Since there is already an "adaptive-B" option, just
use boolean property for B-pyramid enabling.
Fixme: Not sure whether this can be supported in vp8 and vp9.
It could be possible through GPB (b without backward ref) but
can't verify currently. We can move this as common property
once verified with vp8 and vp9 without breaking any backward
compatibility.
https://bugzilla.gnome.org/show_bug.cgi?id=791637
Add a new property "trellis" to enable trellis quantization.
Keeping trellis as a flag value (which is boolean for gst x264 enc element)
since it is possible to enable/disable this seperately for
I,P and B frames through MediaSDK ext option headers.
The subclass implementations always need to inform base-encoder
if it requires the inclusion of Extend Header buffers (mfxExtCodingOption2
and mfxExtCodingOption3).
https://bugzilla.gnome.org/show_bug.cgi?id=791637
This option controls down sampling in look ahead bitrate
control mode. According to spec it is only supported in AVC.
Fixme: Probably HEVC also have support for this in recent
MSDK versions. We could move the enumeration types to common
header usable for multiple codecs.
https://bugzilla.gnome.org/show_bug.cgi?id=791637
