QVision: Qt's Image, Video and Computer Vision Library

00001 /*
00002  *   Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012. PARP Research Group.
00003  *   <http://perception.inf.um.es>
00004  *   University of Murcia, Spain.
00005  *
00006  *   This file is part of the QVision library.
00007  *
00008  *   QVision is free software: you can redistribute it and/or modify
00009  *   it under the terms of the GNU Lesser General Public License as
00010  *   published by the Free Software Foundation, version 3 of the License.
00011  *
00012  *   QVision is distributed in the hope that it will be useful,
00013  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015  *   GNU Lesser General Public License for more details.
00016  *
00017  *   You should have received a copy of the GNU Lesser General Public
00018  *   License along with QVision. If not, see <http://www.gnu.org/licenses/>.
00019  */
00020 
00024 
00025 #include <QString>
00026 #include <QUrl>
00027 #include <QTime>
00028 
00029 #include <qvimageio.h>
00030 
00031 #ifdef QVIPP
00032 #include <qvipp.h>
00033 #endif // QVIPP
00034 
00035 #include <QVYUV4MPEG2Reader>
00036 
00037 bool QVYUV4MPEG2Reader::open(const QString & url_string,
00038                               unsigned int & suggested_cols, unsigned int & suggested_rows,
00039                               unsigned int & suggested_fps, QVVideoReader::OpenOptions & suggested_options,
00040                               QVVideoReader::TSourceMode & source_mode)
00041     {
00042     // Preferred mode: YUV
00043     source_mode = QVVideoReader::YUVMode;
00044 
00045     // File name:
00046     QUrl URL(url_string);
00047     QString fileName = URL.path();
00048 
00049     // noLoop & realTime flags:
00050     noLoop = (suggested_options & QVVideoReader::NoLoop);
00051     realTime = (suggested_options & QVVideoReader::RealTime);
00052 
00053     // Try to open file, and read yuv4mpeg2 header.
00054     videoFile.setFileName(fileName);
00055     if (!videoFile.exists())
00056         {
00057         QString msg = QString("QVYUV4MPEG2Reader::open: File '") + fileName + "' doesn't seem to exist." ;
00058         qWarning() << msg;
00059         return FALSE;
00060         }
00061     else if (!videoFile.open(QIODevice::ReadOnly))
00062         {
00063         QString msg = QString("QVYUV4MPEG2Reader::open: Can't open file '") + fileName + "' in read mode." ;
00064         qWarning() << msg;
00065         return FALSE;
00066         }
00067     else if (!readYUV4MPEG2Header(videoFile, cols, rows, fps))
00068         {
00069         QString msg = QString("QVYUV4MPEG2Reader::open: File '") + fileName + "' doesn't seem to be a valid yuv4mpeg2 video file.";
00070         qWarning() << msg;
00071         return FALSE;
00072         }
00073     else // Everything correct.
00074         {
00075         // By default, ignore input video fps, and force user value (unless realTime option flag is ON):
00076         if(realTime) {
00077             suggested_fps = fps;
00078         }
00079 
00080         // Size of the header:
00081         header_size = videoFile.pos();
00082 
00083         // Output cols and rows. Even rounding of out_rows and out_cols:
00084         // cols = cols + (cols%2);
00085         // rows = rows + (rows%2);
00086 
00087         // Finally, output cols and rows are "returned" to the caller:
00088         suggested_cols = cols;
00089         suggested_rows = rows;
00090 
00091         return TRUE;
00092         }
00093     }
00094 
00095 bool QVYUV4MPEG2Reader::close()
00096     {
00097     videoFile.close();
00098     return TRUE;
00099     }
00100 
00101 bool QVYUV4MPEG2Reader::grab(QVImage<uChar,1> &imgY, QVImage<uChar,1> &imgU, QVImage<uChar,1> &imgV)
00102     {
00103     QVImage<uChar,1> inp_imgY(cols,rows), inp_imgU(cols/2,rows/2), inp_imgV(cols/2,rows/2);
00104     bool ret_value = FALSE;
00105 
00106     if (readYUV4MPEG2Frame(videoFile, inp_imgY, inp_imgU, inp_imgV))
00107         {
00108         ret_value = TRUE;
00109         }
00110     else if (videoFile.atEnd())
00111         {
00112         if (noLoop)
00113             return FALSE;
00114         else
00115             {
00116             // qDebug() << "QVYUV4MPEG2Reader::grabFrame(): Reseting the video at frame " << total_frames;
00117             videoFile.reset();
00118             readYUV4MPEG2Frame(videoFile, inp_imgY, inp_imgU, inp_imgV);
00119             ret_value = TRUE;
00120             }
00121         }
00122     else   {
00123         qFatal("QVYUV4MPEG2Reader::grab(): readYUV4MPEG2Frame() returned FALSE, and videoFile is not at end... aborting\n");
00124         }
00125 
00126     imgY = inp_imgY;
00127     imgU = inp_imgU;
00128     imgV = inp_imgV;
00129 
00130     return ret_value;
00131     }
00132 
00133 int QVYUV4MPEG2Reader::getLength()
00134     {
00135     return (videoFile.size()-header_size)/(cols*rows + cols*rows/2 + 6);
00136     }
00137 
00138 int QVYUV4MPEG2Reader::getPos()
00139     {
00140     return (videoFile.pos()-header_size)/(cols*rows + cols*rows/2 + 6);
00141     }
00142 
00143 bool QVYUV4MPEG2Reader::seek(int pos)
00144     {
00145     videoFile.seek(header_size+pos*(cols*rows + cols*rows/2 + 6));
00146     return TRUE;
00147     }
src/qvio/qvyuv4mpeg2reader.cpp
