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, 2 insertions, 1 deletions

diff --git a/apps/plugins/imageviewer/ppm/ppm.c b/apps/plugins/imageviewer/ppm/ppm.c
index 20200d812e..5e03f8c335 100644
--- a/apps/plugins/imageviewer/ppm/ppm.c
+++ b/apps/plugins/imageviewer/ppm/ppm.c
@@ -150,8 +150,9 @@ static int load_image(char *filename, struct image_info *info,
     return PLUGIN_OK;
 }
 
-static int get_image(struct image_info *info, int ds)
+static int get_image(struct image_info *info, int frame, int ds)
 {
+    (void)frame;
     unsigned char **p_disp = &disp[ds]; /* short cut */
     struct ppm_info *p_ppm = &ppm;