expose

Expose provides a Go package and command tool for extracting and parsing XMP, EXIF and IPTC metadata from image and video files using the exiv2 binary tool. The output data is grouped by type in JSON format.

This example was created for the Feb 2017 GoLangPhilly meetup presentation on Processing Image and Video Metadata by Rob Murtha.

Exiv2 Dependency

This package requires the exiv2 binary (see instructions below). exiv2 website exiv2 download / source

Install go package and tools

go get github.com/robmurtha/expose

Run

Usage: expose [-flags] filename
flags:
  -p    pretty JSON
  -v    verbose logging

Organization

This project includes a main.go for running from the command line and extracting all possible information. An exiv2 parsing package is included and can be used independently.

    // parse XMP tags
    // with output from exiv2 -PXgnycv filename (see main)
	expose := exiv2.New(output)
	fields, _ := expose.Fields()
	jsonBytes, _ := json.Marshal(fields)
	

Installing

mac-os (brew)

brew install exiv2

Compiling on mac with brew

The default brew version has video support disabled, if you need video support follow these instructions.

wget http://exiv2.org/exiv2-0.25.tar.gz
tar -xzf exiv2-0.25.tar.gz
cd exiv2-0.25
brew install exiv2 --only-dependencies
./configure --enable-video
make install

apt-get

apt-get install exiv2

Sample JSON

The JSON records are organized by metadata type as arrays of Field. Organization by group, type and additional parsing of values is up to the user.

{
 "expose": {
  "xmp": [
   {
    "group": "video",
    "name": "FileSize",
    "type": "XmpText",
    "count": 9,
    "value": "0.0515432"
   },
   {
    "group": "video",
    "name": "FileName",
    "type": "XmpText",
    "count": 27,
    "value": "testdata/samsung_galaxy.mp4"
   },
   {
    "group": "video",
    "name": "MimeType",
    "type": "XmpText",
    "count": 15,
    "value": "video/quicktime"
...