[gegl] jpg-save: Add JPEG save op

[Mukund Sivaraman <muks src gnome org>]

commit aebe83954a91256c79a067656f13bd9c0dde9fc8
Author: Mukund Sivaraman <muks banu com>
Date:   Thu Sep 8 12:17:15 2011 +0530

    jpg-save: Add JPEG save op

 operations/external/Makefile.am |    5 +-
 operations/external/jpg-save.c  |  153 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 157 insertions(+), 1 deletions(-)
---
diff --git a/operations/external/Makefile.am b/operations/external/Makefile.am
index 815d16c..2befbb7 100644
--- a/operations/external/Makefile.am
+++ b/operations/external/Makefile.am
@@ -36,9 +36,12 @@ png_save_la_CFLAGS = $(AM_CFLAGS) $(PNG_CFLAGS)
 endif
 
 if HAVE_JPEG
-ops += jpg-load.la
+ops += jpg-load.la jpg-save.la
 jpg_load_la_SOURCES = jpg-load.c
 jpg_load_la_LIBADD = $(op_libs) $(LIBJPEG)
+
+jpg_save_la_SOURCES = jpg-save.c
+jpg_save_la_LIBADD = $(op_libs) $(LIBJPEG)
 endif
 
 if HAVE_CAIRO
diff --git a/operations/external/jpg-save.c b/operations/external/jpg-save.c
new file mode 100644
index 0000000..cf4f8ec
--- /dev/null
+++ b/operations/external/jpg-save.c
@@ -0,0 +1,153 @@
+/* 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 2011 Mukund Sivaraman <muks banu com>
+ */
+
+#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 (between 1 and 100)"))
+gegl_chant_boolean (optimize, _("Optimize"), TRUE,
+                    _("Use optimized huffman tables"))
+gegl_chant_boolean (progressive, _("Progressive"), TRUE,
+                    _("Create progressive JPEG images"))
+
+#else
+
+#define GEGL_CHANT_TYPE_SINK
+#define GEGL_CHANT_C_FILE       "jpg-save.c"
+
+#include "gegl-chant.h"
+#include <stdio.h>
+#include <jpeglib.h>
+
+static gint
+gegl_buffer_export_jpg (GeglBuffer  *gegl_buffer,
+                        const gchar *path,
+                        gint         quality,
+                        gboolean     optimize,
+                        gboolean     progressive,
+                        gint         src_x,
+                        gint         src_y,
+                        gint         width,
+                        gint         height)
+{
+  FILE *fp;
+  struct jpeg_compress_struct cinfo;
+  struct jpeg_error_mgr jerr;
+  gint row_stride;
+  JSAMPROW row_pointer[1];
+
+  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.image_width = width;
+  cinfo.image_height = height;
+  cinfo.input_components = 3;
+  cinfo.in_color_space = JCS_RGB;
+
+  jpeg_set_defaults (&cinfo);
+  jpeg_set_quality (&cinfo, quality, TRUE);
+  cinfo.optimize_coding = optimize;
+  if (progressive)
+    jpeg_simple_progression (&cinfo);
+
+  jpeg_start_compress (&cinfo, TRUE);
+
+  row_stride = width * 3;
+  row_pointer[0] = g_malloc0 (row_stride);
+
+  while (cinfo.next_scanline < cinfo.image_height) {
+    GeglRectangle rect;
+
+    rect.x = src_x;
+    rect.y = src_y + cinfo.next_scanline;
+    rect.width = width;
+    rect.height = 1;
+
+    gegl_buffer_get (gegl_buffer, 1.0, &rect, babl_format ("R'G'B' u8"),
+		     row_pointer[0], GEGL_AUTO_ROWSTRIDE);
+
+    jpeg_write_scanlines (&cinfo, row_pointer, 1);
+  }
+
+  jpeg_finish_compress (&cinfo);
+
+  g_free (row_pointer[0]);
+
+  if (stdout != fp)
+    fclose (fp);
+
+  return 0;
+}
+
+static gboolean
+gegl_jpg_save_process (GeglOperation       *operation,
+                       GeglBuffer          *input,
+                       const GeglRectangle *result)
+{
+  GeglChantO *o = GEGL_CHANT_PROPERTIES (operation);
+
+  gegl_buffer_export_jpg (input, o->path, o->quality,
+                          o->optimize, 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    = gegl_jpg_save_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