genesys: Add output_line_bytes_requested to the session struct

backend/genesys_gl124.cc

@@ -1042,9 +1042,7 @@ static void gl124_init_scan_regs(Genesys_Device* dev, const Genesys_Sensor& sens
     dev->current_setup.max_shift = session.max_color_shift_lines + session.num_staggered_lines;
 
     dev->total_bytes_read = 0;
-    dev->total_bytes_to_read =
-            multiply_by_depth_ceil(session.params.get_requested_pixels() * session.params.lines,
-                                   session.params.depth) * session.params.channels;
+    dev->total_bytes_to_read = session.output_line_bytes_requested * session.params.lines;
 
     DBG(DBG_info, "%s: total bytes to send to frontend = %lu\n", __func__,
         (u_long) dev->total_bytes_to_read);

backend/genesys_gl646.cc

@@ -706,9 +706,7 @@ static void gl646_setup_registers(Genesys_Device* dev,
     dev->current_setup.max_shift = session.max_color_shift_lines + session.num_staggered_lines;
 
     dev->total_bytes_read = 0;
-    dev->total_bytes_to_read =
-            multiply_by_depth_ceil(session.params.get_requested_pixels() * session.params.lines,
-                                   session.params.depth) * session.params.channels;
+    dev->total_bytes_to_read = session.output_line_bytes_requested * session.params.lines;
 
     /* select color filter based on settings */
     regs->find_reg(0x04).value &= ~REG04_FILTER;

backend/genesys_gl841.cc

@@ -1864,9 +1864,7 @@ dummy \ scanned lines
     dev->current_setup.max_shift = session.max_color_shift_lines + session.num_staggered_lines;
 
     dev->total_bytes_read = 0;
-    dev->total_bytes_to_read =
-            multiply_by_depth_ceil(session.params.get_requested_pixels() * session.params.lines,
-                                   session.params.depth) * session.params.channels;
+    dev->total_bytes_to_read = session.output_line_bytes_requested * session.params.lines;
 
   DBG(DBG_info, "%s: total bytes to send = %lu\n", __func__, (u_long) dev->total_bytes_to_read);
 }

backend/genesys_gl843.cc

@@ -1292,9 +1292,7 @@ static void gl843_init_scan_regs(Genesys_Device* dev, const Genesys_Sensor& sens
   dev->current_setup.max_shift = session.max_color_shift_lines + session.num_staggered_lines;
 
   dev->total_bytes_read = 0;
-    dev->total_bytes_to_read =
-            multiply_by_depth_ceil(session.params.get_requested_pixels() * session.params.lines,
-                                   session.params.depth) * session.params.channels;
+    dev->total_bytes_to_read = session.output_line_bytes_requested * session.params.lines;
 
   DBG(DBG_info, "%s: total bytes to send = %lu\n", __func__, (u_long) dev->total_bytes_to_read);
 }

backend/genesys_gl846.cc

@@ -916,9 +916,7 @@ static void gl846_init_scan_regs(Genesys_Device* dev, const Genesys_Sensor& sens
     dev->current_setup.max_shift = session.max_color_shift_lines + session.num_staggered_lines;
 
     dev->total_bytes_read = 0;
-    dev->total_bytes_to_read =
-            multiply_by_depth_ceil(session.params.get_requested_pixels() * session.params.lines,
-                                   session.params.depth) * session.params.channels;
+    dev->total_bytes_to_read = session.output_line_bytes_requested * session.params.lines;
 
   DBG(DBG_info, "%s: total bytes to send = %lu\n", __func__, (u_long) dev->total_bytes_to_read);
 }

backend/genesys_gl847.cc

@@ -927,9 +927,7 @@ static void gl847_init_scan_regs(Genesys_Device* dev, const Genesys_Sensor& sens
     dev->current_setup.max_shift = session.max_color_shift_lines + session.num_staggered_lines;
 
     dev->total_bytes_read = 0;
-    dev->total_bytes_to_read =
-            multiply_by_depth_ceil(session.params.get_requested_pixels() * session.params.lines,
-                                   session.params.depth) * session.params.channels;
+    dev->total_bytes_to_read = session.output_line_bytes_requested * session.params.lines;
 
   DBG(DBG_info, "%s: total bytes to send = %lu\n", __func__, (u_long) dev->total_bytes_to_read);
 /* END TODO */

backend/genesys_low.cc

@@ -1522,6 +1522,9 @@ void compute_session(Genesys_Device* dev, ScanSession& s, const Genesys_Sensor&
             s.params.depth);
     }
 
+    s.output_line_bytes_requested = multiply_by_depth_ceil(
+            s.params.get_requested_pixels() * s.params.channels, s.params.depth);
+
     s.output_total_bytes_raw = s.output_line_bytes_raw * s.output_line_count;
     s.output_total_bytes = s.output_line_bytes * s.output_line_count;
 

backend/genesys_settings.h

@@ -251,6 +251,9 @@ struct ScanSession {
     // Equal to output_line_bytes if sensor does not have segments
     unsigned output_line_bytes_raw = 0;
 
+    // the number of bytes per line as requested by the frontend
+    unsigned output_line_bytes_requested = 0;
+
     // the number of lines in the output of the scanner. This must be larger than the user
     // requested number due to line staggering and color channel shifting.
     unsigned output_line_count = 0;