bttv-0.9.5 + V4L2_FIELD_ALTERNATE

[Thilo Weigel <weigel@xxxxxxxxxxxxxxxxxxxxxxxxxx>]

Hi everybody,
Using Kernel 2.4.20 with the "patch-2.4.20-kraxel" applied and 
bttv-0.9.5 installed I'm getting an error ("invalid argument") when 
setting the field format to V4L2_FIELD_ALTERNATE throught the 
VIDIOC_S_FMT-ioctl.
Everything works fine however when setting the format to 
V4L2_FIELD_INTERLACED.
In a former version (SuSe 7.3, bttv 0.7.91, videodevX.20020303) I used 
"V4L2_FMT_FLAG_TOPFIELD | V4L2_FMT_FLAG_BOTFIELD" and was able to 
capture odd and even frames in separate buffers.
Did I likely make a mistake when adapting my app to the new api or is 
this a "problem" with bttv-0.9.5? In this case should I go back to the 
old configuration with bttv2 and videodevX?

Hints and help are greatly appreciated,

Thanks:

Thilo