I'm trying to download video preview base on remote video URL. In my project, the server cannot return snapshot image of the videos, that's why I have to do it manually.
In table view, I have code like this in cellForItemAt to get video preview
DataManager.sharedInstance.getCachedImage(url: movie.url!, handler: { (image) in
cell.ivCover.image = image
})
and my getCachedImage function in DataManager:
func getCachedImage(url: String, handler: #escaping(_ result:UIImage) -> Void){
DispatchQueue.global().async {
let userDefaults = UserDefaults.standard
if let imageData = userDefaults.object(forKey: url){
if let finalImg = UIImage(data: imageData as! Data){
DispatchQueue.main.async {
handler(finalImg)
}
print("USING CACHED IMG")
}else{
DispatchQueue.main.async {
handler(#imageLiteral(resourceName: "cover"))
}
print("Cannot parse cached data to image. Use default")
}
}else{
let asset = AVURLAsset(url: URL(string: url)!)
let generate = AVAssetImageGenerator(asset: asset)
generate.appliesPreferredTrackTransform = true
var thumbTime = asset.duration
thumbTime.value = 1
var imgRef:CGImage?
do{
print("Downloading thum from url: \(url)")
imgRef = try generate.copyCGImage(at: thumbTime, actualTime: nil)
}catch let error{
print("Error download thum: \(error.localizedDescription)")
}
var finalImg:UIImage
if let _ = imgRef{
finalImg = UIImage(cgImage: imgRef!)
userDefaults.set(UIImagePNGRepresentation(finalImg), forKey: url)
}else{
finalImg = #imageLiteral(resourceName: "cover")
print("Download thumnail failed. Use default")
}
DispatchQueue.main.async {
handler(finalImg)
}
}
}
}
The problem is that, sometimes I scroll the Collection view, UI is freezed, sometimes it's not. Please note that this video is on REMOTE SERVER, NOT local video.
I've spent days to figure out the issue but still not able to find out what went wrong. Please help!
Or is there any existing library I can use?
import UIKit
import Photos
class ImportViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
#IBAction func myButton(_ sender: Any) {
let videoURL = "https://youerdomin.com/file.mp4"
print("1")
DispatchQueue.global(qos: .background).async {
print("2")
if let url = URL(string: videoURL), let urlData = NSData(contentsOf: url) {
print("3")
let documentsPath =
NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0];
let filePath="\(documentsPath)/tempFile.mp4"
DispatchQueue.main.async {
print("4")
urlData.write(toFile: filePath, atomically: true)
PHPhotoLibrary.shared().performChanges({
print("5")
PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: URL(fileURLWithPath: filePath))
}) { completed, error in
print("6")
if completed {
print("Video is saved!")
}else{
print("7: ",filePath)
}
}
}
}else{
print("8")
}
}
}
}
I already have read Read and write data from text file
I need to append the data (a string) to the end of my text file.
One obvious way to do it is to read the file from disk and append the string to the end of it and write it back, but it is not efficient, especially if you are dealing with large files and doing in often.
So the question is "How to append string to the end of a text file, without reading the file and writing the whole thing back"?
so far I have:
let dir:NSURL = NSFileManager.defaultManager().URLsForDirectory(NSSearchPathDirectory.CachesDirectory, inDomains: NSSearchPathDomainMask.UserDomainMask).last as NSURL
let fileurl = dir.URLByAppendingPathComponent("log.txt")
var err:NSError?
// until we find a way to append stuff to files
if let current_content_of_file = NSString(contentsOfURL: fileurl, encoding: NSUTF8StringEncoding, error: &err) {
"\(current_content_of_file)\n\(NSDate()) -> \(object)".writeToURL(fileurl, atomically: true, encoding: NSUTF8StringEncoding, error: &err)
}else {
"\(NSDate()) -> \(object)".writeToURL(fileurl, atomically: true, encoding: NSUTF8StringEncoding, error: &err)
}
if err != nil{
println("CANNOT LOG: \(err)")
}
Here's an update for PointZeroTwo's answer in Swift 3.0, with one quick note - in the playground testing using a simple filepath works, but in my actual app I needed to build the URL using .documentDirectory (or which ever directory you chose to use for reading and writing - make sure it's consistent throughout your app):
extension String {
func appendLineToURL(fileURL: URL) throws {
try (self + "\n").appendToURL(fileURL: fileURL)
}
func appendToURL(fileURL: URL) throws {
let data = self.data(using: String.Encoding.utf8)!
try data.append(fileURL: fileURL)
}
}
extension Data {
func append(fileURL: URL) throws {
if let fileHandle = FileHandle(forWritingAtPath: fileURL.path) {
defer {
fileHandle.closeFile()
}
fileHandle.seekToEndOfFile()
fileHandle.write(self)
}
else {
try write(to: fileURL, options: .atomic)
}
}
}
//test
do {
let dir: URL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).last! as URL
let url = dir.appendingPathComponent("logFile.txt")
try "Test \(Date())".appendLineToURL(fileURL: url as URL)
let result = try String(contentsOf: url as URL, encoding: String.Encoding.utf8)
}
catch {
print("Could not write to file")
}
Thanks PointZeroTwo.
You should use NSFileHandle, it can seek to the end of the file
let dir:NSURL = NSFileManager.defaultManager().URLsForDirectory(NSSearchPathDirectory.CachesDirectory, inDomains: NSSearchPathDomainMask.UserDomainMask).last as NSURL
let fileurl = dir.URLByAppendingPathComponent("log.txt")
let string = "\(NSDate())\n"
let data = string.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false)!
if NSFileManager.defaultManager().fileExistsAtPath(fileurl.path!) {
var err:NSError?
if let fileHandle = NSFileHandle(forWritingToURL: fileurl, error: &err) {
fileHandle.seekToEndOfFile()
fileHandle.writeData(data)
fileHandle.closeFile()
}
else {
println("Can't open fileHandle \(err)")
}
}
else {
var err:NSError?
if !data.writeToURL(fileurl, options: .DataWritingAtomic, error: &err) {
println("Can't write \(err)")
}
}
A variation over some of the posted answers, with following characteristics:
based on Swift 5
accessible as a static function
appends new entries to the end of the file, if it exists
creates the file, if it doesn't exist
no cast to NS objects (more Swiftly)
fails silently if the text cannot be encoded or the path does not exist
class Logger {
static var logFile: URL? {
guard let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first else { return nil }
let formatter = DateFormatter()
formatter.dateFormat = "dd-MM-yyyy"
let dateString = formatter.string(from: Date())
let fileName = "\(dateString).log"
return documentsDirectory.appendingPathComponent(fileName)
}
static func log(_ message: String) {
guard let logFile = logFile else {
return
}
let formatter = DateFormatter()
formatter.dateFormat = "HH:mm:ss"
let timestamp = formatter.string(from: Date())
guard let data = (timestamp + ": " + message + "\n").data(using: String.Encoding.utf8) else { return }
if FileManager.default.fileExists(atPath: logFile.path) {
if let fileHandle = try? FileHandle(forWritingTo: logFile) {
fileHandle.seekToEndOfFile()
fileHandle.write(data)
fileHandle.closeFile()
}
} else {
try? data.write(to: logFile, options: .atomicWrite)
}
}
}
Here is a way to update a file in a much more efficient way.
let monkeyLine = "\nAdding a šµ to the end of the file via FileHandle"
if let fileUpdater = try? FileHandle(forUpdating: newFileUrl) {
// Function which when called will cause all updates to start from end of the file
fileUpdater.seekToEndOfFile()
// Which lets the caller move editing to any position within the file by supplying an offset
fileUpdater.write(monkeyLine.data(using: .utf8)!)
// Once we convert our new content to data and write it, we close the file and thatās it!
fileUpdater.closeFile()
}
Here's a version for Swift 2, using extension methods on String and NSData.
//: Playground - noun: a place where people can play
import UIKit
extension String {
func appendLineToURL(fileURL: NSURL) throws {
try self.stringByAppendingString("\n").appendToURL(fileURL)
}
func appendToURL(fileURL: NSURL) throws {
let data = self.dataUsingEncoding(NSUTF8StringEncoding)!
try data.appendToURL(fileURL)
}
}
extension NSData {
func appendToURL(fileURL: NSURL) throws {
if let fileHandle = try? NSFileHandle(forWritingToURL: fileURL) {
defer {
fileHandle.closeFile()
}
fileHandle.seekToEndOfFile()
fileHandle.writeData(self)
}
else {
try writeToURL(fileURL, options: .DataWritingAtomic)
}
}
}
// Test
do {
let url = NSURL(fileURLWithPath: "test.log")
try "Test \(NSDate())".appendLineToURL(url)
let result = try String(contentsOfURL: url)
}
catch {
print("Could not write to file")
}
In order to stay in the spirit of #PointZero Two.
Here an update of his code for Swift 4.1
extension String {
func appendLine(to url: URL) throws {
try self.appending("\n").append(to: url)
}
func append(to url: URL) throws {
let data = self.data(using: String.Encoding.utf8)
try data?.append(to: url)
}
}
extension Data {
func append(to url: URL) throws {
if let fileHandle = try? FileHandle(forWritingTo: url) {
defer {
fileHandle.closeFile()
}
fileHandle.seekToEndOfFile()
fileHandle.write(self)
} else {
try write(to: url)
}
}
}
Update: I wrote a blog post on this, which you can find here!
Keeping things Swifty, here is an example using a FileWriter protocol with default implementation (Swift 4.1 at the time of this writing):
To use this, have your entity (class, struct, enum) conform to this protocol and call the write function (fyi, it throws!).
Writes to the document directory.
Will append to the text file if the file exists.
Will create a new file if the text file doesn't exist.
Note: this is only for text. You could do something similar to write/append Data.
import Foundation
enum FileWriteError: Error {
case directoryDoesntExist
case convertToDataIssue
}
protocol FileWriter {
var fileName: String { get }
func write(_ text: String) throws
}
extension FileWriter {
var fileName: String { return "File.txt" }
func write(_ text: String) throws {
guard let dir = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first else {
throw FileWriteError.directoryDoesntExist
}
let encoding = String.Encoding.utf8
guard let data = text.data(using: encoding) else {
throw FileWriteError.convertToDataIssue
}
let fileUrl = dir.appendingPathComponent(fileName)
if let fileHandle = FileHandle(forWritingAtPath: fileUrl.path) {
fileHandle.seekToEndOfFile()
fileHandle.write(data)
} else {
try text.write(to: fileUrl, atomically: false, encoding: encoding)
}
}
}
All answers (as of now) recreate the FileHandle for every write operation. This may be fine for most applications, but this is also rather inefficient: A syscall is made, and the filesystem is accessed each time you create the FileHandle.
To avoid creating the filehandle multiple times, use something like:
final class FileHandleBuffer {
let fileHandle: FileHandle
let size: Int
private var buffer: Data
init(fileHandle: FileHandle, size: Int = 1024 * 1024) {
self.fileHandle = fileHandle
self.size = size
self.buffer = Data(capacity: size)
}
deinit { try! flush() }
func flush() throws {
try fileHandle.write(contentsOf: buffer)
buffer = Data(capacity: size)
}
func write(_ data: Data) throws {
buffer.append(data)
if buffer.count > size {
try flush()
}
}
}
// USAGE
// Create the file if it does not yet exist
FileManager.default.createFile(atPath: fileURL.path, contents: nil)
let fileHandle = try FileHandle(forWritingTo: fileURL)
// Seek will make sure to not overwrite the existing content
// Skip the seek to overwrite the file
try fileHandle.seekToEnd()
let buffer = FileHandleBuffer(fileHandle: fileHandle)
for i in 0..<count {
let data = getData() // Your implementation
try buffer.write(data)
print(i)
}
I am using the following code to play music. It plays well :)
var backgroundMusicPlayer = AVAudioPlayer()
func playBackgroundMusic(filename: String) {
let url = NSBundle.mainBundle().URLForResource(filename, withExtension: nil)
guard let newURL = url else {
print("Could not find file: \(filename)")
return
}
do {
backgroundMusicPlayer = try AVAudioPlayer(contentsOfURL: newURL)
backgroundMusicPlayer.numberOfLoops = -1
backgroundMusicPlayer.prepareToPlay()
backgroundMusicPlayer.play()
} catch let error as NSError {
print(error.description)
}
}
playBackgroundMusic("music.wav")
However, I'd like to be able to keep the music playing only through certain transitions. Is this possible?
Cheers :)
i am trying to play audio from parse.com. I am getting the pffile but unable to play audio.
func testing() {
let query = PFQuery(className: "Attractions")
query.whereKey("objectId", equalTo: "hDyP0SwbAQ")
query.findObjectsInBackgroundWithBlock { (result, error) -> Void in
for obj in result! {
let path = obj.objectForKey("attraction_file") as! PFFile
self.playWithURL(path)
}
}
}
func playWithURL(url:PFFile) {
do {
let audioPlayer = try! AVAudioPlayer(contentsOfURL: url)
audioPlayer.prepareToPlay()
audioPlayer.play()
}
}
Thanks In Advance
I Found Answer.
earlier i was using AVAudioPlayer thats why i was getting the error.
now i am using AVPlayer and my code is working perfect.
var avAudioPlayer: AVPlayer? // declared in class
func testing() {
let query = PFQuery(className: "Attractions")
query.whereKey("objectId", equalTo: "hDyP0SwbAQ")
query.findObjectsInBackgroundWithBlock { (result, error) -> Void in
for obj in result! {
let path = obj.objectForKey("SongFile") as! PFFile
self.playWithURL(path)
}
}
}
fun playWithUrl(url : String) {
self.avAudioPlayer = AVPlayer(URL: NSURL(string: url!)!)
avAudioPlayer?.play()
}
I have an App that records and then plays back an audio file. Currently the audio playback is playing through the earpiece speaker. Could someone tell me how Swift would handle coding this to force the audio out the loud speaker instead?
Below is a one of the instances I'm using to play the audio file:
#IBAction func playAudioVader(sender: UIButton) {
playAudioWithVariablePitch(-1000)
}
func playAudioWithVariablePitch(pitch: Float){
audioPlayer.stop()
audioEngine.stop()
audioEngine.reset()
var audioPlayerNode = AVAudioPlayerNode()
audioEngine.attachNode(audioPlayerNode)
var changePitchEffect = AVAudioUnitTimePitch()
changePitchEffect.pitch = pitch
audioEngine.attachNode(changePitchEffect)
audioEngine.connect(audioPlayerNode, to: changePitchEffect, format: nil)
audioEngine.connect(changePitchEffect, to: audioEngine.outputNode, format: nil)
audioPlayerNode.scheduleFile(audioFile, atTime: nil, completionHandler: nil)
audioEngine.startAndReturnError(nil)
audioPlayerNode.play()
}
override func viewDidLoad() {
super.viewDidLoad()
audioPlayer = AVAudioPlayer(contentsOfURL:receivedAudio.filePathURL, error: nil)
audioPlayer.enableRate = true
audioEngine = AVAudioEngine()
audioFile = AVAudioFile(forReading:receivedAudio.filePathURL, error: nil)
}
EDIT July 2017: Refer to Husam's answer for the Swift 2.0 solution.
As of Swift 1.2, you use overrideOutputAudioPort and AVAudioSessionPortOverride. It can be implemented by doing something like this:
if !session.overrideOutputAudioPort(AVAudioSessionPortOverride.Speaker, error:&error) {
println("could not set output to speaker")
if let e = error {
println(e.localizedDescription)
}
}
I'm working on an app that uses this now, and I have a function called setSessionPlayandRecord, which looks like:
func setSessionPlayAndRecord() {
let session:AVAudioSession = AVAudioSession.sharedInstance()
var error: NSError?
if !session.setCategory(AVAudioSessionCategoryPlayAndRecord, error:&error) {
println("could not set session category")
if let e = error {
println(e.localizedDescription)
}
}
if !session.overrideOutputAudioPort(AVAudioSessionPortOverride.Speaker, error:&error) {
println("could not set output to speaker")
if let e = error {
println(e.localizedDescription)
}
}
if !session.setActive(true, error: &error) {
println("could not make session active")
if let e = error {
println(e.localizedDescription)
}
}
}
Swift 2.0 Code
func setSessionPlayerOn()
{
do {
try AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayAndRecord)
} catch _ {
}
do {
try AVAudioSession.sharedInstance().setActive(true)
} catch _ {
}
do {
try AVAudioSession.sharedInstance().overrideOutputAudioPort(AVAudioSessionPortOverride.Speaker)
} catch _ {
}
}
func setSessionPlayerOff()
{
do {
try AVAudioSession.sharedInstance().setActive(false)
} catch _ {
}
}