Hi all,
I just fixed the scaler issue, but don't really know how to make/publish a
patch - I read a bit about it, but since even the tabs are important, I'd
prefer that someone else does it.
The problem itself - when using standard V4L2 loop for image acquisition
from a camera and using scaler at the same time for digital zooming (with
DISP_CMD_LAYER_SET_SRC_WINDOW for instance) the picture will flicker with
contents of the address previously set via DISP_CMD_LAYER_SET_PARA. These
are usually at 0, since framebuffer is set via DISP_CMD_VIDEO_SET_FB ioctl
in the main V4L2 loop. Also, since usually there are multiple V4L2 buffers
(I use 3-5), we cannot set some fixed addresses via
DISP_CMD_LAYER_SET_PARA, as they're constantly changing.
For digital zooming this is a big problem, since scaler uses these
addresses to do reinit, and it will flicker because of scaler
reconfiguration.
The simplest way is to remove scaler reconfig in disp_scaler.c, but this is
extremely dirty (comment out DE_SCAL_Config_Src() in Scaler_Set_SclRegn()
function), and probably doesn't get good scaling results.
Much better fix would be to properly update scaler addresses when video
framebuffer is refreshed - this way scaler will properly reconfigure itself
and there will be no flicker:
So in disp_video.c the function BSP_disp_video_set_fb() should look like:
__s32 BSP_disp_video_set_fb(__u32 sel, __u32 hid, __disp_video_fb_t
*in_addr)
{
__disp_scaler_t *scaler; // added for fix
hid = HANDTOID(hid);
HLID_ASSERT(hid, gdisp.screen[sel].max_layers);
if (g_video[sel][hid].enable) {
memcpy(&g_video[sel][hid].video_new, in_addr,
sizeof(__disp_video_fb_t));
g_video[sel][hid].have_got_frame = TRUE;
g_video[sel][hid].display_cnt = 0;
//---------------------------------------------------------------
// Fix for fb blinking during digital zoom issue:
scaler = &(gdisp.scaler[sel]);
scaler->in_fb.addr[0] = in_addr->addr[0];
scaler->in_fb.addr[1] = in_addr->addr[1];
scaler->in_fb.addr[2] = in_addr->addr[2];
//---------------------------------------------------------------
return DIS_SUCCESS;
} else
return DIS_FAIL;
}
This is the best and cleanest fix I could think of in order not to mess up
the scaler reconfig code.
If anyone is interested in making an official patch out of this, he's
welcome to.
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