hi3531a GVS 问题

[code]stTask.stImgIn.stVFrame.u32Width = pstForeGround->u32Width;
        stTask.stImgIn.stVFrame.u32Height = pstForeGround->u32Height;
        stTask.stImgIn.stVFrame.enPixelFormat = PIXEL_FORMAT_RGB_8888;
        stTask.stImgIn.stVFrame.enVideoFormat = VIDEO_FORMAT_LINEAR;
        stTask.stImgIn.stVFrame.enCompressMode = COMPRESS_MODE_NONE;
        stTask.stImgIn.stVFrame.u32HeaderPhyAddr[0] = pstForeGround->u32PhyAddr;
        stTask.stImgIn.stVFrame.u32HeaderPhyAddr[1] = 0;
        stTask.stImgIn.stVFrame.u32HeaderPhyAddr[2] = 0;
        //stTask.stImgIn.stVFrame.u32HeaderStride[0] = pstForeGround->u32Stride;
        stTask.stImgIn.stVFrame.u32HeaderStride[0] = 960*4;
        stTask.stImgIn.stVFrame.u32HeaderStride[1] = 0;
        stTask.stImgIn.stVFrame.u32HeaderStride[2] = 0;
        stTask.stImgIn.stVFrame.u32PhyAddr[0] = pstForeGround->u32PhyAddr;
        stTask.stImgIn.stVFrame.u32PhyAddr[1] = 0;
        stTask.stImgIn.stVFrame.u32PhyAddr[2] = 0;
        //stTask.stImgIn.stVFrame.u32Stride[0] = pstForeGround->u32Stride;
        stTask.stImgIn.stVFrame.u32Stride[0] = 960*4;
        stTask.stImgIn.stVFrame.u32Stride[1] = 0;
        stTask.stImgIn.stVFrame.u32Stride[2] = 0;


        stTask.stImgOut.stVFrame.u32Width = pstBackGround->u32YWidth;
        stTask.stImgOut.stVFrame.u32Height = pstBackGround->u32YHeight;
        stTask.stImgOut.stVFrame.enPixelFormat = PIXEL_FORMAT_YUV_SEMIPLANAR_420;
        stTask.stImgOut.stVFrame.enVideoFormat = VIDEO_FORMAT_LINEAR;
        stTask.stImgOut.stVFrame.enCompressMode = COMPRESS_MODE_NONE;
        stTask.stImgOut.stVFrame.u32PhyAddr[0] = pstBackGround->u32YPhyAddr;
        stTask.stImgOut.stVFrame.u32PhyAddr[1] = pstBackGround->u32CbCrPhyAddr;
        stTask.stImgOut.stVFrame.u32PhyAddr[2] = 0;
        stTask.stImgOut.stVFrame.u32Stride[0] = pstBackGround->u32YStride;
        stTask.stImgOut.stVFrame.u32Stride[1] = pstBackGround->u32CbCrStride;
        stTask.stImgOut.stVFrame.u32Stride[2] = 0;

        s32Ret = HI_MPI_VGS_AddScaleTask(hHandle,&stTask);
[/code]

想通过vgs  把 rgb8888 转成 yuv420sp  但是报错
cat /dev/logmmp  
<3>[   vgs] [VGS_CheckImage]: 162,<3>[   vgs] input illegal param: in img fmt 10
<3>[   vgs] [VGS_UsrAddScaleTask]: 2709,<3>[   vgs] job (109 ) from user check input img err

是因为vgs 不支持 rgb8888的输入吗 ？

有没有其他办法 把rgb8888 转成 yuv420sp啊