ffmpeg/tests/ref/fate/prores-422

#tb 0: 1/2997
0,          0,          0,        0,  8294400, 0xe8e9d448
0,        100,        100,        0,  8294400, 0xe8e9d448
avconv: saner output video timebase. r_frame_rate should in theory have something to do with input framerate, but in practice it is often made up from thin air by lavf. So unless we are targeting a constant output framerate, it's better to just use input stream timebase. Brings back dropped frames in nuv and cscd tests introduced in cd1ad18a6539bd7fc2dc4c1740fbcbd498c0c0a2 2012-02-07 10:03:33 +00:00			`#tb 0: 1/2997`
			`0, 0, 0, 0, 8294400, 0xe8e9d448`
			`0, 100, 100, 0, 8294400, 0xe8e9d448`