Fix gif playback speed for some gifs

Some gifs don't provide a frametime at all, so we have to guess one for
ourselves.

Fixes #4

2 files changed, 5 insertions, 1 deletions

diff --git a/src/image.c b/src/image.c
index b2bf2c9..c7bac62 100644
--- a/src/image.c
+++ b/src/image.c
@@ -150,6 +150,10 @@ void imv_image_load_next_frame(struct imv_image *img)
     frame_time = *(int*)FreeImage_GetTagValue(tag);
   }
 
+  /* some gifs don't provide a frame time at all */
+  if(frame_time == 0) {
+    frame_time = 100;
+  }
   img->frame_time += frame_time * 0.001;
 
   FreeImage_UnlockPage(img->mbmp, frame, 0);
diff --git a/src/main.c b/src/main.c
index 950b0ff..67bdd33 100644
--- a/src/main.c
+++ b/src/main.c
@@ -265,6 +265,7 @@ int main(int argc, char** argv)
     if(view.playing) {
       double cur_time = SDL_GetTicks() / 1000.0;
       double dt = cur_time - last_time;
+      last_time = SDL_GetTicks() / 1000.0;
       imv_image_play(&img, dt);
     }
 
@@ -279,7 +280,6 @@ int main(int argc, char** argv)
       view.redraw = 0;
       SDL_RenderPresent(renderer);
     }
-    last_time = SDL_GetTicks() / 1000.0;
     SDL_Delay(10);
   }