encode: block.

Signed-off-by: Zhong Cong <congx.zhong@intel.com>
encode: workaround for block.

bitrate calcute is wrong.

Signed-off-by: Zhong Cong <congx.zhong@intel.com>
encode: revise code.

Signed-off-by: Zhong Cong <congx.zhong@intel.com>