In the Xcode project, first decode PNG images and then re encode them into heic images, which can be successfully displayed on iPhone 8 plus and iOS 12.1.2;
Is it a problem with the Mac conversion tool or other issues? Is there a better conversion compatibility solution for PNG to heic? thank you.
The conversion code is as follows:
- (void)test3{
NSString *url = [[NSBundle mainBundle] pathForResource:@"1-m" ofType:@"png"];
CGImageRef ref = createCGImageFromFile(url);
NSString *path_document = NSHomeDirectory();
NSString *imagePath = [path_document stringByAppendingString:@"/Documents/pic.heic"];
[self generateNewHEIC:[UIImage imageWithCGImage:ref] savePath:imagePath];
dispatch_async(dispatch_get_main_queue(), ^{
UIImage *i = [[UIImage alloc] initWithContentsOfFile:imagePath];
NSLog(@"%@", i);
UIImageView *v = [[UIImageView alloc] initWithImage:i];
[self.view addSubview:v];
v.frame = CGRectMake(50, 150, 300, 200);
});
CFRelease(ref);
}
/// create CGImageRef
/// - Parameter path: main bundle
CGImageRef createCGImageFromFile (NSString* path)
{
// Get the URL for the pathname passed to the function.
NSURL *url = [NSURL fileURLWithPath:path];
CGImageRef myImage = NULL;
CGImageSourceRef myImageSource;
CFDictionaryRef myOptions = NULL;
CFStringRef myKeys[2];
CFTypeRef myValues[2];
// Set up options if you want them. The options here are for
// caching the image in a decoded form and for using floating-point
// values if the image format supports them.
myKeys[0] = kCGImageSourceShouldCache;
myValues[0] = (CFTypeRef)kCFBooleanTrue;
myKeys[1] = kCGImageSourceShouldAllowFloat;
myValues[1] = (CFTypeRef)kCFBooleanTrue;
// Create the dictionary
myOptions = CFDictionaryCreate(NULL, (const void **) myKeys,
(const void **) myValues, 2,
&kCFTypeDictionaryKeyCallBacks,
& kCFTypeDictionaryValueCallBacks);
// Create an image source from the URL.
myImageSource = CGImageSourceCreateWithURL((CFURLRef)url, myOptions);
CFRelease(myOptions);
// Make sure the image source exists before continuing
if (myImageSource == NULL){
fprintf(stderr, "Image source is NULL.");
return NULL;
}
// Create an image from the first item in the image source.
myImage = CGImageSourceCreateImageAtIndex(myImageSource, 0, NULL);
CFRelease(myImageSource);
// Make sure the image exists before continuing
if (myImage == NULL){
fprintf(stderr, "Image not created from image source.");
return NULL;
}
return myImage;
}
///
/// - Parameters:
/// - image: <#image description#>
/// - path: <#path description#>
- (void)generateNewHEIC:(UIImage *)image savePath:(NSString *)path{
NSMutableData *imageData = [NSMutableData data];
// HEIC
CFStringRef imageUTType = CFSTR("public.heic");
CGImageDestinationRef destination = CGImageDestinationCreateWithData((__bridge CFMutableDataRef)imageData, imageUTType, 1, NULL);
if (!destination) {
return;
}
CGImageRef imageRef = image.CGImage;
CGImagePropertyOrientation exifOrientation = kCGImagePropertyOrientationDown;
NSMutableDictionary *frameProperties = [NSMutableDictionary dictionary];
// imageProperties[(__bridge_transfer NSString *) kCGImagePropertyExifDictionary] = @(exifOrientation);
CGImageDestinationAddImage(destination, imageRef, (__bridge CFDictionaryRef)frameProperties);
if (CGImageDestinationFinalize(destination) == NO) {
imageData = nil;
}
CFRelease(destination);
if(imageData) {
NSURL *url = [NSURL fileURLWithPath:path];
[imageData writeToURL:url atomically:YES];
}
}
