I was using the services from Parse a while back, and they had implemented an amazing feature for uploading data, with a method something like this:
PFFile *objectToSave...; //An image or whatever, wrapped in a Parse-file
[objectToSave saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
//Do stuff after upload is complete
} progressBlock:^(int percentDone) {
[someLabel setText:[NSString stringWithFormat:#"%i%#", percentDone, #"%"]];
}];
Which let me keep track of the file-upload. Since Parse only let me upload max 10mb files, I chose to move to the cloud-area to explore a bit. I've been testing with Amazon's S3-service now, but the only way I can find how to upload data is by calling [s3 putObject:request];. This will occupy the main thread until it's done, unless I run it on another thread. Either way, I have no idea of letting my users know how far the upload has come. Is there seriously no way of doing this? I read that some browser-API-version of S3's service had to use Flash, or set all uploads to go through another server, and keep track on that server, but I won't do either of those. Anyone? Thanks.
My users are supposed to be uploading video with sizes up to 15mb, do I have to let them stare at a spinning wheel for an unknown amount of time? With a bad connection, they might have to wait for 15 minutes, but they would stare at the screen in hope the entire time.
Seems like I didn't quite do my homework before posting this question in the first place. I found this great tutorial doing exactly what I was asking for. I would delete my question, but I'll let it stay just in case it might help other helpless people like myself.
Basically, it had a delegate-method for this. Do something like this:
S3PutObjectRequest *por = /* your request/file */;
S3TransferManager *tm = /* your transfer manager */;
por.delegate = self;
tm.delegate = self;
[tm upload: por];
Then use this appropriately named delegate-method:
-(void)request:(AmazonServiceRequest *)request
didSendData:(long long)bytesWritten
totalBytesWritten:(long long)totalBytesWritten
totalBytesExpectedToWrite:(long long)totalBytesExpectedToWrite
{
CGFloat progress = ((CGFloat)totalBytesWritten/(CGFloat)totalBytesExpectedToWrite);
}
It will be called for every packet it uploads or something. Just be sure to set the delegates.
(Not sure if you need both delegates to be set though)
Related
I started working on my first non-demo react-native app. I hope it will be a iOS/Android app, but actually I'm focused on iOS only.
I have a one problem actually. How can I get a data (base64, array of pixels, ...) in real-time from the camera without saving to the camera roll.
There is this module: https://github.com/lwansbrough/react-native-camera but base64 is deprecated and is useless for me, because I want a render processed image to user (change picture colors eg.), not the real picture from camera, as it does react-native-camera module.
(I know how to communicate with SWIFT code, but I don't know what the options are in native code, I come here from WebDev)
Thanks a lot.
This may not be optimal but is what I have been using. If anyone can give a better solution, I would appreciate your help, too!
My basic idea is simply to loop (but not simple for-loop, see below) taking still pictures in yuv/rgb format at max resolution, which is reasonably fast (~x0ms with normal exposure duration) and process them. Basically you will setup AVCaptureStillImageOutput that links to you camera (following tutorials everywhere) then set the format to kCVPixelFormatType_420YpCbCr8BiPlanarFullRange (if you want YUV) or kCVPixelFormatType_32BGRA(if you prefer rgba) like
bool usingYUVFormat = true;
NSDictionary *outputFormat = [NSDictionary dictionaryWithObject:
[NSNumber numberWithInt:usingYUVFormat?kCVPixelFormatType_420YpCbCr8BiPlanarFullRange:kCVPixelFormatType_32BGRA]
forKey:(id)kCVPixelBufferPixelFormatTypeKey];
[yourAVCaptureStillImageOutput setOutputSettings:outputFormat];
When you are ready, you can start calling
AVCaptureConnection *captureConnection=[yourAVCaptureStillImageOutput connectionWithMediaType:AVMediaTypeVideo];
[yourAVCaptureStillImageOutput captureStillImageAsynchronouslyFromConnection:captureConnection completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error) {
if(imageDataSampleBuffer){
CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(imageDataSampleBuffer);
CVPixelBufferLockBaseAddress(imageBuffer, 0);
// do your magic with the data buffer imageBuffer
// use CVPixelBufferGetBaseAddressOfPlane(imageBuffer,0/1/2); to get each plane
// use CVPixelBufferGetWidth/CVPixelBufferGetHeight to get dimensions
// if you want more, please google
}
}];
Additionally, use NSNotificationCenter to register your photo-taking action and post a notification after you have processed each frame (with some delay perhaps, to cap your through-put and reduce power consumption) so the loop will keep going.
A quick precaution: the Android counterpart is much worse a headache. Few hardware manufacturers implement api for max-resolution uncompressed photos but only 1080p for preview/video, as I have raised in my question. I am still looking for solutions but gave up most hope. JPEG images are just toooo slow.
WHAT IM DOING I am trying to get an audio file (could be up to an hour long. eg. a Podcast) that I've recorded with AVAudioRecorder to be uploaded to our backend. In addition to being uploaded to the server it needs to be able to be "Paused" and "Resumed" if the user chooses. Because of this, I believe, I need to use dataWithBytesNoCopy:buffer on the NSData class to achieve this.
WHERE IM AT I know for a fact I can get the data with using the passed self.mediaURL property:
if (self.mediaURL) {
NSData *audioData = [NSData dataWithContentsOfURL:self.mediaURL];
if (audioData) {
[payloadDic setObject:audioData forKey:#"audioData"];
}
}
However, this will not give me the desired functionality. I am trying to keep track of the bytes uploaded so that I can resume if the user pauses.
QUESTION How can I use the provided self.mediaURL so that I can retrieve the file and be able to calculate the byte length like this example?
Byte *buffer = (Byte*)malloc((long)audioFile.size);
NSUInteger buffered =[rep getBytes:buffer fromOffset:0.0 length:(long)rep.size error:nil];
NSMutableData *body = [[NSMutableData alloc] init];
body = [NSMutableData dataWithBytesNoCopy:buffer length:buffered freeWhenDone:YES];
Instead of making things more complicated for yourself by trying to reinvent the wheel, use what the system gives you. NSURLSession lets you do a background upload. You hand the task to the session (created using the background session configuration) and just walk away. The upload takes place in pieces, when it can. No "pause" or "resume" needed; the system takes care of everything. Your app doesn't even have to be running. If authentication is needed, your app will be woken up in the background as required. This architecture is just made for the situation you describe.
If the problem is that you want random access to file data without having to read the whole thing into a massive NSData, use NSFileHandle.
I am trying to use Path's FastImageCache library to handle photos in my app. The sample they provide simply reads the images from disk. Does anyone know how I might modify it to read from a url? In the section about providing source images to the cache they have
- (void)imageCache:(FICImageCache *)imageCache wantsSourceImageForEntity:(id<FICEntity>)entity withFormatName:(NSString *)formatName completionBlock:(FICImageRequestCompletionBlock)completionBlock {
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
// Fetch the desired source image by making a network request
NSURL *requestURL = [entity sourceImageURLWithFormatName:formatName];
UIImage *sourceImage = [self _sourceImageForURL:requestURL];
dispatch_async(dispatch_get_main_queue(), ^{
completionBlock(sourceImage);
});
});
}
Has anyone used this api before and know how to get the source from the server to pass to the cache? Another example that still uses hard disk is
- (void)imageCache:(FICImageCache *)imageCache wantsSourceImageForEntity:(id<FICEntity>)entity withFormatName:(NSString *)formatName completionBlock:(FICImageRequestCompletionBlock)completionBlock {
// Images typically come from the Internet rather than from the app bundle directly, so this would be the place to fire off a network request to download the image.
// For the purposes of this demo app, we'll just access images stored locally on disk.
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
UIImage *sourceImage = [(FICDPhoto *)entity sourceImage];
dispatch_async(dispatch_get_main_queue(), ^{
completionBlock(sourceImage);
});
});
}
I worked on Fast Image Cache while I was at Path. The critical portion of Fast Image Cache is that it is the absolute fastest way to go from image data on disk to being rendered by Core Animation. No decoding happens, none of the image data is kept in memory by your app, and no image copies occur.
That said, the responsibility is yours to figure out how to download the images. There's nothing inherently special about downloading images. You can use NSURLConnection or one of many popular networking libraries (like AFNetworking) to actually download the image data from your server. Once you have that image data, you can call the relevant completion block for Fast Image Cache to have it optimize it for future rendering.
If you're looking for a simple way to download an image and display it when it's finished, then use something like SDWebImage. It's great for simple cases like that. If you are running into performance bottlenecks—especially with scrolling—as a result of your app needing to display tons of images quickly, then Fast Image Cache is perfect for you.
Your Approach Seems a Lot Like Lazy Loading Images from the URL, I had to do this once I had Used the following Library to do it, It dosent stores the Images in the disk, but uses cached Images..the below is its link..
https://github.com/nicklockwood/AsyncImageView
I added the networking logic to our fork > https://github.com/DZNS/FastImageCache#dezine-zync-additions-to-the-class
It utilizes NSURLSessionDownloadTasks, has a couple of configuration options (optional). All you need to do is create a new instance of DZFICNetworkController and set it as the delegate for FICImageCache's sharedCache instance object. It'll take care of downloading images with reference to the sourceImageURLWithFormatName: method on your objects conforming to <FICEntity>.
As I assume you'd use this in a UITableView or UICollectionView, calling cancelImageRetrievalForEntity:withFormatName: on the imageCache will cancel the download operation (if it's still in-flight or hasn't started).
I'm trying to work with FTP Servers.
I have googled around for everything and everything is hard to understand for beginners like me. SimpleFTPSample is hard to understand because it is so much at a time. views, buttons, labels, textflelds, upload, download, request, list, get. Same with BlackRaccoon and everything else.
How to Simply and programily upload "test.txt" to FTP Server: "192.168.1.111" in Xcode (iPhone app) without views or button. Just code that can be in the ViewDidLoad for example.
Maybe something like this?:
NSURL* url = [NSURL URLWithString:#"ftp://username:pw#189.92.32.34"];
CFReadStreamRef stream = CFReadStreamCreateWithFTPURL(NULL, (__bridge CFURLRef) url);
stream.delegate= self;
[stream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[stream open];
but which file?
expand this, or write a new code. i don't know, this is new for me.
Thanks Jonathan
As the writer of Black Raccoon perhaps I'm biased (well, I KNOW I'm biased), but I've attempted to make it as simple and powerful as possible. Let's look at what you want to do, upload a file:
There are four things we need to upload a file - start up code, then four delegate methods: overwrite check, data, success and the fail. Let's assume that you read the entire file into memory (okay for small files less than 2 megs).
First, you need this in your header:
BRRequestUpload *uploadData; // Black Raccoon's upload object
NSData *uploadData; // data we plan to upload
Now for the code part:
- (IBAction) uploadFile :(id)sender
{
//----- get the file path for the item we want to upload
NSString *applicationDocumentsDir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *filepath = [NSString stringWithFormat: #"%#/%#", applicationDocumentsDir, #"file.text"];
//----- read the entire file into memory (small files only)
uploadData = [NSData dataWithContentsOfFile: filepath];
//----- create our upload object
uploadFile = [[BRRequestUpload alloc] initWithDelegate: self];
//----- for anonymous login just leave the username and password nil
uploadFile.path = #"/home/user/myfile.txt";
uploadFile.hostname = #"192.168.1.100";
uploadFile.username = #"yourusername";
uploadFile.password = #"yourpassword";
//----- we start the request
[uploadFile start];
}
The first will be asking your code if you want to overwrite an existing file.
-(BOOL) shouldOverwriteFileWithRequest: (BRRequest *) request
{
//----- set this as appropriate if you want the file to be overwritten
if (request == uploadFile)
{
//----- if uploading a file, we set it to YES (if set to NO, nothing happens)
return YES;
}
}
Next, Black Raccoon will ask you for chunks of data to send. If you have a very large file you NEVER want to try to send it all in one shot - Apple's API will choke and drop data. However, we only have one small chunk so we do this:
- (NSData *) requestDataToSend: (BRRequestUpload *) request
{
//----- returns data object or nil when complete
//----- basically, first time we return the pointer to the NSData.
//----- and BR will upload the data.
//----- Second time we return nil which means no more data to send
NSData *temp = uploadData; // this is a shallow copy of the pointer
uploadData = nil; // next time around, return nil...
return temp;
}
Remember we can ONLY do this for a small file.
Next we have our completion handler (if things worked according to plan):
-(void) requestCompleted: (BRRequest *) request
{
if (request == uploadFile)
{
NSLog(#"%# completed!", request);
uploadFile = nil;
}
}
Lastly we have our failure handler:
-(void) requestFailed:(BRRequest *) request
{
if (request == uploadFile)
{
NSLog(#"%#", request.error.message);
uploadFile = nil;
}
}
It would be WONDERFUL if it was as simple as saying [BRFtpUploadTo: dest srcfile: srcFile destfile: dstFile] but there are many reasons why you SHOULDN'T. Part of it has to do with how Apple has implemented their internal FTP. There are also the issues of blocking, errors, etc. In the end, FTP sounds like it should be trivial but ends up being a bit of a nightmare.
FTP is non-trivial which is why there are so many implementations. I'm not arguing that Black Raccoon is the best, but it is maintained with response to issues being between minutes to a couple of days.
It may look daunting at first, but Black Raccoon is, in my opinion, one of the better FTP libraries. I've spent a lot of time and effort to make it a quality product with excellent response to issues. How do I do this for free? Volume. ;)
Good luck with whatever FTP software you end up with!
Upload path is required when uploading. That is the way FTP works.
The port is the standard FTP port. I know of no way to change this without violating the API. If you figure it out, you stand a good chance of not passing Apple's check.
This code will upload/download any file.
I do not know how to make this work under secure conditions. This uses Apple's FTP protocol. There are other FTP packages that have built this from scratch and are far more intelligent. I would look into them.
BR was designed because I needed simple FTP communication. White Raccoon didn't do this for me because at the time (it has since been modernized).
I am trying to build a nice function to access the network for images, if they are found on the web, I store them in a cache system I made.
If the image was already stored on the cache, I return it.
The function is called getImageFromCache and returns an image if it is in the cache, else, it would go to the network and fetch.
The code might look like this:
UIImageView* backgroundTiles = [[UIImageView alloc] initWithImage[self getImageFromCache:#"http://www.example.com/1.jpg"]];
Now, I am moving on to using threads because of big latencies due to network traffic. So I want images to show a temp image before I get the result from the web.
What I want to know is how can I keep track of so many images being accessed sequentially, being added to UIImageViews by this function (getImageFromCache).
Something just won't work there:
-(UIImage*)getImageFromCache:(NSString*)forURL{
__block NSError* error = nil;
__block NSData *imageData;
__block UIImage* tmpImage;
if(forURL==nil) return nil;
if(![self.imagesCache objectForKey:forURL])
{
// Setting a temporary image until we start getting results
tmpImage = [UIImage imageNamed:#"noimage.png"];
NSURL *imageURL = [NSURL URLWithString:forURL];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^{
imageData = [NSData dataWithContentsOfURL:imageURL options:NSDataReadingUncached error:&error];
if(imageData)
{
NSLog(#"Thread fetching image URL:%#",imageURL);
dispatch_async(dispatch_get_main_queue(), ^{
tmpImage = [UIImage imageWithData:imageData];
if(tmpImage)
{
[imagesCache setObject:tmpImage forKey:forURL];
}
else
// Couldn't build an image of this data, probably bad URL
[imagesCache setObject:[UIImage imageNamed:#"imageNotFound.png"] forKey:forURL];
});
}
else
// Couldn't build an image of this data, probably bad URL
[imagesCache setObject:[UIImage imageNamed:#"imageNotFound.png"] forKey:forURL];
});
}
else
return [imagesCache objectForKey:forURL];
return tmpImage;
}
This is not a direct answer to your question, but are you aware that there is no need to use GCD to download things asynchronously (on a background thread)? Just use NSURLConnection and its delegate methods. All your code will be on the main thread but the actual connection and downloading will happen in the background.
(And in fact I have written a class, MyDownloader, that takes care of all this for you:
http://www.apeth.com/iOSBook/ch37.html#_http_requests
Scroll down to the part about MyDownloader and its subclass MyImageDownloader, which is doing exactly the sort of thing you need done here. Moreover, note the subsequent code in that chapter showing how to use a notification when a download completes, prompting the table view that need these images to reload the row that contains the image view whose image has just arrived.)
its good your building it from scratch but if you want to save the all the work, there's a drop in Replacement SDWebImage Library with support for remote images coming from the web, and has all the functionality Like Temp Image, Asychronous Loading, Caching etc, you said you need
In your background thread, once the download has completed and you've saved the image to the cache, I'd suggest you post a notification using the NSNotificationCenter to let other parts of your app know that the cache has been updated.
This assumes that whichever part of the app manages the image views has registered its interest in those notification with the addObserverForName method. When it receives such a notification, it can then attempt to retrieve the images from the cache again and update its image views if appropriate.
Depending on the number of image views, you may want to pass through the image url in the notification in some way (e.g. in the userInfo dictionary), and then based on that decide which image views should be refreshed rather than refreshing them all.
I should add that I would also recommend getting rid of the inner dispatch_async call. There's no need for that, although you may need to add synchronisation to your cache object so it can be safely accessed from the main thread as well as the download thread.