#include "stdafx.h"
#include "jpeglib.h"
#include "filetools.h"

JpegLib::JpegLib() :
img_buffer(NULL), sizeBuffer(0)
{
	handle = std::shared_ptr<void> (tjInitDecompress(),tjDestroy);
}

JpegLib::~JpegLib()
{
	clear();
}

void JpegLib::clear()
{
	img_buffer.reset();
	sizeBuffer = 0;
}

cv::Mat JpegLib::decode(cv::Mat& buf, int pixelFormat)
{
	if(buf.rows != 1)
		return cv::Mat();
	decode(buf.data, buf.cols, pixelFormat);
	return cv::Mat(getHeight(), getWidth(), pixelFormat == TJPF_BGR ? CV_8UC3 : CV_8UC1, getData());
	
}

void JpegLib::decode(unsigned char* buff, unsigned long buff_size, int pixelFormat)
{


	tjDecompressHeader(handle.get(), buff, buff_size, &width, &height);
	int size = width * height *tjPixelSize[pixelFormat];

	if (sizeBuffer != size)
	{
		clear();
		img_buffer = std::shared_ptr<unsigned char>(tjAlloc(size), tjFree);
		sizeBuffer = size;
	}

	if (img_buffer)
	{
		tjDecompress2(handle.get(), buff, buff_size, img_buffer.get(), width, 0, height, pixelFormat, 0);
	}
}

int JpegLib::getWidth()
{
	return width;
}

int JpegLib::getHeight()
{
	return height;
}

int JpegLib::getBufferSize()
{
	return sizeBuffer;
}

unsigned char* JpegLib::getData()
{
	return img_buffer.get();
}