those are the options for -m which one did you try.
VGA_640_480 -iw 640 -ih 480 -m 0
QVGA_320_240 -iw 320 -ih 240 -m 1
NTSC_720_480 -iw 720 -ih 480 -m 2
PAL_720_576 -iw 720 -ih 576 -m 3
720P_1280_720 -iw 1280 -ih 720 -m 4
1080P_1920_1080 -iw 1920 -ih 1080 -m 5
QSXGA_2592_1944 -iw 2592 -ih 1944 -m 6
QCIF_176_144 -iw 176 -ih144 -m 7
XGA_1024_768 -iw 1024 -ih 768 -m 8
did you check if the CSI registers change ?
CSI_SENS_FRM_SIZE_ suppose to change.