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我正在尝试在ios设备上将jpg图像与mov带有objective-c的文件一起加载以显示实时照片,并且我制作了以下代码片段以在viewDidLoad函数中执行此操作:

- (void)viewDidLoad {
    [super viewDidLoad];

    PHLivePhotoView *photoView = [[PHLivePhotoView alloc]initWithFrame:self.view.bounds];

    NSURL *imageUrl = [[NSBundle mainBundle] URLForResource:@"livePhoto" withExtension:@"jpg"];
    NSURL *videoUrl = [[NSBundle mainBundle] URLForResource:@"livePhoto" withExtension:@"mov"];

    [PHLivePhoto requestLivePhotoWithResourceFileURLs:@[videoUrl, imageUrl] placeholderImage:[UIImage imageNamed:@"livePhoto.jpg"] targetSize:self.view.bounds.size contentMode:PHImageContentModeAspectFit resultHandler:^(PHLivePhoto *livePhoto, NSDictionary *info){
        NSLog(@"we are in handler");
        photoView.livePhoto = livePhoto;
        photoView.contentMode = UIViewContentModeScaleAspectFit;
        photoView.tag = 87;
        [self.view addSubview:photoView];
        [self.view sendSubviewToBack:photoView];
    }];


}

我已将文件拖到Xcode 项目livePhoto.jpglivePhoto.mov

但是在构建这个 Xcode 时会记录这个错误:

2017-11-28 17:46:08.568455+0800 Live Photos[3669:1276778] we are in handler
2017-11-28 17:46:08.580439+0800 Live Photos[3669:1276778] we are in handler
2017-11-28 17:46:08.597147+0800 Live Photos[3669:1276806] Error: Invalid image metadata
2017-11-28 17:46:08.607881+0800 Live Photos[3669:1276806] Error: Invalid video metadata
2017-11-28 17:46:08.608329+0800 Live Photos[3669:1276778] we are in handler

有什么想法吗?谢谢。

还有一件事要问:

为什么resultHandler根据打印的内容被调用两次?

4

1 回答 1

2

TL;博士

以下是存储 Live Photo 并将其上传到服务器的代码:
1. 捕获 Live Photo

- (void)captureOutput:(AVCapturePhotoOutput *)output didFinishProcessingPhotoSampleBuffer:(CMSampleBufferRef)photoSampleBuffer previewPhotoSampleBuffer:(CMSampleBufferRef)previewPhotoSampleBuffer resolvedSettings:(AVCaptureResolvedPhotoSettings *)resolvedSettings bracketSettings:(AVCaptureBracketedStillImageSettings *)bracketSettings error:(NSError *)error {
    if (error) {
        [self raiseError:error];
        return;
    }
    NSData *imageData = [AVCapturePhotoOutput JPEGPhotoDataRepresentationForJPEGSampleBuffer:photoSampleBuffer previewPhotoSampleBuffer:previewPhotoSampleBuffer];
    CIImage *image = [CIImage imageWithData:imageData];
    [self.expectedAsset addInput:image.properties]; // 1. This is the metadata (which will be lost in step 2.)
    [self.expectedAsset addInput:[UIImage imageWithCIImage:image]]; // 2. Creating image, but UIImage is not designed to contain the required metadata
}
- (void)captureOutput:(AVCapturePhotoOutput *)output 
didFinishProcessingLivePhotoToMovieFileAtURL:(NSURL *)outputFileURL duration:(CMTime)duration photoDisplayTime:(CMTime)photoDisplayTime resolvedSettings:(AVCaptureResolvedPhotoSettings *)resolvedSettings error:(nullable NSError *)error {
    if (error) {
        [self raiseError:error];
    } else {
        [self.expectedAsset addInput:outputFileURL]; // 3. Store the URL to the actual video file
    }
}

expectedAsset只是一个包含所有必需信息的对象。您可以改用 NSDictionary。并且由于此代码片段是 >= iOS 11 API,因此这是“已弃用”iOS 的代码片段...

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wunguarded-availability"
- (void)captureOutput:(AVCapturePhotoOutput *)output didFinishProcessingPhoto:(AVCapturePhoto *)photo error:(NSError *)error {
    if (error) {
        [self raiseError:error];
    } else {
        [self.expectedAsset addInput:[photo metadata]];
        [self.expectedAsset addInput:[UIImage imageWithData:[photo fileDataRepresentation]]];
    }
}
#pragma clang diagnostic pop 


2.生成NSData

- (NSData*)imageData {
        NSData *jpgData = UIImageJPEGRepresentation(self.image, 1); // This is the UIImage (without metadata) from step 2 above
        CGImageSourceRef source = CGImageSourceCreateWithData((__bridge CFDataRef) jpgData, NULL);
        NSMutableData *dest_data = [NSMutableData data];
        CFStringRef uti = CGImageSourceGetType(source);
        NSMutableDictionary *maker = [NSMutableDictionary new];
        [maker setObject:[self.imageMetadata objectForKey:(NSString*)kCGImagePropertyMakerAppleDictionary] forKey:(NSString *)kCGImagePropertyMakerAppleDictionary];    // imageMetadata is the dictionary form step 1 above
        CGImageDestinationRef destination = CGImageDestinationCreateWithData((__bridge CFMutableDataRef)dest_data,uti,1,NULL);
        CGImageDestinationAddImageFromSource(destination, source , 0, (__bridge CFDictionaryRef) maker);
        CGImageDestinationFinalize(destination);
        return dest_data;
    }

- (void)dataRepresentation:(DataRepresentationLoaded)callback {
    callback(@{@"image": self.imageData, @"video": [NSData dataWithContentsOfURL:self.livePhotoURL]}); // LivePhotoURL is the url from step 3 above
}

长答案

这是由视频/图像文件中的错误元数据引起的。创建实时照片时,PHLivePhoto 会搜索密钥 17 in kCGImagePropertyMakerAppleDictionary(即资产标识符)并将其与com.apple.quicktime.content.identifiermov 文件的 匹配。mov 文件还需要有一个用于捕获静止图像的时间的条目 ( com.apple.quicktime.still-image-time)。

确保您的文件没有在某处被编辑(或导出)。事件 UIImageJPEGRepresentation 函数将从图像中删除此数据。

这是我用来将 UIImage 转换为 NSData 的代码片段:

- (NSData*)imageData {
    NSData *jpgData = UIImageJPEGRepresentation(self.image, 1);
    CGImageSourceRef source = CGImageSourceCreateWithData((__bridge CFDataRef) jpgData, NULL);
    NSMutableData *dest_data = [NSMutableData data];
    CFStringRef uti = CGImageSourceGetType(source);
    NSMutableDictionary *maker = [NSMutableDictionary new];
    [maker setObject:[self.imageMetadata objectForKey:(NSString*)kCGImagePropertyMakerAppleDictionary] forKey:(NSString *)kCGImagePropertyMakerAppleDictionary];
    CGImageDestinationRef destination = CGImageDestinationCreateWithData((__bridge CFMutableDataRef)dest_data,uti,1,NULL);
    CGImageDestinationAddImageFromSource(destination, source , 0, (__bridge CFDictionaryRef) maker);
    CGImageDestinationFinalize(destination);
    return dest_data;
}

处理程序被调用两次,第一次告诉你损坏的数据,第二次告诉你进程的取消(这是两个不同的键)。

编辑:

这是您的 mov 数据:

    $ ffmpeg -i cf70b7de66bd89654967aeef1d557816.mov
    元数据:
        主要品牌:qt  
        次要版本:0
        兼容品牌:qt  
        创建时间:2018-01-27T11:07:38.000000Z
        com.apple.quicktime.content.identifier:cf70b7de66bd89654967aeef1d557816
      持续时间:00:00:15.05,开始:0.000000,比特率:1189 kb/s
        流 #0:0(und):视频:h264(高)(avc1 / 0x31637661)、yuv420p(渐进式)、540x960、1051 kb/s、29.84 fps、29.97 tbr、30k tbn、59.94 tbc(默认)
        元数据:
          创建时间:2018-01-27T11:07:38.000000Z
          handler_name : 核心媒体数据处理程序
          编码器:'avc1'
        流 #0:1(und):音频:aac (LC) (mp4a / 0x6134706D),44100 Hz,立体声,fltp,128 kb/s(默认)
        元数据:
          创建时间:2018-01-27T11:07:38.000000Z
          handler_name : 核心媒体数据处理程序

这里com.apple.quicktime.still-image-time缺少关键。

这是元数据的外观:

    元数据:
        主要品牌:qt  
        次要版本:0
        兼容品牌:qt  
        创建时间:2017-12-15T12:41:00.000000Z
        com.apple.quicktime.content.identifier:89CB44DA-D129-43F3-A0BC-2C980767B810
        com.apple.quicktime.location.ISO6709:+51.5117+007.4668+086.000/
        com.apple.quicktime.make:苹果
        com.apple.quicktime.model: iPhone X
        com.apple.quicktime.software:11.1.2
        com.apple.quicktime.creation 日期:2017-12-15T13:41:00+0100
      持续时间:00:00:01.63,开始:0.000000,比特率:8902 kb/s
        流 #0:0(und):视频:h264(高)(avc1 / 0x31637661)、yuvj420p(pc、smpte170m/smpte432/bt709)、1440x1080、8135 kb/s、26.94 fps、30 tbr、600 tbn、1200 tbc (默认)
        元数据:
          旋转:90
          创建时间:2017-12-15T12:41:00.000000Z
          handler_name : 核心媒体数据处理程序
          编码器:H.264
        侧面数据:
          显示矩阵:旋转 -90.00 度
        流 #0:1(und):音频:pcm_s16le (lpcm / 0x6D63706C),44100 Hz,单声道,s16,705 kb/s(默认)
        元数据:
          创建时间:2017-12-15T12:41:00.000000Z
          handler_name : 核心媒体数据处理程序
        流 #0:2(und):数据:无(mebx / 0x7862656D),12 kb/s(默认)
        元数据:
          创建时间:2017-12-15T12:41:00.000000Z
          handler_name : 核心媒体数据处理程序
        流 #0:3(und):数据:无(mebx / 0x7862656D),43 kb/s(默认)
        元数据:
          创建时间:2017-12-15T12:41:00.000000Z
          handler_name : 核心媒体数据处理程序

仅供参考,这是您的 JPEG 数据:

    $ magick identify -format %[EXIF:*] cf70b7de66bd89654967aeef1d557816.jpg
    exif:色彩空间=1
    exif:ExifImageLength=960
    exif:ExifImageWidth=540
    exif:ExifOffset=26
    exif:MakerNote=65, 112, 112, 108, 101, 32, 105, 79, 83, 0, 0, 1, 77, 77, 0, 1, 0, 17, 0, 2, 0, 0, 0, 33, 0, 0, 0, 32, 0, 0, 0, 0, 99, 102, 55, 48, 98, 55, 100, 101, 54, 54, 98, 100, 56, 57, 54, 53, 52、57、54、55、97、101、101、102、49、100、53、53、55、56、49、54、0、0

于 2018-02-07T22:18:35.523 回答