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-rw-r--r--Source/WebCore/platform/image-encoders/JPEGImageEncoder.cpp135
1 files changed, 135 insertions, 0 deletions
diff --git a/Source/WebCore/platform/image-encoders/JPEGImageEncoder.cpp b/Source/WebCore/platform/image-encoders/JPEGImageEncoder.cpp
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+++ b/Source/WebCore/platform/image-encoders/JPEGImageEncoder.cpp
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+/*
+ * Copyright (C) 2009 Torch Mobile, Inc. All rights reserved.
+ * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with this library; see the file COPYING.LIB. If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+
+#include "config.h"
+#include "JPEGImageEncoder.h"
+
+#include "IntSize.h"
+// FIXME: jpeglib.h requires stdio.h to be included first for FILE
+#include <stdio.h>
+#include "jpeglib.h"
+#include <setjmp.h>
+
+namespace WebCore {
+
+class JPEGDestinationManager : public jpeg_destination_mgr {
+public:
+ explicit JPEGDestinationManager(Vector<char>& toDump)
+ : m_dump(toDump)
+ {
+ // Zero base class memory.
+ jpeg_destination_mgr* base = this;
+ memset(base, 0, sizeof(jpeg_destination_mgr));
+ }
+ Vector<char> m_buffer;
+ Vector<char>& m_dump;
+};
+
+class JPEGCompressErrorMgr : public jpeg_error_mgr {
+public:
+ JPEGCompressErrorMgr()
+ {
+ // Zero memory
+ memset(this, 0, sizeof(JPEGCompressErrorMgr));
+ }
+
+ jmp_buf m_setjmpBuffer;
+};
+
+static void jpegInitializeDestination(j_compress_ptr compressData)
+{
+ JPEGDestinationManager* dest = static_cast<JPEGDestinationManager*>(compressData->dest);
+ dest->m_buffer.resize(4096);
+ dest->next_output_byte = reinterpret_cast<JOCTET*>(dest->m_buffer.data());
+ dest->free_in_buffer = dest->m_buffer.size();
+}
+
+static boolean jpegEmptyOutputBuffer(j_compress_ptr compressData)
+{
+ JPEGDestinationManager* dest = static_cast<JPEGDestinationManager*>(compressData->dest);
+ dest->m_dump.append(dest->m_buffer.data(), dest->m_buffer.size() - dest->free_in_buffer);
+ dest->next_output_byte = reinterpret_cast<JOCTET*>(dest->m_buffer.data());
+ dest->free_in_buffer = dest->m_buffer.size();
+ return TRUE;
+}
+
+static void jpegTerminateDestination(j_compress_ptr compressData)
+{
+ JPEGDestinationManager* dest = static_cast<JPEGDestinationManager*>(compressData->dest);
+ dest->m_dump.append(dest->m_buffer.data(), dest->m_buffer.size() - dest->free_in_buffer);
+}
+
+static void jpegErrorExit(j_common_ptr compressData)
+{
+ JPEGCompressErrorMgr* err = static_cast<JPEGCompressErrorMgr*>(compressData->err);
+ longjmp(err->m_setjmpBuffer, -1);
+}
+
+bool compressRGBABigEndianToJPEG(unsigned char* rgbaBigEndianData, const IntSize& size, Vector<char>& jpegData)
+{
+ struct jpeg_compress_struct compressData = { 0 };
+ JPEGCompressErrorMgr err;
+ compressData.err = jpeg_std_error(&err);
+ err.error_exit = jpegErrorExit;
+
+ jpeg_create_compress(&compressData);
+
+ JPEGDestinationManager dest(jpegData);
+ compressData.dest = &dest;
+ dest.init_destination = jpegInitializeDestination;
+ dest.empty_output_buffer = jpegEmptyOutputBuffer;
+ dest.term_destination = jpegTerminateDestination;
+
+ compressData.image_width = size.width();
+ compressData.image_height = size.height();
+ compressData.input_components = 3;
+ compressData.in_color_space = JCS_RGB;
+ jpeg_set_defaults(&compressData);
+ jpeg_set_quality(&compressData, 65, FALSE);
+
+ // rowBuffer must be defined here so that its destructor is always called even when "setjmp" catches an error.
+ Vector<JSAMPLE, 600 * 3> rowBuffer;
+
+ if (setjmp(err.m_setjmpBuffer))
+ return false;
+
+ jpeg_start_compress(&compressData, TRUE);
+ rowBuffer.resize(compressData.image_width * 3);
+
+ const unsigned char* pixel = rgbaBigEndianData;
+ const unsigned char* pixelEnd = pixel + compressData.image_width * compressData.image_height * 4;
+ while (pixel < pixelEnd) {
+ JSAMPLE* output = rowBuffer.data();
+ for (const unsigned char* rowEnd = pixel + compressData.image_width * 4; pixel < rowEnd;) {
+ *output++ = static_cast<JSAMPLE>(*pixel++ & 0xFF); // red
+ *output++ = static_cast<JSAMPLE>(*pixel++ & 0xFF); // green
+ *output++ = static_cast<JSAMPLE>(*pixel++ & 0xFF); // blue
+ ++pixel; // skip alpha
+ }
+ output = rowBuffer.data();
+ jpeg_write_scanlines(&compressData, &output, 1);
+ }
+
+ jpeg_finish_compress(&compressData);
+ return true;
+}
+
+} // namespace WebCore