.

• Generating larger size movies can cause some ios devices to crash.

• Generating exceptionally long movies has not been tested

• FileFormats other than the default AVFileTypeQuickTimeMovie have not been tested

##TODO

• Add better image fitting options to handle images of various sizes
• Add ability to specify display time for each image individually
• Add ability to set background color