use dm816x scaler while capturing a 1080i video input through tvp7002

xiangliang chen

Other Parts Discussed in Thread: TVP7002

I was using a dm816 board. I capture a 1080i video through tvp7002 and demo saLoopBackScale returns error. So i modified this demo.

I masked follow source code in saLoopBackScale demo, because it's interlaced and the VIDIOC_S_CROP and VIDIOC_S_FMT retrun error.

capt.crop.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

capt.crop.c.left = 0;

capt.crop.c.top = 0;

capt.crop.c.width = capt.fmt.fmt.pix.width;

capt.crop.c.height = capt.fmt.fmt.pix.height;

if (ioctl(capt.fd, VIDIOC_S_CROP, &capt.crop)) {

perror("cap VIDIOC_S_CROP fail:");

exit(2);

}

capt.fmt_win.type = V4L2_BUF_TYPE_VIDEO_OVERLAY;

capt.fmt_win.fmt.win.w.left = 0;

capt.fmt_win.fmt.win.w.top = 0;

capt.fmt_win.fmt.win.w.width = 720;

capt.fmt_win.fmt.win.w.height = 480;

if (ioctl(capt.fd, VIDIOC_S_FMT, &capt.fmt_win)) {

perror("Setting cap window format failed\n");

exit(2);

}

After these, the demo works well. Now, i want to user scaler.I find in video outpud driver file ti81xxvin_main.c, there is a defalut ioctl---TISET_SCALAR_PARAMS may be can enable sacling. It can enable scaling and de-interlacing. But, the question is, the cmd arg :

struct ti81xxvid_scalarparam {

int scalar_enable;

int inframe_width;

int inframe_height;

int yframe_offset;

int yframe_size;

int yoffset_flag;

int chroma_offset;

void *scoutbuf;

};

what value should i set ? It's really good to provide an example.

Anybody can help me? Thanks.