bool ImageCodecJpg::getDimension(xs::Stream* input,uint& width,uint& height,uint& depth)
{
struct jpeg_decompress_struct cinfo;
struct jpeg_error_mgr jerr;
int loc = 0;
// We have to set up the error handler, in case initialization fails.
cinfo.err = jpeg_std_error(&jerr);
// Initialize the JPEG decompression object.
jpeg_create_decompress(&cinfo);
// Specify data source (eg, a file, for us, memory)
uint fileLength = input->getLength();
SharedPtr<uchar>safeBuffer(new uchar[fileLength]);
uchar *pMem = safeBuffer.getPointer();
input->read(pMem,fileLength);
jpeg_memory_src(&cinfo,pMem,fileLength);
// Read the parameters with jpeg_read_header()
jpeg_read_header(&cinfo,TRUE);
// Start decompressor
jpeg_start_decompress(&cinfo);
// Get and set the values of interest to this object
// Prepare the pointer object for the pixel data
width = cinfo.output_width;
height = cinfo.output_height;
depth = 1;
// Release JPEG decompression object
jpeg_destroy_decompress(&cinfo);
return true;
}
safeBuffer TXFMSHA1::getFragmentId() {
return safeBuffer(""); // Empty string
}
bool ImageCodecJpg::decode(xs::Stream* input,ImageData& data,const void *p1,const void *p2) const
{
struct jpeg_decompress_struct cinfo;
struct jpeg_error_mgr jerr;
int loc = 0;
// We have to set up the error handler, in case initialization fails.
cinfo.err = jpeg_std_error(&jerr);
// Initialize the JPEG decompression object.
jpeg_create_decompress(&cinfo);
// Specify data source (eg, a file, for us, memory)
uint fileLength = input->getLength();
SharedPtr<uchar>safeBuffer(new uchar[fileLength]);
uchar *pMem = safeBuffer.getPointer();
input->read(pMem,fileLength);
jpeg_memory_src(&cinfo,pMem,fileLength);
// Read the parameters with jpeg_read_header()
jpeg_read_header(&cinfo,TRUE);
// Set parameters for decompression
// (We do nothing here since the defaults are fine)
// Start decompressor
jpeg_start_decompress(&cinfo);
// JSAMPLEs per row in output buffer
int bpp = cinfo.output_components;
if(bpp != 1 && bpp != 3 && bpp != 4)
{
Error("JPG Channels must be 1,3,4;");
return false;
}
int row_stride = cinfo.output_width * bpp;
// Get and set the values of interest to this object
// Prepare the pointer object for the pixel data
data.width = cinfo.output_width;
data.height = cinfo.output_height;
data.depth = 1;
data.num_mipmaps = 1;
//渲染引擎是大头的，因此PF_R8G8B8不被D3D9支持，所以将解码后的格式改为PF_B8G8R8
//data.format = PF_R8G8B8;
data.format = PF_B8G8R8;
data.flags = 0;
data.size = data.width * data.height * 3;
data.pData = new uchar[data.size];
// Make a one-row-high sample array that will go away when done with image
JSAMPARRAY temp = (*cinfo.mem->alloc_sarray)((j_common_ptr)&cinfo,JPOOL_IMAGE,row_stride,1);
// Read data on a scanline by scanline basis
while(cinfo.output_scanline < cinfo.output_height)
{
// We may need to adjust the output based on the
// number of channels it has.
switch (bpp)
{
case 1:
// Grayscale; decompress to temp.
jpeg_read_scanlines(&cinfo, temp, 1);
// Expand to three channels
{
uchar* scan = &(data.pData[(loc/1) * 3]);
uchar* endScan = scan + (data.width * 3);
uchar* t = *temp;
while (scan < endScan)
{
uchar value = t[0];
// Spread the value 3x.
scan[0] = value;
scan[1] = value;
scan[2] = value;
scan += 3;
t += 1;
}
}
break;
case 3:
// Read directly into the array
{
#if 0
// Need one extra level of indirection.
uchar* scan = data.pData + loc;
JSAMPARRAY ptr = &scan;
jpeg_read_scanlines(&cinfo, ptr, 1);
#else //将格式转化为 PF_B8G8R8
// Need one extra level of indirection.
uchar* scan = data.pData + (loc/3)*3;
JSAMPARRAY ptr = &scan;
jpeg_read_scanlines(&cinfo, ptr, 1);
uchar * endScan = scan + data.width * 3;
uchar swap = 0;
while( scan < endScan)
{
swap = scan[0];
scan[0] = scan[2];
scan[2] = swap;
scan += 3;
}
#endif
}
break;
case 4:
// RGBA; decompress to temp.
jpeg_read_scanlines(&cinfo, temp, 1);
// Drop the 3rd channel
{
#if 0
uchar* scan = &(data.pData[loc * 3]);//这个指针有错误
uchar* endScan = scan + data.width * 3;
uchar* t = *temp;
while (scan < endScan)
{
scan[0] = t[0];
scan[1] = t[1];
scan[2] = t[2];
scan += 3;
t += 4;
}
#else //将格式转化为 PF_B8G8R8
uchar* scan = &( data.pData[(loc/4)*3] );
uchar* endScan = scan + data.width * 3;
uchar* t = *temp;
while (scan < endScan)
{
scan[0] = t[2];
scan[1] = t[1];
scan[2] = t[0];
scan += 3;
t += 4;
}
#endif
}
break;
}
loc += row_stride;
}
// Finish decompression
jpeg_finish_decompress(&cinfo);
// Release JPEG decompression object
jpeg_destroy_decompress(&cinfo);
return true;
}
safeBuffer DSIGKeyInfoValue::getKeyName(void) {
return safeBuffer("");
}
