Notes of a Developer » iPhone

Create movie from array of images

Vladimir Boychentsov — Mon, 30 Jan 2012 21:22:59 +0000

Create movie from images seq.

First part of method, initialize

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- (void) writeImagesAsMovie:(NSArray *)array toPath:(NSString*)path {

NSString *documents = [NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex: 0];
documents = [documents stringByAppendingPathComponent:currentWorkspace];

//NSLog(path);
NSString *filename = [documents stringByAppendingPathComponent:[array objectAtIndex:0]];
UIImage *first = [UIImage imageWithContentsOfFile:filename];

CGSize frameSize = first.size;

NSError *error = nil;
AVAssetWriter *videoWriter = [[AVAssetWriter alloc] initWithURL:
[NSURL fileURLWithPath:path] fileType:AVFileTypeQuickTimeMovie
error:&error];

if(error) {
NSLog(@"error creating AssetWriter: %@",[error description]);
}
NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
AVVideoCodecH264, AVVideoCodecKey,
[NSNumber numberWithInt:frameSize.width], AVVideoWidthKey,
[NSNumber numberWithInt:frameSize.height], AVVideoHeightKey,
nil];

AVAssetWriterInput* writerInput = [[AVAssetWriterInput
assetWriterInputWithMediaType:AVMediaTypeVideo
outputSettings:videoSettings] retain];

NSMutableDictionary *attributes = [[NSMutableDictionary alloc] init];
[attributes setObject:[NSNumber numberWithUnsignedInt:kCVPixelFormatType_32ARGB] forKey:(NSString*)kCVPixelBufferPixelFormatTypeKey];
[attributes setObject:[NSNumber numberWithUnsignedInt:frameSize.width] forKey:(NSString*)kCVPixelBufferWidthKey];
[attributes setObject:[NSNumber numberWithUnsignedInt:frameSize.height] forKey:(NSString*)kCVPixelBufferHeightKey];

AVAssetWriterInputPixelBufferAdaptor *adaptor = [AVAssetWriterInputPixelBufferAdaptor
assetWriterInputPixelBufferAdaptorWithAssetWriterInput:writerInput
sourcePixelBufferAttributes:attributes];

[videoWriter addInput:writerInput];

// fixes all errors
writerInput.expectsMediaDataInRealTime = YES;

//Start a session:
BOOL start = [videoWriter startWriting];
NSLog(@"Session started? %d", start);
[videoWriter startSessionAtSourceTime:kCMTimeZero];

Second part, writing

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CVPixelBufferRef buffer = NULL;
buffer = [self pixelBufferFromCGImage:[first CGImage]];
BOOL result = [adaptor appendPixelBuffer:buffer withPresentationTime:kCMTimeZero];

if (result == NO) //failes on 3GS, but works on iphone 4
NSLog(@"failed to append buffer");

if(buffer)
CVBufferRelease(buffer);

[NSThread sleepForTimeInterval:0.05];

int reverseSort = NO;
NSArray *newArray = [array sortedArrayUsingFunction:sort context:&reverseSort];

delta = 1.0/[newArray count];

int fps = (int)fpsSlider.value;

int i = 0;
for (NSString *filename in newArray)
{
if (adaptor.assetWriterInput.readyForMoreMediaData)
{

i++;
NSLog(@"inside for loop %d %@ ",i, filename);
CMTime frameTime = CMTimeMake(1, fps);
CMTime lastTime=CMTimeMake(i, fps);
CMTime presentTime=CMTimeAdd(lastTime, frameTime);

NSString *filePath = [documents stringByAppendingPathComponent:filename];

UIImage *imgFrame = [UIImage imageWithContentsOfFile:filePath] ;
buffer = [self pixelBufferFromCGImage:[imgFrame CGImage]];
BOOL result = [adaptor appendPixelBuffer:buffer withPresentationTime:presentTime];

if (result == NO) //failes on 3GS, but works on iphone 4
{
NSLog(@"failed to append buffer");
NSLog(@"The error is %@", [videoWriter error]);
}
if(buffer)
CVBufferRelease(buffer);
[NSThread sleepForTimeInterval:0.05];
}
else
{
NSLog(@"error");
i--;
}
[NSThread sleepForTimeInterval:0.02];
}

//Finish the session:
[writerInput markAsFinished];
[videoWriter finishWriting];
CVPixelBufferPoolRelease(adaptor.pixelBufferPool);
[videoWriter release];
[writerInput release];
}

Convert UIImage to CVPixelBufferRef

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- (CVPixelBufferRef) pixelBufferFromCGImage: (CGImageRef) image
{
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithBool:YES], kCVPixelBufferCGImageCompatibilityKey,
[NSNumber numberWithBool:YES], kCVPixelBufferCGBitmapContextCompatibilityKey,
nil];
CVPixelBufferRef pxbuffer = NULL;

CVPixelBufferCreate(kCFAllocatorDefault, CGImageGetWidth(image),
CGImageGetHeight(image), kCVPixelFormatType_32ARGB, (CFDictionaryRef) options,
&pxbuffer);

CVPixelBufferLockBaseAddress(pxbuffer, 0);
void *pxdata = CVPixelBufferGetBaseAddress(pxbuffer);

CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef context = CGBitmapContextCreate(pxdata, CGImageGetWidth(image),
CGImageGetHeight(image), 8, 4*CGImageGetWidth(image), rgbColorSpace,
kCGImageAlphaNoneSkipFirst);

CGContextConcatCTM(context, CGAffineTransformMakeRotation(0));

CGAffineTransform flipVertical = CGAffineTransformMake(
1, 0, 0, -1, 0, CGImageGetHeight(image)
);
CGContextConcatCTM(context, flipVertical);

CGAffineTransform flipHorizontal = CGAffineTransformMake(
-1.0, 0.0, 0.0, 1.0, CGImageGetWidth(image), 0.0
);

CGContextConcatCTM(context, flipHorizontal);

CGContextDrawImage(context, CGRectMake(0, 0, CGImageGetWidth(image),
CGImageGetHeight(image)), image);
CGColorSpaceRelease(rgbColorSpace);
CGContextRelease(context);

CVPixelBufferUnlockBaseAddress(pxbuffer, 0);

return pxbuffer;
}

Masked Shape layer with gradient

Vladimir Boychentsov — Sat, 28 Jan 2012 14:07:19 +0000

Layer with CGPathRef and animated. And added masked gradient for layer.

ViewLayers.h

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//
// ViewLayers.h
// layers
//
// Created by Volodymyr Boichentsov on 1/28/12.
// Copyright (c) 2012 www.injoit.com. All rights reserved.
//

#import
#import

@interface ViewLayers : UIView {

CGRect firstRect;
CGRect secondRect;

int cornerRadius;
CGMutablePathRef mainPath;
CGMutablePathRef secondPath;

CAShapeLayer *maskLayer;

CAShapeLayer *shapeLayer;
CAGradientLayer *gradientLayer;
}

- (CGMutablePathRef) createPathWithFrame:(CGRect)bubbleRect;
- (void) setupLayers;
- (void) animation;

@end

ViewLayers.m

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//
// ViewLayers.m
// layers
//
// Created by Volodymyr Boichentsov on 1/28/12.
// Copyright (c) 2012 www.injoit.com. All rights reserved.
//

#import "ViewLayers.h"
#import

- (id) initWithCoder:(NSCoder *)aDecoder {
self = [super initWithCoder:aDecoder];
if (self) {

firstRect = CGRectMake(30, 60, 100, 100);
secondRect = CGRectMake(20, 20, 280, 420);

cornerRadius = 10;
mainPath = [self createPathWithFrame:firstRect];
secondPath = [self createPathWithFrame:secondRect];
[self setupLayers];
// Initialization code
}
return self;
}

- (CGMutablePathRef) createPathWithFrame:(CGRect)bubbleRect {
CGMutablePathRef bubblePath = CGPathCreateMutable();

CGPathMoveToPoint(bubblePath, NULL, bubbleRect.origin.x+cornerRadius
, bubbleRect.origin.y);

CGPathAddArcToPoint(bubblePath, NULL,
bubbleRect.origin.x+bubbleRect.size.width, bubbleRect.origin.y,
bubbleRect.origin.x+bubbleRect.size.width, bubbleRect.origin.y+cornerRadius,
cornerRadius);

CGPathAddArcToPoint(bubblePath, NULL,
bubbleRect.origin.x+bubbleRect.size.width, bubbleRect.origin.y+bubbleRect.size.height,
bubbleRect.origin.x+bubbleRect.size.width-cornerRadius, bubbleRect.origin.y+bubbleRect.size.height,
cornerRadius);

CGPathAddArcToPoint(bubblePath, NULL,
bubbleRect.origin.x, bubbleRect.origin.y+bubbleRect.size.height,
bubbleRect.origin.x, bubbleRect.origin.y+bubbleRect.size.height-cornerRadius,
cornerRadius);

CGPathAddArcToPoint(bubblePath, NULL,
bubbleRect.origin.x, bubbleRect.origin.y,
bubbleRect.origin.x+cornerRadius, bubbleRect.origin.y,
cornerRadius);

CGPathCloseSubpath(bubblePath);

return bubblePath;
}

- (void) setupLayers {
shapeLayer = [CAShapeLayer layer];
shapeLayer.fillColor = [UIColor clearColor].CGColor;
shapeLayer.fillRule = kCAFillRuleEvenOdd;

shapeLayer.lineWidth = 1;
shapeLayer.lineCap = kCALineCapRound;
shapeLayer.strokeColor = [UIColor blackColor].CGColor;
shapeLayer.path = mainPath;
[self.layer addSublayer:shapeLayer];

maskLayer = [CAShapeLayer layer];
maskLayer.fillColor = [UIColor grayColor].CGColor;
maskLayer.fillRule = kCAFillRuleEvenOdd;
maskLayer.path = mainPath;
[shapeLayer addSublayer:maskLayer];

gradientLayer = [CAGradientLayer layer];
gradientLayer.frame = self.bounds;

gradientLayer.colors = [NSArray arrayWithObjects:
(id)[UIColor lightGrayColor].CGColor,
(id)[UIColor darkGrayColor].CGColor,
nil];
gradientLayer.needsDisplayOnBoundsChange = YES;
[shapeLayer addSublayer:gradientLayer];
[gradientLayer setMask:maskLayer];
[gradientLayer setNeedsDisplay];

[self performSelector:@selector(animation) withObject:nil afterDelay:1];
}

- (void) animation {
CABasicAnimation *_animation = [CABasicAnimation animationWithKeyPath:@"path"];
_animation.duration = 0.4;
_animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
_animation.delegate = self;
_animation.fromValue = (__bridge id)mainPath;
_animation.toValue = (__bridge id)secondPath;
[shapeLayer addAnimation:_animation forKey:@"animatePath"];
[maskLayer addAnimation:_animation forKey:@"animatePath"];
}

- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag {
shapeLayer.path = secondPath;
maskLayer.path = secondPath;
}

@end

Result:

Good post about CAShapeLayer

Vladimir Boychentsov — Fri, 27 Jan 2012 10:16:46 +0000

Animating the drawing of a CGPath with CAShapeLayer

Thanks for Ole Begemann.

UIBezierPath

Vladimir Boychentsov — Fri, 27 Jan 2012 09:58:58 +0000

UIBezierPath is a convenient object for creating rounded-rectangular shapes.
Starting from 3.2, this class becomes public, but the interface is dramatically changed to match that of NSBezierPath.

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-(void)drawRect:(CGRect)rect {
UIBezierPath* roundedRect = [UIBezierPath roundedRectBezierPath:CGRectInset(rect, 5, 5)
withRoundedCorners:UIBezierPathRoundedTopLeftCorner|
UIBezierPathRoundedTopRightCorner|
UIBezierPathRoundedBottomLeftCorner|
UIBezierPathRoundedBottomRightCorner
withCornerRadius:5];
[[UIColor blackColor] setFill];
[roundedRect fill];
}

UIBezierPath.h

from iphonedevwiki.net

Convert one day to one minute

Vladimir Boychentsov — Tue, 24 Jan 2012 16:06:39 +0000

I create simple project for iOS, “One minute”. This project create video from photos on iOS device.

Results of app:

UIColor from hex

Vladimir Boychentsov — Tue, 10 Jan 2012 12:40:23 +0000

I added 2 new methods to category UIColor.

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+ (UIColor* ) colorWithHex:(int)color {

float red = (color & 0xff000000) >> 24;
float green = (color & 0x00ff0000) >> 16;
float blue = (color & 0x0000ff00) >> 8;
float alpha = (color & 0x000000ff);

return [UIColor colorWithRed:red/255.0 green:green/255.0 blue:blue/255.0 alpha:alpha/255.0];
}

+ (UIColor *) colorWithHexRed:(int)red green:(char)green blue:(char)blue alpha:(char)alpha {
int x = 0;
x |= (red & 0xff) << 24;
x |= (green & 0xff) << 16;
x |= (blue & 0xff) << 8;
x |= (alpha & 0xff);
return [UIColor colorWithHex:x];
}

Example:

1	UIColor *redColor = [UIColor colorWithHex:0xff0000ff];

First 6 symbols like HTML color, latest 2 symbols it’s alpha.

GLKit and MSAA

Vladimir Boychentsov — Wed, 04 Jan 2012 13:03:58 +0000

Enable MSAA Anti-Aliasing in GLKit.

Just enable:

1 2	GLKView view = (GLKView )self.view; view.drawableMultisample = GLKViewDrawableMultisample4X;

Without MSAA:

With MSAA:

GLKit_MSAA_Sample

ScrollView with scroll’s indicators, which are shown all the time.

Vladimir Boychentsov — Thu, 22 Dec 2011 09:53:13 +0000

My simple solution by writing category for UIImageView, because scroller is imageview.

How to use :)
Just setup tag for your scrollview and you will get one with scroll indicators, which are shown all the time.

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#define noDisableVerticalScrollTag 836913
#define noDisableHorizontalScrollTag 836914

@implementation UIImageView (ForScrollView)

- (void) setAlpha:(float)alpha {

if (self.superview.tag == noDisableVerticalScrollTag) {
if (alpha == 0 && self.autoresizingMask == UIViewAutoresizingFlexibleLeftMargin) {
if (self.frame.size.width < 10 && self.frame.size.height > self.frame.size.width) {
UIScrollView *sc = (UIScrollView*)self.superview;
if (sc.frame.size.height < sc.contentSize.height) {
return;
}
}
}
}

if (self.superview.tag == noDisableHorizontalScrollTag) {
if (alpha == 0 && self.autoresizingMask == UIViewAutoresizingFlexibleTopMargin) {
if (self.frame.size.height < 10 && self.frame.size.height < self.frame.size.width) {
UIScrollView *sc = (UIScrollView*)self.superview;
if (sc.frame.size.width < sc.contentSize.width) {
return;
}
}
}
}

[super setAlpha:alpha];
}
@end

If you want both scroll it’s easy to change code.

AVPlayer – looping video without “hiccup”/delays

Vladimir Boychentsov — Sat, 17 Dec 2011 10:35:35 +0000

I tried create loop by AVQueuePlayer, this method has delays between end and start play.

for looping AVQueuePlayer i use this code:

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[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(playerItemDidReachEnd:)
name:AVPlayerItemDidPlayToEndTimeNotification
object:self.mPlayerItem];

[self player].actionAtItemEnd = AVPlayerActionAtItemEndNone;

and playerItemDidReachEnd

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- (void)playerItemDidReachEnd:(NSNotification *)notification
{
AVPlayerItem *p = [notification object];
[p seekToTime:kCMTimeZero];
}

Another solution without hiccups/delays based on AVMutableComposition!

Easily solution, I use one AVURLAsset for inserting to composition. No memory leaks and warnings, because used just one object.

Solution:

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- (AVAsset*) makeAssetComposition {

int numOfCopies = 25;

AVMutableComposition *composition = [[[AVMutableComposition alloc] init] autorelease];
AVURLAsset* sourceAsset = [AVURLAsset URLAssetWithURL:mURL options:nil];

// calculate time
CMTimeRange editRange = CMTimeRangeMake(CMTimeMake(0, 600), CMTimeMake(sourceAsset.duration.value, sourceAsset.duration.timescale));

NSError *editError;

// and add into your composition
BOOL result = [composition insertTimeRange:editRange ofAsset:sourceAsset atTime:composition.duration error:&editError];

if (result) {
for (int i = 0; i < numOfCopies; i++) {
[composition insertTimeRange:editRange ofAsset:sourceAsset atTime:composition.duration error:&editError];
}
}

return composition;
}

Play composition:

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AVAsset *composition = [self makeAssetComposition];

// create an AVPlayer with your composition
AVPlayer* mp = [AVPlayer playerWithPlayerItem:[AVPlayerItem playerItemWithAsset:composition]];

// Add the player to your UserInterface
// Create a PlayerLayer:
AVPlayerLayer *playerLayer = [AVPlayerLayer playerLayerWithPlayer:mp];

// integrate it to your view. Here you can customize your player (Fullscreen, or a small preview)
[[self window].layer insertSublayer:playerLayer atIndex:0];
playerLayer.frame = [self window].layer.bounds;
playerLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
//And finally play your video:

[mp play];

Any questions to comments please.

AudioSession AudioRouteChange

Vladimir Boychentsov — Sat, 17 Dec 2011 09:56:46 +0000

if you will use or used AVPlayer or you want just know about changes, you can check AudioRouteChange.

Simple solution:

Add framework AudioToolbox and add import to file

#import

Insert into init method or any other

1	AudioSessionAddPropertyListener (kAudioSessionProperty_AudioRouteChange, callbackHeadphone_func, self);

Listener callback

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void callbackHeadphone_func ( void *inClientData, AudioSessionPropertyID inID, UInt32 inDataSize, const void *inData ) {
if ( inID == kAudioSessionProperty_AudioRouteChange ) {
[mainViewController performSelector:@selector(isHeadsetPluggedIn)];
}
}

- (void) isHeadsetPluggedIn {

UInt32 routeSize = sizeof (CFStringRef); CFStringRef route;

AudioSessionGetProperty (kAudioSessionProperty_AudioRoute, &routeSize, &route);
/* Known values of route:
"Headset"
"Headphone"
"Speaker"
"SpeakerAndMicrophone"
"HeadphonesAndMicrophone"
"HeadsetInOut"
"ReceiverAndMicrophone"
"Lineout" */

NSString* routeStr = (NSString*)route;
DLog(@"%@",routeStr);
}