libmix: lower delay of output one decoded buffer

BZ: 146948

1) AVC: the original design will call endDecodingFrame for the previous frame
   when a new frame is detected; adjust the calling sequence for low delay mode;
2) VP8: enable low delay mode to allow one frame to be outputted at once.

Change-Id: Iac6a941a713d1ed43c21ccc35591f015ad237ab8
Signed-off-by: Dan Liang <>
3 files changed