Jpeg encoder problem with CMemBuffOutput

[cks2k2]

I am having problems with encoding a bytestream into Jpeg when the output is memory (CMemBuffOutput) but no problems at all when the output is a file (CStdFileOutput).

The encoding code is called from C# using pinvoke.

[csharp]

public static class FrameEncoder
{
public static MemoryStream EncodeJPG(IntPtr data, int width, int height, int stride, int pxFormat, bool needFlipY, int size)
{
var jpeg = new byte[size];
MyDll.EncodeJpg(data, jpeg, size, 3, width, height, stride);
var stream = new MemoryStream(jpeg, 0, size, false, true);
return stream;
}
}

[DllImport("encoderDll.dll")]
private static extern int encodeJpeg(IntPtr input, byte[] output, int length, int numChannels, int width,
int height, int step);

public static int EncodeJpg(IntPtr input, byte[] output, int length, int numChannels, int width, int height,
int step)
{
return encodeJpeg(input, output, length, numChannels, width, height, step);
}
[/csharp]

[cpp]
int WINAPI encodeJpeg(unsigned char* input, unsigned char* output, int length, int numChannels, int width, int height, int step)
{

//copied from UIC sample
CMemBuffOutput out;
UIC::Point origin;
UIC::RectSize size;
UIC::Rect refGrid;
UIC::Image imgCn;
UIC::JPEGEncoder encoder;
UIC::ImageDataPtr dataPtr;
UIC::ImageColorSpec colorSpec;
UIC::ImageDataOrder dataOrder;
UIC::ImageSamplingGeometry geo;
UIC::ExcStatus status;

if(!BaseStream::IsOk(out.Open(output, length)))
{
return -1;
}

// test
/*char* outputFile = "test.jpg";
CStdFileOutput outputF;*/
/*if(!BaseStream::IsOk(outputF.Open(outputFile)))
{
return -1;
}*/

status = encoder.Init();
if(status == ExcStatusFail)
{
return -1;
}

status = encoder.AttachStream(out);
//status = encoder.AttachStream(outputF);
dataOrder.SetDataType(UIC::ImageDataType::T8u);
size.SetWidth(width);
size.SetHeight(height);
origin.SetX(0);
origin.SetY(0);
refGrid.SetOrigin(origin);
refGrid.SetSize(size);
geo.SetRefGridRect(refGrid);
geo.ReAlloc(numChannels);
dataOrder.ReAlloc(UIC::ImageComponentOrder::Interleaved, numChannels);
dataOrder.PixelStep()[0] = numChannels;
dataOrder.LineStep()[0] = step;
status = imgCn.ColorSpec().ReAlloc(numChannels);
imgCn.ColorSpec().SetColorSpecMethod(Enumerated);
imgCn.ColorSpec().SetComponentToColorMap(Direct);

for(int i = 0; i < numChannels; i++)
{
imgCn.ColorSpec().DataRange().SetAsRange8u(255);
}

imgCn.ColorSpec().SetEnumColorSpace(UIC::ImageEnumColorSpace::RGB);

dataPtr.p8u = input;
status = imgCn.Buffer().Attach(&dataPtr, dataOrder, geo);
if(status == ExcStatusFail)
{
return -1;
}

status = encoder.AttachImage(imgCn);
if(status == ExcStatusFail)
{
return -1;
}

status = encoder.SetParams(JMODE::JPEG_BASELINE, JCOLOR::JC_RGB, JSS::JS_444, 0, 0, 75);
if(status == ExcStatusFail)
{
return -1;
}

status = encoder.WriteHeader();
if(status == ExcStatusFail)
{
return -1;
}

status = encoder.WriteData();
if(status == ExcStatusFail)
{
return -1;
}
[/cpp]

When output is CMemBuffOutput, the values in output are always the same, even when the input data (the camera captured image) has changed. For instance if i cover the camera (total black) the input data values reflect this but output values don't change.

Any idea what i'm doing wrong?

[Chao_Y_Intel]

Hello,

It is not easy to catch some error from the code piece. You may possiblly debug into the following function, see find why the write is actually not happenning.

JERRCODE CMemBuffOutput::Write(void* buf,uic_size_t len,uic_size_t* cnt) {....}

Thanks,
Chao

[Sathish_S_]

I am also facing the same issue. 

did you found the solution for it?. If so could you please share it.

Regards,

Sathish