Problem with IPU : Rotation by 90 and 270 degree

[rinkeshpatel]

We are using i.MX6 SabreSD Dual board.

We are trying to perform captured frames using IPU.

We are working on resolutions 720p and 1080p.

We tried both capture(V4L2_CID_MXC_ROT) and display(V4L2_CID_ROTATE) IOCTLs for rotation. But rotation is only possible for 180 and 0 degree.

Where as we are getting below error while doing rotation of 90 and 270 degrees.

mxc_v4l2_output mxc_v4l2_output.0: display work fail ret = -22.

we observed that IPU rotation(90 and 270 degree) works fine for VGA resolution but not for 720p and 1080p.

Can you please suggest any possible approach?

[binjiao]

Hi Rinkesh Patel,

Could you tell me how to capture(V4L2_CID_MXC_ROT) and display(V4L2_CID_ROTATE) IOCTLS for rotation?When I use USB camera to capture images and use IPU to ratote images before display,IPU can only process the first frame and stoped.I can't find the solution.Could you give me some suggestions.

Thanks very much.

[rinkeshpatel]

Hi,

According to below analysis, it seems like IPU doesn't support all 90 degree related rotations(90=90Right,270=90Left,etc. mentioned below).

/* ipu.h */

typedef enum {

    IPU_ROTATE_NONE = 0,

    IPU_ROTATE_VERT_FLIP = 1,

    IPU_ROTATE_HORIZ_FLIP = 2,

    IPU_ROTATE_180 = 3,

    IPU_ROTATE_90_RIGHT = 4,

    IPU_ROTATE_90_RIGHT_VFLIP = 5,

    IPU_ROTATE_90_RIGHT_HFLIP = 6,

    IPU_ROTATE_90_LEFT = 7,

} ipu_rotate_mode_t;

After debugging calling sequence, below are the observations. Please refer NOTE for more detail.

mxc_vout.c

mxc_vidioc_s_crop()->mxc_vout_try_task()->ipu_try_task()->ipu_check_task()

ipu_device.c

ipu_check_task()->check_task()->update_split_setting()

NOTE :

1) mxc_vidioc_s_crop is being called when ioctl VIDIOC_S_CROP is invoked from application

2) Update_split_setting() is being called if crop width or crop height is > 1024

3) Inside update_split_setting(), at the start of function if requested rotation in case of split(i.e. crop width/height is greater than 1024) is related to 90degree, then error IPU_CHECK_ERR_SPLIT_WITH_ROT is returned. Refer below code.

/* ipu_device.c */

static int update_split_setting(struct ipu_task_entry *t, bool vdi_split)

{

    :

    if (t->output.rotate >= IPU_ROTATE_90_RIGHT)

        return IPU_CHECK_ERR_SPLIT_WITH_ROT;

    :

}

Please provide suggestions on below query

1) Is above understanding correct?

2) Is it feasible to modify driver to support 90 degree rotation for resolution above 1024X1024?

3) Are there any hardware IPU limitations due to which 90 degree rotation is not achievable above 1024X1024 resolution?

[alejandrolozan1]

Hi,

I.MX6 IPU does not support rotation (limitation of IC module) above 1024x1024,

so one needs to split image on smaller areas and rotate them, after that

combine to whole image. Unfortunately I lack of an example like that.

/Alejandro

[binjiao]

Hi alejandrolozano,

Could you tell me how to capture and display for rotation at real time?When I use USB camera to capture images and use IPU(ioctl(fd_ipu, IPU_QUEUE_TASK, &task) to ratote images before display,IPU can only process the first frame and stoped.I can't find the solution.Could you give me some suggestions?

Thanks very much.