![]() Wow, it works!!! the latency is just about 200ms which is unachievable with HLS/ MPEG-DASH streaming.Base64. frame # access global variable, need to change later condition : # wait for a new frame frame_buffer. ![]() notify_all () class StreamingHandler ( SimpleHTTPRequestHandler ): def do_GET ( self ): if self. ![]() startswith ( b ' \xff\xd8 ' ): with self. condition = Condition () def write ( self, buf ): if buf. BytesIO () # synchronize between threads self. Then add a Condition object in FrameBuffer, and use it in StreamingHandler:įrom threading import Condition class FrameBuffer ( object ): def _init_ ( self ): self. If the calling thread has not acquired the lock when this method is called, a RuntimeError is raised. This method acts like notify(), but wakes up all waiting threads instead of one. notify_all () Wake up all threads waiting on this condition. Once awakened or timed out, it re-acquires the lock and returns. This method releases the underlying lock, and then blocks until it is awakened by a notify() or notify_all() call for the same condition variable in another thread, or until the optional timeout occurs. Wait until notified or until a timeout occurs. Otherwise, a new RLock object is created and used as the underlying lock. If the lock argument is given and not None, it must be a Lock or RLock object, and it is used as the underlying lock. A condition variable allows one or more threads to wait until they are notified by another thread. This class implements condition variable objects. Python has implemented a lock mechanism between threads: class threading. Need to find a way to synchronize between camera thread and web server thread: send a frame only when it is available. When run the above code, the web page shows up but with only one frame displayed, CPU is locked up at 100%, because the block while True : loop causes the problem. Request Handler #īased on SimpleHTTPRequestHandler, create a new class StreamingHandler and only override do_GET() method to just print requested path and then call the base method as it is already implemented. Let’s start with SimpleHTTPRequestHandler which has some implemented features. The do_GET() and do_HEAD() functions are modified to run CGI scripts and serve the output, instead of serving files, if the request leads to somewhere below the cgi_directories path. Only directory-based CGI are used - the other common server configuration is to treat special extensions as denoting CGI scripts. The class will however, run the CGI script, instead of serving it as a file, if it guesses it to be a CGI script. Note that mapping HTTP hierarchic structure to local directory structure is exactly as in SimpleHTTPRequestHandler. This class is used to serve either files or output of CGI scripts from the current directory and below. This class implements the do_GET() and do_HEAD() functions. A lot of the work, such as parsing the request, is done by the base class BaseHTTPRequestHandler. SimpleHTTPRequestHandler This class serves files from the current directory and below, directly mapping the directory structure to HTTP requests. Subclasses should not need to override or extend the _init_() method. All the relevant information is stored in instance variables of the handler. For example, for the request method SPAM, the do_SPAM() method will be called with no arguments. The method name is constructed from the request. The handler will parse the request and the headers, then call a method specific to the request type. ![]() It must be sub-classed to handle each request method (e.g. The save () method will automatically identify the extension that you passed and then save the image in the identified format. You just need to pass the new filename and extension as a parameter to the save () method. By itself, it cannot respond to any actual HTTP requests BaseHTTPRequestHandler just provides a number of class and instance variables, and methods for use by subclasses. How to Convert Image Format Using Python You can simply convert the file format of an image using the save () method. This class is used to handle the HTTP requests that arrive at the server. Python 3 codes to encode an image in Base64 After you had decided to encode your image in Base64, you can proceed with coding a utility function with Python 3: 1 2 3 4 5 import base64 def getbase64encodedimage (imagepath): with open(imagepath, 'rb') as imgfile: return base64.b64encode (imgfile.read ()). Now, look at some pre-defined Request Handler classes: class http. ![]() From rver import HTTPServer, BaseHTTPRequestHandler def run ( server_class = HTTPServer, handler_class = BaseHTTPRequestHandler ): server_address = ( '', 8000 ) httpd = server_class ( server_address, handler_class ) httpd. ![]()
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