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/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkJpegDecoderMgr.h"
#include "SkJpegUtility.h"
/*
* Print information, warning, and error messages
*/
static void print_message(const j_common_ptr info, const char caller[]) {
char buffer[JMSG_LENGTH_MAX];
info->err->format_message(info, buffer);
SkCodecPrintf("libjpeg error %d <%s> from %s\n", info->err->msg_code, buffer, caller);
}
/*
* Reporting function for error and warning messages.
*/
static void output_message(j_common_ptr info) {
print_message(info, "output_message");
}
static void progress_monitor(j_common_ptr info) {
int scan = ((j_decompress_ptr)info)->input_scan_number;
// Progressive images with a very large number of scans can cause the
// decoder to hang. Here we use the progress monitor to abort on
// a very large number of scans. 100 is arbitrary, but much larger
// than the number of scans we might expect in a normal image.
if (scan >= 100) {
skjpeg_err_exit(info);
}
}
bool JpegDecoderMgr::returnFalse(const char caller[]) {
print_message((j_common_ptr) &fDInfo, caller);
return false;
}
SkCodec::Result JpegDecoderMgr::returnFailure(const char caller[], SkCodec::Result result) {
print_message((j_common_ptr) &fDInfo, caller);
return result;
}
bool JpegDecoderMgr::getEncodedColor(SkEncodedInfo::Color* outColor) {
switch (fDInfo.jpeg_color_space) {
case JCS_GRAYSCALE:
*outColor = SkEncodedInfo::kGray_Color;
return true;
case JCS_YCbCr:
*outColor = SkEncodedInfo::kYUV_Color;
return true;
case JCS_RGB:
*outColor = SkEncodedInfo::kRGB_Color;
return true;
case JCS_YCCK:
*outColor = SkEncodedInfo::kYCCK_Color;
return true;
case JCS_CMYK:
*outColor = SkEncodedInfo::kInvertedCMYK_Color;
return true;
default:
return false;
}
}
JpegDecoderMgr::JpegDecoderMgr(SkStream* stream)
: fSrcMgr(stream)
, fInit(false)
{
// Error manager must be set before any calls to libjeg in order to handle failures
fDInfo.err = jpeg_std_error(&fErrorMgr);
fErrorMgr.error_exit = skjpeg_err_exit;
}
void JpegDecoderMgr::init() {
jpeg_create_decompress(&fDInfo);
fInit = true;
fDInfo.src = &fSrcMgr;
fDInfo.err->output_message = &output_message;
fDInfo.progress = &fProgressMgr;
fProgressMgr.progress_monitor = &progress_monitor;
}
JpegDecoderMgr::~JpegDecoderMgr() {
if (fInit) {
jpeg_destroy_decompress(&fDInfo);
}
}
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