Added support for PNG/XMP. Indentation. And fixed pull mode to parse the file.

Original commit message from CVS:
Added support for PNG/XMP. Indentation. And fixed pull mode to parse the file.

1 files changed, 245 insertions, 0 deletions

diff --git a/ext/metadata/metadataparsepng.c b/ext/metadata/metadataparsepng.c
new file mode 100644
index 00000000..9c3241cf
--- /dev/null
+++ b/ext/metadata/metadataparsepng.c
@@ -0,0 +1,245 @@
+/*
+ * GStreamer
+ * Copyright 2007 Edgard Lima <edgard.lima@indt.org.br>
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Alternatively, the contents of this file may be used under the
+ * GNU Lesser General Public License Version 2.1 (the "LGPL"), in
+ * which case the following provisions apply instead of the ones
+ * mentioned above:
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include "metadataparsepng.h"
+
+#include <string.h>
+
+static int
+metadataparse_png_reading (PngData * png_data, guint8 ** buf,
+    guint32 * bufsize, guint8 ** next_start, guint32 * next_size);
+
+static int
+metadataparse_png_xmp (PngData * png_data, guint8 ** buf,
+    guint32 * bufsize, guint8 ** next_start, guint32 * next_size);
+
+static int
+metadataparse_png_jump (PngData * png_data, guint8 ** buf,
+    guint32 * bufsize, guint8 ** next_start, guint32 * next_size);
+
+#define READ(buf, size) ( (size)--, *((buf)++) )
+
+void
+metadataparse_png_init (PngData * png_data, GstAdapter ** adpt_exif,
+    GstAdapter ** adpt_iptc, GstAdapter ** adpt_xmp)
+{
+  png_data->state = PNG_NULL;
+  png_data->adpt_xmp = adpt_xmp;
+  png_data->read = 0;
+
+  metadataparse_xmp_init ();
+}
+
+void
+metadataparse_png_dispose (PngData * png_data)
+{
+  metadataparse_xmp_dispose ();
+
+  png_data->adpt_xmp = NULL;
+}
+
+int
+metadataparse_png_parse (PngData * png_data, guint8 * buf,
+    guint32 * bufsize, guint8 ** next_start, guint32 * next_size)
+{
+
+  int ret = 0;
+  guint8 mark[8];
+
+  *next_start = buf;
+
+  if (png_data->state == PNG_NULL) {
+
+    if (*bufsize < 8) {
+      *next_size = (buf - *next_start) + 8;
+      ret = 1;
+      goto done;
+    }
+
+    mark[0] = READ (buf, *bufsize);
+    mark[1] = READ (buf, *bufsize);
+    mark[2] = READ (buf, *bufsize);
+    mark[3] = READ (buf, *bufsize);
+    mark[4] = READ (buf, *bufsize);
+    mark[5] = READ (buf, *bufsize);
+    mark[6] = READ (buf, *bufsize);
+    mark[7] = READ (buf, *bufsize);
+
+    if (mark[0] != 0x89 || mark[1] != 0x50 || mark[2] != 0x4E || mark[3] != 0x47
+        || mark[4] != 0x0D || mark[5] != 0x0A || mark[6] != 0x1A
+        || mark[7] != 0x0A) {
+      ret = -1;
+      goto done;
+    }
+
+    png_data->state = PNG_READING;
+
+  }
+
+  while (ret == 0) {
+    switch (png_data->state) {
+      case PNG_READING:
+        ret =
+            metadataparse_png_reading (png_data, &buf, bufsize, next_start,
+            next_size);
+        break;
+      case PNG_JUMPING:
+        ret =
+            metadataparse_png_jump (png_data, &buf, bufsize, next_start,
+            next_size);
+        break;
+      case PNG_XMP:
+        ret =
+            metadataparse_png_xmp (png_data, &buf, bufsize, next_start,
+            next_size);
+        break;
+      case PNG_DONE:
+        goto done;
+        break;
+      default:
+        ret = -1;
+        break;
+    }
+  }
+
+done:
+
+  return ret;
+
+}
+
+
+/* look for markers */
+static int
+metadataparse_png_reading (PngData * png_data, guint8 ** buf,
+    guint32 * bufsize, guint8 ** next_start, guint32 * next_size)
+{
+
+  int ret = -1;
+  guint8 mark[4];
+  guint32 chunk_size = 0;
+
+  static const char XmpHeader[] = "XML:com.adobe.xmp";
+
+  *next_start = *buf;
+
+  if (*bufsize < 8) {
+    *next_size = (*buf - *next_start) + 8;
+    ret = 1;
+    goto done;
+  }
+
+  chunk_size = READ (*buf, *bufsize) << 24;
+  chunk_size += READ (*buf, *bufsize) << 16;
+  chunk_size += READ (*buf, *bufsize) << 8;
+  chunk_size += READ (*buf, *bufsize);
+
+  mark[0] = READ (*buf, *bufsize);
+  mark[1] = READ (*buf, *bufsize);
+  mark[2] = READ (*buf, *bufsize);
+  mark[3] = READ (*buf, *bufsize);
+
+  if (mark[0] == 'I' && mark[1] == 'E' && mark[2] == 'N' && mark[3] == 'D') {
+    ret = 0;
+    png_data->state = PNG_DONE;
+    goto done;
+  }
+
+  if (mark[0] == 'i' && mark[1] == 'T' && mark[2] == 'X' && mark[3] == 't') {
+    if (chunk_size >= 22) {     /* "XML:com.adobe.xmp" plus some flags */
+      if (*bufsize < 22) {
+        *next_size = (*buf - *next_start) + 22;
+        ret = 1;
+        goto done;
+      }
+
+      if (png_data->adpt_xmp) {
+        if (0 == memcmp (XmpHeader, *buf, 18)) {
+          *buf += 22;           /* jump "XML:com.adobe.xmp" plus some flags */
+          *bufsize -= 22;
+          png_data->read = chunk_size - 22;     /* four CRC bytes at the end will be jumped after */
+          png_data->state = PNG_XMP;
+          ret = 0;
+          goto done;
+        }
+      }
+    }
+  }
+
+  /* just set jump sise  */
+  png_data->read = chunk_size + 4;      /* four CRC bytes at the end */
+  png_data->state = PNG_JUMPING;
+  ret = 0;
+
+done:
+
+  return ret;
+
+
+}
+
+static int
+metadataparse_png_jump (PngData * png_data, guint8 ** buf,
+    guint32 * bufsize, guint8 ** next_start, guint32 * next_size)
+{
+  png_data->state = PNG_READING;
+  return metadataparse_util_jump_chunk (&png_data->read, buf,
+      bufsize, next_start, next_size);
+}
+
+static int
+metadataparse_png_xmp (PngData * png_data, guint8 ** buf,
+    guint32 * bufsize, guint8 ** next_start, guint32 * next_size)
+{
+  int ret;
+
+  ret = metadataparse_util_hold_chunk (&png_data->read, buf,
+      bufsize, next_start, next_size, png_data->adpt_xmp);
+  if (ret == 0) {
+    /* jump four CRC bytes at the end of chunk */
+    png_data->read = 4;
+    png_data->state = PNG_JUMPING;
+  }
+  return ret;
+
+}