YUV to RG color conversion with G2D problem

[ivan_garcia]

Hi!
We are trying to convert YUV frames captured using libuvc (usb cameras) to RGB, but we are not able to get the right color.

The format that libuvc gives the frames in is YUV422 acording with the headers:

enum uvc_frame_format {
....
 UVC_FRAME_FORMAT_COMPRESSED,
/** YUYV/YUV2/YUV422: YUV encoding with one luminance value per pixel and
* one UV (chrominance) pair for every two pixels.
*/

With dimensions 1920x1024, stride 3840 (1920*2)

And the code we are using to convert the color is:

cv::Mat ConvertFrame(uvc_frame_t *frame, int inputFormat=G2D_YUYV){
void *G2D_Handler=NULL;
if (g2d_open(&G2D_Handler)!=0){
puts("G2D_Start: Error opening g2d device");
};

int size = frame->data_bytes;
struct g2d_buf *srcM = g2d_alloc (size,1);
struct g2d_buf *dstM = g2d_alloc (frame->width * frame->height * 3,1);
memcpy(srcM->buf_vaddr, frame->data, size);

struct g2d_surface src,dst;
src.planes[0] = srcM->buf_paddr;
src.planes[1] = 0; //srcM->buf_paddr;
src.planes[2] = 0; //srcM->buf_paddr;
src.left = 0;
src.top = 0;
src.right = frame->width;
src.bottom = frame->height;
src.stride = frame->step;
src.width = frame->width;
src.height = frame->height;
src.rot = G2D_ROTATION_0;
src.format = inputFormat;


cv::Mat out(frame->height, frame->width, CV_8UC3, dstM->buf_vaddr );
dst.planes[0] = dstM->buf_paddr;
dst.left = 0;
dst.top = 0;
dst.right = out.cols;
dst.bottom = out.rows;
dst.stride = out.step1();
dst.width = out.cols;
dst.height = out.rows;
dst.rot = G2D_ROTATION_0;
dst.format = G2D_RGB888 ;

int r = g2d_blit(G2D_Handler, &src, &dst);
if (r!=0) puts("convertFrame :: ERROR g2d_blit");
r=g2d_finish(G2D_Handler);
if (r!=0) puts("convertFrame :: ERROR g2d_finish");

char name[128];
snprintf(name,128,"g2dOutput_%d.png", inputFormat );
cv::imwrite(name,out);

g2d_free (srcM);
return out;
}

The better results we could get are with inputFormat = G2D_YUYV, but as can be seen in the attached image, this is far to be correct.

Can someone give us an idea on how to solve this problem?

Thanks in advance!

[ivan_garcia]

Hi everybody,

Yes, I was able to fix the problem:
It was only a problem of the sizes used.

void *G2D::convert(void *imageBuffer, int width, int height){
		int size = width * height *2;

		struct g2d_surface src,dst;
		src.planes[0] = srcM->buf_paddr;
		src.planes[1] = 0;
		src.planes[2] = 0;
		src.left = 0;
		src.top = 0;
		src.right = width;
		src.bottom = height/2;
		src.stride = width *2;
		src.width = width;
		src.height = height/2;
		src.rot = G2D_ROTATION_0;
		src.format = G2D_YUYV;


		dst.planes[0] = dstM->buf_paddr;
		dst.left = 0;
		dst.top = 0;
		dst.right = width;
		dst.bottom = height;
		dst.stride = width ;
		dst.width = width;
		dst.height = height;
		dst.rot = G2D_ROTATION_0;
		dst.format = G2D_RGB888 ;


		memcpy(srcM->buf_vaddr, imageBuffer, size);

		int r = g2d_blit(G2D_Handler, &src, &dst);
		if (r!=0) puts("convertFrame :: ERROR g2d_blit");
		r=g2d_finish(G2D_Handler);
		if (r!=0) puts("convertFrame :: ERROR g2d_finish");

		return dstM->buf_vaddr;
	}

Hope it is useful for you!

[malik_cisse]

Thank you for the swift feedback Ivan,

I implemented your solution but my image is still broken (see attachment). I also attached the code, maybe you find something obvious.

What CPU are you using.

Not sure why you have 
src.bottom = height/2;
src.height = height/2;
Thx

[malik_cisse]

Hi Ivan,

Could you solve this problem?
I am facing same issue.
Thx

[malik_cisse]

Hello @Bio_TICFSL ,

I have exact same problem:

On NXP imx8mp G2D GPU (GC520L) YUYV to RGBX works fine:
G2D_YUYV to G2D_RGBX8888 works fine

However YUYV to RGB (24bit RGB888) does not work. I have same broken pictures as above.
G2D_YUYV to G2D_RGB888

Any hints how I can solve this problem?
Thank you

[Bio_TICFSL]

Hello ivan_garcia

Currently, libg2d does not support YUYV convert to BGR. I will discuss with R&D team to enable.

Regards

[quercuspau]

Hello @Bio_TICFSL ,

any news related to this topic?

BR