使用 ffprobe 查看用手机录的视频的时候，发现视频信息里面有一项是
com.apple.quicktime.location.ISO6709: +40.0713+116.4351+040.260，因此查询了一下关于 ISO 6709 的信息。

ISO 6709, Standard representation of geographic point location by coordinates, is the international standard for representation of latitude, longitude and altitude for geographic point locations.
国际标准表示地理点位置的纬度、经度和海拔高度

General rules

Items

A geographical point is specified by the following four items:

  • First horizontal coordinate(ϕ or y), such as latitude (negative number south of equator and positive north of equator)
  • Second horizontal coordinate(λ or x), such as longitude (negative values west of Preme Meridian and positive values east of Prime Meridian)
  • Vertical coordinate, i.e. height or depth (optional)
  • Identification of coordinate reference system (CRS) (optional)
    The first three items are numerical values called coordinates. The CRS gives the relationship between the coordinates and a point on the earch.

Order, sign, and units

supposed to be defined by the CRS, if CRS missing then:

  • Latitude comes before longitude
  • North latitude is positive
  • East longitude is positive
  • Fraction of degrees is perferred in digital data exchange, while sexagesimal notation is tolerated for compatibility
    (No such interpretation rule for vertical coordinates)

Representation at the human interface

  1. Coordinate values (latitude, longitude, and altitude) should be delimited by spaces
  2. The decimal point is a part of the value, thus must usually be configuraed by the operating system
  3. Muliple locations should be represented by multiple lines
  4. Latitude and longitude should be displayed by sexagesimal fractions (i.e. minutes and seconds).
  5. When minutes and seconds are less than ten, leading zeroes should be shown.
  6. Degree, minutes and seconds should be followed by the symbols ° (U+00B0), ′ (U+2032), and ″ (U+2033), without spaces between the number and symbol.
  7. North and south latitudes should be indicated by N and S following immediately after the digits.
  8. East and west longitudes should be indicated by E and W following immediately after the digits.
  9. Units of elevation or depth should be given by symbols, immediately after the digits
  10. Elevation below reference level or depth above reference level should be indicated by a minus sign -(U+2212)

Examples:

  • 50°40′46.461″N 95°48′26.533″W 123.45m
  • 50°03′46.461″S 125°48′26.533″E 978.90m

My location
+38.0713+114.4351+040.260
equals to
38.0713°N 114.4351°N 40.26m

想把这个位置信息显示在地图上，需要学习谷歌地图或者其他地图工具提供的api