encode: support multi-frame encode.

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

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

Signed-off-by: Zhong Cong <congx.zhong@intel.com>
encode: add parse option 1.

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