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, 99 insertions, 0 deletions

diff --git a/apps/plugins/imageviewer/gif/gif_err.c b/apps/plugins/imageviewer/gif/gif_err.c
new file mode 100644
index 0000000..abfb579
--- /dev/null
+++ b/apps/plugins/imageviewer/gif/gif_err.c
@@ -0,0 +1,99 @@
+/*****************************************************************************
+
+gif_err.c - handle error reporting for the GIF library.
+
+****************************************************************************/
+
+/* #include <stdio.h> */
+
+#include "gif_lib.h"
+#include "gif_lib_private.h"
+
+/*****************************************************************************
+ Return a string description of  the last GIF error
+*****************************************************************************/
+char *
+GifErrorString(int ErrorCode)
+{
+    char *Err;
+
+    switch (ErrorCode) {
+#if 0
+      case E_GIF_ERR_OPEN_FAILED:
+        Err = "Failed to open given file";
+        break;
+      case E_GIF_ERR_WRITE_FAILED:
+        Err = "Failed to write to given file";
+        break;
+      case E_GIF_ERR_HAS_SCRN_DSCR:
+        Err = "Screen descriptor has already been set";
+        break;
+      case E_GIF_ERR_HAS_IMAG_DSCR:
+        Err = "Image descriptor is still active";
+        break;
+      case E_GIF_ERR_NO_COLOR_MAP:
+        Err = "Neither global nor local color map";
+        break;
+      case E_GIF_ERR_DATA_TOO_BIG:
+        Err = "Number of pixels bigger than width * height";
+        break;
+      case E_GIF_ERR_NOT_ENOUGH_MEM:
+        Err = "Failed to allocate required memory";
+        break;
+      case E_GIF_ERR_DISK_IS_FULL:
+        Err = "Write failed (disk full?)";
+        break;
+      case E_GIF_ERR_CLOSE_FAILED:
+        Err = "Failed to close given file";
+        break;
+      case E_GIF_ERR_NOT_WRITEABLE:
+        Err = "Given file was not opened for write";
+        break;
+#endif
+      case D_GIF_ERR_OPEN_FAILED:
+        Err = "Failed to open given file";
+        break;
+      case D_GIF_ERR_READ_FAILED:
+        Err = "Failed to read from given file";
+        break;
+      case D_GIF_ERR_NOT_GIF_FILE:
+        Err = "Data is not in GIF format";
+        break;
+      case D_GIF_ERR_NO_SCRN_DSCR:
+        Err = "No screen descriptor detected";
+        break;
+      case D_GIF_ERR_NO_IMAG_DSCR:
+        Err = "No Image Descriptor detected";
+        break;
+      case D_GIF_ERR_NO_COLOR_MAP:
+        Err = "Neither global nor local color map";
+        break;
+      case D_GIF_ERR_WRONG_RECORD:
+        Err = "Wrong record type detected";
+        break;
+      case D_GIF_ERR_DATA_TOO_BIG:
+        Err = "Number of pixels bigger than width * height";
+        break;
+      case D_GIF_ERR_NOT_ENOUGH_MEM:
+        Err = "Failed to allocate required memory";
+        break;
+      case D_GIF_ERR_CLOSE_FAILED:
+        Err = "Failed to close given file";
+        break;
+      case D_GIF_ERR_NOT_READABLE:
+        Err = "Given file was not opened for read";
+        break;
+      case D_GIF_ERR_IMAGE_DEFECT:
+        Err = "Image is defective, decoding aborted";
+        break;
+      case D_GIF_ERR_EOF_TOO_SOON:
+        Err = "Image EOF detected before image complete";
+        break;
+      default:
+        Err = NULL;
+        break;
+    }
+    return Err;
+}
+
+/* end */