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/*
* Copyright 2007 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkImageEncoderPriv.h"
#ifdef SK_HAS_JPEG_LIBRARY
#include "SkColorPriv.h"
#include "SkImageEncoderFns.h"
#include "SkJPEGWriteUtility.h"
#include "SkStream.h"
#include "SkTemplates.h"
#include <stdio.h>
extern "C" {
#include "jpeglib.h"
#include "jerror.h"
}
/**
* Returns true if |info| is supported by the jpeg encoder and false otherwise.
* |jpegColorType| will be set to the proper libjpeg-turbo type for input to the library.
* |numComponents| will be set to the number of components in the |jpegColorType|.
* |proc| will be set if we need to pre-convert the input before passing to
* libjpeg-turbo. Otherwise will be set to nullptr.
*/
// TODO (skbug.com/1501):
// Should we fail on non-opaque encodes?
// Or should we change alpha behavior (ex: unpremultiply when the input is premul)?
// Or is ignoring the alpha type and alpha channel ok here?
static bool set_encode_config(J_COLOR_SPACE* jpegColorType, int* numComponents,
transform_scanline_proc* proc, const SkImageInfo& info) {
*proc = nullptr;
switch (info.colorType()) {
case kRGBA_8888_SkColorType:
*jpegColorType = JCS_EXT_RGBA;
*numComponents = 4;
return true;
case kBGRA_8888_SkColorType:
*jpegColorType = JCS_EXT_BGRA;
*numComponents = 4;
return true;
case kRGB_565_SkColorType:
*proc = transform_scanline_565;
*jpegColorType = JCS_RGB;
*numComponents = 3;
return true;
case kARGB_4444_SkColorType:
*proc = transform_scanline_444;
*jpegColorType = JCS_RGB;
*numComponents = 3;
return true;
case kIndex_8_SkColorType:
*proc = transform_scanline_index8_opaque;
*jpegColorType = JCS_RGB;
*numComponents = 3;
return true;
case kGray_8_SkColorType:
SkASSERT(info.isOpaque());
*jpegColorType = JCS_GRAYSCALE;
*numComponents = 1;
return true;
case kRGBA_F16_SkColorType:
if (!info.colorSpace() || !info.colorSpace()->gammaIsLinear()) {
return false;
}
*proc = transform_scanline_F16_to_8888;
*jpegColorType = JCS_EXT_RGBA;
*numComponents = 4;
return true;
default:
return false;
}
}
bool SkEncodeImageAsJPEG(SkWStream* stream, const SkPixmap& pixmap, const SkEncodeOptions& opts) {
SkASSERT(!pixmap.colorSpace() || pixmap.colorSpace()->gammaCloseToSRGB() ||
pixmap.colorSpace()->gammaIsLinear());
SkPixmap src = pixmap;
if (SkTransferFunctionBehavior::kIgnore == opts.fUnpremulBehavior) {
src.setColorSpace(nullptr);
} else {
// kCorrect behavior requires a color space. It's not actually critical in the
// jpeg case (since jpegs are opaque), but Skia color correct behavior generally
// requires pixels to be tagged with color spaces.
if (!src.colorSpace()) {
return false;
}
}
return SkEncodeImageAsJPEG(stream, src, 100);
}
bool SkEncodeImageAsJPEG(SkWStream* stream, const SkPixmap& pixmap, int quality) {
if (!pixmap.addr()) {
return false;
}
jpeg_compress_struct cinfo;
skjpeg_error_mgr sk_err;
skjpeg_destination_mgr sk_wstream(stream);
// Declare before calling setjmp.
SkAutoTMalloc<uint8_t> storage;
cinfo.err = jpeg_std_error(&sk_err);
sk_err.error_exit = skjpeg_error_exit;
if (setjmp(sk_err.fJmpBuf)) {
return false;
}
J_COLOR_SPACE jpegColorSpace;
int numComponents;
transform_scanline_proc proc;
if (!set_encode_config(&jpegColorSpace, &numComponents, &proc, pixmap.info())) {
return false;
}
jpeg_create_compress(&cinfo);
cinfo.dest = &sk_wstream;
cinfo.image_width = pixmap.width();
cinfo.image_height = pixmap.height();
cinfo.input_components = numComponents;
cinfo.in_color_space = jpegColorSpace;
jpeg_set_defaults(&cinfo);
// Tells libjpeg-turbo to compute optimal Huffman coding tables
// for the image. This improves compression at the cost of
// slower encode performance.
cinfo.optimize_coding = TRUE;
jpeg_set_quality(&cinfo, quality, TRUE /* limit to baseline-JPEG values */);
jpeg_start_compress(&cinfo, TRUE);
if (pixmap.colorSpace()) {
sk_sp<SkData> icc = icc_from_color_space(*pixmap.colorSpace());
if (icc) {
// Create a contiguous block of memory with the icc signature followed by the profile.
sk_sp<SkData> markerData =
SkData::MakeUninitialized(kICCMarkerHeaderSize + icc->size());
uint8_t* ptr = (uint8_t*) markerData->writable_data();
memcpy(ptr, kICCSig, sizeof(kICCSig));
ptr += sizeof(kICCSig);
*ptr++ = 1; // This is the first marker.
*ptr++ = 1; // Out of one total markers.
memcpy(ptr, icc->data(), icc->size());
jpeg_write_marker(&cinfo, kICCMarker, markerData->bytes(), markerData->size());
}
}
if (proc) {
storage.reset(numComponents * pixmap.width());
}
const void* srcRow = pixmap.addr();
const SkPMColor* colors = pixmap.ctable() ? pixmap.ctable()->readColors() : nullptr;
while (cinfo.next_scanline < cinfo.image_height) {
JSAMPLE* jpegSrcRow = (JSAMPLE*) srcRow;
if (proc) {
proc((char*)storage.get(), (const char*)srcRow, pixmap.width(), numComponents, colors);
jpegSrcRow = storage.get();
}
(void) jpeg_write_scanlines(&cinfo, &jpegSrcRow, 1);
srcRow = SkTAddOffset<const void>(srcRow, pixmap.rowBytes());
}
jpeg_finish_compress(&cinfo);
jpeg_destroy_compress(&cinfo);
return true;
}
#endif
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