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/*
* Copyright (c) 2017 ARM Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
* not be construed as granting a license to any other intellectual
* property including but not limited to intellectual property relating
* to a hardware implementation of the functionality of the software
* licensed hereunder. You may use the software subject to the license
* terms below provided that you ensure that this notice is replicated
* unmodified and in its entirety in all distributions of the software,
* modified or unmodified, in source code or in binary form.
*
* 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 the copyright holders 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.
*
* Authors: Giacomo Travaglini
*/
/**
* @file Definition of a class that writes a frame buffer to a png
*/
#include "base/pngwriter.hh"
extern "C"
{
#include <png.h>
}
#include <cstdio>
#include <cstdlib>
#include "base/logging.hh"
const char* PngWriter::_imgExtension = "png";
/**
* Write callback to use with libpng APIs
*
* @param pngPtr pointer to the png_struct structure
* @param data pointer to the data being written
* @param length number of bytes being written
*/
static void
writePng(png_structp pngPtr, png_bytep data, png_size_t length)
{
// Here we get our IO pointer back from the write struct
// and we cast it into a ostream* type.
std::ostream* strmPtr = reinterpret_cast<std::ostream*>(
png_get_io_ptr(pngPtr)
);
// Write length bytes to data
strmPtr->write(reinterpret_cast<const char *>(data), length);
}
struct PngWriter::PngStructHandle {
private:
// Make PngStructHandle uncopyable
PngStructHandle(const PngStructHandle&) = delete;
PngStructHandle& operator=(const PngStructHandle&) = delete;
public:
PngStructHandle() :
pngWriteP(NULL), pngInfoP(NULL)
{
// Creating write structure
pngWriteP = png_create_write_struct(
PNG_LIBPNG_VER_STRING, NULL, NULL, NULL
);
if (pngWriteP) {
// Creating info structure
pngInfoP = png_create_info_struct(pngWriteP);
}
}
~PngStructHandle()
{
if (pngWriteP) {
png_destroy_write_struct(&pngWriteP, &pngInfoP);
}
}
/** Pointer to PNG Write struct */
png_structp pngWriteP;
/** Pointer to PNG Info struct */
png_infop pngInfoP;
};
void
PngWriter::write(std::ostream &png) const
{
// Height of the frame buffer
unsigned height = fb.height();
unsigned width = fb.width();
// Do not write if frame buffer is empty
if (!fb.area()) {
png.flush();
return;
}
// Initialize Png structures
PngStructHandle handle;
// Png info/write pointers.
png_structp pngPtr = handle.pngWriteP;
png_infop infoPtr = handle.pngInfoP;
if (!pngPtr) {
warn("Frame buffer dump aborted: Unable to create"
"Png Write Struct\n");
return;
}
if (!infoPtr) {
warn("Frame buffer dump aborted: Unable to create"
"Png Info Struct\n");
return;
}
// We cannot use default libpng write function since it requires
// a file pointer (FILE*), whereas we want to use the ostream.
// The following function replaces the write function with a custom
// one provided by us (writePng)
png_set_write_fn(pngPtr, (png_voidp)&png, writePng, NULL);
png_set_IHDR(pngPtr, infoPtr, width, height, 8,
PNG_COLOR_TYPE_RGB,
PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT,
PNG_FILTER_TYPE_DEFAULT);
png_write_info(pngPtr, infoPtr);
// libpng requires an array of pointers to the frame buffer's rows.
std::vector<PixelType> rowPacked(width);
for (unsigned y=0; y < height; ++y) {
for (unsigned x=0; x < width; ++x) {
rowPacked[x] = fb.pixel(x, y);
}
png_write_row(pngPtr,
reinterpret_cast<png_bytep>(rowPacked.data())
);
}
// End of write
png_write_end(pngPtr, NULL);
}
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