I am working with ffmpeg to decode H264 stream from server.
I referenced DecoderWrapper from http://github.com/dropcam/dropcam_for_iphone.
I compiled it successfully, but I don't know how use it.
Here are the function that has problem.
- (id)initWithCodec:(enum VideoCodecType)codecType
colorSpace:(enum VideoColorSpace)colorSpace
width:(int)width
height:(int)height
privateData:(NSData*)privateData {
if(self = [super init]) {
codec = avcodec_find_decoder(CODEC_ID_H264);
codecCtx = avcodec_alloc_context();
// Note: for H.264 RTSP streams, the width and height are usually not specified (width and height are 0).
// These fields will become filled in once the first frame is decoded and the SPS is processed.
codecCtx->width = width;
codecCtx->height = height;
codecCtx->extradata = av_malloc([privateData length]);
codecCtx->extradata_size = [privateData length];
[privateData getBytes:codecCtx->extradata length:codecCtx->extradata_size];
codecCtx->pix_fmt = PIX_FMT_YUV420P;
#ifdef SHOW_DEBUG_MV
codecCtx->debug_mv = 0xFF;
#endif
srcFrame = avcodec_alloc_frame();
dstFrame = avcodec_alloc_frame();
int res = avcodec_open(codecCtx, codec);
if (res < 0)
{
NSLog(#"Failed to initialize decoder");
}
}
return self;
}
What is the privateData parameter of this function? I don't know how to set the parameter...
Now avcodec_decode_video2 returns -1;
The framedata is coming successfully.
How solve this problem.
Thanks a lot.
Take a look at your ffmpeg example, where in PATH/TO/FFMPEG/doc/example/decoder_encoder.c,
and this link:
http://cekirdek.pardus.org.tr/~ismail/ffmpeg-docs/api-example_8c-source.html
Be careful, this code just too old, some function's name has already changed.
Related
I am new to iOS programming and multimedia and I was going through a sample project named RosyWriter provided by apple at this link. Here I saw that in the code there is a function named captureOutput:didOutputSampleBuffer:fromConnection in the code given below:
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection
{
CMFormatDescriptionRef formatDescription = CMSampleBufferGetFormatDescription(sampleBuffer);
if ( connection == videoConnection ) {
// Get framerate
CMTime timestamp = CMSampleBufferGetPresentationTimeStamp( sampleBuffer );
[self calculateFramerateAtTimestamp:timestamp];
// Get frame dimensions (for onscreen display)
if (self.videoDimensions.width == 0 && self.videoDimensions.height == 0)
self.videoDimensions = CMVideoFormatDescriptionGetDimensions( formatDescription );
// Get buffer type
if ( self.videoType == 0 )
self.videoType = CMFormatDescriptionGetMediaSubType( formatDescription );
CVImageBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
// Synchronously process the pixel buffer to de-green it.
[self processPixelBuffer:pixelBuffer];
// Enqueue it for preview. This is a shallow queue, so if image processing is taking too long,
// we'll drop this frame for preview (this keeps preview latency low).
OSStatus err = CMBufferQueueEnqueue(previewBufferQueue, sampleBuffer);
if ( !err ) {
dispatch_async(dispatch_get_main_queue(), ^{
CMSampleBufferRef sbuf = (CMSampleBufferRef)CMBufferQueueDequeueAndRetain(previewBufferQueue);
if (sbuf) {
CVImageBufferRef pixBuf = CMSampleBufferGetImageBuffer(sbuf);
[self.delegate pixelBufferReadyForDisplay:pixBuf];
CFRelease(sbuf);
}
});
}
}
CFRetain(sampleBuffer);
CFRetain(formatDescription);
dispatch_async(movieWritingQueue, ^{
if ( assetWriter ) {
BOOL wasReadyToRecord = (readyToRecordAudio && readyToRecordVideo);
if (connection == videoConnection) {
// Initialize the video input if this is not done yet
if (!readyToRecordVideo)
readyToRecordVideo = [self setupAssetWriterVideoInput:formatDescription];
// Write video data to file
if (readyToRecordVideo && readyToRecordAudio)
[self writeSampleBuffer:sampleBuffer ofType:AVMediaTypeVideo];
}
else if (connection == audioConnection) {
// Initialize the audio input if this is not done yet
if (!readyToRecordAudio)
readyToRecordAudio = [self setupAssetWriterAudioInput:formatDescription];
// Write audio data to file
if (readyToRecordAudio && readyToRecordVideo)
[self writeSampleBuffer:sampleBuffer ofType:AVMediaTypeAudio];
}
BOOL isReadyToRecord = (readyToRecordAudio && readyToRecordVideo);
if ( !wasReadyToRecord && isReadyToRecord ) {
recordingWillBeStarted = NO;
self.recording = YES;
[self.delegate recordingDidStart];
}
}
CFRelease(sampleBuffer);
CFRelease(formatDescription);
});
}
Here a function named pixelBufferReadyForDisplay is called which expects a parameter of type CVPixelBufferRef
Prototype of pixelBufferReadyForDisplay
- (void)pixelBufferReadyForDisplay:(CVPixelBufferRef)pixelBuffer;
But in the code above while calling this function it passes the variable pixBuf which is of type CVImageBufferRef
So my question is that isn't it required to use any function or typecasting to convert a CVImageBufferRef to CVPixelBufferRef or is this done implicitly by the compiler?
Thanks.
If you do a search on CVPixelBufferRef in the Xcode docs, you'll find the following:
typedef CVImageBufferRef CVPixelBufferRef;
So a CVImageBufferRef is a synonym for a CVPixelBufferRef. They are interchangeable.
You are looking at some pretty gnarly code. RosyWriter, and another sample app called "Chromakey" do some pretty low-level processing on pixel buffers. If you're new to iOS development AND new to multimedia you might not want to dig so deep, so fast. It's a bit like a first year medical student trying to perform a heart-lung transplant.
I'm trying to use OpenCV on iOS to do some pixel analysis on video frames. I've tried several .MOV files (all MPEG-4 AVC) but none of them seem to decode properly.
Problems:
- All cvGetCaptureProperty calls return a value of 1
- cvGrabFrame(capture) always returns true (it doesn't seem to find the last frame)
Things that are actually working
- Frame height and width are correctly determined
Any ideas? I have OpenCV 2.3.2 from http://aptogo.co.uk/2011/09/opencv-framework-for-ios/
NSURL *file = [[NSBundle mainBundle] URLForResource:#"sky" withExtension:#"MOV"];
CvCapture* capture = cvCaptureFromFile([[file path] UTF8String]);
if (!capture)
{
NSLog(#"Error loading file");
return;
}
cvQueryFrame(capture);
int width = cvGetCaptureProperty(capture, CV_CAP_PROP_FRAME_WIDTH);
int height = cvGetCaptureProperty(capture, CV_CAP_PROP_FRAME_HEIGHT);
NSLog(#"dimensions = %dx%d", width, height); // returns 1x1
double framesPerSecond = cvGetCaptureProperty(capture, CV_CAP_PROP_FPS);
NSLog(#"framesPerSecond = %f", framesPerSecond); // returns 1
int frameCount = (int)cvGetCaptureProperty(capture, CV_CAP_PROP_FRAME_COUNT);
NSLog(#"frameCount = %d", frameCount); // returns 1
int frameCounter = 0;
while (cvGrabFrame(capture))
{
frameCounter++;
//NSLog(#"got a frame! %d", frameCounter);
if (frameCounter % 50 == 0)
{
IplImage* frame = cvRetrieveFrame(capture);
NSLog(#"frame width: %d", frame->width); // works correctly
NSLog(#"frame height: %d", frame->height); // works correctly
}
if (frameCounter > 1000)
break; // this is here because the loop never stops on its own
}
cvReleaseCapture(&capture);
Hey there, I am trying to access raw data from iphone camera using AVCaptureSession. I follow the guide provided by Apple (link here).
The raw data from the samplebuffer is in YUV format ( Am I correct here about the raw video frame format?? ), how to directly obtain the data for Y component out of the raw data stored in the samplebuffer.
When setting up the AVCaptureVideoDataOutput that returns the raw camera frames, you can set the format of the frames using code like the following:
[videoOutput setVideoSettings:[NSDictionary dictionaryWithObject:[NSNumber numberWithInt:kCVPixelFormatType_32BGRA] forKey:(id)kCVPixelBufferPixelFormatTypeKey]];
In this case a BGRA pixel format is specified (I used this for matching a color format for an OpenGL ES texture). Each pixel in that format has one byte for blue, green, red, and alpha, in that order. Going with this makes it easy to pull out color components, but you do sacrifice a little performance by needing to make the conversion from the camera-native YUV colorspace.
Other supported colorspaces are kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange and kCVPixelFormatType_420YpCbCr8BiPlanarFullRange on newer devices and kCVPixelFormatType_422YpCbCr8 on the iPhone 3G. The VideoRange or FullRange suffix simply indicates whether the bytes are returned between 16 - 235 for Y and 16 - 240 for UV or full 0 - 255 for each component.
I believe the default colorspace used by an AVCaptureVideoDataOutput instance is the YUV 4:2:0 planar colorspace (except on the iPhone 3G, where it's YUV 4:2:2 interleaved). This means that there are two planes of image data contained within the video frame, with the Y plane coming first. For every pixel in your resulting image, there is one byte for the Y value at that pixel.
You would get at this raw Y data by implementing something like this in your delegate callback:
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection
{
CVImageBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
CVPixelBufferLockBaseAddress(pixelBuffer, 0);
unsigned char *rawPixelBase = (unsigned char *)CVPixelBufferGetBaseAddress(pixelBuffer);
// Do something with the raw pixels here
CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);
}
You could then figure out the location in the frame data for each X, Y coordinate on the image and pull the byte out that corresponds to the Y component at that coordinate.
Apple's FindMyiCone sample from WWDC 2010 (accessible along with the videos) shows how to process raw BGRA data from each frame. I also created a sample application, which you can download the code for here, that performs color-based object tracking using the live video from the iPhone's camera. Both show how to process raw pixel data, but neither of these work in the YUV colorspace.
In addition to Brad's answer, and your own code, you want to consider the following:
Since your image has two separate planes, the function CVPixelBufferGetBaseAddress will not return the base address of the plane but rather the base address of an additional data structure. It's probably due to the current implementation that you get an address close enough to the first plane so that you can see the image. But it's the reason it's shifted and has garbage at the top left. The correct way to receive the first plane is:
unsigned char *rowBase = CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 0);
A row in the image might be longer than the width of the image (due to rounding). That's why there are separate functions for getting the width and the number of bytes per row. You don't have this problem at the moment. But that might change with the next version of iOS. So your code should be:
int bufferHeight = CVPixelBufferGetHeight(pixelBuffer);
int bufferWidth = CVPixelBufferGetWidth(pixelBuffer);
int bytesPerRow = CVPixelBufferGetBytesPerRowOfPlane(pixelBuffer, 0);
int size = bufferHeight * bytesPerRow ;
unsigned char *pixel = (unsigned char*)malloc(size);
unsigned char *rowBase = CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 0);
memcpy (pixel, rowBase, size);
Please also note that your code will miserably fail on an iPhone 3G.
If you only need the luminance channel, I recommend against using BGRA format, as it comes with a conversion overhead. Apple suggest using BGRA if you're doing rendering stuff, but you don't need it for extracting the luminance information. As Brad already mentioned, the most efficient format is the camera-native YUV format.
However, extracting the right bytes from the sample buffer is a bit tricky, especially regarding the iPhone 3G with it's interleaved YUV 422 format. So here is my code, which works fine with the iPhone 3G, 3GS, iPod Touch 4 and iPhone 4S.
#pragma mark -
#pragma mark AVCaptureVideoDataOutputSampleBufferDelegate Methods
#if !(TARGET_IPHONE_SIMULATOR)
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection;
{
// get image buffer reference
CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
// extract needed informations from image buffer
CVPixelBufferLockBaseAddress(imageBuffer, 0);
size_t bufferSize = CVPixelBufferGetDataSize(imageBuffer);
void *baseAddress = CVPixelBufferGetBaseAddress(imageBuffer);
CGSize resolution = CGSizeMake(CVPixelBufferGetWidth(imageBuffer), CVPixelBufferGetHeight(imageBuffer));
// variables for grayscaleBuffer
void *grayscaleBuffer = 0;
size_t grayscaleBufferSize = 0;
// the pixelFormat differs between iPhone 3G and later models
OSType pixelFormat = CVPixelBufferGetPixelFormatType(imageBuffer);
if (pixelFormat == '2vuy') { // iPhone 3G
// kCVPixelFormatType_422YpCbCr8 = '2vuy',
/* Component Y'CbCr 8-bit 4:2:2, ordered Cb Y'0 Cr Y'1 */
// copy every second byte (luminance bytes form Y-channel) to new buffer
grayscaleBufferSize = bufferSize/2;
grayscaleBuffer = malloc(grayscaleBufferSize);
if (grayscaleBuffer == NULL) {
NSLog(#"ERROR in %#:%#:%d: couldn't allocate memory for grayscaleBuffer!", NSStringFromClass([self class]), NSStringFromSelector(_cmd), __LINE__);
return nil; }
memset(grayscaleBuffer, 0, grayscaleBufferSize);
void *sourceMemPos = baseAddress + 1;
void *destinationMemPos = grayscaleBuffer;
void *destinationEnd = grayscaleBuffer + grayscaleBufferSize;
while (destinationMemPos <= destinationEnd) {
memcpy(destinationMemPos, sourceMemPos, 1);
destinationMemPos += 1;
sourceMemPos += 2;
}
}
if (pixelFormat == '420v' || pixelFormat == '420f') {
// kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange = '420v',
// kCVPixelFormatType_420YpCbCr8BiPlanarFullRange = '420f',
// Bi-Planar Component Y'CbCr 8-bit 4:2:0, video-range (luma=[16,235] chroma=[16,240]).
// Bi-Planar Component Y'CbCr 8-bit 4:2:0, full-range (luma=[0,255] chroma=[1,255]).
// baseAddress points to a big-endian CVPlanarPixelBufferInfo_YCbCrBiPlanar struct
// i.e.: Y-channel in this format is in the first third of the buffer!
int bytesPerRow = CVPixelBufferGetBytesPerRowOfPlane(imageBuffer, 0);
baseAddress = CVPixelBufferGetBaseAddressOfPlane(imageBuffer,0);
grayscaleBufferSize = resolution.height * bytesPerRow ;
grayscaleBuffer = malloc(grayscaleBufferSize);
if (grayscaleBuffer == NULL) {
NSLog(#"ERROR in %#:%#:%d: couldn't allocate memory for grayscaleBuffer!", NSStringFromClass([self class]), NSStringFromSelector(_cmd), __LINE__);
return nil; }
memset(grayscaleBuffer, 0, grayscaleBufferSize);
memcpy (grayscaleBuffer, baseAddress, grayscaleBufferSize);
}
// do whatever you want with the grayscale buffer
...
// clean-up
free(grayscaleBuffer);
}
#endif
This is simply the culmination of everyone else's hard work, above and on other threads, converted to swift 3 for anyone that finds it useful.
func captureOutput(_ captureOutput: AVCaptureOutput!, didOutputSampleBuffer sampleBuffer: CMSampleBuffer!, from connection: AVCaptureConnection!) {
if let pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer) {
CVPixelBufferLockBaseAddress(pixelBuffer, CVPixelBufferLockFlags.readOnly)
let pixelFormatType = CVPixelBufferGetPixelFormatType(pixelBuffer)
if pixelFormatType == kCVPixelFormatType_420YpCbCr8BiPlanarFullRange
|| pixelFormatType == kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange {
let bufferHeight = CVPixelBufferGetHeight(pixelBuffer)
let bufferWidth = CVPixelBufferGetWidth(pixelBuffer)
let lumaBytesPerRow = CVPixelBufferGetBytesPerRowOfPlane(pixelBuffer, 0)
let size = bufferHeight * lumaBytesPerRow
let lumaBaseAddress = CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 0)
let lumaByteBuffer = unsafeBitCast(lumaBaseAddress, to:UnsafeMutablePointer<UInt8>.self)
let releaseDataCallback: CGDataProviderReleaseDataCallback = { (info: UnsafeMutableRawPointer?, data: UnsafeRawPointer, size: Int) -> () in
// https://developer.apple.com/reference/coregraphics/cgdataproviderreleasedatacallback
// N.B. 'CGDataProviderRelease' is unavailable: Core Foundation objects are automatically memory managed
return
}
if let dataProvider = CGDataProvider(dataInfo: nil, data: lumaByteBuffer, size: size, releaseData: releaseDataCallback) {
let colorSpace = CGColorSpaceCreateDeviceGray()
let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.noneSkipFirst.rawValue)
let cgImage = CGImage(width: bufferWidth, height: bufferHeight, bitsPerComponent: 8, bitsPerPixel: 8, bytesPerRow: lumaBytesPerRow, space: colorSpace, bitmapInfo: bitmapInfo, provider: dataProvider, decode: nil, shouldInterpolate: false, intent: CGColorRenderingIntent.defaultIntent)
let greyscaleImage = UIImage(cgImage: cgImage!)
// do what you want with the greyscale image.
}
}
CVPixelBufferUnlockBaseAddress(pixelBuffer, CVPixelBufferLockFlags.readOnly)
}
}
I am going insane with this one - have looked everywhere and tried anything and everything I can thinks of.
Am making an iPhone app that uses AVFoundation - specifically AVCapture to capture video using the iPhone camera.
I need to have a custom image that is overlayed on the video feed included in the recording.
So far I have the AVCapture session set up, can display the feed, access the frame, save it as a UIImage and marge the overlay Image onto it. Then convert this new UIImage into a CVPixelBufferRef. annnd to double check that the bufferRef is working I converted it back to a UIImage and it displays the image fine still.
The trouble starts when I try to convert the CVPixelBufferRef into a CMSampleBufferRef to append to the AVCaptureSessions assetWriterInput. The CMSampleBufferRef always returning NULL when I attempt to create it.
Here is the -(void)captureOutput function
- (void)captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
fromConnection:(AVCaptureConnection *)connection
{
UIImage *botImage = [self imageFromSampleBuffer:sampleBuffer];
UIImage *wheel = [self imageFromView:wheelView];
UIImage *finalImage = [self overlaidImage:botImage :wheel];
//[previewImage setImage:finalImage]; <- works -- the image is being merged into one UIImage
CVPixelBufferRef pixelBuffer = NULL;
CGImageRef cgImage = CGImageCreateCopy(finalImage.CGImage);
CFDataRef image = CGDataProviderCopyData(CGImageGetDataProvider(cgImage));
int status = CVPixelBufferCreateWithBytes(NULL,
self.view.bounds.size.width,
self.view.bounds.size.height,
kCVPixelFormatType_32BGRA,
(void*)CFDataGetBytePtr(image),
CGImageGetBytesPerRow(cgImage),
NULL,
0,
NULL,
&pixelBuffer);
if(status == 0){
OSStatus result = 0;
CMVideoFormatDescriptionRef videoInfo = NULL;
result = CMVideoFormatDescriptionCreateForImageBuffer(NULL, pixelBuffer, &videoInfo);
NSParameterAssert(result == 0 && videoInfo != NULL);
CMSampleBufferRef myBuffer = NULL;
result = CMSampleBufferCreateForImageBuffer(kCFAllocatorDefault,
pixelBuffer, true, NULL, NULL, videoInfo, NULL, &myBuffer);
NSParameterAssert(result == 0 && myBuffer != NULL);//always null :S
NSLog(#"Trying to append");
if (!CMSampleBufferDataIsReady(myBuffer)){
NSLog(#"sampleBuffer data is not ready");
return;
}
if (![assetWriterInput isReadyForMoreMediaData]){
NSLog(#"Not ready for data :(");
return;
}
if (![assetWriterInput appendSampleBuffer:myBuffer]){
NSLog(#"Failed to append pixel buffer");
}
}
}
Another solution I keep hearing about is using a AVAssetWriterInputPixelBufferAdaptor which eliminates the need to do the messy CMSampleBufferRef wrapping. However I have scoured stacked and apple developer forums and docs and can't find a clear description or example on how to set this up or how to use it. If anyone has a working example of it could you please show me or help me nut out the above issue - have been working on this non-stop for a week and am at wits end.
Let me know if you need any other info
Thanks in advance,
Michael
You need AVAssetWriterInputPixelBufferAdaptor, here is the code to create it :
// Create dictionary for pixel buffer adaptor
NSDictionary *bufferAttributes = [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithInt:kCVPixelFormatType_32BGRA], kCVPixelBufferPixelFormatTypeKey, nil];
// Create pixel buffer adaptor
m_pixelsBufferAdaptor = [[AVAssetWriterInputPixelBufferAdaptor alloc] initWithAssetWriterInput:assetWriterInput sourcePixelBufferAttributes:bufferAttributes];
And the code to use it :
// If ready to have more media data
if (m_pixelsBufferAdaptor.assetWriterInput.readyForMoreMediaData) {
// Create a pixel buffer
CVPixelBufferRef pixelsBuffer = NULL;
CVPixelBufferPoolCreatePixelBuffer(NULL, m_pixelsBufferAdaptor.pixelBufferPool, &pixelsBuffer);
// Lock pixel buffer address
CVPixelBufferLockBaseAddress(pixelsBuffer, 0);
// Create your function to set your pixels data in the buffer (in your case, fill with your finalImage data)
[self yourFunctionToPutDataInPixelBuffer:CVPixelBufferGetBaseAddress(pixelsBuffer)];
// Unlock pixel buffer address
CVPixelBufferUnlockBaseAddress(pixelsBuffer, 0);
// Append pixel buffer (calculate currentFrameTime with your needing, the most simplest way is to have a frame time starting at 0 and increment each time you write a frame with the time of a frame (inverse of your framerate))
[m_pixelsBufferAdaptor appendPixelBuffer:pixelsBuffer withPresentationTime:currentFrameTime];
// Release pixel buffer
CVPixelBufferRelease(pixelsBuffer);
}
And don't forget to release your pixelsBufferAdaptor.
I do it by using CMSampleBufferCreateForImageBuffer() .
OSStatus ret = 0;
CMSampleBufferRef sample = NULL;
CMVideoFormatDescriptionRef videoInfo = NULL;
CMSampleTimingInfo timingInfo = kCMTimingInfoInvalid;
timingInfo.presentationTimeStamp = pts;
timingInfo.duration = duration;
ret = CMVideoFormatDescriptionCreateForImageBuffer(NULL, pixel, &videoInfo);
if (ret != 0) {
NSLog(#"CMVideoFormatDescriptionCreateForImageBuffer failed! %d", (int)ret);
goto done;
}
ret = CMSampleBufferCreateForImageBuffer(kCFAllocatorDefault, pixel, true, NULL, NULL,
videoInfo, &timingInfo, &sample);
if (ret != 0) {
NSLog(#"CMSampleBufferCreateForImageBuffer failed! %d", (int)ret);
goto done;
}
I would like to have my error handling code behave differently if it is running under the debugger. Specifically, if I am running on a handset, not attached to a debugger and fail an assertion I want to send the error to my server. When I am under gdb, I want to break into the debugger.
Although I can imagine how Apple would write the code, I can't find any documentation of a runtime way to test for the presence of the debugger.
The method described here worked fine for me
I tested by placing it in -(void)viewDidLoad
- (void)viewDidLoad {
[super viewDidLoad];
int mib[4];
size_t bufSize = 0;
int local_error = 0;
struct kinfo_proc kp;
mib[0] = CTL_KERN;
mib[1] = KERN_PROC;
mib[2] = KERN_PROC_PID;
mib[3] = getpid();
bufSize = sizeof (kp);
if ((local_error = sysctl(mib, 4, &kp, &bufSize, NULL, 0)) < 0) {
label.text = #"Failure calling sysctl";
return;
}
if (kp.kp_proc.p_flag & P_TRACED)
label.text = #"I am traced";
else
label.text = #"I am not traced";
}
Why not redefine assert to do what you want, when not compiled for debug?
Another option, is to create your own assert function, where you can then add a breakpoint on loading into GDB.
The assert prototype is
void assert(int expression);
void assert(int expression)
{
if( !expression )
{
// enable break point here
// log to server
}
}
or add the break point into the log to server code.