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/*
* Copyright (c) 2010, Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "JPEGImageEncoder.h"
#include "ImageData.h"
#include "IntSize.h"
#include "SkBitmap.h"
#include "SkColorPriv.h"
#include "SkUnPreMultiply.h"
extern "C" {
#include <stdio.h> // jpeglib.h needs stdio.h FILE
#include "jpeglib.h"
#include <setjmp.h>
}
namespace WebCore {
struct JPEGOutputBuffer : public jpeg_destination_mgr {
Vector<unsigned char>* output;
Vector<unsigned char> buffer;
};
static void prepareOutput(j_compress_ptr cinfo)
{
JPEGOutputBuffer* out = static_cast<JPEGOutputBuffer*>(cinfo->dest);
const size_t internalBufferSize = 8192;
out->buffer.resize(internalBufferSize);
out->next_output_byte = out->buffer.data();
out->free_in_buffer = out->buffer.size();
}
static boolean writeOutput(j_compress_ptr cinfo)
{
JPEGOutputBuffer* out = static_cast<JPEGOutputBuffer*>(cinfo->dest);
out->output->append(out->buffer.data(), out->buffer.size());
out->next_output_byte = out->buffer.data();
out->free_in_buffer = out->buffer.size();
return TRUE;
}
static void finishOutput(j_compress_ptr cinfo)
{
JPEGOutputBuffer* out = static_cast<JPEGOutputBuffer*>(cinfo->dest);
const size_t size = out->buffer.size() - out->free_in_buffer;
out->output->append(out->buffer.data(), size);
}
static void handleError(j_common_ptr common)
{
jmp_buf* jumpBufferPtr = static_cast<jmp_buf*>(common->client_data);
longjmp(*jumpBufferPtr, -1);
}
static void preMultipliedBGRAtoRGB(const void* pixels, unsigned int pixelCount, unsigned char* output)
{
const SkPMColor* input = static_cast<const SkPMColor*>(pixels);
for (; pixelCount-- > 0; ++input) {
*output++ = SkGetPackedR32(*input);
*output++ = SkGetPackedG32(*input);
*output++ = SkGetPackedB32(*input);
}
}
static void RGBAtoRGB(const unsigned char* input, unsigned int pixels, unsigned char* output)
{
for (; pixels-- > 0; input += 4) {
*output++ = input[0];
*output++ = input[1];
*output++ = input[2];
}
}
static bool encodePixels(const IntSize& inputSize, unsigned char* inputPixels,
bool premultiplied, int quality, Vector<unsigned char>* output)
{
IntSize imageSize(inputSize);
imageSize.clampNegativeToZero();
JPEGOutputBuffer destination;
destination.output = output;
Vector<JSAMPLE> row;
jpeg_compress_struct cinfo;
jpeg_error_mgr error;
cinfo.err = jpeg_std_error(&error);
error.error_exit = handleError;
jmp_buf jumpBuffer;
cinfo.client_data = &jumpBuffer;
if (setjmp(jumpBuffer)) {
jpeg_destroy_compress(&cinfo);
return false;
}
jpeg_create_compress(&cinfo);
cinfo.dest = &destination;
cinfo.dest->init_destination = prepareOutput;
cinfo.dest->empty_output_buffer = writeOutput;
cinfo.dest->term_destination = finishOutput;
cinfo.image_height = imageSize.height();
cinfo.image_width = imageSize.width();
cinfo.in_color_space = JCS_RGB;
cinfo.input_components = 3;
jpeg_set_defaults(&cinfo);
jpeg_set_quality(&cinfo, quality, TRUE);
jpeg_start_compress(&cinfo, TRUE);
unsigned char* pixels = inputPixels;
row.resize(cinfo.image_width * cinfo.input_components);
while (cinfo.next_scanline < cinfo.image_height) {
if (premultiplied)
preMultipliedBGRAtoRGB(pixels, cinfo.image_width, row.data());
else
RGBAtoRGB(pixels, cinfo.image_width, row.data());
jpeg_write_scanlines(&cinfo, row.dataSlot(), 1);
pixels += cinfo.image_width * 4;
}
jpeg_finish_compress(&cinfo);
jpeg_destroy_compress(&cinfo);
return true;
}
bool JPEGImageEncoder::encode(const SkBitmap& bitmap, int quality, Vector<unsigned char>* output)
{
if (bitmap.config() != SkBitmap::kARGB_8888_Config)
return false; // Only support ARGB 32 bpp skia bitmaps.
SkAutoLockPixels bitmapLock(bitmap);
IntSize imageSize(bitmap.width(), bitmap.height());
return encodePixels(imageSize, static_cast<unsigned char *>(bitmap.getPixels()),
true, quality, output);
}
bool JPEGImageEncoder::encode(const ImageData& imageData, int quality, Vector<unsigned char>* output)
{
return encodePixels(imageData.size(), imageData.data()->data()->data(),
false, quality, output);
}
} // namespace WebCore
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