Port the width/height force feature from jpegtran v8d.

git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@881 632fc199-4ca6-4c93-a231-07263d6284db

1 files changed, 23 insertions, 9 deletions

diff --git a/transupp.c b/transupp.c
index ef137217..9e805838 100644
--- a/transupp.c
+++ b/transupp.c
@@ -2,7 +2,7 @@
  * transupp.c
  *
  * This file was part of the Independent JPEG Group's software:
- * Copyright (C) 1997-2009, Thomas G. Lane, Guido Vollbeding.
+ * Copyright (C) 1997-2011, Thomas G. Lane, Guido Vollbeding.
  * Modifications:
  * Copyright (C) 2010, D. R. Commander.
  * For conditions of distribution and use, see the accompanying README file.
@@ -783,7 +783,7 @@ jt_read_integer (const char ** strptr, JDIMENSION * result)
  * The routine returns TRUE if the spec string is valid, FALSE if not.
  *
  * The crop spec string should have the format
- *	<width>x<height>{+-}<xoffset>{+-}<yoffset>
+ *	<width>[f]x<height>[f]{+-}<xoffset>{+-}<yoffset>
  * where width, height, xoffset, and yoffset are unsigned integers.
  * Each of the elements can be omitted to indicate a default value.
  * (A weakness of this style is that it is not possible to omit xoffset
@@ -805,14 +805,22 @@ jtransform_parse_crop_spec (jpeg_transform_info *info, const char *spec)
     /* fetch width */
     if (! jt_read_integer(&spec, &info->crop_width))
       return FALSE;
-    info->crop_width_set = JCROP_POS;
+    if (*spec == 'f' || *spec == 'F') {
+      spec++;
+      info->crop_width_set = JCROP_FORCE;
+    } else
+      info->crop_width_set = JCROP_POS;
   }
-  if (*spec == 'x' || *spec == 'X') {	
+  if (*spec == 'x' || *spec == 'X') {
     /* fetch height */
     spec++;
     if (! jt_read_integer(&spec, &info->crop_height))
       return FALSE;
-    info->crop_height_set = JCROP_POS;
+    if (*spec == 'f' || *spec == 'F') {
+      spec++;
+      info->crop_height_set = JCROP_FORCE;
+    } else
+      info->crop_height_set = JCROP_POS;
   }
   if (*spec == '+' || *spec == '-') {
     /* fetch xoffset */
@@ -997,10 +1005,16 @@ jtransform_request_workspace (j_decompress_ptr srcinfo,
     else
       yoffset = info->crop_yoffset;
     /* Now adjust so that upper left corner falls at an iMCU boundary */
-    info->output_width =
-      info->crop_width + (xoffset % info->iMCU_sample_width);
-    info->output_height =
-      info->crop_height + (yoffset % info->iMCU_sample_height);
+    if (info->crop_width_set == JCROP_FORCE)
+      info->output_width = info->crop_width;
+    else
+      info->output_width =
+        info->crop_width + (xoffset % info->iMCU_sample_width);
+    if (info->crop_height_set == JCROP_FORCE)
+      info->output_height = info->crop_height;
+    else
+      info->output_height =
+        info->crop_height + (yoffset % info->iMCU_sample_height);
     /* Save x/y offsets measured in iMCUs */
     info->x_crop_offset = xoffset / info->iMCU_sample_width;
     info->y_crop_offset = yoffset / info->iMCU_sample_height;