SubRip subtitles for video mapping (.srt) (subrip)

This format can...

  • write tracks

This format has the following options: video_time, gps_time, gps_date, format .

This is a write-only format for geotagging videos. It is used for videomapping, i.e. filming a trip while creating a GPS trace. It will produce a subtitle file in SubRip (.srt) format.

Unless the video and the GPS trace start at exactly the same time, you will need to synchronize both. For this purpose, film the display of your GPS receiver (or any other device) showing GPS time. (Important: you need precise GPS time for this; local time, especially from an inaccurate clock, will not do for this.)

Determine the position in the video at which the GPS time is visible (in hours, minutes and seconds from the beginning of the video) and the GPS date and time shown. Specify these as command line options; you will need to do this once for each video file.

To use these files, choose the same name as for the associated video, changing just the extension to .srt, and place the srt file in the same directory as the video. Open the video in a media player and the GPS coordinates will be shown as subtitles (tested on VLC, your mileage may vary).

video_time option

Video position for which exact GPS time is known (hhmmss[.sss], default is 00:00:00,000).

Video position (relative to beginning of video) for which the corresponding GPS timestamp is known.

Format is hhmmss. If omitted, 0:00:00 (beginning of video) is assumed.

The GPS timestamp can be set with the gps_time and gps_date options.

gps_time option

GPS time at position video_time (hhmmss[.sss], default is first timestamp of track).

The time part of the GPS timestamp which corresponds to a known position in the video.

Format is hhmmss. This option must be used together with gps_date; if one or both are missing, the timestamp of the first GPS trackpoint is used.

The video position to which the timestamp corresponds can be set with the video_time option.

gps_date option

GPS date at position video_time (yyyymmdd, default is first timestamp of track).

The date part of the GPS timestamp which corresponds to a known position in the video.

Format is yyyymmdd. This option must be used together with gps_time; if one or both are missing, the timestamp of the first GPS trackpoint is used.

The video position to which the timestamp corresponds can be set with the video_time option.

format option

Format for subtitles.

Format for output subtitles.

Table 3.19. Supported format characters for subrip

format chardescription
%sspeed in km/h
%eelevation in meters
%vvertical speed in m/s
%ttimestamp
%lcoordinates
%cpedal cadence
%hheart rate
%groad gradient
\nnewline

Default format (used when option isn't specified) is "%s km/h %e m\n%t %l". Suggested format for bicycle video is "'%s km/h %h ❤\n %e m %c rpm".