IOS 11 全网首发使用AVCapturePhotoOutpu

首先给出几篇文章让大家了解一下什么是 HIEF(HEIC)

官方的链接--一个pdf文件
HEIF & HEVC 你知道多少
iOS 影音新格式 HEIF HEVC
GitHubHEIC扩展方法

关于AVCapturePhotoOutput,大家可以参考一下下面的链接,就知道怎么使用了,从ios11开始我们就可以使用HIEF(HEIC)格式来存储图片和视频了.这种格式体积小速度快(硬解码),所以作为一个android程序员的我看到这种好玩的东西也忍不住来凑热闹, 但是找了很多资料,都没有如何直接捕获(不是通过JPEG转换)HEIF(HEIC)格式图片.
ios 11新增了一个方法

- (void)captureOutput:(AVCapturePhotoOutput *)output didFinishProcessingPhoto:(AVCapturePhoto *)photo error:(nullable NSError *)error NS_AVAILABLE_IOS(11_0);
新增了一种采集格式AVVideoCodecHEVC

大家先看看之前的JPEG是如何采集的

接下来就是上关键源码

开始拍照

关键代码@{AVVideoCodecKey: AVVideoCodecHEVC} 原来的是{AVVideoCodecKey: AVVideoCodecJPEG}
注意_outputSettings必须每次都用新的

if (@available(iOS 10.0, *)) {
        AVCapturePhotoOutput *_newCaptureImageOutput = (AVCapturePhotoOutput *) _captureImageOutput;

        // 图片输出格式,如果支持使用HEIF(HEIC)那么使用,否则使用JPEG
        NSDictionary *format = @{AVVideoCodecKey: AVVideoCodecJPEG};
        NSArray<AVVideoCodecType> *availablePhotoCodecTypes = _newCaptureImageOutput.availablePhotoCodecTypes;
        if ([availablePhotoCodecTypes containsObject:AVVideoCodecHEVC]) {
            format = @{AVVideoCodecKey: AVVideoCodecHEVC};
        }
        _outputSettings = [AVCapturePhotoSettings photoSettingsWithFormat:format];
        _outputSettings.autoStillImageStabilizationEnabled = YES;//默认值就是yes
        _outputSettings.flashMode = AVCaptureFlashModeOff;//关闭闪光灯

        // 预览图设置
        id photoPixelFormatType = _outputSettings.availablePreviewPhotoPixelFormatTypes.firstObject;
        NSDictionary *preview =
                @{
                        (NSString *) kCVPixelBufferPixelFormatTypeKey: photoPixelFormatType,
                        (NSString *) kCVPixelBufferWidthKey: @1440,
                        (NSString *) kCVPixelBufferHeightKey: @1440
                };
        _outputSettings.previewPhotoFormat = preview;

        // 缩略图设置
        id thumbnailPhotoCodecType = _outputSettings.availableEmbeddedThumbnailPhotoCodecTypes.firstObject;
        NSDictionary *thumbnail =
                @{
                        (NSString *) kCVPixelBufferPixelFormatTypeKey: thumbnailPhotoCodecType,
                        (NSString *) kCVPixelBufferWidthKey: @(NBUAsset.thumbnailSize.width),
                        (NSString *) kCVPixelBufferHeightKey: @(NBUAsset.thumbnailSize.height)
                };
        //_outputSettings.embeddedThumbnailPhotoFormat = thumbnail;


        [_newCaptureImageOutput setPhotoSettingsForSceneMonitoring:_outputSettings];
        [_newCaptureImageOutput capturePhotoWithSettings:_outputSettings delegate:self];
        return;
    }

监听 继承AVCapturePhotoCaptureDelegate

- (void)   captureOutput:(AVCapturePhotoOutput *)output
didFinishProcessingPhoto:(AVCapturePhoto *)photo
                   error:(nullable NSError *)error NS_AVAILABLE_IOS(11_0) {
        // 这个就是HEIF(HEIC)的文件数据,直接保存即可
        NSData *data = photo.fileDataRepresentation;
        UIImage *image = [UIImage imageWithData:data];
        // 保存图片到相册 UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);
}