src/net/instaweb/rewriter/webp_optimizer_test.cc

/*
 * Copyright 2010 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
// Author: vchudnov@google.com (Victor Chudnovsky)

// Unit tests for the routines in webp_optimizer.cc.

#include "net/instaweb/rewriter/public/webp_optimizer.h"

#include "pagespeed/kernel/base/basictypes.h"
#include "pagespeed/kernel/base/gtest.h"
#include "pagespeed/kernel/base/string.h"
#include "pagespeed/kernel/base/string_util.h"  // for StrCat
#include "pagespeed/kernel/image/test_utils.h"

#ifdef USE_SYSTEM_LIBWEBP
#include "webp/encode.h"
#include "webp/decode.h"
#else
#include "third_party/libwebp/src/webp/decode.h"
#endif

namespace net_instaweb {

using pagespeed::image_compression::ReadFile;

const char kTestData[] = "/net/instaweb/rewriter/testdata/";
const char kTransparentWebP[] = "chromium-24.webp";

TEST(WebpOptimizerTest, ReduceWebpImageQualityPreservesAlpha) {
  // This test verifies that ReduceWebpImageQuality preserves the
  // alpha channel.

  GoogleString input_image, output_image;
  EXPECT_TRUE(ReadFile(StrCat(GTestSrcDir(), kTestData, kTransparentWebP),
                       &input_image));

  WebPBitstreamFeatures features;
  EXPECT_EQ(VP8_STATUS_OK,
            WebPGetFeatures(
                reinterpret_cast<const uint8_t*>(input_image.c_str()),
                input_image.length(), &features));
  EXPECT_TRUE(features.has_alpha);

  EXPECT_TRUE(ReduceWebpImageQuality(input_image, 50, &output_image));
  EXPECT_NE(input_image, output_image);

  EXPECT_EQ(VP8_STATUS_OK,
            WebPGetFeatures(
                reinterpret_cast<const uint8_t*>(output_image.c_str()),
                output_image.length(), &features));
  EXPECT_TRUE(features.has_alpha);
}
}  // namespace net_instaweb