diff --git a/Makefile b/Makefile
index c9f0abb..f3c0be5 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,4 @@
 RM      := rm -f
-CC      := gcc
 CFLAGS  := -O3 -Wall -Isrc -I/usr/include/ffmpeg
 LIBS    := -lavformat -lavutil -lavcodec
 LDFLAGS :=
diff --git a/src/stat.c b/src/stat.c
index f654906..535280a 100644
--- a/src/stat.c
+++ b/src/stat.c
@@ -30,6 +30,11 @@ int main(int argc, char *argv[])
         return -1;
     }
 
+    if (avformat_find_stream_info(format, NULL) < 0) {
+        printf("Couldn't read file \n");
+        return -1;
+    }
+
     if (!mediatools_validate_video(format)) {
         // Error is printed by validation function
         return -1;
diff --git a/src/validation.c b/src/validation.c
index d1a5e91..7b02e16 100644
--- a/src/validation.c
+++ b/src/validation.c
@@ -62,7 +62,7 @@ int mediatools_validate_video(AVFormatContext *format)
                 ;
             }
         }
-    } else if (strstr(iformat->name, "gif")) {
+    } else if (strcmp(iformat->name, "gif") == 0) {
         switch (vpar->codec_id) {
         default:
             printf("Bad video codec for GIF container (must be GIF)\n");
@@ -70,18 +70,43 @@ int mediatools_validate_video(AVFormatContext *format)
         case AV_CODEC_ID_GIF:
             ;
         }
+    } else if (strcmp(iformat->name, "image2") == 0) {
+        switch (vpar->codec_id) {
+        default:
+            printf("Bad video codec for image2 container (must be JPEG)\n");
+            return false;
+        case AV_CODEC_ID_MJPEG:
+            ;
+        }
+    } else if (strcmp(iformat->name, "png_pipe") == 0 || strcmp(iformat->name, "apng") == 0) {
+        switch (vpar->codec_id) {
+        default:
+            printf("Bad video codec for PNG container (must be PNG)\n");
+            return false;
+        case AV_CODEC_ID_PNG:
+        case AV_CODEC_ID_APNG:
+            ;
+        }
+    } else if (strcmp(iformat->name, "svg_pipe") == 0) {
+        switch (vpar->codec_id) {
+        default:
+            printf("Bad video codec for SVG container (must be SVG)\n");
+            return false;
+        case AV_CODEC_ID_SVG:
+            ;
+        }
     } else {
         printf("Unknown input format\n");
         return false;
     }
 
-    if (vpar->width < 2 || vpar->width > 4096) {
-        printf("Bad width %d (must be 2..4096)\n", vpar->width);
+    if (vpar->width < 1 || vpar->width > 4096) {
+        printf("Bad width %d (must be 1..4096)\n", vpar->width);
         return false;
     }
 
-    if (vpar->height < 2 || vpar->height > 4096) {
-        printf("Bad height %d (must be 2..4096)\n", vpar->height);
+    if (vpar->height < 1 || vpar->height > 4096) {
+        printf("Bad height %d (must be 1..4096)\n", vpar->height);
         return false;
     }