topic Re: problem of VPU 720p mjpg decode with rotation in i.MX Processors

problem of VPU 720p mjpg decode with rotation

usrg_s — Tue, 03 May 2016 05:50:04 GMT

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

Re: problem of VPU 720p mjpg decode with rotation

HongzhangYang — Wed, 04 May 2016 03:13:27 GMT

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

Re: problem of VPU 720p mjpg decode with rotation

usrg_s — Wed, 04 May 2016 05:24:24 GMT

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,

Re: problem of VPU 720p mjpg decode with rotation

HongzhangYang — Wed, 04 May 2016 07:26:49 GMT

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

Re: problem of VPU 720p mjpg decode with rotation

usrg_s — Thu, 05 May 2016 04:05:55 GMT

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,

Re: problem of VPU 720p mjpg decode with rotation

HongzhangYang — Thu, 05 May 2016 08:18:03 GMT

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