Files
openalpr-base/src/videobuffer.cpp
2014-07-03 15:13:44 -04:00

153 lines
3.2 KiB
C++

/*
* Copyright (c) 2013 New Designs Unlimited, LLC
* Opensource Automated License Plate Recognition [http://www.openalpr.com]
*
* This file is part of OpenAlpr.
*
* OpenAlpr is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License
* version 3 as published by the Free Software Foundation
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "videobuffer.h"
void imageCollectionThread(void* arg);
VideoBuffer::VideoBuffer()
{
dispatcher = NULL;
}
VideoBuffer::~VideoBuffer()
{
if (dispatcher != NULL)
{
dispatcher->active = false;
}
}
void VideoBuffer::connect(std::string mjpeg_url, int fps)
{
if (hasEnding(mjpeg_url, ".mjpg") == false)
{
// The filename doesn't end with ".mjpg" so the downstream processing may not treat it as such
// OpenCV doesn't have a way to force the rendering, other than via URL path. So, let's add it to the URL
std::size_t found = mjpeg_url.find("?");
if (found!=std::string::npos)
{
// URL already contains a "?"
mjpeg_url = mjpeg_url + "&openalprfiletype=file.mjpg";
}
else
{
// URL does not contain a "?"
mjpeg_url = mjpeg_url + "?openalprfiletype=file.mjpg";
}
}
dispatcher = new VideoDispatcher(mjpeg_url, fps);
tthread::thread* t = new tthread::thread(imageCollectionThread, (void*) dispatcher);
}
int VideoBuffer::getLatestFrame(cv::Mat* frame)
{
if (dispatcher == NULL)
return -1;
return dispatcher->getLatestFrame(frame);
}
void VideoBuffer::disconnect()
{
if (dispatcher != NULL)
{
dispatcher->active = false;
}
dispatcher = NULL;
}
void imageCollectionThread(void* arg)
{
VideoDispatcher* dispatcher = (VideoDispatcher*) arg;
while (dispatcher->active)
{
try
{
cv::VideoCapture cap=cv::VideoCapture();
cap.open(dispatcher->mjpeg_url);
cv::Mat frame;
while (dispatcher->active)
{
while (dispatcher->active)
{
dispatcher->mMutex.lock();
bool hasImage = false;
try
{
hasImage = cap.read(frame);
dispatcher->setLatestFrame(&frame);
}
catch (int e)
{
// Error occured while trying to gather image. Retry, don't exit.
std::cerr << "Exception happened " << e << std::endl;
}
// Double check the image to make sure it's valid.
if (frame.cols == 0 || frame.rows == 0)
hasImage = false;
dispatcher->mMutex.unlock();
if (hasImage == false)
break;
// Delay 15ms
usleep(15000);
}
// Delay 100ms
usleep(100000);
}
}
catch (const std::runtime_error& error)
{
// Error occured while trying to gather image. Retry, don't exit.
std::cerr << "VideoBuffer exception: " << error.what() << std::endl;
}
// Delay 1 second
usleep(1000000);
}
}