tests/ref/fate/filter-vectorscope_gray

#tb 0: 1/25
#media_type 0: video
#codec_id 0: rawvideo
#dimensions 0: 256x256
#sar 0: 1/1
0,          0,          0,        1,   196608, 0x79ba71e2
0,          1,          1,        1,   196608, 0x909271e2
0,          2,          2,        1,   196608, 0x143971e2