cwebp: add webpdec

simple webp decoding, no metadata support

Change-Id: I2752fd1442c87513922878cbf72f001d45b631bc

examples/webpdec.h

@@ -0,0 +1,33 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// WebP decode.
+
+#ifndef WEBP_EXAMPLES_WEBPDEC_H_
+#define WEBP_EXAMPLES_WEBPDEC_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct Metadata;
+struct WebPPicture;
+
+// Reads a WebP from 'in_file', returning the decoded output in 'pic'.
+// If 'keep_alpha' is true and the WebP has an alpha channel, the output is
+// RGBA otherwise it will be RGB.
+// Returns true on success.
+int ReadWebP(const char* const in_file, struct WebPPicture* const pic,
+             int keep_alpha, struct Metadata* const metadata);
+
+#ifdef __cplusplus
+}    // extern "C"
+#endif
+
+#endif  // WEBP_EXAMPLES_WEBPDEC_H_