imageviewer: gif viewer based on giflib-5.0.2

This adds ability to view gif images in rockbox.
Works both on color and gray/monochrome targets (greylib).
Aspect correction is supported as well.

Limitations:
- animated gifs are restricted to 32 frames
- animated gifs loop always (loopcount is ignored)
- plain text extension is not supported
- animated gifs with interframe delay = 0 are treated as still
  images (web browsers usually treat delay 0 as 100ms to prevent
  exhaustive CPU load by such images)

Change-Id: I61501f801ddcd403410e38d83e6bddc9883e7ede

1 files changed, 44 insertions, 0 deletions

diff --git a/apps/plugins/imageviewer/gif/rb_glue.h b/apps/plugins/imageviewer/gif/rb_glue.h
new file mode 100644
index 0000000000..6cd46b0e56
--- /dev/null
+++ b/apps/plugins/imageviewer/gif/rb_glue.h
@@ -0,0 +1,44 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ *
+ * Copyright (c) 2012 Marcin Bukat
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+#include "plugin.h"
+#include <tlsf.h>
+
+#undef  memset
+#define memset(a,b,c)      rb->memset((a),(b),(c))
+#undef  memmove
+#define memmove(a,b,c)     rb->memmove((a),(b),(c))
+#undef  memcmp
+#define memcmp(a,b,c)      rb->memcmp((a),(b),(c))
+#undef  strncmp
+#define strncmp(a,b,c)     rb->strncmp((a),(b),(c))
+
+#define fread(ptr, size, nmemb, stream) rb->read(stream, ptr, size*nmemb)
+#define fclose(stream) rb->close(stream)
+#define fdopen(a,b) ((a))
+
+#define malloc(a) tlsf_malloc((a))
+#define free(a)   tlsf_free((a))
+#define realloc(a, b) tlsf_realloc((a),(b))
+#define calloc(a,b) tlsf_calloc((a),(b))
+
+#ifndef SIZE_MAX
+#define SIZE_MAX INT_MAX
+#endif