[gegl] jpg-save: Add support for saving JPEG images

[Mukund Sivaraman <muks src gnome org>]

commit 3302521bbe7fba67cb65b268b019dcfac9944bdb
Author: Mukund Sivaraman <muks banu com>
Date:   Sat Jun 11 16:22:54 2011 +0530

    jpg-save: Add support for saving JPEG images

 operations/workshop/external/Makefile.am |    6 +
 operations/workshop/external/jpg-save.c  |  167 ++++++++++++++++++++++++++++++
 2 files changed, 173 insertions(+), 0 deletions(-)
---
diff --git a/operations/workshop/external/Makefile.am b/operations/workshop/external/Makefile.am
index 6496ab5..7c64e11 100644
--- a/operations/workshop/external/Makefile.am
+++ b/operations/workshop/external/Makefile.am
@@ -32,5 +32,11 @@ gluas_la_LIBADD  = $(op_libs) $(LUA_LIBS)
 gluas_la_CFLAGS  = $(LUA_CFLAGS) $(BABL_CFLAGS) $(GLIB_CFLAGS)
 endif
 
+if HAVE_JPEG
+ops += jpg-save.la
+jpg_save_la_SOURCES = jpg-save.c
+jpg_save_la_LIBADD = $(op_libs) $(LIBJPEG)
+endif
+
 opdir = $(libdir)/gegl- GEGL_API_VERSION@
 op_LTLIBRARIES = $(ops)
diff --git a/operations/workshop/external/jpg-save.c b/operations/workshop/external/jpg-save.c
new file mode 100644
index 0000000..502ad1d
--- /dev/null
+++ b/operations/workshop/external/jpg-save.c
@@ -0,0 +1,167 @@
+/* This file is an image processing operation for GEGL
+ *
+ * GEGL is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * GEGL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with GEGL; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2006 �yvind Kolås <pippin gimp org>
+ *           2006 Dominik Ernst <dernst gmx de>
+ */
+
+#include "config.h"
+#include <glib/gi18n-lib.h>
+
+
+#ifdef GEGL_CHANT_PROPERTIES
+
+gegl_chant_string (path, _("File"), "",
+                   _("Target path and filename, use '-' for stdout."))
+gegl_chant_int    (quality, _("Quality"),
+                   1, 100, 90, _("JPEG compression quality from 1 to 100"))
+gegl_chant_int    (smoothing, _("Smoothing"),
+                   0, 100, 0, _("Smoothing factor from 1 to 100; 0 disables smoothing"))
+gegl_chant_boolean (progressive, _("Progressive"), TRUE,
+                    _("Whether to create progressive JPEGs"))
+
+#else
+
+#define GEGL_CHANT_TYPE_SINK
+#define GEGL_CHANT_C_FILE       "jpg-save.c"
+
+#include "gegl-chant.h"
+#include <glib/gstdio.h>
+#include <jpeglib.h>
+#include <jerror.h>
+#include <stdio.h>
+
+static gint
+gegl_buffer_export_jpeg (GeglBuffer  *gegl_buffer,
+                         const gchar *path,
+                         gint         quality,
+                         gint         smoothing,
+                         gboolean     progressive,
+                         gint         src_x,
+                         gint         src_y,
+                         gint         width,
+                         gint         height)
+{
+  FILE                        *fp;
+  struct jpeg_compress_struct  cinfo;
+  struct jpeg_error_mgr        jerr;
+  guchar                      *pixels;
+
+  if (!strcmp (path, "-"))
+    fp = stdout;
+  else
+    fp = fopen (path, "wb");
+
+  if (!fp)
+    return -1;
+
+  cinfo.err = jpeg_std_error (&jerr);
+  jpeg_create_compress (&cinfo);
+
+  jpeg_stdio_dest (&cinfo, fp);
+
+  cinfo.input_components = 3;
+  cinfo.image_width = width;
+  cinfo.image_height = height;
+  cinfo.in_color_space = JCS_RGB;
+
+  jpeg_set_defaults (&cinfo);
+  jpeg_set_quality (&cinfo, quality, TRUE);
+
+  cinfo.smoothing_factor = smoothing;
+  cinfo.optimize_coding = TRUE;
+
+  if (progressive)
+    jpeg_simple_progression (&cinfo);
+
+  /* Use 1x1,1x1,1x1 MCUs and no subsampling */
+  cinfo.comp_info[0].h_samp_factor = 1;
+  cinfo.comp_info[0].v_samp_factor = 1;
+  cinfo.comp_info[1].h_samp_factor = 1;
+  cinfo.comp_info[1].v_samp_factor = 1;
+  cinfo.comp_info[2].h_samp_factor = 1;
+  cinfo.comp_info[2].v_samp_factor = 1;
+
+  /* No restart markers */
+  cinfo.restart_interval = 0;
+  cinfo.restart_in_rows = 0;
+
+  jpeg_start_compress (&cinfo, TRUE);
+
+  pixels = g_malloc0 (cinfo.image_width * cinfo.input_components);
+
+  while (cinfo.next_scanline < cinfo.image_height)
+    {
+      GeglRectangle rect;
+
+      rect.x = src_x;
+      rect.y = src_y + cinfo.next_scanline;
+      rect.width = cinfo.image_width;
+      rect.height = 1;
+
+      gegl_buffer_get (gegl_buffer, 1.0, &rect,
+                       babl_format ("R'G'B' u8"),
+                       pixels, GEGL_AUTO_ROWSTRIDE);
+
+      jpeg_write_scanlines (&cinfo, (JSAMPARRAY) &pixels, 1);
+    }
+
+  jpeg_finish_compress (&cinfo);
+  jpeg_destroy_compress (&cinfo);
+
+  g_free (pixels);
+
+  if (stdout != fp)
+    fclose (fp);
+
+  return 0;
+}
+
+static gboolean
+process (GeglOperation       *operation,
+         GeglBuffer          *input,
+         const GeglRectangle *result)
+{
+  GeglChantO *o = GEGL_CHANT_PROPERTIES (operation);
+
+  gegl_buffer_export_jpeg (input, o->path, o->quality,
+                           o->smoothing, o->progressive,
+                           result->x, result->y,
+                           result->width, result->height);
+  return  TRUE;
+}
+
+
+static void
+gegl_chant_class_init (GeglChantClass *klass)
+{
+  GeglOperationClass     *operation_class;
+  GeglOperationSinkClass *sink_class;
+
+  operation_class = GEGL_OPERATION_CLASS (klass);
+  sink_class      = GEGL_OPERATION_SINK_CLASS (klass);
+
+  sink_class->process    = process;
+  sink_class->needs_full = TRUE;
+
+  operation_class->name        = "gegl:jpg-save";
+  operation_class->categories  = "output";
+  operation_class->description =
+    _("JPEG image saver (passes the buffer through, saves as a side-effect.)");
+
+  gegl_extension_handler_register_saver (".jpg", "gegl:jpg-save");
+}
+
+#endif