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// Copyright (C) 2010 Dirk Vanden Boer <dirk.vdb@gmail.com>
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#include "pngwriter.h"
#include <stdexcept>
#include <cassert>
#include <cstring>
using namespace std;
namespace ffmpegthumbnailer
{
static void writeDataCallback(png_structp png_ptr, png_bytep data, png_size_t length);
PngWriter::PngWriter(const string& outputFile)
: ImageWriter()
, m_FilePtr(nullptr)
, m_PngPtr(nullptr)
, m_InfoPtr(nullptr)
{
init();
m_FilePtr = outputFile == "-" ? stdout : fopen(outputFile.c_str(), "wb");
if (!m_FilePtr)
{
throw logic_error(string("Failed to open output file: ") + outputFile);
}
png_init_io(m_PngPtr, m_FilePtr);
}
PngWriter::PngWriter(std::vector<uint8_t>& outputBuffer)
: ImageWriter()
, m_FilePtr(nullptr)
, m_PngPtr(nullptr)
, m_InfoPtr(nullptr)
{
init();
png_set_write_fn(m_PngPtr, (png_voidp)&outputBuffer, writeDataCallback, nullptr);
}
PngWriter::~PngWriter()
{
if (m_FilePtr)
{
fclose(m_FilePtr);
}
png_destroy_write_struct(&m_PngPtr, &m_InfoPtr);
}
void PngWriter::init()
{
m_PngPtr = png_create_write_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
if (!m_PngPtr)
{
throw logic_error("Failed to create png write structure");
}
m_InfoPtr = png_create_info_struct(m_PngPtr);
if (!m_InfoPtr)
{
png_destroy_write_struct(&m_PngPtr, (png_infopp) nullptr);
throw logic_error("Failed to create png info structure");
}
}
void PngWriter::setText(const string& key, const string& value)
{
png_text pngText;
pngText.compression = -1;
pngText.key = const_cast<char*>(key.c_str());
pngText.text = const_cast<char*>(value.c_str());
png_set_text(m_PngPtr, m_InfoPtr, &pngText, 1);
}
void PngWriter::writeFrame(uint8_t** rgbData, int width, int height, int /*quality*/)
{
if (setjmp(png_jmpbuf(m_PngPtr)))
{
throw logic_error("Writing png file failed");
}
png_set_IHDR(m_PngPtr, m_InfoPtr, width, height, 8,
PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
png_set_rows(m_PngPtr, m_InfoPtr, rgbData);
png_write_png(m_PngPtr, m_InfoPtr, 0, nullptr);
}
void writeDataCallback(png_structp png_ptr, png_bytep data, png_size_t length)
{
vector<uint8_t>& outputBuffer = *(reinterpret_cast<vector<uint8_t>* >(png_get_io_ptr(png_ptr)));
int prevBufSize = outputBuffer.size();
outputBuffer.resize(outputBuffer.size() + length);
memcpy(&outputBuffer[prevBufSize], data, length);
}
}
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