Linux/DRA71: viddec3test how to run in vsdk ?

I have run ipumm in IPU2. and run viddec3test( weston) ok.

but I stop weston, run error

please guide me to solve the issue.

the error as below:
root@dra7xx-evm:/opt/vision_sdk# viddec3test -s 24:1920x720 /usr/share/ti/video/TearOfSteel-Short-720x420.264 --fps 30
0x33008: Opening Display..
Forcing playback rate at 30 fps.
ERROR:connector_find_mode:492: failed to find mode "1920x720"
using 1 connectors, 0x0 display, multiplanar: 1
ERROR:alloc_buffer:182: drmModeAddFB2 failed: Invalid argument (-22)
ERROR:alloc_buffers:226: allocation failed
Segmentation fault (core dumped)

I use vDRM and modetest as below.
root@dra7xx-evm:/opt/vision_sdk# modetest -M vdrm
Encoders:
id crtc type possible crtcs possible clones
23 0 Virtual 0x00000001 0x00000000

Connectors:
id encoder status name size (mm) modes encoders
24 0 connected Virtual-1 0x0 1 23
modes:
name refresh (Hz) hdisp hss hse htot vdisp vss vse vtot)
1920x720 60 1920 1939 1943 1952 720 727 728 731 flags: phsync, pvsync; type: preferred, driver
props:
2 DPMS:
flags: enum
enums: On=0 Standby=1 Suspend=2 Off=3
value: 3

CRTCs:
id fb pos size
26 0 (0,0) (0x0)
0 0 0 0 0 0 0 0 0 flags: ; type:
props:

Planes:
id crtc fb CRTC x,y x,y gamma size possible crtcs
25 26 0 0,0 0,0 0 0x00000001
formats: XR24
props:
5 type:
flags: immutable enum
enums: Overlay=0 Primary=1 Cursor=2
value: 1

Frame buffers:
id size pitch