Decode Base64 data

[paolomorabito (Paolo)]

Hi, I have a sensor

- platform: template
  sensors:
    trasmettitore_rc_potenza:
      friendly_name: "Potenza Trasmettitore RC"
      unit_of_measurement: "W"
      value_template: >
        {{ state_attr('sensor.trasmettitore_rc', 'PARAM')[5] }}

The value is Base64. Is there a way to decode it directly on the value_template parameter?

E.g.

IDEwMDA= -> 1000

Thanks

[123 (Taras)]

@paolomorabito

a way to decode it directly

Use base64_decode.

Example:

Specifically for your sample value:

[paolomorabito (Paolo)]

Thank you! It works!

[markusBPunkt (Markus)]

I was stumbiling over this solution while trying to decode a datapacket from a Lora-Node.

Unfortunately this today does not work (anymore?)

I get this errormessage:
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xb3 in position 0: invalid start byte

[123 (Taras)]

Perhaps the problem might be that the supplied string isn’t encoded correctly.

Because decoding works with an encoded string.

[paulusbrand (Paul Brand)]

The problem is that LoraWAN networks send raw byte payloads base64 encoded. So these can not be decoded into utf-8 character strings.

Keep an eye on Base64 decode encoding by paulusbrand · Pull Request #116603 · home-assistant/core · GitHub.

This pull request will enable the option to decode the base64 string into raw bytes, example:

[uiguy]

Hi,

I am trying to decode a base64 image received over MQTT.

I ran however the template and got the error

UnicodeDecodeError: 'utf-8' codec can't decode byte 0xff in position 0: invalid start byte

When I insert the same payload into Base64 to Image | Base64 Decode | Base64 Converter | Base64 It resolves the image.

As a side, my mqtt looks like this:

camera:
  name: anpr_camera
  topic: Test01_TrafficMessagePostImage #(This is the image only object in base64)
  json_attributes_topic: Test01_TrafficMessage
  image_encoding: b64
  unique_id: anplrcamera2

However I cannot seem to get the image to display which is possibly down to the error when I try and use the template?

I appreciate this topic is closed, however this does not appear to work for me, maybe due to the image aspect of the base64?

Also, it is not a big image:

File Info

• Resolution: 124×56
• MIME type: image/jpeg
• Extension: jpg
• Size: 3.08 KB
• Channels: 3
• Bit depth: 8

Any help or pointers would be most welcome!

Many thanks