From ab2d08a8425359c982599fb2730463669e61f55c Mon Sep 17 00:00:00 2001
From: James Zern <jzern@google.com>
Date: Thu, 19 Nov 2020 19:15:57 -0800
Subject: [PATCH 1/2] [cd]webp: document lack of animated webp support

Bug: webp:479
Change-Id: Iee2d7401400a5ff0a11682028194e561b365ab78
---
 README           | 5 ++++-
 examples/cwebp.c | 1 +
 examples/dwebp.c | 3 ++-
 man/cwebp.1      | 3 ++-
 man/dwebp.1      | 3 ++-
 5 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/README b/README
index 0baba6ab..89be96f2 100644
--- a/README
+++ b/README
@@ -225,6 +225,7 @@ Usage:
 
 If input size (-s) for an image is not specified, it is
 assumed to be a PNG, JPEG, TIFF or WebP file.
+Note: Animated PNG and WebP files are not supported.
 
 Options:
   -h / -help ............. short help
@@ -344,7 +345,9 @@ The full list of options is available using -h:
 > dwebp -h
 Usage: dwebp in_file [options] [-o out_file]
 
-Decodes the WebP image file to PNG format [Default]
+Decodes the WebP image file to PNG format [Default].
+Note: Animated WebP files are not supported.
+
 Use following options to convert into alternate image formats:
   -pam ......... save the raw RGBA samples as a color PAM
   -ppm ......... save the raw RGB samples as a color PPM
diff --git a/examples/cwebp.c b/examples/cwebp.c
index 68b960d2..927063a4 100644
--- a/examples/cwebp.c
+++ b/examples/cwebp.c
@@ -527,6 +527,7 @@ static void HelpLong(void) {
   printf(" cwebp [-preset <...>] [options] in_file [-o out_file]\n\n");
   printf("If input size (-s) for an image is not specified, it is\n"
          "assumed to be a PNG, JPEG, TIFF or WebP file.\n");
+  printf("Note: Animated PNG and WebP files are not supported.\n");
 #ifdef HAVE_WINCODEC_H
   printf("Windows builds can take as input any of the files handled by WIC.\n");
 #endif
diff --git a/examples/dwebp.c b/examples/dwebp.c
index cc75cb77..5cfb0fb1 100644
--- a/examples/dwebp.c
+++ b/examples/dwebp.c
@@ -76,7 +76,8 @@ static int SaveOutput(const WebPDecBuffer* const buffer,
 
 static void Help(void) {
   printf("Usage: dwebp in_file [options] [-o out_file]\n\n"
-         "Decodes the WebP image file to PNG format [Default]\n"
+         "Decodes the WebP image file to PNG format [Default].\n"
+         "Note: Animated WebP files are not supported.\n\n"
          "Use following options to convert into alternate image formats:\n"
          "  -pam ......... save the raw RGBA samples as a color PAM\n"
          "  -ppm ......... save the raw RGB samples as a color PPM\n"
diff --git a/man/cwebp.1 b/man/cwebp.1
index 9bf3342d..89fc8ad3 100644
--- a/man/cwebp.1
+++ b/man/cwebp.1
@@ -1,5 +1,5 @@
 .\"                                      Hey, EMACS: -*- nroff -*-
-.TH CWEBP 1 "January 11, 2019"
+.TH CWEBP 1 "November 19, 2020"
 .SH NAME
 cwebp \- compress an image file to a WebP file
 .SH SYNOPSIS
@@ -13,6 +13,7 @@ command.
 .PP
 \fBcwebp\fP compresses an image using the WebP format.
 Input format can be either PNG, JPEG, TIFF, WebP or raw Y'CbCr samples.
+Note: Animated PNG and WebP files are not supported.
 .SH OPTIONS
 The basic options are:
 .TP
diff --git a/man/dwebp.1 b/man/dwebp.1
index d4b60ed8..04168c4c 100644
--- a/man/dwebp.1
+++ b/man/dwebp.1
@@ -1,5 +1,5 @@
 .\"                                      Hey, EMACS: -*- nroff -*-
-.TH DWEBP 1 "June 23, 2016"
+.TH DWEBP 1 "November 19, 2020"
 .SH NAME
 dwebp \- decompress a WebP file to an image file
 .SH SYNOPSIS
@@ -12,6 +12,7 @@ This manual page documents the
 command.
 .PP
 \fBdwebp\fP decompresses WebP files into PNG, PAM, PPM or PGM images.
+Note: Animated WebP files are not supported.
 .SH OPTIONS
 The basic options are:
 .TP

From 26faf7706bff08e5a47abdc85d3aa2bb2ec27c9d Mon Sep 17 00:00:00 2001
From: James Zern <jzern@google.com>
Date: Thu, 19 Nov 2020 19:49:11 -0800
Subject: [PATCH 2/2] wicdec: fail with animated images

this matches the behavior of other decoders (WebP) in imageio.

Bug: webp:479
Change-Id: Ifcae0f38d7eebde31cd294070a6dd1f80cb30043
---
 imageio/wicdec.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/imageio/wicdec.c b/imageio/wicdec.c
index 249d1c21..a6694133 100644
--- a/imageio/wicdec.c
+++ b/imageio/wicdec.c
@@ -298,9 +298,15 @@ int ReadPictureWithWIC(const char* const filename,
           factory, stream, NULL,
           WICDecodeMetadataCacheOnDemand, &decoder));
   IFS(IWICBitmapDecoder_GetFrameCount(decoder, &frame_count));
-  if (SUCCEEDED(hr) && frame_count == 0) {
-    fprintf(stderr, "No frame found in input file.\n");
-    hr = E_FAIL;
+  if (SUCCEEDED(hr)) {
+    if (frame_count == 0) {
+      fprintf(stderr, "No frame found in input file.\n");
+      hr = E_FAIL;
+    } else if (frame_count > 1) {
+      // WIC will be tried before native WebP decoding so avoid duplicating the
+      // error message.
+      hr = E_FAIL;
+    }
   }
   IFS(IWICBitmapDecoder_GetFrame(decoder, 0, &frame));
   IFS(IWICBitmapFrameDecode_GetPixelFormat(frame, &src_pixel_format));