Creates a new Caps object based on the parameters provided.
| format | the VideoFormat describing the raw video format |
| par_n | numerator of pixel aspect ratio |
| par_d | denominator of pixel aspect ratio |
| interlaced |
true if the format is interlaced |
| width | width of video |
| framerate_n | numerator of frame rate |
| height | height of video |
| framerate_d | denominator of frame rate |
| a new Caps object, or NULL if there was an error |