Purpose

Stream any number of video/image sequences to any number of browser windows, using opencv and boost::asio. This could be used as the basis for a web browser based video stream viewer, powered by opencv. Currently using multipart/x-mixed-replace of jpeg images. See http://en.wikipedia.org/wiki/Motion_JPEG Future goals include more sophisticated video streams, e.g. webm.

Dependencies ^^^^^^^^^^^^

• boost >= 1.40
• opencv >= 2.2
• cmake >= 2.8
• optional ecto https://github.com/plasmodic/ecto

build it ^^^^^^^^ ::

% git clone git://github.com/ethanrublee/streamer.git % cd streamer % mkdir build % cd build % cmake .. % make

try it ^^^^^^ ::

% cd streamer % build/bin/httpserv 0.0.0.0 9090 1 . Visit: 0.0.0.0:9090/stream_0

What ^^^^ Server is based off of http://www.boost.org/doc/libs/1_40_0/doc/html/boost_asio/examples.html#boost_asio.examples.http_server_3

Optional ecto cells and python bindings. https://github.com/plasmodic/ecto

main.cpp shows the server's use, generates a random color and streams it.

dir_reader.py demoes the servers use from ecto. see module.cpp for an ecto cell that uses the server.

http interface

The a GET or POST to the url /_all is used for listing all available streams, as a text file with each line containing a url path.::

% curl -X GET http://localhost:9090/_all /foobar /stream_0 /stream_1

Also supports a listing based on a regular expression, where the base expression is _all<CUSTOM_REGEX>(.*), e.g.::

% curl -X GET http://localhost:9090/_all/stream_ /stream_0 /stream_1 % curl -X GET "http://localhost:9090/_all/(.*)bar" /foobar

POST may also be used::

%curl -X POST "http://localhost:9090/_all/(.*)bar" /foobar

A GET of a /foobar will recieve a 302 redirect::

% curl -vX GET "http://localhost:9090/foobar"

• About to connect() to localhost port 9090 (#0)
• Trying 127.0.0.1... connected
• Connected to localhost (127.0.0.1) port 9090 (#0)

GET /foobar HTTP/1.1 User-Agent: curl/7.21.3 (x86_64-pc-linux-gnu) libcurl/7.21.3 OpenSSL/0.9.8o zlib/1.2.3.4 libidn/1.18 Host: localhost:9090 Accept: /

• HTTP 1.0, assume close after body
  < HTTP/1.0 302 Moved Temporarily
  < Location: _stream/foobar/1303455736
  <
• Closing connection #0

This redirect is meant to fool the browser into not caching the connection, and returns a unique URL per GET. Each stream is found at /_stream/<STREAM_PATH>/(.*)::

% curl -vX GET "http://localhost:9090/_stream/foobar/12323" > /dev/null

• About to connect() to localhost port 9090 (#0)
• Trying 127.0.0.1... connected
• Connected to localhost (127.0.0.1) port 9090 (#0)

GET /_stream/foobar/12323 HTTP/1.1 User-Agent: curl/7.21.3 (x86_64-pc-linux-gnu) libcurl/7.21.3 OpenSSL/0.9.8o zlib/1.2.3.4 libidn/1.18 Host: localhost:9090 Accept: /

• HTTP 1.0, assume close after body
  < HTTP/1.0 200 OK
  < Connection: close
  < Max-Age: 0
  < Expires: 0
  < Cache-Control: no-cache
  < Pragma: no-cache
  < Content-Type: multipart/x-mixed-replace; boundary=--BOUNDARYSTRING
  <
  { [data not shown]

The server will also return any file that is relative to where the document root given at startup, including auto resolving index.html...::

% curl -X GET "http://localhost:9090"

c++ interface ^^^^^^^^^^^^^ Quick start::

#include <opencv2/core/core.hpp> #include "mjpeg_server.hpp" void doit() { using namespace http::server; // Run server in background thread. std::size_t num_threads = 8; std::string doc_root = "./"; //this initializes the redirect behavor, and the /_all handlers server_ptr s = init_streaming_server("0.0.0.0", "9090", doc_root, num_threads); streamer_ptr stmr(new streamer);//a stream per image, you can register any number of these. register_streamer(s, stmr2, "/stream_0"); s->start(); while (true) { cv::Mat image; //fill image somehow here. from camera or something. bool wait = false; //don't wait for there to be more than one webpage looking at us. int quality = 75; //quality of jpeg compression [0,100] int n_viewers = stmr->post_image(image,quality, wait); //use boost sleep so that our loop doesn't go out of control. boost::this_thread::sleep(boost::posix_time::milliseconds(33)); //30 FPS } }