problem of VPU 720p mjpg decode with rotation

[usrg_s]

Hello NXP experts,

We are developing a product which uses 720p(1280x720)  UVC camera. To get high frame rate, we use MJPG format input of the UVC camera and use VPU decode before pipe to 720p ( 720x1280) LCD display.  I found the VPU output with rotation has ghost effect. I reproduced problem on i.MX6Q Sabre-SD board with mxc_vpu_test

Software version : L3.14.52_1.1.0-ga_images_MX6QDLSOLO

Hardware: i.MX6Q sabre-sd

command: /unit_tests/mxc_vpu_test.out -D "-i mjpg0.jpg -o YUV422.raw -f 7 -r 90 -t 0"

1. in the below picture, the left is mjpg0.jpg, the right is the YUV output with above command

2. The VPU output is YUV422P

3. If don't use rotation option, the VPU output is correct.

4. VPU version:

          Product Info: i.MX6Q/D/S

          VPU firmware version: 3.1.1_r46070

          VPU library version: 5.4.32

5. I attached the mjpg0.jpg and output YUV422.raw  and YUV422_norot.raw

Please help to check.

Regards

G

[HongzhangYang]

Hi, G,

The chroma format of mjpg0.jpg is 4:2:2 (horizontal), 1/2 horizontal subsampling.

The 90 degree rotated image is 4:2:2 (vertical), 1/2 vertical subsampling.

You need to select the correct chroma format in viewer.

Regards,

Hongzhang

[usrg_s]

Hello Hongzhang,

Thanks for your clarification. Could you give me V4L2 fourcc code of "4:2:2 (vertical), 1/2 vertical subsampling"?

I could not find the correct V4L2 format to display it.

Thanks.

/* Luminance+Chrominance formats */

#define V4L2_PIX_FMT_YVU410  v4l2_fourcc('Y', 'V', 'U', '9') /*  9  YVU 4:1:0     */

#define V4L2_PIX_FMT_YVU420  v4l2_fourcc('Y', 'V', '1', '2') /* 12  YVU 4:2:0     */

#define V4L2_PIX_FMT_YUYV    v4l2_fourcc('Y', 'U', 'Y', 'V') /* 16  YUV 4:2:2     */

#define V4L2_PIX_FMT_YYUV    v4l2_fourcc('Y', 'Y', 'U', 'V') /* 16  YUV 4:2:2     */

#define V4L2_PIX_FMT_YVYU    v4l2_fourcc('Y', 'V', 'Y', 'U') /* 16 YVU 4:2:2 */

#define V4L2_PIX_FMT_UYVY    v4l2_fourcc('U', 'Y', 'V', 'Y') /* 16  YUV 4:2:2     */

#define V4L2_PIX_FMT_VYUY    v4l2_fourcc('V', 'Y', 'U', 'Y') /* 16  YUV 4:2:2     */

#define V4L2_PIX_FMT_YUV422P v4l2_fourcc('4', '2', '2', 'P') /* 16  YVU422 planar */

#define V4L2_PIX_FMT_YUV411P v4l2_fourcc('4', '1', '1', 'P') /* 16  YVU411 planar */

#define V4L2_PIX_FMT_Y41P    v4l2_fourcc('Y', '4', '1', 'P') /* 12  YUV 4:1:1     */

#define V4L2_PIX_FMT_YUV444  v4l2_fourcc('Y', '4', '4', '4') /* 16  xxxxyyyy uuuuvvvv */

#define V4L2_PIX_FMT_YUV555  v4l2_fourcc('Y', 'U', 'V', 'O') /* 16  YUV-5-5-5     */

#define V4L2_PIX_FMT_YUV565  v4l2_fourcc('Y', 'U', 'V', 'P') /* 16  YUV-5-6-5     */

#define V4L2_PIX_FMT_YUV32   v4l2_fourcc('Y', 'U', 'V', '4') /* 32  YUV-8-8-8-8   */

#define V4L2_PIX_FMT_YUV410  v4l2_fourcc('Y', 'U', 'V', '9') /*  9  YUV 4:1:0     */

#define V4L2_PIX_FMT_YUV420  v4l2_fourcc('Y', 'U', '1', '2') /* 12  YUV 4:2:0     */

#define V4L2_PIX_FMT_HI240   v4l2_fourcc('H', 'I', '2', '4') /*  8  8-bit color   */

#define V4L2_PIX_FMT_HM12    v4l2_fourcc('H', 'M', '1', '2') /*  8  YUV 4:2:0 16x16 macroblocks */

#define V4L2_PIX_FMT_M420    v4l2_fourcc('M', '4', '2', '0') /* 12  YUV 4:2:0 2 lines y, 1 line uv interleaved */

Regards,

G

[HongzhangYang]

Hi G,

It should be like V4L2_PIX_FMT_YUV440P but I can't find it in linux/videodev2.h. Maybe this format is rarely used now.

Can you configure your camera to use 4:2:0 format?

Regards,

Hongzhang

[usrg_s]

Hello Hongzhang,

Our camera can't configure to 4:2:0 mjpg.   I will use VPU to decode and use G2D to rotate and convert to RGB, then draw to frame buffer directly.  Thanks for your help.

Regards,

G

[HongzhangYang]

It's a good idea. VPU is good at decoding, and GPU/IPU is more efficient in post processing.