/*
* Copyright (C) 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "jpeg_reader.h"
#include "error_codes.h"
#include "jpeg_hook.h"
#include <setjmp.h>
JpegReader::JpegReader() :
mInfo(),
mErrorManager(),
mScanlineBuf(NULL),
mScanlineIter(NULL),
mScanlineBuflen(0),
mScanlineUnformattedBuflen(0),
mScanlineBytesRemaining(0),
mFormat(),
mFinished(false),
mSetup(false) {}
JpegReader::~JpegReader() {
if (reset() != J_SUCCESS) {
LOGE("Failed to destroy compress object, JpegReader may leak memory.");
}
}
int32_t JpegReader::setup(JNIEnv *env, jobject in, int32_t* width, int32_t* height,
Jpeg_Config::Format format) {
if (mFinished || mSetup) {
return J_ERROR_FATAL;
}
if (env->ExceptionCheck()) {
return J_EXCEPTION;
}
// Setup error handler
SetupErrMgr(reinterpret_cast<j_common_ptr>(&mInfo), &mErrorManager);
// Set jump address for error handling
if (setjmp(mErrorManager.setjmp_buf)) {
return J_ERROR_FATAL;
}
// Call libjpeg setup
jpeg_create_decompress(&mInfo);
// Setup our data source object, this allocates java global references
int32_t flags = MakeSrc(&mInfo, env, in);
if (flags != J_SUCCESS) {
LOGE("Failed to make source with error code: %d ", flags);
return flags;
}
// Reads jpeg file header
jpeg_read_header(&mInfo, TRUE);
jpeg_calc_output_dimensions(&mInfo);
const int components = (static_cast<int>(format) & 0xff);
// Do setup for input format
switch (components) {
case 1:
mInfo.out_color_space = JCS_GRAYSCALE;
mScanlineUnformattedBuflen = mInfo.output_width;
break;
case 3:
case 4:
mScanlineUnformattedBuflen = mInfo.output_width * components;
if (mInfo.jpeg_color_space == JCS_CMYK
|| mInfo.jpeg_color_space == JCS_YCCK) {
// Always use cmyk for output in a 4 channel jpeg.
// libjpeg has a builtin cmyk->rgb decoder.
mScanlineUnformattedBuflen = mInfo.output_width * 4;
mInfo.out_color_space = JCS_CMYK;
} else {
mInfo.out_color_space = JCS_RGB;
}
break;
default:
return J_ERROR_BAD_ARGS;
}
mScanlineBuflen = mInfo.output_width * components;
mScanlineBytesRemaining = mScanlineBuflen;
mScanlineBuf = (JSAMPLE *) (mInfo.mem->alloc_small)(
reinterpret_cast<j_common_ptr>(&mInfo), JPOOL_PERMANENT,
mScanlineUnformattedBuflen * sizeof(JSAMPLE));
mScanlineIter = mScanlineBuf;
jpeg_start_decompress(&mInfo);
// Output image dimensions
if (width != NULL) {
*width = mInfo.output_width;
}
if (height != NULL) {
*height = mInfo.output_height;
}
mFormat = format;
mSetup = true;
return J_SUCCESS;
}
int32_t JpegReader::read(int8_t* bytes, int32_t offset, int32_t count) {
if (!mSetup) {
return J_ERROR_FATAL;
}
if (mFinished) {
return J_DONE;
}
// Set jump address for error handling
if (setjmp(mErrorManager.setjmp_buf)) {
return J_ERROR_FATAL;
}
if (count <= 0) {
return J_ERROR_BAD_ARGS;
}
int32_t total_length = count;
while (mInfo.output_scanline < mInfo.output_height) {
if (count < mScanlineBytesRemaining) {
// read partial scanline and return
if (bytes != NULL) {
// Treat NULL bytes as a skip
memcpy((void*) (bytes + offset), (void*) mScanlineIter,
count * sizeof(int8_t));
}
mScanlineBytesRemaining -= count;
mScanlineIter += count;
return total_length;
} else if (count > 0) {
// read full scanline
if (bytes != NULL) {
// Treat NULL bytes as a skip
memcpy((void*) (bytes + offset), (void*) mScanlineIter,
mScanlineBytesRemaining * sizeof(int8_t));
bytes += mScanlineBytesRemaining;
}
count -= mScanlineBytesRemaining;
mScanlineBytesRemaining = 0;
}
// Scanline buffer exhausted, read next scanline
if (jpeg_read_scanlines(&mInfo, &mScanlineBuf, 1) != 1) {
// Always read full scanline, no IO suspension
return J_ERROR_FATAL;
}
// Do in-place pixel formatting
formatPixels(static_cast<uint8_t*>(mScanlineBuf),
mScanlineUnformattedBuflen);
// Reset iterators
mScanlineIter = mScanlineBuf;
mScanlineBytesRemaining = mScanlineBuflen;
}
// Read all of the scanlines
jpeg_finish_decompress(&mInfo);
mFinished = true;
return total_length - count;
}
void JpegReader::updateEnv(JNIEnv *env) {
UpdateSrcEnv(&mInfo, env);
}
// Does in-place pixel formatting
void JpegReader::formatPixels(uint8_t* buf, int32_t len) {
uint8_t *iter = buf;
// Do cmyk->rgb conversion if necessary
switch (mInfo.out_color_space) {
case JCS_CMYK:
// Convert CMYK to RGB
int r, g, b, c, m, y, k;
for (int i = 0; i < len; i += 4) {
c = buf[i + 0];
m = buf[i + 1];
y = buf[i + 2];
k = buf[i + 3];
// Handle fmt for weird photoshop markers
if (mInfo.saw_Adobe_marker) {
r = (k * c) / 255;
g = (k * m) / 255;
b = (k * y) / 255;
} else {
r = (255 - k) * (255 - c) / 255;
g = (255 - k) * (255 - m) / 255;
b = (255 - k) * (255 - y) / 255;
}
*iter++ = r;
*iter++ = g;
*iter++ = b;
}
break;
case JCS_RGB:
iter += (len * 3 / 4);
break;
case JCS_GRAYSCALE:
default:
return;
}
// Do endianness and alpha for output format
if (mFormat == Jpeg_Config::FORMAT_RGBA) {
// Set alphas to 255
uint8_t* end = buf + len - 1;
for (int i = len - 1; i >= 0; i -= 4) {
buf[i] = 255;
buf[i - 1] = *--iter;
buf[i - 2] = *--iter;
buf[i - 3] = *--iter;
}
} else if (mFormat == Jpeg_Config::FORMAT_ABGR) {
// Reverse endianness and set alphas to 255
uint8_t* end = buf + len - 1;
int r, g, b;
for (int i = len - 1; i >= 0; i -= 4) {
b = *--iter;
g = *--iter;
r = *--iter;
buf[i] = r;
buf[i - 1] = g;
buf[i - 2] = b;
buf[i - 3] = 255;
}
}
}
int32_t JpegReader::reset() {
// Set jump address for error handling
if (setjmp(mErrorManager.setjmp_buf)) {
return J_ERROR_FATAL;
}
// Clean up global java references
CleanSrc(&mInfo);
// Wipe decompress struct, free memory pools
jpeg_destroy_decompress(&mInfo);
mFinished = false;
mSetup = false;
return J_SUCCESS;
}