ALAsset from PHAsset

AssetConversion.m

@implementation PHImageManager (MRCApp)

+ (RACSignal *)p_fetchALAssetForVideoAsset:(PHAsset *)asset {
    POSRX_CHECK(asset);
    PHVideoRequestOptions *options = [PHVideoRequestOptions new];
    options.version = PHVideoRequestOptionsVersionCurrent;
    options.deliveryMode = PHVideoRequestOptionsDeliveryModeHighQualityFormat;
    options.networkAccessAllowed = YES;
    return [self p_fetchALAssetForAsset:asset withURL:asset.mrc_videoAssetURL];
}

+ (RACSignal *)p_fetchALAssetForAsset:(PHAsset *)asset withURL:(nullable NSURL *)assetURL {
    if (!assetURL) {
        return [RACSignal error:[NSError mrc_internalErrorWithFormat:@"Failed to build ALAsset URL for %@", asset]];
    }
    ALAssetsLibrary *assetsLibrary = [ALAssetsLibrary new];
    return [[assetsLibrary mrc_fetchAssetForURL:assetURL] flattenMap:^RACSignal *(ALAsset *compatibleAsset) {
        ALAssetRepresentation *assetRepresentation = compatibleAsset.defaultRepresentation;
        if (!assetRepresentation) {
            return [RACSignal error:[NSError mrc_internalErrorWithFormat:
                                     @"ALAsset was not found for %@ with '%@'", asset, assetURL]];
        }
        return [RACSignal return:RACTuplePack(compatibleAsset, assetsLibrary)];
    }];
}

@end

#pragma mark -

@implementation PHAsset (MRCApp)

- (nullable NSURL *)mrc_videoAssetURL {
    return [self p_directURLWithExtension:@"MOV"];
}

- (nullable NSURL *)p_directURLWithExtension:(NSString *)extension {
    NSString *assetID = [[self.localIdentifier componentsSeparatedByString:@"/"] firstObject];
    if (extension && assetID) {
        return [NSURL URLWithString:[NSString stringWithFormat:@"assets-library://asset/asset.%@?id=%@&ext=%@",
                                     extension, assetID, extension]];
    }
    return nil;
}

@end