user: Question: What bit depth average has a video bit rate, Mbit/s of 25 (CBR), and 4:1:1 as color sampling?
Columns: ['Format name', 'Container', 'Video coding', 'Bit depth', 'Color sampling', 'Frame size', 'Video bit rate, Mbit/s', 'Audio coding']
Types: ['text', 'text', 'text', 'real', 'text', 'text', 'text', 'text']
Sample row: ['DVCAM', 'MXF , DV-AVI', 'DV', 8.0, '4:2:0', '720x576', '25 (CBR)', 'PCM 4 ch/16 bit/48kHz']
SQL:

assistant: SELECT AVG("Bit depth") FROM "Table" WHERE "Video bit rate, Mbit/s" = '25 (CBR)' AND "Color sampling" = '4:1:1';