how about using this patch?
--- a/plugins/vpu/gstvpu.h
+++ b/plugins/vpu/gstvpu.h
@@ -45,7 +45,7 @@ static VPUMapper vpu_mappers[] = {
{VPU_V_VP9, "video/x-vp9"},
{VPU_V_VP8, "video/x-vp8"},
{VPU_V_VP6, "video/x-vp6-flash"},
- {VPU_V_AVC, "video/x-h264"},
+ {VPU_V_AVC, "video/x-h264,alignment=au"},
{VPU_V_MPEG2, "video/mpeg, systemstream=(boolean)false, mpegversion=(int){1,2}"},
{VPU_V_MPEG4, "video/mpeg, mpegversion=(int)4"},
{VPU_V_H263, "video/x-h263"},
--