topic Based on which parameters these values are hardcoded in mxc_v4l2_capture driver cam->v2f.fmt.pix.sizeimage = 352 * 288 * 3 / 2; in i.MX Processors

Based on which parameters these values are hardcoded in mxc_v4l2_capture driver cam->v2f.fmt.pix.sizeimage = 352 * 288 * 3 / 2;

sirivella — Mon, 12 Sep 2016 09:35:03 GMT

Hello

1. In mxc_v4l2_capture.c capture driver we are setting up the camera cropping stuff in init function

cam->v2f.fmt.pix.sizeimage = 352 * 288 * 3 / 2;
   cam->v2f.fmt.pix.bytesperline = 288 * 3 / 2;
   cam->v2f.fmt.pix.width = 288;
   cam->v2f.fmt.pix.height = 352;
   cam->v2f.fmt.pix.pixelformat = V4L2_PIX_FMT_YUV420;
   cam->win.w.width = 160;
   cam->win.w.height = 160;

based on which parameters the values are hardcoded??

2. I have tried this below link sample code for memory map

http://trac.gateworks.com/wiki/linux/v4l2 its working fine for 640 * 480 pixels

is it possible for 1920 * 1080 pixels capturing image??

when i tried iam not able to see image for 1920 * 1080.

can anyone help me

Thanks.

Re: Based on which parameters these values are hardcoded in mxc_v4l2_capture driver cam->v2f.fmt.pix.sizeimage = 352 * 288 * 3 / 2;

joanxie — Mon, 19 Sep 2016 09:35:33 GMT

for 1080P, pls check your capture paramter, refer to the RM,

For parallel interface, the maximum speed of the interface is 240Mhz. The required
operating frequency of the interface is calculated in the following way:
F = FH * FW * FPS * BI * DF
Where
• FH = frame height (in pixels)
• FW = Frame width (in pixels)
• fps = frame rate (frames per second)
• BI = typically 35% overhead, should be assumed as 1.35. The actual blanking
intervals are a parameter of the attached device.
• DF = data format, defines the number of cycles needed to send a single pixel.

Re: Based on which parameters these values are hardcoded in mxc_v4l2_capture driver cam->v2f.fmt.pix.sizeimage = 352 * 288 * 3 / 2;

sirivella — Tue, 20 Sep 2016 11:38:46 GMT

Thanks for reply, Jaon Xie,

well in user space application, if i use other than 640 * 480 pixel image will i need to change the code in driver side.

if changes to be done means. what changes i should do?

say for example 800 * 600

Thanks

Re: Based on which parameters these values are hardcoded in mxc_v4l2_capture driver cam->v2f.fmt.pix.sizeimage = 352 * 288 * 3 / 2;

joanxie — Wed, 21 Sep 2016 03:18:32 GMT

if you need to change the resolution for good, you one can change the source code, if you want to get temporary change, you just change the parameter in the user space, like "mxc_v4l2_capture.out -iw * -ih* "

Re: Based on which parameters these values are hardcoded in mxc_v4l2_capture driver cam->v2f.fmt.pix.sizeimage = 352 * 288 * 3 / 2;

sirivella — Wed, 21 Sep 2016 05:28:56 GMT

Thanks for reply Joan Xie,

sure we need to change kernel driver code.

what changes exactly should i do in driver code?

Thanks