[Digikam-devel] extragear/graphics/digikam/libs/dimg/loaders

[Marcel Wiesweg]

SVN commit 576737 by mwiesweg:

RAW loader progress:
Any progress is better than no progress, so for the RAW loader, we now have progress.
As dcraw does not allow us to have real progress information, do some guessing and emit fake progress.
It works pretty well on my machine, and the progress curve is sigmoidal not linear so I hope it works on most
machines well enough.

CCMAIL: digikam-devel at kde.org


 M  +41 -14    rawloader.cpp  


--- trunk/extragear/graphics/digikam/libs/dimg/loaders/rawloader.cpp #576736:576737
@@ -34,7 +34,9 @@
 // QT includes.
 
 #include <qapplication.h>
+#include <qdatetime.h>
 #include <qfile.h>
+#include <qfileinfo.h>
 #include <qcstring.h>
 #include <qimage.h>
 #include <qtimer.h>
@@ -95,6 +97,21 @@
     // trigger startProcess and loop to wait dcraw decoding
     QApplication::postEvent(this, new QCustomEvent(QEvent::User));
 
+
+    // The time from starting dcraw to when it first outputs something takes
+    // much longer than the time while it outputs the data and the time while
+    // we process the data.
+    // We do not have progress information for this, but it is much more promising to the user
+    // if there is progress which does not stay at a fixed value.
+    // So we make up some progress (0% - 90%), using the file size as an indicator how long it might take.
+    QTime dcrawStartTime = QTime::currentTime();
+    int fileSize = QFileInfo(m_filePath).size();
+    // This is the magic number that describes how fast the function grows
+    // It _should_ be dependent on how fast the computer is, but we dont have this piece of information
+    // So this is a number that works well on my computer.
+    double K50 = 3000.0*fileSize;
+    int checkpointTime = 0;
+
     int checkpoint = 0;
 
     // The shuttingDown is a hack needed to prevent hanging when this KProcess-based loader
@@ -104,12 +121,31 @@
     while (m_running && !m_observer->isShuttingDown())
     {
 
-        if (m_dataPos > checkpoint)
+        if (m_dataPos == 0)
         {
+            int elapsedMsecs = dcrawStartTime.msecsTo(QTime::currentTime());
+            if (elapsedMsecs > checkpointTime)
+            {
+                checkpointTime += 300;
+            }
+            if (observer)
+            {
+                // What we do here is a sigmoidal curve, it starts slowly,
+                // then grows more rapidly, slows down again and
+                // get asymptotically closer to the maximum.
+                // (this is the Hill Equation, 2.8 the Hill Coefficient, to pour some blood in this)
+                double elapsedMsecsPow = pow(elapsedMsecs, 2.8);
+                double part = (elapsedMsecsPow) / (K50 + elapsedMsecsPow);
+                observer->progressInfo(m_image, 0.9*part );
+            }
+        }
+        else if (m_dataPos > checkpoint)
+        {
+            // While receiving data, progress from 90% to 95%
             int size = m_width * m_height * (m_rawDecodingSettings.sixteenBitsImage ? 6 : 3);
-            checkpoint += granularity(observer, size, 0.8);
+            checkpoint += granularity(observer, size, 0.05);
             if (observer)
-                observer->progressInfo(m_image, 0.1 + 0.8*(((float)m_dataPos)/((float)size)) );
+                observer->progressInfo(m_image, 0.9 + 0.05*(((float)m_dataPos)/((float)size)) );
         }
 
         QMutexLocker lock(&m_mutex);
@@ -148,7 +184,7 @@
                     m_data = 0;
                     return false;
                 }
-                observer->progressInfo(m_image, 0.9 + 0.1*(((float)h)/((float)m_height)) );
+                observer->progressInfo(m_image, 0.95 + 0.05*(((float)h)/((float)m_height)) );
             }
 
             for (int w = 0; w < m_width; w++)
@@ -184,7 +220,7 @@
                     m_data = 0;
                     return false;
                 }
-                observer->progressInfo(m_image, 0.9 + 0.1*(((float)h)/((float)m_height)) );
+                observer->progressInfo(m_image, 0.95 + 0.05*(((float)h)/((float)m_height)) );
             }
 
             for (int w = 0; w < m_width; w++)
@@ -378,11 +414,6 @@
     kdDebug() << "Running dcraw command " << m_process->args() << endl;
 #endif
 
-    // post one progress info before starting the program.
-    // There may be a delay before the first data is read.
-    if (m_observer)
-        m_observer->progressInfo(m_image, 0.05);
-
     // actually start the process
     if ( !m_process->start(KProcess::NotifyOnExit, KProcess::Communication(KProcess::Stdout | KProcess::Stderr)) )
     {
@@ -407,10 +438,6 @@
             m_process->wait();
             m_normalExit = false;
         }
-
-        // Post progress while dcraw has not yet given any output
-        if (!m_dataPos)
-            m_observer->progressInfo(m_image, 0.1);
     }
 }