1

I'm trying to recognize faces in a video stream using these instructions but I couldn't find any help to implement PutMedia operation using Python. I'm using Ubuntu 16.04 and Python 3.6. Any hint please so I can implement it using Python.

1 Answer 1

1

maybe it is too late, but hope it can help you. the answer is from this article, and i have changed just a little. to use the code below, you need add your own configurations shown in "<>"

Amazon Kinesis Video PutMedia Using Python

import requests
import sys
import os
import datetime
import hashlib
import hmac
import time


def sign(key, msg):
    return hmac.new(key, msg.encode("utf-8"), hashlib.sha256).digest()


def get_signature_key(key, date_stamp, regionName, serviceName):
    kDate = sign(('AWS4' + key).encode('utf-8'), date_stamp)
    kRegion = sign(kDate, regionName)
    kService = sign(kRegion, serviceName)
    kSigning = sign(kService, 'aws4_request')
    return kSigning


# ************* REQUEST VALUES *************
method = 'POST'
service = 'kinesisvideo'
host = 'kinesisvideo.us-east-1.amazonaws.com'
region = 'us-east-1'    
endpoint = 'https://**<the endpoint you get with get_data_endpoint>**/PutMedia'
# POST requests use a content type header. For DynamoDB,
# the content is JSON.
content_type = 'application/json'
start_tmstp = repr(time.time())
localfile = 'test_1.png'
with open(localfile, 'rb') as image:
    request_parameters = image.read()

# Read AWS access key from env. variables or configuration file. Best practice is NOT
# to embed credentials in code.
access_key = '*************************'
secret_key = '*************************'
if access_key is None or secret_key is None:
    print('No access key is available.')
    sys.exit()

# Create a date for headers and the credential string
t = datetime.datetime.utcnow()
amz_date = t.strftime('%Y%m%dT%H%M%SZ')
date_stamp = t.strftime('%Y%m%d')  # Date w/o time, used in credential scope

# ************* TASK 1: CREATE A CANONICAL REQUEST *************
# http://docs.aws.amazon.com/general/latest/gr/sigv4-create-canonical-request.html

# Step 1 is to define the verb (GET, POST, etc.)--already done.

# Step 2: Create canonical URI--the part of the URI from domain to query
# string (use '/' if no path)
canonical_uri = '/'

## Step 3: Create the canonical query string. In this example, request
# parameters are passed in the body of the request and the query string
# is blank.
canonical_querystring = ''

# Step 4: Create the canonical headers. Header names must be trimmed
# and lowercase, and sorted in code point order from low to high.
# Note that there is a trailing \n.
canonical_headers = 'content-type:' + content_type + '\n' + 'host:' + host + '\n' + 'x-amz-content-sha256:' + 'UNSIGNED-PAYLOAD' + '\n' + 'x-amz-date:' + amz_date + '\n' + 'x-amzn-fragment-timecode-type:' + 'ABSOLUTE' + '\n' + 'x-amzn-producer-start-timestamp:' + start_tmstp + '\n' + 'x-amzn-stream-name:' + <your_stream_name> + '\n'

# Step 5: Create the list of signed headers. This lists the headers
# in the canonical_headers list, delimited with ";" and in alpha order.
# Note: The request can include any headers; canonical_headers and
# signed_headers include those that you want to be included in the
# hash of the request. "Host" and "x-amz-date" are always required.
# For DynamoDB, content-type and x-amz-target are also required.
signed_headers = 'content-type;host;x-amz-content-sha256;x-amz-date;x-amz-target;x-amzn-fragment-timecode-type;x-amzn-producer-start-timestamp;x-amzn-stream-name'

# Step 6: Create payload hash. In this example, the payload (body of
# the request) contains the request parameters.

# Step 7: Combine elements to create canonical request
canonical_request = method + '\n' + canonical_uri + '\n' + canonical_querystring + '\n' + canonical_headers + '\n' + signed_headers

# ************* TASK 2: CREATE THE STRING TO SIGN*************
# Match the algorithm to the hashing algorithm you use, either SHA-1 or
# SHA-256 (recommended)
algorithm = 'AWS4-HMAC-SHA256'
credential_scope = date_stamp + '/' + region + '/' + service + '/' + 'aws4_request'
string_to_sign = algorithm + '\n' + amz_date + '\n' + credential_scope + '\n' + hashlib.sha256(
    canonical_request.encode('utf-8')).hexdigest()

# ************* TASK 3: CALCULATE THE SIGNATURE *************
# Create the signing key using the function defined above.
signing_key = get_signature_key(secret_key, date_stamp, region, service)

# Sign the string_to_sign using the signing_key
signature = hmac.new(signing_key, (string_to_sign).encode('utf-8'),
                     hashlib.sha256).hexdigest()

# ************* TASK 4: ADD SIGNING INFORMATION TO THE REQUEST *************
# Put the signature information in a header named Authorization.
authorization_header = algorithm + ' ' + 'Credential=' + access_key + '/' + credential_scope + ', ' + 'SignedHeaders=' + signed_headers + ', ' + 'Signature=' + signature

# # Python note: The 'host' header is added automatically by the Python 'requests' library.
headers = {
    'Content-Type': content_type,
    'x-amzn-fragment-timecode-type': 'ABSOLUTE',
    'x-amzn-producer-start-timestamp': start_tmstp,
    'x-amzn-stream-name': <your_stream_name>,
    # 'X-Amz-Target': amz_target,
    # 'x-amz-content-sha256': 'UNSIGNED-PAYLOAD',
    'Authorization': authorization_header
}

# ************* SEND THE REQUEST *************
print('\nBEGIN REQUEST++++++++++++++++++++++++++++++++++++')
print('Request URL = ' + endpoint)

r = requests.post(endpoint, data=request_parameters, headers=headers)

print('\nRESPONSE++++++++++++++++++++++++++++++++++++')
print('Response code: %d\n' % r.status_code)
print(r.text)
Sign up to request clarification or add additional context in comments.

2 Comments

this can only get the right signature, but failed to post the right payload of PutMedia
after adding a few more changes, it's working. thank you for sharing the initial code here! stackoverflow.com/a/59551573/362754

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.