Added webp image format plugin

Also added auto test and config test.

This plugin was disabled on winrt and android.

[ChangeLog] Added webp image format plugin.

Task-number: QTBUG-14205

Done-with: Liang Qi <liang.qi@digia.com>
Change-Id: I9409e894d7fc1aef9dce4ffdff8bdf483d689774
Reviewed-by: Ivan Komissarov <ABBAPOH@gmail.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

1 files changed, 213 insertions, 0 deletions

diff --git a/src/plugins/imageformats/webp/qwebphandler.cpp b/src/plugins/imageformats/webp/qwebphandler.cpp
new file mode 100644
index 0000000..8834820
--- /dev/null
+++ b/src/plugins/imageformats/webp/qwebphandler.cpp
@@ -0,0 +1,213 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the WebP plugins in the Qt ImageFormats module.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qwebphandler_p.h"
+#include "webp/encode.h"
+#include <qimage.h>
+#include <qdebug.h>
+#include <qvariant.h>
+
+static const int riffHeaderSize = 12; // RIFF_HEADER_SIZE from webp/format_constants.h
+
+QWebpHandler::QWebpHandler() :
+    m_lossless(false),
+    m_quality(75),
+    m_scanState(ScanNotScanned)
+{
+}
+
+bool QWebpHandler::canRead() const
+{
+    if (m_scanState == ScanNotScanned && !canRead(device()))
+        return false;
+
+    if (m_scanState != ScanError) {
+        setFormat(QByteArrayLiteral("webp"));
+        return true;
+    }
+    return false;
+}
+
+bool QWebpHandler::canRead(QIODevice *device)
+{
+    if (!device) {
+        qWarning("QWebpHandler::canRead() called with no device");
+        return false;
+    }
+
+    QByteArray header = device->peek(riffHeaderSize);
+    return header.startsWith("RIFF") && header.endsWith("WEBP");
+}
+
+bool QWebpHandler::ensureScanned() const
+{
+    if (m_scanState != ScanNotScanned)
+        return m_scanState == ScanSuccess;
+
+    m_scanState = ScanError;
+
+    if (device()->isSequential()) {
+        qWarning() << "Sequential devices are not supported";
+        return false;
+    }
+
+    qint64 oldPos = device()->pos();
+    device()->seek(0);
+
+    QWebpHandler *that = const_cast<QWebpHandler *>(this);
+    QByteArray header = device()->peek(sizeof(WebPBitstreamFeatures));
+    if (WebPGetFeatures((const uint8_t*)header.constData(), header.size(), &(that->m_features)) == VP8_STATUS_OK)
+        m_scanState = ScanSuccess;
+
+    device()->seek(oldPos);
+
+    return m_scanState == ScanSuccess;
+}
+
+bool QWebpHandler::read(QImage *image)
+{
+    if (!ensureScanned() || device()->isSequential())
+        return false;
+
+    QByteArray data = device()->readAll();
+    QImage result(m_features.width, m_features.height, QImage::Format_ARGB32);
+    uint8_t *output = result.bits();
+    size_t output_size = result.byteCount();
+#if Q_BYTE_ORDER == Q_LITTLE_ENDIAN
+    if (!WebPDecodeBGRAInto(reinterpret_cast<const uint8_t*>(data.constData()), data.size(), output, output_size, result.bytesPerLine()))
+#else
+    if (!WebPDecodeARGBInto(reinterpret_cast<const uint8_t*>(data.constData()), data.size(), output, output_size, result.bytesPerLine()))
+#endif
+        return false;
+
+    *image = result;
+    return true;
+}
+
+static int pictureWriter(const quint8 *data, size_t data_size, const WebPPicture *const pic)
+{
+    QIODevice *io = reinterpret_cast<QIODevice*>(pic->custom_ptr);
+
+    return data_size ? ((quint64)(io->write((const char*)data, data_size)) == data_size) : 1;
+}
+
+bool QWebpHandler::write(const QImage &image)
+{
+    if (image.isNull()) {
+        qWarning() << "source image is null.";
+        return false;
+    }
+
+    QImage srcImage = image;
+    if (srcImage.format() != QImage::Format_ARGB32)
+        srcImage = srcImage.convertToFormat(QImage::Format_ARGB32);
+
+    WebPPicture picture;
+    WebPConfig config;
+
+    if (!WebPPictureInit(&picture) || !WebPConfigInit(&config)) {
+        qWarning() << "failed to init webp picture and config";
+        return false;
+    }
+
+    picture.width = srcImage.width();
+    picture.height = srcImage.height();
+    picture.use_argb = 1;
+    if (!WebPPictureImportBGRA(&picture, srcImage.bits(), srcImage.bytesPerLine())) {
+        qWarning() << "failed to import image data to webp picture.";
+
+        WebPPictureFree(&picture);
+        return false;
+    }
+
+    config.lossless = m_lossless;
+    config.quality = m_quality;
+    picture.writer = pictureWriter;
+    picture.custom_ptr = device();
+
+    if (!WebPEncode(&config, &picture)) {
+        qWarning() << "failed to encode webp picture, error code: " << picture.error_code;
+        WebPPictureFree(&picture);
+        return false;
+    }
+
+    WebPPictureFree(&picture);
+
+    return true;
+}
+
+QVariant QWebpHandler::option(ImageOption option) const
+{
+    if (!supportsOption(option) || !ensureScanned())
+        return QVariant();
+
+    switch (option) {
+    case Quality:
+        return m_quality;
+    case Size:
+        return QSize(m_features.width, m_features.height);
+    default:
+        return QVariant();
+    }
+}
+
+void QWebpHandler::setOption(ImageOption option, const QVariant &value)
+{
+    switch (option) {
+    case Quality:
+        m_quality = qBound(0, value.toInt(), 100);
+        m_lossless = (m_quality >= 100);
+        return;
+    default:
+        break;
+    }
+    return QImageIOHandler::setOption(option, value);
+}
+
+bool QWebpHandler::supportsOption(ImageOption option) const
+{
+    return option == Quality || option == Size;
+}
+
+QByteArray QWebpHandler::name() const
+{
+    return QByteArrayLiteral("webp");
+}