TMS320DM355: About the issue that the top lines becomes black after resizing

Hi,

My customer resizes the encoded video data using the function of DM 355, but the upper two lines of the image are black lines after resizing.
They have confirmed that there is no black line in the image data before resizing.

They use "dvsdk_1 _ 30 _ 01 _ 41" and make the following settings for the resizing.

---
width : 640
height : 480
o_width : 320
o_height: 240
---
if (ioctl(fd, IPIPE_SET_PARAM, NULL) == -1) {
printf("Failed IPIPE_SET_PARAM default\n");
return SMOOTH_FAILURE;
}

if (ioctl(fd, IPIPE_GET_PARAM, &params) == -1) {
printf("Failed IPIPE_GET_PARAM\n");
return SMOOTH_FAILURE;
}

params.ipipeif_param.source = SDRAM_YUV;
params.ipipeif_param.hnum = width;
params.ipipeif_param.vnum = height;
params.ipipeif_param.glob_hor_size = width + 8;
params.ipipeif_param.glob_ver_size = height + 10;
params.ipipeif_param.adofs = ((width * 2 + 31) & (~31));
params.ipipeif_param.gain = 0x200;
params.ipipeif_param.clk_div = DIVIDE_SIXTH;

params.ipipe_dpaths_fmt = YUV2YUV;
params.ipipe_vst = 0;
params.ipipe_hst = 0;
params.ipipe_vsz = height - 1;
params.ipipe_hsz = width - 1;

params.rsz_rsc_param[1].rsz_h_dif = (int) (width *256 /o_width);
params.rsz_rsc_param[1].rsz_v_dif = (int) (((height *256) /o_height));
params.rsz_rsc_param[1].rsz_o_hsz = o_width - 1;
params.rsz_rsc_param[1].rsz_o_vsz = o_height - 1;

params.ext_mem_param[1].rsz_sdr_oft = (o_width * 2 + 31) & ~31;
params.ext_mem_param[1].rsz_sdr_ptr_e = o_height;
params.rsz_en[1] = ENABLE;
params.rsz_en[0] = DISABLE;

params.prefilter.pre_en = DISABLE;
params.false_color_suppresion.fcs_en = DISABLE;
params.edge_enhancer.yee_emf = DISABLE;
params.rgb2yuv.yuv_adj_ctr = 0x20;
params.wb.wb2_dgn = 0x200;
params.wb.wb2_wg_r = 0x110;
params.wb.wb2_wg_gr = 0xf0;
params.wb.wb2_wg_gb = 0xf0;
params.wb.wb2_wg_b = 0x130;

hSmooth->bufSize = width * height * 2;

if(ioctl(fd, IPIPE_SET_PARAM, &params) == -1) {
printf("Failed IPIPE_SET_PARAM\n");
return SMOOTH_FAILURE;
}
---

What can be thought of as a cause of occurrence of the black lines?

Best regards,
H.U