I attached 3 screenshots about my video capture device capabilities.
In prefferedMediaTypes.PNG you can see my device's capabilities.
Only 320*240 for each video media subtypes rgb24, UYVY, ...
All those video media subtypes are correctly listed by :
IPin_QueryInterface (capture_pin, &IID_IAMStreamConfig, (void **)
&streamcaps)) (code from gstdshowvideosrc.c)
But in pinCapturerProperties.PNG you can see that it is possible to choose
an other size, for example 720*576.
And I can use it, see selectedMediaType.PNG.
So it seems that your code is listing only media subtype with default
So actually it is not possible to use other video size than default video
size with the actual gstdshowvideosrc.c.