iOS使用AVFoundation展示视频

//
// Capter2ViewController.m
// IosTest
//
// Created by garin on 13-7-19.
// Copyright (c) 2013年 garin. All rights reserved.
//
 
#import "Capter2ViewController.h"
 
@interface Capter2ViewController ()
@end
@implementation Capter2ViewController
-(void) dealloc
{
  [session release];
  [super dealloc];
}
 
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
  self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
  if (self) {
    // Custom initialization
  }
  return self;
}
 
- (void)viewDidLoad
{
  [super viewDidLoad];
  videoPreviewView=[[UIView alloc] initWithFrame:CGRectMake(10, 10, 320, 200)];
  [self.view addSubview:videoPreviewView];
  [videoPreviewView release];
 // Do any additional setup after loading the view.
  
  //在viewdidload调用下面的函数显示摄像信息
  [self setupCaptureSession];
  
//  imgView=[[UIImageView alloc] initWithFrame:CGRectMake(10, 230, 320, 100)];
//  imgView.backgroundColor=[UIColor grayColor];
//  [self.view addSubview:imgView];
//  [imgView release];
  
  UIButton *cloeseBtn=[UIButton buttonWithType:UIButtonTypeRoundedRect];
  cloeseBtn.frame=CGRectMake(10, 220, 300, 50);
  [cloeseBtn setTitle:@"Press" forState:UIControlStateNormal];
  [cloeseBtn addTarget:self action:@selector(closeBtnClick:) forControlEvents:UIControlEventTouchUpInside];
  [self.view addSubview:cloeseBtn];
}
 
-(void) closeBtnClick:(id) sender
{
  [session stopRunning];
}
 
- (void)didReceiveMemoryWarning
{
  [super didReceiveMemoryWarning];
  // Dispose of any resources that can be recreated.
}
 
- (void)setupCaptureSession
{
  NSError *error = nil;
  
  // Create the session
  session = [[AVCaptureSession alloc] init];
  
  // Configure the session to produce lower resolution video frames, if your
  // processing algorithm can cope. We'll specify medium quality for the
  // chosen device.
  session.sessionPreset = AVCaptureSessionPresetLow;
  
  // Find a suitable AVCaptureDevice
  AVCaptureDevice *device = [AVCaptureDevice
                defaultDeviceWithMediaType:AVMediaTypeVideo];
  
  // Create a device input with the device and add it to the session.
  AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device
                                    error:&error];
  if (!input) {
    // Handling the error appropriately.
  }
  [session addInput:input];
  
  // Create a VideoDataOutput and add it to the session
  AVCaptureVideoDataOutput *output = [[[AVCaptureVideoDataOutput alloc] init] autorelease];
  [session addOutput:output];
  
  // Configure your output.
  dispatch_queue_t queue = dispatch_queue_create("myQueue", NULL);
  [output setSampleBufferDelegate:self queue:queue];
  dispatch_release(queue);
  
  // Specify the pixel format
  output.videoSettings =
  [NSDictionary dictionaryWithObject:
   [NSNumber numberWithInt:kCVPixelFormatType_32BGRA]
                forKey:(id)kCVPixelBufferPixelFormatTypeKey];
  
  
  // If you wish to cap the frame rate to a known value, such as 15 fps, set
  // minFrameDuration.
  //output.minFrameDuration = CMTimeMake(1, 15);
  //AVCaptureConnection *avcaptureconn=[[AVCaptureConnection alloc] init];
  //[avcaptureconn setVideoMinFrameDuration:CMTimeMake(1, 15)];
  // Start the session running to start the flow of data
  [session startRunning];
  AVCaptureVideoPreviewLayer* previewLayer = [AVCaptureVideoPreviewLayer layerWithSession: session];
  previewLayer.frame = videoPreviewView.bounds; //视频显示到的UIView
  previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
//  [previewLayer setOrientation:AVCaptureVideoOrientationLandscapeRight];
  //  if(previewLayer.orientationSupported){
  //   previewLayer.orientation = mOrientation;
  //  }
  
  [videoPreviewView.layer addSublayer: previewLayer];
  
  if(![session isRunning]){
    [session startRunning];
  }
  
  // Assign session to an ivar.
  //[self setSession:session];
}
 
//得到视频流
- (void)captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
    fromConnection:(AVCaptureConnection *)connection
{
  // Create a UIImage from the sample buffer data
  return;
  
  UIImage *image = [self imageFromSampleBuffer:sampleBuffer];
  //得到的视频流图片
  imgView.image=image;
}
 
// Create a UIImage from sample buffer data
- (UIImage *) imageFromSampleBuffer:(CMSampleBufferRef) sampleBuffer
{
  // Get a CMSampleBuffer's Core Video image buffer for the media data
  CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
  // Lock the base address of the pixel buffer
  CVPixelBufferLockBaseAddress(imageBuffer, 0);
  
  // Get the number of bytes per row for the pixel buffer
  void *baseAddress = CVPixelBufferGetBaseAddress(imageBuffer);
  
  // Get the number of bytes per row for the pixel buffer
  size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);
  // Get the pixel buffer width and height
  size_t width = CVPixelBufferGetWidth(imageBuffer);
  size_t height = CVPixelBufferGetHeight(imageBuffer);
  
  // Create a device-dependent RGB color space
  CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
  
  // Create a bitmap graphics context with the sample buffer data
  CGContextRef context = CGBitmapContextCreate(baseAddress, width, height, 8,
                         bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst);
  // Create a Quartz image from the pixel data in the bitmap graphics context
  CGImageRef quartzImage = CGBitmapContextCreateImage(context);
  // Unlock the pixel buffer
  CVPixelBufferUnlockBaseAddress(imageBuffer,0);
  
  // Free up the context and color space
  CGContextRelease(context);
  CGColorSpaceRelease(colorSpace);
  
  // Create an image object from the Quartz image
  UIImage *image = [UIImage imageWithCGImage:quartzImage];
  
  // Release the Quartz image
  CGImageRelease(quartzImage);
  
  return (image);
}
 
@end