From 723847d5d71d891d8830a3171bc6eb68967bd683 Mon Sep 17 00:00:00 2001
From: James Zern <jzern@google.com>
Date: Sun, 17 Mar 2013 18:08:01 -0700
Subject: [PATCH] gif2webp: only write error messages to stderr

also output something if -o is not given, but the process succeeded

Change-Id: I466c377f0cbf8c9f45bb1839191b04dada9c5f0f
---
 examples/gif2webp.c | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/examples/gif2webp.c b/examples/gif2webp.c
index 5f4d275c..53694417 100644
--- a/examples/gif2webp.c
+++ b/examples/gif2webp.c
@@ -343,11 +343,11 @@ int main(int argc, const char *argv[]) {
           goto End;
         }
         if (verbose) {
-          fprintf(stderr, "Added frame %dx%d (offset:%d,%d duration:%d) ",
-                  view.width, view.height, frame.x_offset, frame.y_offset,
-                  frame.duration);
-          fprintf(stderr, "dispose:%d transparent index:%d\n",
-                  frame.dispose_method, transparent_index);
+          printf("Added frame %dx%d (offset:%d,%d duration:%d) ",
+                 view.width, view.height, frame.x_offset, frame.y_offset,
+                 frame.duration);
+          printf("dispose:%d transparent index:%d\n",
+                 frame.dispose_method, transparent_index);
         }
         WebPDataClear(&frame.bitstream);
         break;
@@ -392,7 +392,7 @@ int main(int argc, const char *argv[]) {
               if (data == NULL) goto End;  // Loop count sub-block missing.
               if (data[0] != 3 && data[1] != 1) break;   // wrong size/marker
               anim.loop_count = data[2] | (data[3] << 8);
-              if (verbose) fprintf(stderr, "Loop count: %d\n", anim.loop_count);
+              if (verbose) printf("Loop count: %d\n", anim.loop_count);
             } else if (!memcmp(data + 1, "XMP dataXMP", 11)) {
               // Read XMP metadata.
               WebPData xmp;
@@ -401,7 +401,7 @@ int main(int argc, const char *argv[]) {
               xmp.bytes = (uint8_t*)data;
               xmp.size = data[0] + 1;
               WebPMuxSetChunk(mux, "XMP ", &xmp, 1);
-              if (verbose) fprintf(stderr, "XMP size: %zu\n", xmp.size);
+              if (verbose) printf("XMP size: %zu\n", xmp.size);
             } else if (!memcmp(data + 1, "ICCRGBG1012", 11)) {
               // Read ICC profile.
               WebPData icc;
@@ -410,7 +410,7 @@ int main(int argc, const char *argv[]) {
               icc.bytes = (uint8_t*)data;
               icc.size = data[0] + 1;
               WebPMuxSetChunk(mux, "ICCP", &icc, 1);
-              if (verbose) fprintf(stderr, "ICC size: %zu\n", icc.size);
+              if (verbose) printf("ICC size: %zu\n", icc.size);
             }
             break;
           }
@@ -454,7 +454,13 @@ int main(int argc, const char *argv[]) {
       fprintf(stderr, "Error writing output file: %s\n", out_file);
       goto End;
     }
-    if (!quiet) fprintf(stderr, "Saved output file: %s\n", out_file);
+    if (!quiet) {
+      printf("Saved output file: %s\n", out_file);
+    }
+  } else {
+    if (!quiet) {
+      printf("Nothing written; use -o flag to save the result.\n");
+    }
   }
 
   // All OK.