请教下：海思3519DV500 VDEC后，获取解码后数据要怎么处理才能拿到正确的YUV数据？

看/dev/logmpp日志，送进去的数据解码没有出错，但是取出来的数据写YUV，看到数据不正确。

    td_s32 milli_sec = -1;// -1堵塞; 0 非堵塞；正值：超时值，无上限。单位ms.
    ot_video_frame_info frame_info;
    ot_vdec_supplement_info supplement;

    td_s32 ret = ss_mpi_vdec_get_frame(m_vdecChn, &frame_info, &supplement, milli_sec);

    if (TD_SUCCESS == ret)
    {
        printf("mod_id = %d, pool_id = %d.\n", frame_info.mod_id, frame_info.pool_id);
        printfPixelFormat((int)frame_info.video_frame.pixel_format);

        printf("pixel_format=%d compress_mode=%d.\n",
            frame_info.video_frame.pixel_format, frame_info.video_frame.compress_mode);

        td_s32 length = frame_info.video_frame.stride[0] * frame_info.video_frame.height * 3 / 2;
        td_s32 u32YLength = frame_info.video_frame.stride[0] * frame_info.video_frame.height;
        td_s32 u32UVLength = frame_info.video_frame.stride[1] * frame_info.video_frame.height / 2;
        // ss_mpi_sys_mmap_cached
        td_char* pYFrame = (td_char*)ss_mpi_sys_mmap(frame_info.video_frame.phys_addr[0], u32YLength);
        td_char* pVUFrame = (td_char*)ss_mpi_sys_mmap(frame_info.video_frame.phys_addr[1], u32UVLength);

        if ( !pYFrame)
        {
            printf("ss_mpi_sys_mmap_cached for pY_map fail!!\n");
            return 0;
        }
        if (!pVUFrame)
        {
            printf("ss_mpi_sys_mmap_cached for pVU_map fail!!\n");
            ss_mpi_sys_munmap(pYFrame, u32YLength);
            return 0;
        }
        printf("yuv frame w-h:{%d-%d} length=%d %d.\n", 
            frame_info.video_frame.stride[0], frame_info.video_frame.height,
            length, pYFrame[0]);

        //writeYUV(pYFrame, u32YLength);
        //writeYUV(pVUFrame, u32UVLength);
        td_char* pYUV = new td_char[u32YLength + u32UVLength];
        memcpy(pYUV, pYFrame, u32YLength);
        memcpy(pYUV + u32YLength, pVUFrame, u32UVLength);
        writeYUV(pYUV, u32UVLength + u32YLength);
        delete[]pYUV;

        ss_mpi_sys_munmap(pYFrame, u32YLength);
        ss_mpi_sys_munmap(pVUFrame, u32UVLength);
        //freeFrame(pYuvFrame, length);
        ret = ss_mpi_vdec_release_frame(m_vdecChn, &frame_info);
        //printf("ss_mpi_vdec_release_frame %#x. \n", ret);
    }