genesys: Compute what image processing will be needed in session

backend/genesys.cc

@@ -3597,10 +3597,6 @@ static void genesys_read_ordered_data(Genesys_Device* dev, SANE_Byte* destinatio
   uint8_t *work_buffer_dst;
   unsigned int dst_lines;
   unsigned int step_1_mode;
-  unsigned int needs_reorder;
-  unsigned int needs_ccd;
-  unsigned int needs_shrink;
-  unsigned int needs_reverse;
   Genesys_Buffer *src_buffer;
   Genesys_Buffer *dst_buffer;
 
@@ -3619,36 +3615,6 @@ static void genesys_read_ordered_data(Genesys_Device* dev, SANE_Byte* destinatio
 
   src_pixels = dev->current_setup.pixels;
 
-  needs_reorder = 1;
-    if (channels != 3 && depth != 16) {
-        needs_reorder = 0;
-    }
-#ifndef WORDS_BIGENDIAN
-    if (channels != 3 && depth == 16) {
-        needs_reorder = 0;
-    }
-    if (channels == 3 && depth == 16 && !dev->model->is_cis &&
-        dev->model->line_mode_color_order == ColorOrder::RGB)
-    {
-        needs_reorder = 0;
-    }
-#endif
-    if (channels == 3 && depth == 8 && !dev->model->is_cis &&
-        dev->model->line_mode_color_order == ColorOrder::RGB)
-    {
-        needs_reorder = 0;
-    }
-
-  needs_ccd = dev->current_setup.max_shift > 0;
-  needs_shrink = dev->settings.requested_pixels != src_pixels;
-  needs_reverse = depth == 1;
-
-  DBG(DBG_info, "%s: using filters:%s%s%s%s\n", __func__,
-      needs_reorder ? " reorder" : "",
-      needs_ccd ? " ccd" : "",
-      needs_shrink ? " shrink" : "",
-      needs_reverse ? " reverse" : "");
-
   DBG(DBG_info, "%s: frontend requested %lu bytes\n", __func__, (u_long) * len);
 
   DBG(DBG_info, "%s: bytes_to_read=%lu, total_bytes_read=%lu\n", __func__,
@@ -3733,8 +3699,7 @@ Problems with the first approach:
   src_buffer = &(dev->read_buffer);
 
 /* maybe reorder components/bytes */
-  if (needs_reorder)
-    {
+    if (dev->session.pipeline_needs_reorder) {
         if (depth == 1) {
             throw SaneException("Can't reorder single bit data\n");
         }
@@ -3828,8 +3793,8 @@ Problems with the first approach:
       src_buffer = dst_buffer;
     }
 
-/* maybe reverse effects of ccd layout */
-  if (needs_ccd)
+    // maybe reverse effects of ccd layout
+    if (dev->session.pipeline_needs_ccd)
     {
         // should not happen with depth == 1.
         if (depth == 1) {
@@ -3878,9 +3843,8 @@ Problems with the first approach:
       src_buffer = dst_buffer;
     }
 
-/* maybe shrink(or enlarge) lines */
-  if (needs_shrink)
-    {
+    // maybe shrink(or enlarge) lines
+    if (dev->session.pipeline_needs_shrink) {
 
       dst_buffer = &(dev->out_buffer);
 
@@ -3933,8 +3897,7 @@ Problems with the first approach:
     bytes = *len;
   work_buffer_src = src_buffer->get_read_pos();
 
-  if (needs_reverse)
-    {
+    if (dev->session.pipeline_needs_reverse) {
         genesys_reverse_bits(work_buffer_src, destination, bytes);
       *len = bytes;
     }

backend/genesys_low.cc

@@ -1204,6 +1204,35 @@ void compute_session_buffer_sizes(AsicType asic, ScanSession& s)
     }
 }
 
+void compute_session_pipeline(const Genesys_Device* dev, ScanSession& s)
+{
+    auto channels = s.params.channels;
+    auto depth = s.params.depth;
+
+    s.pipeline_needs_reorder = true;
+    if (channels != 3 && depth != 16) {
+        s.pipeline_needs_reorder = false;
+    }
+#ifndef WORDS_BIGENDIAN
+    if (channels != 3 && depth == 16) {
+        s.pipeline_needs_reorder = false;
+    }
+    if (channels == 3 && depth == 16 && !dev->model->is_cis &&
+        dev->model->line_mode_color_order == ColorOrder::RGB)
+    {
+        s.pipeline_needs_reorder = false;
+    }
+#endif
+    if (channels == 3 && depth == 8 && !dev->model->is_cis &&
+        dev->model->line_mode_color_order == ColorOrder::RGB)
+    {
+        s.pipeline_needs_reorder = false;
+    }
+    s.pipeline_needs_ccd = s.max_color_shift_lines + s.num_staggered_lines > 0;
+    s.pipeline_needs_shrink = dev->settings.requested_pixels != s.output_pixels;
+    s.pipeline_needs_reverse = depth == 1;
+}
+
 void compute_session(Genesys_Device* dev, ScanSession& s, const Genesys_Sensor& sensor)
 {
     DBG_HELPER(dbg);
@@ -1385,6 +1414,7 @@ void compute_session(Genesys_Device* dev, ScanSession& s, const Genesys_Sensor&
     }
 
     compute_session_buffer_sizes(dev->model->asic_type, s);
+    compute_session_pipeline(dev, s);
 }
 
 static std::size_t get_usb_buffer_read_size(AsicType asic, const ScanSession& session)
@@ -2106,6 +2136,11 @@ void debug_dump(unsigned level, const ScanSession& session)
     DBG(level, "    buffer_size_read : %zu\n", session.buffer_size_lines);
     DBG(level, "    buffer_size_shrink : %zu\n", session.buffer_size_shrink);
     DBG(level, "    buffer_size_out : %zu\n", session.buffer_size_out);
+    DBG(level, "    filters:%s%s%s%s\n",
+        session.pipeline_needs_reorder ? " reorder" : "",
+        session.pipeline_needs_ccd ? " ccd" : "",
+        session.pipeline_needs_shrink ? " shrink" : "",
+        session.pipeline_needs_reverse ? " reverse" : "");
     debug_dump(level, session.params);
 }
 

backend/genesys_settings.h

@@ -294,6 +294,12 @@ struct ScanSession {
     // whether to enable ledadd functionality
     bool enable_ledadd = false;
 
+    // what pipeline modifications are needed
+    bool pipeline_needs_reorder = false;
+    bool pipeline_needs_ccd = false;
+    bool pipeline_needs_shrink = false;
+    bool pipeline_needs_reverse = false;
+
     void assert_computed() const
     {
         if (!computed) {