Base64 Encoding

When passing video to the Video Intelligence API, you can either pass a Cloud Storage URI, or you can embed video data directly within the request's content field, which must be base64 encoded.

Embedding Base64 encoded video

Video data is binary data. Within a gRPC request, you can simply write the binary data out directly; however, JSON is used when making a REST request. JSON is a text format that does not directly support binary data, so you will need to convert such binary data into text using Base64 encoding.

To base64 encode a video file:

Linux

Encode the video file using the base64 command line tool, making sure to prevent line-wrapping by using the -w 0 flag:

    $ base64 source_video_file -w 0 > dest_text_file

Mac OSX

Encode the video file using the base64 command line tool:

    $ base64 source_video_file > dest_text_file

Windows

Encode the video file using the Base64.exe tool:

    C:> Base64.exe -e source_video_file > dest_text_file

The base64-encoded data is written out to the specified destination file. Pass the data in a Video Intelligence API request as the value of the content field:

{
  "requests":[
    {
      "image":{
        "content": "ZkxhQwAAACIQABAAAAUJABtAA+gA8AB+W8FZndQvQAyjv..."
      },
      "features": [
        {
          "type":"LABEL_DETECTION",
          "maxResults":1
        }
      ]
    }
  ]
}

Embedding video content programmatically

Copying encoded video data manually into your requests is not always practical; the preferred method is to embed base64-encoded files into client code. All supported programming languages have built-in mechanisms for base64-encoding content:

Python

In Python, base64 encode video files as follows:

# Import the base64 encoding library.
import base64

# Pass the video data to an encoding function.
def encode_video(video):
  video_content = video.read()
  return base64.b64encode(video_content)

Node.js

In Node.js, base64 encode video files as follows:

// Read the file into memory.
var fs = require('fs');
var videoFile = fs.readFileSync('/path/to/file');

// Convert the video data to a Buffer and base64 encode it.
var encoded = new Buffer(videoFile).toString('base64');

Java

In Java, you can base64 encode image files as follows:

// Import the Base64 encoding library.
import org.apache.commons.codec.binary.Base64;

// Encode the video.
byte[] videoData = Base64.encodeBase64(videoFile.getBytes());