Move "rate-control" mode and "bitrate" properties to the GstVaapiEncode
base class. The actual range of supported rate control modes is currently
implemented as a plug-in element hook. This ought to be determined from
the GstVaapiEncoder object instead, i.e. from libgstvaapi.
Add a GST_VAAPIENCODE_CAST() helper to avoid run-time checks against
the GObject type system. We are guaranteed to only deal with the same
plug-in element object.
Add GstVaapiEncodeMPEG2 element object. The actual plug-in element
is called "vaapiencode_mpeg2".
Valid properties:
- rate-control: rate control mode (default: cqp - constant QP)
- bitrate: desired bitrate in kbps (default: auto-calculated)
- key-period: maximal distance between two key frames (default: 30)
- max-bframes: number of B-frames between I and P (default: 2)
- quantizer: constant quantizer (default: 8)
Signed-off-by: Gwenole Beauchesne <gwenole.beauchesne@intel.com>
