JPEG Resize

[vardar]

Hello all,

does it possible to resize a decoded raw video frame so that it will be half of its dimensions.

I have a piece of code which encodes to JPEG without changing the original dimensions.

I will be glad, if you can give me a sample code to accomplish this task.

Many Thanks.

Here is my code;

...

CJPEGEncoder my_encoder;

JERRCODE jerr;

IppiSize dimensions;

dimensions.height = out->GetHeight(); // out is type of VideoData*

dimensions.width = out->GetWidth();

Ipp8u* pSrcs[3] = {(Ipp8u*)out->GetPlanePointer(0),

(Ipp8u*)out->GetPlanePointer(1),

(Ipp8u*)out->GetPlanePointer(2)};

Ipp32s pSrcSteps[3] = { out->GetPlanePitch(0),

out->GetPlanePitch(1),

out->GetPlanePitch(2)};

jerr = my_encoder.CJPEGEncoder::SetSource(pSrcs, pSrcSteps, dimensions, 3, JC_YCBCR, JS_422);

if (jerr != JPEG_OK) {

printf(" f1 ");

}

jerr = my_encoder.CJPEGEncoder::SetParams(JPEG_BASELINE, JC_YCBCR, JS_422, 0, 0, tParam->quality);

if (jerr != JPEG_OK) {

printf(" f2 ");

}

...

[Sergey_Ryadno]

Hi, it not cleare for me from you post, do you need resize during encode or decode process?

[Vladimir_Dudnik]

With UIC picnic application we demonstrate how to use JPEG ability to produce 1:2, 1:4 and 1:8 downsampled images at decoding stage.

Regards,
Vladimir

[vardar]

Let me make it clear.

Above "out" is type ofVideoData pointer whichpoints to a decoded MPEG4 frame.

And its original resolution is 4 CIF.

I want to encode this frame as JPEG but as 2 CIF for example.

many thanks

[Vladimir_Dudnik]

Then there is nothing JPEG encoder can help you. You will just need to do resize before JPEG encoding

Regards,
Vladimir