I'm setting custom exposure/iso with the camera using:
AVCaptureDevice* cd = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
[cd setExposureModeCustomWithDuration:cmtime ISO:iso completionHandler:nil];
This works fine. However, for the duration of the app's session these custom settings persist. Is there a way to reset the capture device's exposure/iso settings? I've tried something like:
if([captureDevice lockForConfiguration:&error]){
[captureDevice setExposureModeCustomWithDuration:captureDevice.activeFormat.minExposureDuration ISO:captureDevice.activeFormat.minISO completionHandler:nil];
[captureDevice unlockForConfiguration];
}
But this doesn't reset the camera to the default settings.
You can store exposure mode before customising it
AVCaptureDevice* cd = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
self.defaultExposureMode = cd.exposureMode; // store in some property
if([cd lockForConfiguration:&error]){
[cd setExposureModeCustomWithDuration:cmtime ISO:iso completionHandler:nil];
[cd unlockForConfiguration];
}
and then restore it when needed
AVCaptureDevice* cd = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
if([cd lockForConfiguration:&error]){
cd.exposureMode = self.defaultExposureMode;
[cd unlockForConfiguration];
}
Related
How to stop the auto focusing in UIimagepickercontroller camera in iPhone sdk?
set showsCameraControls to NO like bellow..
picker.showsCameraControls = NO;
Also see another answer from this link iphone-ios-4-3-camera-focus-square-removeable-programatically
You may want to try to lock the focus to disable auto-focus. Here is a sample code:
NSArray *devices = [AVCaptureDevice devices];
NSError *error;
for (AVCaptureDevice *device in devices) {
if (([device hasMediaType:AVMediaTypeVideo]) &&
([device position] == AVCaptureDevicePositionBack) ) {
[device lockForConfiguration:&error];
if ([device isFocusModeSupported:AVCaptureFocusModeLocked]) {
device.focusMode = AVCaptureFocusModeLocked;
NSLog(#"Focus locked");
}
[device unlockForConfiguration];
}
}
Also you can try setting the .showsCameraControls property of your picker controller to NO should remove the focus square (it did pre 4.3, I don't think anything has changed), but the downside is you'll need to provide your own controls (to take photos, etc).
I'm building a turn-by-turn navigation app that plays periodic, short clips of sound. Sound should play regardless of whether the screen is locked, should mix with other music playing, and should make other music duck when this audio plays.
Apple discusses the turn-by-turn use case in detail in the "WWDC 2010 session 412 Audio Development for iPhone OS part 1" video at minute 29:20. The implementation works great, but there is one problem - when the app is running, pressing the hardware volume controls adjust the ringer volume, not the app volume. If you want to change the app volume, you must press the volume buttons while a prompt is playing.
Apple is very specific in the video that you shouldn't leave the AVAudioSession active, but if the AVAudioSession is inactive, the volume buttons won't control the volume of my app.
Here is the code I'm using to set things up:
UInt32 sessionCategory = kAudioSessionCategory_MediaPlayback;
propertySetError = AudioSessionSetProperty(kAudioSessionProperty_AudioCategory, sizeof(sessionCategory), &sessionCategory);
UInt32 allowMixing = true;
propertySetError = AudioSessionSetProperty(kAudioSessionProperty_OverrideCategoryMixWithOthers, sizeof(allowMixing), &allowMixing);
UInt32 shouldDuck = true;
propertySetError = AudioSessionSetProperty(kAudioSessionProperty_OtherMixableAudioShouldDuck, sizeof(shouldDuck), &shouldDuck);
OSStatus activationResult = AudioSessionSetActive(true);
NSError* err = nil;
_player = [[AVAudioPlayer alloc] initWithData:audioData error:&err];
_player.delegate = self;
[_player play];
And I set the session active to NO at the end, as Apple recommends:
OSStatus activationResult = AudioSessionSetActive(false);
NSAssert(activationResult == kAudioSessionNoError, #"Error deactivating audio session");
Is there something I'm missing, or do I have to go against what they recommended in the video?
In your case, you don't want to set the audio session inactive. What you need to do is use two methods, one to set the session up for playing a sound, and the other to set it up for being idle. The first method sets up a mix+duck audio mode, and the second uses a background-audio-friendly mode like ambient.
Something like this:
- (void)setActive {
UInt32 mix = 1;
UInt32 duck = 1;
NSError* errRet;
AVAudioSession* session = [AVAudioSession sharedInstance];
[session setActive:NO error:&errRet];
[session setCategory:AVAudioSessionCategoryPlayback error:&errRet];
NSAssert(errRet == nil, #"setCategory!");
AudioSessionSetProperty(kAudioSessionProperty_OverrideCategoryMixWithOthers, sizeof(mix), &mix);
AudioSessionSetProperty(kAudioSessionProperty_OtherMixableAudioShouldDuck, sizeof(duck), &duck);
[session setActive:YES error:&errRet];
}
- (void)setIdle {
NSError* errRet;
AVAudioSession* session = [AVAudioSession sharedInstance];
[session setActive:NO error:&errRet];
[session setCategory:AVAudioSessionCategoryAmbient error:&errRet];
NSAssert(errRet == nil, #"setCategory!");
[session setActive:YES error:&errRet];
}
Then to call it:
[self setActive];
[self _playAudio:nil];
To clean up after playing:
- (void)audioPlayerDidFinishPlaying:(AVAudioPlayer*)player
successfully:(BOOL)flag {
[self setIdle];
}
To be a good citizen, your app should set the audio session inactive when the it isn't navigating (i.e., performing its main function), but when it is, there is absolutely nothing wrong with keeping the audio session active and using modes to peacefully coexist with other apps. You can duplicate Apple's navigation app functionality using the code above.
I am using the iPhone/iPad camera to get a video stream and doing recognition on the stream, but with lighting changes it has a negative impact on the robustness. I have tested different settings in different light and can get it to work, but trying to get the settings to adjust at run time is what I need.
I can calculate a simple brightness check on each frame, but the camera adjusts and throws my results off. I can watch for sharp changes and run checks then, but gradual changes would throw my results off as well.
Ideally I'd be like to access the camera/EXIF data for the stream and see what it is registering the unfiltered brightness as, is there a way to do this?
(I am working for devices iOS 5 and above)
Thank you
Available in iOS 4.0 and above. It's possible to get EXIF information from CMSampleBufferRef.
//Import ImageIO & include framework in your project.
#import <ImageIO/CGImageProperties.h>
In your sample buffer delegate toll-free bridging will get a NSDictionary of results from CoreMedia's CMGetAttachment.
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection {
NSDictionary* dict = (NSDictionary*)CMGetAttachment(sampleBuffer, kCGImagePropertyExifDictionary, NULL);
Complete code, as used in my own app:
- (void)setupAVCapture {
//-- Setup Capture Session.
_session = [[AVCaptureSession alloc] init];
[_session beginConfiguration];
//-- Set preset session size.
[_session setSessionPreset:AVCaptureSessionPreset1920x1080];
//-- Creata a video device and input from that Device. Add the input to the capture session.
AVCaptureDevice * videoDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
if(videoDevice == nil)
assert(0);
//-- Add the device to the session.
NSError *error;
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:&error];
if(error)
assert(0);
[_session addInput:input];
//-- Create the output for the capture session.
AVCaptureVideoDataOutput * dataOutput = [[AVCaptureVideoDataOutput alloc] init];
[dataOutput setAlwaysDiscardsLateVideoFrames:YES]; // Probably want to set this to NO when recording
//-- Set to YUV420.
[dataOutput setVideoSettings:[NSDictionary dictionaryWithObject:[NSNumber numberWithInt:kCVPixelFormatType_420YpCbCr8BiPlanarFullRange]
forKey:(id)kCVPixelBufferPixelFormatTypeKey]]; // Necessary for manual preview
// Set dispatch to be on the main thread so OpenGL can do things with the data
[dataOutput setSampleBufferDelegate:self queue:dispatch_get_main_queue()];
[_session addOutput:dataOutput];
[_session commitConfiguration];
[_session startRunning];
}
- (void)captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
fromConnection:(AVCaptureConnection *)connection
{
CFDictionaryRef metadataDict = CMCopyDictionaryOfAttachments(NULL,
sampleBuffer, kCMAttachmentMode_ShouldPropagate);
NSDictionary *metadata = [[NSMutableDictionary alloc]
initWithDictionary:(__bridge NSDictionary*)metadataDict];
CFRelease(metadataDict);
NSDictionary *exifMetadata = [[metadata
objectForKey:(NSString *)kCGImagePropertyExifDictionary] mutableCopy];
self.autoBrightness = [[exifMetadata
objectForKey:(NSString *)kCGImagePropertyExifBrightnessValue] floatValue];
float oldMin = -4.639957; // dark
float oldMax = 4.639957; // light
if (self.autoBrightness > oldMax) oldMax = self.autoBrightness; // adjust oldMax if brighter than expected oldMax
self.lumaThreshold = ((self.autoBrightness - oldMin) * ((3.0 - 1.0) / (oldMax - oldMin))) + 1.0;
NSLog(#"brightnessValue %f", self.autoBrightness);
NSLog(#"lumaThreshold %f", self.lumaThreshold);
}
The lumaThreshold variable is sent as a uniform variable to my fragment shader, which multiplies the Y sampler texture to find the ideal luminosity based on the brightness of the environment. Right now, it uses the back camera; I'll probably switch to the front camera, since I'm only changing the "brightness" of the screen to adjust for indoor/outdoor viewing, and the user's eyes are on the front of the camera (and not the back).
I created a 'mirror'-like view in my app that uses the front camera to show a 'mirror' to the user. The problem I'm having is that I have not touched this code in weeks (and it did work then) but now I'm testing it again and it's not working. The code is the same as before, there are no errors coming up, and the view in the storyboard is exactly the same as before. I have no idea what is going on, so I was hoping that this website would help.
Here is my code:
if([UIImagePickerController isCameraDeviceAvailable:UIImagePickerControllerCameraDeviceFront]) {
//If the front camera is available, show the camera
AVCaptureSession *session = [[AVCaptureSession alloc] init];
AVCaptureOutput *output = [[AVCaptureStillImageOutput alloc] init];
[session addOutput:output];
//Setup camera input
NSArray *possibleDevices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
//You could check for front or back camera here, but for simplicity just grab the first device
AVCaptureDevice *device = [possibleDevices objectAtIndex:1];
NSError *error = nil;
// create an input and add it to the session
AVCaptureDeviceInput* input = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error]; //Handle errors
//set the session preset
session.sessionPreset = AVCaptureSessionPresetHigh; //Or other preset supported by the input device
[session addInput:input];
AVCaptureVideoPreviewLayer *previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:session];
//Now you can add this layer to a view of your view controller
[cameraView.layer addSublayer:previewLayer];
previewLayer.frame = self.cameraView.bounds;
[session startRunning];
if ([session isRunning]) {
NSLog(#"The session is running");
}
if ([session isInterrupted]) {
NSLog(#"The session has been interupted");
}
} else {
//Tell the user they don't have a front facing camera
}
Thank You in advanced.
Not sure if this is the problem but there is an inconsistency between your code and the comments. The inconsistency is with the following line of code:
AVCaptureDevice *device = [possibleDevices objectAtIndex:1];
In the comment above it says: "...for simplicity just grab the first device". However, the code is grabbing the second device, NSArray is indexed from 0. I believe the comment should be corrected as I think you are assuming the front camera will be the second device in the array.
If you are working on the assumption that the first device is the back camera and the second device is the front camera then this is a dangerous assumption. It would be much safer and more future proof to check the list of possibleDevices for the device that is the front camera.
The following code will enumerate the list of possibleDevices and create input using the front camera.
// Find the front camera and create an input and add it to the session
AVCaptureDeviceInput* input = nil;
for(AVCaptureDevice *device in possibleDevices) {
if ([device position] == AVCaptureDevicePositionFront) {
NSError *error = nil;
input = [AVCaptureDeviceInput deviceInputWithDevice:device
error:&error]; //Handle errors
break;
}
}
Update: I have just cut and pasted the code exactly as it is in the question into a simple project and it is working fine for me. I am seeing the video from the front camera. You should probably look elsewhere for the issue. First, I would be inclined to check the cameraView and associated layers.
in my program I want the user to be able to:
record his voice,
pause the recording process,
listen to what he recorded
and then continue recording.
I have managed to get to the point where I can record and play the recordings with AVAudioRecorder and AVAudioPlayer. But whenever I try to record, pause recording and then play, the playing part fails with no error.
I can guess that the reason it's not playing is because the audio file hasn't been saved yet and is still in memory or something.
Is there a way I can play paused recordings?
If there is please tell me how
I'm using xcode 4.3.2
If you want to play the recording, then yes you have to stop recording before you can load the file into the AVAudioPlayer instance.
If you want to be able to playback some of the recording, then add more to the recording after listening to it, or say record in the middle.. then you're in for some trouble.
You have to create a new audio file and then combine them together.
This was my solution:
// Generate a composition of the two audio assets that will be combined into
// a single track
AVMutableComposition* composition = [AVMutableComposition composition];
AVMutableCompositionTrack* audioTrack = [composition addMutableTrackWithMediaType:AVMediaTypeAudio
preferredTrackID:kCMPersistentTrackID_Invalid];
// grab the two audio assets as AVURLAssets according to the file paths
AVURLAsset* masterAsset = [[AVURLAsset alloc] initWithURL:[NSURL fileURLWithPath:self.masterFile] options:nil];
AVURLAsset* activeAsset = [[AVURLAsset alloc] initWithURL:[NSURL fileURLWithPath:self.newRecording] options:nil];
NSError* error = nil;
// grab the portion of interest from the master asset
[audioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, masterAsset.duration)
ofTrack:[[masterAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0]
atTime:kCMTimeZero
error:&error];
if (error)
{
// report the error
return;
}
// append the entirety of the active recording
[audioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, activeAsset.duration)
ofTrack:[[activeAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0]
atTime:masterAsset.duration
error:&error];
if (error)
{
// report the error
return;
}
// now export the two files
// create the export session
// no need for a retain here, the session will be retained by the
// completion handler since it is referenced there
AVAssetExportSession* exportSession = [AVAssetExportSession
exportSessionWithAsset:composition
presetName:AVAssetExportPresetAppleM4A];
if (nil == exportSession)
{
// report the error
return;
}
NSString* combined = #"combined file path";// create a new file for the combined file
// configure export session output with all our parameters
exportSession.outputURL = [NSURL fileURLWithPath:combined]; // output path
exportSession.outputFileType = AVFileTypeAppleM4A; // output file type
[exportSession exportAsynchronouslyWithCompletionHandler:^{
// export status changed, check to see if it's done, errored, waiting, etc
switch (exportSession.status)
{
case AVAssetExportSessionStatusFailed:
break;
case AVAssetExportSessionStatusCompleted:
break;
case AVAssetExportSessionStatusWaiting:
break;
default:
break;
}
NSError* error = nil;
// your code for dealing with the now combined file
}];
I can't take full credit for this work, but it was pieced together from the input of a couple of others:
AVAudioRecorder / AVAudioPlayer - append recording to file
(I can't find the other link at the moment)
We had the same requirements for our app as the OP described, and ran into the same issues (i.e., the recording has to be stopped, instead of paused, if the user wants to listen to what she has recorded up to that point). Our app (project's Github repo) uses AVQueuePlayer for playback and a method similar to kermitology's answer to concatenate the partial recordings, with some notable differences:
implemented in Swift
concatenates multiple recordings into one
no messing with tracks
The rationale behind the last item is that simple recordings with AVAudioRecorder will have one track, and the main reason for this whole workaround is to concatenate those single tracks in the assets (see Addendum 3). So why not use AVMutableComposition's insertTimeRange method instead, that takes an AVAsset instead of an AVAssetTrack?
Relevant parts: (full code)
import UIKit
import AVFoundation
class RecordViewController: UIViewController {
/* App allows volunteers to record newspaper articles for the
blind and print-impaired, hence the name.
*/
var articleChunks = [AVURLAsset]()
func concatChunks() {
let composition = AVMutableComposition()
/* `CMTimeRange` to store total duration and know when to
insert subsequent assets.
*/
var insertAt = CMTimeRange(start: kCMTimeZero, end: kCMTimeZero)
repeat {
let asset = self.articleChunks.removeFirst()
let assetTimeRange =
CMTimeRange(start: kCMTimeZero, end: asset.duration)
do {
try composition.insertTimeRange(assetTimeRange,
of: asset,
at: insertAt.end)
} catch {
NSLog("Unable to compose asset track.")
}
let nextDuration = insertAt.duration + assetTimeRange.duration
insertAt = CMTimeRange(start: kCMTimeZero, duration: nextDuration)
} while self.articleChunks.count != 0
let exportSession =
AVAssetExportSession(
asset: composition,
presetName: AVAssetExportPresetAppleM4A)
exportSession?.outputFileType = AVFileType.m4a
exportSession?.outputURL = /* create URL for output */
// exportSession?.metadata = ...
exportSession?.exportAsynchronously {
switch exportSession?.status {
case .unknown?: break
case .waiting?: break
case .exporting?: break
case .completed?: break
case .failed?: break
case .cancelled?: break
case .none: break
}
}
/* Clean up (delete partial recordings, etc.) */
}
This diagram helped me to get around what expects what and inherited from where. (NSObject is implicitly implied as superclass where there is no inheritance arrow.)
Addendum 1: I had my reservations regarding the switch part instead of using KVO on AVAssetExportSessionStatus, but the docs are clear that exportAsynchronously's callback block "is invoked when writing is complete or in the event of writing failure".
Addendum 2: Just in case if someone has issues with AVQueuePlayer: 'An AVPlayerItem cannot be associated with more than one instance of AVPlayer'
Addendum 3: Unless you are recording in stereo, but mobile devices have one input as far as I know. Also, using fancy audio mixing would also require the use of AVCompositionTrack. A good SO thread: Proper AVAudioRecorder Settings for Recording Voice?
RecordAudioViewController.h
#import <UIKit/UIKit.h>
#import <AVFoundation/AVFoundation.h>
#import <CoreAudio/CoreAudioTypes.h>
#interface record_audio_testViewController : UIViewController <AVAudioRecorderDelegate> {
IBOutlet UIButton * btnStart;
IBOutlet UIButton * btnPlay;
IBOutlet UIActivityIndicatorView * actSpinner;
BOOL toggle;
//Variables setup for access in the class:
NSURL * recordedTmpFile;
AVAudioRecorder * recorder;
NSError * error;
}
#property (nonatomic,retain)IBOutlet UIActivityIndicatorView * actSpinner;
#property (nonatomic,retain)IBOutlet UIButton * btnStart;
#property (nonatomic,retain)IBOutlet UIButton * btnPlay;
- (IBAction) start_button_pressed;
- (IBAction) play_button_pressed;
#end
RecordAudioViewController.m
#synthesize actSpinner, btnStart, btnPlay;
- (void)viewDidLoad {
[super viewDidLoad];
//Start the toggle in true mode.
toggle = YES;
btnPlay.hidden = YES;
//Instanciate an instance of the AVAudioSession object.
AVAudioSession * audioSession = [AVAudioSession sharedInstance];
//Setup the audioSession for playback and record.
//We could just use record and then switch it to playback leter, but
//since we are going to do both lets set it up once.
[audioSession setCategory:AVAudioSessionCategoryPlayAndRecord error: &error];
//Activate the session
[audioSession setActive:YES error: &error];
}
- (IBAction) start_button_pressed{
if(toggle)
{
toggle = NO;
[actSpinner startAnimating];
[btnStart setTitle:#"Stop Recording" forState: UIControlStateNormal ];
btnPlay.enabled = toggle;
btnPlay.hidden = !toggle;
//Begin the recording session.
//Error handling removed. Please add to your own code.
//Setup the dictionary object with all the recording settings that this
//Recording sessoin will use
//Its not clear to me which of these are required and which are the bare minimum.
//This is a good resource: http://www.totodotnet.net/tag/avaudiorecorder/
NSMutableDictionary* recordSetting = [[NSMutableDictionary alloc] init];
[recordSetting setValue :[NSNumber numberWithInt:kAudioFormatAppleIMA4] forKey:AVFormatIDKey];
[recordSetting setValue:[NSNumber numberWithFloat:44100.0] forKey:AVSampleRateKey];
[recordSetting setValue:[NSNumber numberWithInt: 2] forKey:AVNumberOfChannelsKey];
//Now that we have our settings we are going to instanciate an instance of our recorder instance.
//Generate a temp file for use by the recording.
//This sample was one I found online and seems to be a good choice for making a tmp file that
//will not overwrite an existing one.
//I know this is a mess of collapsed things into 1 call. I can break it out if need be.
recordedTmpFile = [NSURL fileURLWithPath:[NSTemporaryDirectory() stringByAppendingPathComponent: [NSString stringWithFormat: #"%.0f.%#", [NSDate timeIntervalSinceReferenceDate] * 1000.0, #"caf"]]];
NSLog(#"Using File called: %#",recordedTmpFile);
//Setup the recorder to use this file and record to it.
recorder = [[ AVAudioRecorder alloc] initWithURL:recordedTmpFile settings:recordSetting error:&error];
//Use the recorder to start the recording.
//Im not sure why we set the delegate to self yet.
//Found this in antother example, but Im fuzzy on this still.
[recorder setDelegate:self];
//We call this to start the recording process and initialize
//the subsstems so that when we actually say "record" it starts right away.
[recorder prepareToRecord];
//Start the actual Recording
[recorder record];
//There is an optional method for doing the recording for a limited time see
//[recorder recordForDuration:(NSTimeInterval) 10]
}
else
{
toggle = YES;
[actSpinner stopAnimating];
[btnStart setTitle:#"Start Recording" forState:UIControlStateNormal ];
btnPlay.enabled = toggle;
btnPlay.hidden = !toggle;
NSLog(#"Using File called: %#",recordedTmpFile);
//Stop the recorder.
[recorder stop];
}
}
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
-(IBAction) play_button_pressed{
//The play button was pressed...
//Setup the AVAudioPlayer to play the file that we just recorded.
AVAudioPlayer * avPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:recordedTmpFile error:&error];
[avPlayer prepareToPlay];
[avPlayer play];
}
- (void)viewDidUnload {
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
//Clean up the temp file.
NSFileManager * fm = [NSFileManager defaultManager];
[fm removeItemAtPath:[recordedTmpFile path] error:&error];
//Call the dealloc on the remaining objects.
[recorder dealloc];
recorder = nil;
recordedTmpFile = nil;
}
- (void)dealloc {
[super dealloc];
}
#end
RecordAudioViewController.xib
take 2 Buttons. 1 for begin recording and another for Play recording