iOS HEIF/HEVC 格式

iOS 11更新后，iPhone 7及以上设备，在拍摄照片时的默认图像存储格式是 .heic 。.heic 格式相比普通的jpg、png格式来说，占用手机的内存更小，而且拍摄下来的照片无损度也非常高，这也就是为什么iOS 11会采用这种文件的原因。如下图：

修改相机格式操作截图：

详见：
1、关于 iOS 11 更新
https://support.apple.com/zh-cn/HT208067#11
2、在 Apple 设备上使用 HEIF 或 HEVC 媒体
https://support.apple.com/zh-cn/HT207022

遇到的问题

APP在图片选择的时候，无法显示图片，需要 heic 格式图片转 jpg 才能显示
插件：cordova-plugin-mediapicker-dmcsdk

1、识别HEIF

__block BOOL isHEIF = NO;
if (iOSVersionGreaterThanOrEqualTo(@"9.0")) {
    NSArray *resourceList = [PHAssetResource assetResourcesForAsset:phAsset];
    [resourceList enumerateObjectsUsingBlock:^(id  _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
        PHAssetResource *resource = obj;
        NSString *UTI = resource.uniformTypeIdentifier;
        if ([UTI isEqualToString:@"public.heif"] || [UTI isEqualToString:@"public.heic"]) {
            isHEIF = YES;
            *stop = YES;
        }
    }];
} else {
    NSString *UTI = [phAsset valueForKey:@"uniformTypeIdentifier"];
    isHEIF = [UTI isEqualToString:@"public.heif"] || [UTI isEqualToString:@"public.heic"];
}

2、转换

[[PHImageManager defaultManager] requestImageDataForAsset:phAsset options:nil resultHandler:^(NSData * _Nullable imageData, NSString * _Nullable dataUTI, UIImageOrientation orientation, NSDictionary * _Nullable info) {
    if (isHEIF) {
        CIImage *ciImage = [CIImage imageWithData:imageData];
        CIContext *context = [CIContext context];
        NSData *jpgData = [context JPEGRepresentationOfImage:ciImage colorSpace:ciImage.colorSpace options:@{}];
    } else {
    }
}];

3、修改插件源码

#define iOSVersionGreaterThanOrEqualTo(v)([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch]!=NSOrderedAscending)

...

[[PHImageManager defaultManager] requestImageDataForAsset:asset  options:options resultHandler:^(NSData * _Nullable imageData, NSString * _Nullable dataUTI, UIImageOrientation orientation, NSDictionary * _Nullable info) {
    NSString *filename=[asset valueForKey:@"filename"];
    NSString *fullpath=[NSString stringWithFormat:@"%@/%@%@", dmcPickerPath,[[NSProcessInfo processInfo] globallyUniqueString], filename];
        
    //增加 判断如果heic图片 转换一次
    __block BOOL isHEIF = NO;
    if (iOSVersionGreaterThanOrEqualTo(@"9.0")) {
        NSArray *resourceList = [PHAssetResource assetResourcesForAsset:asset];
        [resourceList enumerateObjectsUsingBlock:^(id  _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
            PHAssetResource *resource = obj;
            NSString *UTI = resource.uniformTypeIdentifier;
            if ([UTI isEqualToString:@"public.heif"] || [UTI isEqualToString:@"public.heic"]) {
                isHEIF = YES;
                *stop = YES;
            }
        }];
    } else {
        NSString *UTI = [asset valueForKey:@"uniformTypeIdentifier"];
        isHEIF = [UTI isEqualToString:@"public.heif"] || [UTI isEqualToString:@"public.heic"];
    }
        
        
    if (isHEIF) {
        CIImage *ciImage = [CIImage imageWithData:imageData];
        CIContext *context = [CIContext context];
        imageData = [context JPEGRepresentationOfImage:ciImage colorSpace:ciImage.colorSpace options:@{}];
    }
    //增加 判断如果heic图片 转换一次  end

    //对图片进行压缩
    UIImage *photo = [UIImage imageWithData: imageData];
    NSData *data;
    if ((limit_width > 0 || limit_height > 0) && limit_quality > 0) {
        float q = (float)limit_quality/100;
            
        CGFloat imgWidth = photo.size.width;
        CGFloat imgHeight = photo.size.height;
            
        //limit_width设置为0 不限宽 最大宽度为图片原宽
        int max_width=limit_width==0?imgWidth:limit_width;
        //limit_height设置为0 不限高 最大高度为图片原高
        int max_height=limit_height==0?imgHeight:limit_height;
            
        data = [UIImage compressScale:photo maxWidth:max_width maxHeight:max_height quality:q];
    } else {
        data = [UIImage lubanCompressImage:photo];
    }
    
    NSString *dmcPickerPath = [NSTemporaryDirectory() stringByAppendingPathComponent:@"dmcPicker"];
    NSFileManager *fileManager = [NSFileManager defaultManager];
    if(![fileManager fileExistsAtPath:dmcPickerPath ]){
        [fileManager createDirectoryAtPath:dmcPickerPath withIntermediateDirectories:YES attributes:nil error:nil];
    }
    filename = [NSString stringWithFormat:@"%@%@%@",@"dmcMediaPickerCompress", [self currentTimeStr],@".jpg"];
    fullpath = [NSString stringWithFormat:@"%@/%@", dmcPickerPath,filename];
    NSNumber* size = [NSNumber numberWithLong: data.length];
        
    NSError *error = nil;
    if (![data writeToFile:fullpath options:NSAtomicWrite error:&error]) {
        NSLog(@"%@", [error localizedDescription]);
        [self.commandDelegate sendPluginResult:[CDVPluginResult resultWithStatus:CDVCommandStatus_ERROR messageAsString:[error localizedDescription]] callbackId:callbackId];
    } else {
        NSDictionary *dict=[NSDictionary dictionaryWithObjectsAndKeys:fullpath,@"path",[[NSURL fileURLWithPath:fullpath] absoluteString],@"uri",@"image",@"mediaType",size,@"size",[NSNumber numberWithInt:index],@"index", nil];
        [aListArray addObject:dict];
        if([aListArray count]==[selectArray count]){
            [self.commandDelegate sendPluginResult:[CDVPluginResult resultWithStatus:CDVCommandStatus_OK messageAsArray:aListArray] callbackId:callbackId];
        }
    }
}];

参考：https://www.jianshu.com/p/a63c7d5d98a9