安卓的 live photo 有统一标准吗？ OPPO 和小米有点像，但又不完全一样

1. 今天重新看，一加拍的照片在一加的Google Photos上能动了。昨天我还特意检查Google Photos是最新版，可能是有什么bug……
2. 感谢 @Biggoldfish 和 @Muniesa 贴的谷歌文档，里面提到以MicroVideo开头的属性"These properties were part of the Microvideo V1 specification. They are deleted in this specification and must be ignored if present." 于是我怀疑oppo和小米用了不同的spec，找了一个叫pyexiv2的python库解开metadata，果然：

OPPO:

<Xmp.GCamera.MotionPhoto [] = 1>
<Xmp.GCamera.MotionPhotoVersion [] = 1>
<Xmp.GCamera.MotionPhotoPresentationTimestampUs [] = 1599696>
<Xmp.OpCamera.MotionPhotoPrimaryPresentationTimestampUs [] = 1599696>
<Xmp.OpCamera.MotionPhotoOwner [] = oplus>
<Xmp.OpCamera.OLivePhotoVersion [] = 2>
<Xmp.OpCamera.VideoLength [] = 5195253>

小米：

<Xmp.GCamera.MicroVideoVersion [] = 1>
<Xmp.GCamera.MicroVideo [] = 1>
<Xmp.GCamera.MicroVideoOffset [] = 4893135>
<Xmp.GCamera.MicroVideoPresentationTimestampUs [] = 859793>

看起来小米还在用旧方案，而OPPO用了更新的（可能是后发优势），它们各自的系统相册都只支持其中一种。好在两者都遵守了Google的规范，通用性比较强，将来需要的话也很容易互相转换。

另一个GitHub仓库也提到了这一点

- Motion Photo - Describes a Google authored specification for a file that contains both a still and a video. The still must be a JPEG or HEIC, and the video must be an MP4.
- Microvideo - Describes a now deprecated specification that is replaced by motion photos.