avfoundation

I am building an iOS application (my first) that processes video still frames on the fly. To dive into this, I followed an example from the AV* documentation from Apple. The process involves setting up an input (the camera) and an output. The output works with a delegate, which in this case is the controller itself (it conforms and implements the method needed). The problem I am having is that the delegate method never gets called. The code below is the implementation of the controller and it has a couple of NSLogs. I can see the "started" message, but the "delegate method called" never shows.

I'm using AVPlayer in a Cocoa app, and I've implemented a command that jumps to the end of the video. The problem is, AVPlayer doesn't seek to where I told it to. For example, one of the videos I have is 4 minutes and 14 seconds long. When I seek to the end, AVPlayer seeks to 4 minutes and 12 seconds—two seconds short. If I then hit play, the player will play for two seconds, then reach the end. My first attempt was this: [self.player seekToTime:self.player.currentItem.duration]; I've switched it to this: [self.player seekToTime:self.player.currentItem.duration toleranceBefore

I am trying to capture a picture from a video on my iPad. I used Apple's AVCam example as a starting point. I was able to see the video in my application and to take pictures from it. My problem is that the pixel size of the result image is wrong. I want a fullscreen picture (1024x768) but I get a smaller one (1024x720). Those are my instance variables: @property (retain) AVCaptureStillImageOutput *stillImageOutput; @property (retain) AVCaptureVideoPreviewLayer *previewLayer; @property (retain) AVCaptureSession *captureSession; @property (retain) AVCaptureConnection *captureConnection;

Is there any way to poll the mic input volume with AVFoundation? I have seen the CoreAudio examples like SpeakHere but I really only need the current value. Is CA my only option? You should checkout SCListener. It's a simple way just to get the average or peak level of the mic. http://github.com/stephencelis/sc_listener 来源： https://stackoverflow.com/questions/477020/iphone-mic-volume

Can someone point me to documentation that will help me get correct SPS and PPS values for iPhone. Question is a bit unclear... Picture Parameter Set is described in the latest ITU-T release of the standard in chapter 7.3.2.2 Sequence Parameter Set is described in chapter 7.3.2.1. You can encode a single frame to a file and then extract the sps and pps from that file. I have an example that shows how to do exactly that at http://www.gdcl.co.uk/2013/02/20/iOS-Video-Encoding.html I am sure you know, but you can only save H264 encoded video into a file(.mp4, .mov) on iOS. There is no access to

I am trying to combine video with GIF image, For this I am using MainCompositionInst.animationTool = [AVVideoCompositionCoreAnimationTool videoCompositionCoreAnimationToolWithPostProcessingAsVideoLayer:videoLayer inLayer:parentLayer]; and in the video layer I was set GIF image but unfortunately it was not animating, So my question is that is it possible to do this ? please suggest me.. Thanks in advance. Apple's support for GIF is fairly limited. You could use this code to convert from GIF to Video: (With the current code the gif will be cropped to 480x480. For some resolutions the output