GoPro Metadata Format Parser

Introduction

This is a fork of JuanIrache gopro-utils that retains only the package, to be used in other Golang code.

Upstream info

I have recently switched my efforts to a more comprehensive JavaScript version of these tools, but feel free to send a PR if you think you can improve this one

Examples of what can be achieved: https://goprotelemetryextractor.com/gallery

User friendly and cross-platform tool for extracting the telemetry: https://goprotelemetryextractor.com/free

The Protocol

Data starts with a label that describes the data following it. Values are all big endian, and floats are IEEE 754. Everything is packed to 4 bytes where applicable, padded with zeroes so it's 32-bit aligned.

• Labels - human readable types of proceeding data
• Type - single ascii character describing data
• Size - how big is the data type
• Count - how many values are we going to get
• Length = size * count

Labels include:

• ACCL - accelerometer reading x/y/z
• DEVC - device
• DVID - device ID, possibly hard-coded to 0x1
• DVNM - devicde name, string "Camera"
• EMPT - empty packet
• GPS5 - GPS data (lat, lon, alt, speed, 3d speed)
• GPSF - GPS fix (none, 2d, 3d)
• GPSP - GPS positional accuracy in cm
• GPSU - GPS acquired timestamp; potentially different than "camera time"
• GYRO - gryroscope reading x/y/z
• SCAL - scale factor, a multiplier for subsequent data
• SIUN - SI units; strings (m/s², rad/s)
• STRM - ¯\_(ツ)_/¯
• TMPC - temperature
• TSMP - total number of samples
• UNIT - alternative units; strings (deg, m, m/s)

Types include:

• c - single char
• L - unsigned long
• s - signed short
• S - unsigned short
• f - 32 float

For implementation details, see reader.go and other corresponding files in telemetry/.