Check out example codes for "Ionic 3 camera plugin not returning video from photo library on ios". It will help you in understanding the concepts better.

Code Example 1

//Well the problem is with the apache cordova camera plugin it provides the temporary path to the video file to come out from this error implement below changes in camera plugin.
//in CDVCamera.m change THIS:

(CDVPluginResult*)resultForVideo:(NSDictionary*)info
{
NSString* moviePath = [[info objectForKey:UIImagePickerControllerMediaURL] absoluteString];
return [CDVPluginResult resultWithStatus:CDVCommandStatus_OK messageAsString:filePath];
}

//to THIS:

(CDVPluginResult*)resultForVideo:(NSDictionary*)info
{
NSString* moviePath = [[info objectForKey:UIImagePickerControllerMediaURL] path];

NSArray* spliteArray = [moviePath componentsSeparatedByString: @"/"];
NSString* lastString = [spliteArray lastObject];
NSError *error;
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *documentsDirectory = [NSHomeDirectory() stringByAppendingPathComponent:@"tmp"];
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:lastString];
[fileManager copyItemAtPath:moviePath toPath:filePath error:&error];

return [CDVPluginResult resultWithStatus:CDVCommandStatus_OK messageAsString:filePath];
}

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