Anyhow, as of recently its been tasked upon us to work with some streaming video. Now, the hardware we will be using for our client are some nice IP/H.264 compatible cameras. Well, I personally do not have one but needed a solution by which I could test and work with. I have one of those little eye ball looking cameras and found some free software (WebCamXP) that would run a simple MJPEG stream. (Yea, yea…its windows but who doesn’t have a windows box to hack and slash on? Ha!) After this is up and running you have a basic MJPEG stream that is running and accessible via http://10.0.0.99:8080/webcamp_1.cgi (or whatever your internal IP is and the port you configured in the software)

** Note: This tutorial uses iPhone references as thats what I worked with first. I’ll update with the Android version later. I am also using Linux (Ubuntu) to do the encoding and serving of the new video stream. Also assuming you have Apache or another web server up and running.

Now, this .cgi page/script ‘can’ be placed as the source of a UIWebview and works ok.

NSString *urlAddress = @"http://10.0.0.99:8080/cam_1.cgi";
NSURL *url = [NSURL URLWithString:urlAddress];
NSURLRequest *requestObj = [NSURLRequest requestWithURL:url];
[streamWebView loadRequest:requestObj];

But, ultimately this is not what we’re looking for. We need to get a nice H.264 compatible stream rolling out so that we can play this directly to the iPhone (MPMoivePlayerController) or be able to hook into a streaming server (as we’re planning on doing) so that we can re-broadcast to several devices at once.

So…how might we convert this MJPEG (.cgi) into an H.264 compatible stream? VLC Media Player to the rescue.

On your Linux box install VLC and the x264 libraries.

# apt-get install vlc x264

A few of the tutorials you read on this all reference using the command: vlc. However, if you don’t have X11 installed on your system (as I do not) you will run into a few errors with regards to this. But, have no fear, VLC provided a command line option: cvlc.

Now what we need to do is fire up VLC with a bunch of options that will read in the MJPEG (.cgi) convert it to H.264 and then provide us with a means of accessing the stream (via the Linux server – 10.0.0.69). So, on the command prompt do something like:

cvlc --intf=rc http://10.0.0.99:8080/cam_1.cgi --sout '#transcode{fps=25,
vcodec=h264,venc=x264{aud,profile=baseline,level=30,keyint=30,
bframes=0,ref=1,nocabac},acodec=mp3,ab=56,audio-sync,deinterlace}
:standard{mux=ts,access=http,dst=10.0.0.69:8090/myStream.mp4}'

Now, on the command prompt you’ll see a bunch of stuff start scrolling by. This is what you want. Its reading in frames from the original MJPEG stream and converting them. But, you’re not done yet. In order to get this to play via MPMoviePlayerController on the iPhone, we need to setup the .m3u8 or the playlist file.

In your web server directory create a file myStream.m3u8 and put the following in and save:

#EXTM3U
#EXT-X-TARGETDURATION:10
#EXT-X-MEDIA-SEQUENCE:0
#EXTINF:10, 

http://10.0.0.69:8090/myStream.mp4

Now you’re ready for some iPhone code to show the stream.

NSURL *url = [NSURL URLWithString:@"http://10.0.0.69/myStream.m3u8"];
MPMoviePlayerController *player = [[MPMoviePlayerController alloc] initWithContentURL:url];
player.controlStyle = MPMovieControlStyleNone;
[player.view setFrame:CGRectMake(0, 120, 320 , 200)];
[self.view addSubview:player.view];
[player play];

This should basically do it. I don’t believe I left out any steps. I’ll update if I run across any missing steps or you guys let me know. When you run the app, it can sometimes take a few seconds before the video starts playing. At one point I set a background color to the mpmovieplayercontroller’s view so that I could tell where it was being

With MPMoviePlayerController there are several other options you may be interested in using/implementing.

When setting up the player you can have your containing view controller listen for some of the playback events (can help with some debugging) with:

//Defined in the above MPMoviePlayerController allocation
[[NSNotificationCenter defaultCenter] addObserver:self  selector:@selector(moviePlayerPlaybackStateDidChange:)  name:MPMoviePlayerPlaybackStateDidChangeNotification  object:nil];

//NSNotification callback function
- (void)moviePlayerPlaybackStateDidChange:(NSNotification*)notification {
     NSLog(@"playbackDidChanged");
     MPMoviePlayerController *moviePlayer = notification.object;

     MPMoviePlaybackState playbackState = moviePlayer.playbackState;

     if(playbackState == MPMoviePlaybackStateStopped) {
          NSLog(@"MPMoviePlaybackStateStopped");
     } else if(playbackState == MPMoviePlaybackStatePlaying) {
          NSLog(@"MPMoviePlaybackStatePlaying");
     } else if(playbackState == MPMoviePlaybackStatePaused) {
          NSLog(@"MPMoviePlaybackStatePaused");
     } else if(playbackState == MPMoviePlaybackStateInterrupted) {
          NSLog(@"MPMoviePlaybackStateInterrupted");
     } else if(playbackState == MPMoviePlaybackStateSeekingForward) {
          NSLog(@"MPMoviePlaybackStateSeekingForward");
     } else if(playbackState == MPMoviePlaybackStateSeekingBackward) {
          NSLog(@"MPMoviePlaybackStateSeekingBackward");
     }
}

Please let me know if I’ve left out any steps or you have any issues and I’ll be happy to help and work through it with you. This was a quick and dirty how-to with a ways to go before I push anything out to production. Just wanted to share my research and discovery. Good luck!

References:
Apple – Reference: MPMoviePlayerController
StackOverflow – HTTP stream without extension in MPMoviePlayerController

At some point define the max size you want the font to be. I typically put this in my .h file

#define kDefaultFontSize 24.0

Then in your .m file where you add the text to the UITextView you would place something like:

myTextView.text = @"Some long string that will be in the UITextView";
myTextView.font = [UIFont systemFontOfSize:kDefaultFontSize];

//setup text resizing check here
if (myTextView.contentSize.height > myTextView.frame.size.height) {
    int fontIncrement = 1;
    while (myTextView.contentSize.height > myTextView.frame.size.height) {
        myTextView.font = [UIFont systemFontOfSize:kDefaultFontSize-fontIncrement];
        fontIncrement++;
    }
}

Hope this helps! Enjoy!

There are already some very good tutorials on revamping the whole table view.  Google it! The best I came across was from Cocoa with Love – Custom UITableView.

However, this can be a bit overkill for some situations. It can also take a good bit of time to setup all the necessary images. What I needed was a quick and easy way to ‘theme’ the application and thus the selection style for a UITableViewCell. This needed to work with both plain and grouped table view styles and custom cells as well. You can see now why this may take  a while using the above methods.

Here is a quick and easy method to do just that.

SomeViewController.h

#import <UIKit/UIKit.h>

@interface SomeViewController : UITableViewController {
     UITableViewCell *currentSelectedCell;
}

@property (nonatomic, retain) UITableViewCell *currentSelectedCell;

- (void)setSelectedCell:(UITableViewCell *)selectedCell
     deselectedCell:(UITableViewCell *)deselectedCell;

@end

SomeViewController.m

#import "SomeViewController.h"

@implementation SomeViewController

@synthesize currentSelectedCell;

- (void)setSelectedCell:(UITableViewCell *)selectedCell deselectedCell:(UITableViewCell *)deselectedCell {
     //revert deselected cell
     if (deselectedCell != nil) {
          deselectedCell.backgroundColor = [UIColor whiteColor];
          for (UIView *subView in [deselectedCell.contentView subviews]) {
               if ([subView isKindOfClass:[UILabel class]]) {
                    UILabel *label = (UILabel *)subView;
                    label.textColor = [UIColor blackColor];
               }

               if ([subView isKindOfClass:[UITextField class]]) {
                    UITextField *textField = (UITextField *)subView;
                    textField.textColor = [UIColor blackColor];
               }
          }
     }

     //setup selected cell
     selectedCell.backgroundColor = [UIColor redColor]; //Some defined UIColor
     for (UIView *subView in [selectedCell.contentView subviews]) {
          if ([subView isKindOfClass:[UILabel class]]) {
               UILabel *label = (UILabel *)subView;
               label.textColor = [UIColor whiteColor];
          }

          if ([subView isKindOfClass:[UITextField class]]) {
               UITextField *textField = (UITextField *)subView;
               textField.textColor = [UIColor whiteColor];
          }
     }
}

#pragma mark -
#pragma mark Table View Delegate Methods

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:
     (NSIndexPath *)indexPath {

     setSelectedCell:[tableView cellForRowAtIndexPath:indexPath]
          deselectedCell:currentSelectedCell];

     currentSelectedCell = [tableView cellForRowAtIndexPath:indexPath];
}

#pragma mark -
#pragma mark Table View Data Source Methods

- (UITableViewCell *)tableView:(UITableView *)tableView
     cellForRowAtIndexPath:(NSIndexPath *)indexPath {

     //........Setup UITableViewCell...........//

     cell.selectionStyle = UITableViewCellSelectionStyleNone;

     return cell;
}

- (NSInteger)tableView:(UITableView *)table numberOfRowsInSection:
     (NSInteger)section {

     return count;
}

@end

Now, I’ve provided this in one class but what I’ve done is setup an ‘application’ singleton that has this function and is called from each UITableView’s didSelectRowAtIndexPath delegate. Works great on standard, custom, plain, and grouped views.

For the following examples we will assume the global variable you are trying to implement is a User object.

User.h

#import <Foundation/Foundation.h>

@interface User : NSObject {

NSString *username;

NSString *password;

NSString *accountType;

}

@property (nonatomic, retain) NSString *username;

@property (nonatomic, retain) NSString *password;

@property (nonatomic, retain) NSString *accountType;

User.m

#import “User.h”

@implementation User

@synthesize username;

@synthesize password;

@synthesize accountType;

ApplicationAppDelegate.h

#import “User.h”

@interface ApplicationAppDelegate : NSObject <UIApplicationDelegate> {

NSManagedObjectModel *managedObjectModel;

NSManagedObjectContext *managedObjectContext;

NSPersistentStoreCoordinator *persistentStoreCoordinator;

UIWindow *window;

User *user;

}

@property (nonatomic, retain, readonly) NSManagedObjectModel *managedObjectModel;

@property (nonatomic, retain, readonly) NSManagedObjectContext *managedObjectContext;

@property (nonatomic, retain, readonly) NSPersistentStoreCoordinator *persistentStoreCoordinator;

@property (nonatomic, retain) IBOutlet UIWindow *window;

@property (nonatomic, retain) User *user;

ApplicationAppDelegate.m

#import “ApplicationAppDelegate.h”

@implementation ApplicationAppDelegate

@synthesize window;

@synthesize user;

#pragma mark -

#pragma mark Application lifecycle

- (void)applicationDidFinishLaunching:(UIApplication *)application {

[window addSubview:tabBarController.view];

// Override point for customization after app launch

[window makeKeyAndVisible];

user = [[User alloc] init];

}

Then from any view controller you can access the Delegate variable as such.

SomeViewController.m

UIApplication *app = [UIApplication sharedApplication];

app.user.username = @”Username”;

While this can be done and will work. The overall use of the AppDelegate for this functionality is incorrect. The AppDelegate should be used for the following 2 reasons:

• implemenations of the NSApplication delegate methods (includingapplicationDidFinishLaunching: to finalize application construction)
• handling menu items for items that don’t exist in a window (for example, opening the application Preferences window)

So, on that note, lets implement a Singleton. The ‘correct’ way of creating a single global instance of an object that can be accessed and manipulated by the view controllers.

First we need to make some changes to our User class as such:

User.h

#import <Foundation/Foundation.h>

@interface User : NSObject {

NSString *username;

NSString *password;

NSString *accountType;

}

@property (nonatomic, retain) NSString *username;

@property (nonatomic, retain) NSString *password;

@property (nonatomic, retain) NSString *accountType;

+ (User *)sharedUser;

@end

User.m

#import “User.h”

static User *sharedUser = nil;

@implementation User

@synthesize username;

@synthesize password;

@synthesize accountType;

#pragma mark -

#pragma mark Singleton Methods

+ (User *)sharedUser {

if(sharedUser == nil){

sharedUser = [[super allocWithZone:NULL] init];

}

return sharedUser;

}

+ (id)allocWithZone:(NSZone *)zone {

return [[self sharedManager] retain];

}

- (id)copyWithZone:(NSZone *)zone {

return self;

}

- (id)retain {

return self;

}

- (unsigned)retainCount {

return NSUIntegerMax;

}

- (void)release {

//do nothing

}

- (id)autorelease {

return self;

}

@end

Now, in any view controller we need to access/manipulate the ‘global’ user we can do:

SomeViewController.m

#import “SomeViewController.h”

#import “User.h”

@implementation SomeViewController

- (void)someFunction{

User *user = [User sharedUser];

user.username = @”Username”;

}

@end

References and resources that made this post and my learning possible.

• Cocoa’s Fundamentals Guide (by Apple)
• Cocoa With Love
• Matt Galloway
• Stack Overflow

- Updated: 11.17.09 – Reviewed Apple’s documentation on singletons and made the proper changes. Apple’s Singleton Documentation