From 3f13a98135d7bfe8d03c6603b435cc99e2051355 Mon Sep 17 00:00:00 2001
From: heckflosse <heckflosse67@gmx.de>
Date: Tue, 1 Nov 2016 02:20:43 +0100
Subject: [PATCH] Prepare rtengine to allow extraction of individual frames
 from multi frame raw files (i.e. Pentax pixel shift)

---
 rtengine/rawimage.cc | 4 +++-
 rtengine/rawimage.h  | 9 ++++++++-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/rtengine/rawimage.cc b/rtengine/rawimage.cc
index 382ebe0a7..2d778a3b5 100644
--- a/rtengine/rawimage.cc
+++ b/rtengine/rawimage.cc
@@ -398,7 +398,7 @@ skip_block:
     }
 }
 
-int RawImage::loadRaw (bool loadData, bool closeFile, ProgressListener *plistener, double progressRange)
+int RawImage::loadRaw (bool loadData, bool closeFile, ProgressListener *plistener, double progressRange, unsigned int frameNum)
 {
     ifname = filename.c_str();
     image = nullptr;
@@ -435,6 +435,8 @@ int RawImage::loadRaw (bool loadData, bool closeFile, ProgressListener *plistene
         return 2;
     }
 
+    setFrameNumber(frameNum);
+
     if (flip == 5) {
         this->rotate_deg = 270;
     } else if (flip == 3) {
diff --git a/rtengine/rawimage.h b/rtengine/rawimage.h
index 88ef5d710..c3da24f0d 100644
--- a/rtengine/rawimage.h
+++ b/rtengine/rawimage.h
@@ -106,7 +106,7 @@ public:
     explicit RawImage( const Glib::ustring &name );
     ~RawImage();
 
-    int loadRaw (bool loadData = true, bool closeFile = true, ProgressListener *plistener = nullptr, double progressRange = 1.0);
+    int loadRaw (bool loadData = true, bool closeFile = true, ProgressListener *plistener = nullptr, double progressRange = 1.0, unsigned int frameNum = 0);
     void get_colorsCoeff( float* pre_mul_, float* scale_mul_, float* cblack_, bool forceAutoWB );
     void set_prefilters()
     {
@@ -307,6 +307,13 @@ public:
         return zero_is_bad == 1 ? true : false;
     }
 
+    void setFrameNumber(unsigned int frameNum) {
+        // a single raw file can contain more than one frame.
+        // Variable is_raw holds the number of frames in the raw file
+        // use setFrameNumber() to set the number of the frame [0; is_raw - 1] to be processed
+        shot_select = std::min(std::max(is_raw, 1) - 1, frameNum);
+    }
+
 public:
     // dcraw functions
     void scale_colors()