JPEG(JFIF only) directly embedded into PDF

tests/PDFJpegEmbedTest.cpp

+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkDocument.h"
+#include "SkCanvas.h"
+#include "SkImageGenerator.h"
+#include "SkData.h"
+#include "SkStream.h"
+#include "SkDecodingImageGenerator.h"
+
+#include "Resources.h"
+#include "Test.h"
+
+// Returned bitmap is lazy.  Only lazy bitmaps hold onto the original data.
+static SkBitmap bitmap_from_data(SkData* data) {
+    SkASSERT(data);
+    SkBitmap bm;
+    SkInstallDiscardablePixelRef(
+            SkDecodingImageGenerator::Create(
+                    data, SkDecodingImageGenerator::Options()), &bm);
+    return bm;
+}
+
+static bool is_subset_of(SkData* smaller, SkData* larger) {
+    SkASSERT(smaller && larger);
+    if (smaller->size() > larger->size()) {
+        return false;
+    }
+    size_t size = smaller->size();
+    size_t size_diff = larger->size() - size;
+    for (size_t i = 0; i <= size_diff; ++i) {
+        if (0 == memcmp(larger->bytes() + i, smaller->bytes(), size)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+
+static SkData* load_resource(
+        skiatest::Reporter* r, const char* test, const char* filename) {
+    SkString path(GetResourcePath(filename));
+    SkData* data = SkData::NewFromFileName(path.c_str());
+    if (!data && r->verbose()) {
+        SkDebugf("\n%s: Resource '%s' can not be found.\n",
+                 test, filename);
+    }
+    return data;  // May return NULL.
+}
+
+/**
+ *  Test that for Jpeg files that use the JFIF colorspace, they are
+ *  directly embedded into the PDF (without re-encoding) when that
+ *  makes sense.
+ */
+DEF_TEST(PDFJpegEmbedTest, r) {
+    const char test[] = "PDFJpegEmbedTest";
+    SkAutoTUnref<SkData> mandrillData(
+            load_resource(r, test, "mandrill_512_q075.jpg"));
+    SkAutoTUnref<SkData> cmykData(load_resource(r, test, "CMYK.jpg"));
+    if (!mandrillData || !cmykData) {
+        return;
+    }
+
+    SkDynamicMemoryWStream pdf;
+    SkAutoTUnref<SkDocument> document(SkDocument::CreatePDF(&pdf));
+    SkCanvas* canvas = document->beginPage(642, 1028);
+
+    canvas->clear(SK_ColorLTGRAY);
+
+    SkBitmap bm1(bitmap_from_data(mandrillData));
+    canvas->drawBitmap(bm1, 65.0, 0.0, NULL);
+    SkBitmap bm2(bitmap_from_data(cmykData));
+    canvas->drawBitmap(bm2, 0.0, 512.0, NULL);
+
+    canvas->flush();
+    document->endPage();
+    document->close();
+    SkAutoTUnref<SkData> pdfData(pdf.copyToData());
+    SkASSERT(pdfData);
+    pdf.reset();
+
+    REPORTER_ASSERT(r, is_subset_of(mandrillData, pdfData));
+
+    // This JPEG uses a nonstandard colorspace - it can not be
+    // embedded into the PDF directly.
+    REPORTER_ASSERT(r, !is_subset_of(cmykData, pdfData));
+
+    // The following is for debugging purposes only.
+    const char* outputPath = getenv("SKIA_TESTS_PDF_JPEG_EMBED_OUTPUT_PATH");
+    if (outputPath) {
+        SkFILEWStream output(outputPath);
+        if (output.isValid()) {
+            output.write(pdfData->data(), pdfData->size());
+        }
+    }
+}