我正在使用 python 将 USB 摄像头直接直播到 kinesis-video-stream。在尝试'PutMedia'从 aws (链接) 实现 API 时，虽然我能够上传本地存储的视频，参考以下代码here。
这是我稍作修改的代码：
import datetime
import hashlib
import hmac
import os
import sys
import time
#import cv2
#import pickle
import requests
# AWS requests
import pprint
your_env_access_key_var = 'AWS_KVS_USER_ACCESS_KEY'
your_env_secret_key_var = 'AWS_KVS_USER_SECRET_KEY'
your_stream_name = 'my-video-stream-test'
def get_endpoint_boto():
import boto3
client = boto3.client('kinesisvideo', region_name='us-east-1',
aws_secret_access_key=your_env_secret_key_var,
aws_access_key_id=your_env_access_key_var)
response = client.get_data_endpoint(
StreamName=your_stream_name,
APIName='PUT_MEDIA'
)
print(response)
endpoint = response.get('DataEndpoint', None)
print("endpoint %s" % endpoint)
if endpoint is None:
raise Exception("endpoint none")
return endpoint
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
def get_host_from_endpoint(endpoint):
# u'https://s-123abc78.kinesisvideo.us-east-2.amazonaws.com'
if not endpoint.startswith('https://'):
return None
retv = endpoint[len('https://'):]
return str(retv)
def get_region_from_endpoint(endpoint):
# u'https://s-123abc78.kinesisvideo.us-east-2.amazonaws.com'
if not endpoint.startswith('https://'):
return None
retv = endpoint[len('https://'):].split('.')[2]
return str(retv)
class gen_request_parameters:
def __init__(self):
self._data = ''
if True:
localfile = './temp.mkv' # upload ok
# localfile = 'big-buck-bunny_trailer.webm' # error fragment duration over limit
with open(localfile, 'rb') as image:
print('here')
request_parameters = image.read()
self._data = request_parameters
self._pointer = 0
self._size = len(self._data)
def __iter__(self):
return self
def __next__(self):
if self._pointer >= self._size:
raise StopIteration # signals "the end"
left = self._size - self._pointer
chunksz = 16000
if left < 16000:
chunksz = left
pointer_start = self._pointer
self._pointer += chunksz
print("Data: chunk size %d" % chunksz)
return self._data[pointer_start:self._pointer]
# ************* REQUEST VALUES *************
endpoint = get_endpoint_boto()
method = 'POST'
service = 'kinesisvideo'
host = get_host_from_endpoint(endpoint)
region = get_region_from_endpoint(endpoint)
##endpoint = 'https://**<the endpoint you get with get_data_endpoint>**/PutMedia'
endpoint += '/putMedia' # Concatenating the API call
# POST requests use a content type header. For DynamoDB,
# the content is JSON.
content_type = 'application/json'
start_tmstp = repr(time.time())
# Read AWS access key from env. variables or configuration file. Best practice is NOT
# to embed credentials in code.
access_key = your_env_access_key_var # '*************************'
secret_key = your_env_secret_key_var # '*************************'
while True: # scope
k = os.getenv(your_env_access_key_var)
if k is not None and type(k) is str and k.startswith('AKIA5'):
access_key = k
k = os.getenv(your_env_secret_key_var)
if k is not None and type(k) is str and len(k) > 4:
secret_key = k
break # scope
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 = '/'
canonical_uri = '/putMedia' # endpoint[len('https://'):]
## 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.
# 'host:' + host + '\n' +
canonical_headers = ''
# canonical_headers += 'Accept: */*\r\n'
canonical_headers += 'connection:keep-alive\n'
canonical_headers += 'content-type:application/json\n'
canonical_headers += 'host:' + host + '\n'
canonical_headers += 'transfer-encoding:chunked\n'
# canonical_headers += 'x-amz-content-sha256: ' + 'UNSIGNED-PAYLOAD' + '\r\n'
canonical_headers += 'user-agent:AWS-SDK-KVS/2.0.2 GCC/7.4.0 Linux/4.15.0-46-generic x86_64\n'
canonical_headers += 'x-amz-date:' + amz_date + '\n'
canonical_headers += 'x-amzn-fragment-acknowledgment-required:1\n'
canonical_headers += 'x-amzn-fragment-timecode-type:ABSOLUTE\n'
canonical_headers += 'x-amzn-producer-start-timestamp:' + start_tmstp + '\n'
canonical_headers += '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.
#
# in original sample after x-amz-date : + 'x-amz-target;'
signed_headers = 'connection;content-type;host;transfer-encoding;user-agent;'
signed_headers += 'x-amz-date;x-amzn-fragment-acknowledgment-required;'
signed_headers += '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
canonical_request += '\n'
canonical_request += hashlib.sha256(''.encode('utf-8')).hexdigest()
# ************* 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 + ', '
authorization_header += 'SignedHeaders=' + signed_headers + ', ' + 'Signature=' + signature
# # Python note: The 'host' header is added automatically by the Python 'requests' library.
headers = {
'Accept': '*/*',
'Authorization': authorization_header,
'connection': 'keep-alive',
'content-type': content_type,
# 'host': host,
'transfer-encoding': 'chunked',
# 'x-amz-content-sha256': 'UNSIGNED-PAYLOAD',
'user-agent': 'AWS-SDK-KVS/2.0.2 GCC/7.4.0 Linux/4.15.0-46-generic x86_64',
'x-amz-date': amz_date,
'x-amzn-fragment-acknowledgment-required': '1',
'x-amzn-fragment-timecode-type': 'ABSOLUTE',
'x-amzn-producer-start-timestamp': start_tmstp,
'x-amzn-stream-name': your_stream_name,
'Expect': '100-continue'
}
# ************* SEND THE REQUEST *************
print('\nBEGIN REQUEST++++++++++++++++++++++++++++++++++++')
print('Request URL = ' + endpoint)
r = requests.post(endpoint, data=gen_request_parameters(), headers=headers)
print('\nRESPONSE++++++++++++++++++++++++++++++++++++')
print('Response code: %d\n' % r.status_code)
print(r.text)
另外，请帮助我理解这个类gen_request_parameters。