全志V85x内G2D模块实现图片格式步骤方法

G2D主要功能：

1）旋转：支持90、180、270旋转；

2）scale：放缩；

3）镜像反转：H / V；

4）透明叠加：实现两个rgb图片叠加；

5）格式转换：yuv转rgb等多种格式相互间转换；

6）矩形填充，等诸多功能；

G2D配置

源码目录

tina-v853-docker/kernel/linux-4.9/drivers/char/sunxi_g2d

make kernel_menuconfig 配置

Device Drivers > Character devices > sunxi g2d driver

Device Tree 设备树配置

sun8iw21p1.dtsi路径：

tina-v853-docker/kernel/linux-4.9/arch/arm/boot/dts/sun8iw21p1.dtsi

 g2d: g2d@05410000 {
   compatible = "allwinner,sunxi-g2d";
   reg = <0x0 0x05410000 0x0 0xbffff>;
   interrupts = ;
   clocks = <&clk_g2d>;
   iommus = <&mmu_aw 3 1>;
   status = "okay";
  };

注：status 要设定为“okay” 状态。

重新编译内核

使用烧录工具PhoenixSuit 将编译打包好的img镜像烧录到开发板。

adb shell 打开控制终端查看设备节点G2D：

通过G2D设备节点进行操作

static int SampleG2d_G2dOpen(SAMPLE_G2D_CTX *p_g2d_ctx)
{
  int ret = 0;
  p_g2d_ctx->mG2dFd = open("/dev/g2d", O_RDWR, 0);
  if (p_g2d_ctx->mG2dFd < 0)
    {
        aloge("fatal error! open /dev/g2d failed");
        ret = -1;
    }
    return ret;
}

G2D sample具体应用

G2D sample目录

进行rotation，scale，格式转换

具体实现：将 nv21 格式的1920x1080图转换成rgb888 格式并放缩为640x360 大小。具体用到两个功能，格式转换和放缩。

首先根据1920x1080 nv21 格式以及 640x360 rgb888 格式申请虚拟地址空间以及转换成物理地址（注意：g2d 转换是在物理地址中完成的）

1920x1080 nv21 格式空间大小（输入文件）：

Y 占 19201080 = 2073600 字节

UV 占 19201080 / 2 = 1036800 字节

640x360 rgb888 格式空间大小（输出文件）：

RGB 占 6403603 = 691200 字节

另外：虚拟地址转换成物理地址使用如下函数：

g2d_getPhyAddrByVirAddr（）

申请虚拟空间并转换成物理空间完整函数如下：

static int PrepareFrmBuff(SAMPLE_G2D_CTX *p_g2d_ctx)
{
  SampleG2dConfig *pConfig = NULL;
  unsigned int size = 0;


  pConfig = &p_g2d_ctx->mConfigPara;
  
  p_g2d_ctx->src_frm_info.frm_width = pConfig->mSrcWidth;
  p_g2d_ctx->src_frm_info.frm_height = pConfig->mSrcHeight;


  p_g2d_ctx->dst_frm_info.frm_width = pConfig->mDstWidth;
  p_g2d_ctx->dst_frm_info.frm_height = pConfig->mDstHeight;


  size = ALIGN(p_g2d_ctx->src_frm_info.frm_width, 16)*ALIGN(p_g2d_ctx->src_frm_info.frm_height, 16);
  if(pConfig->mPicFormat == MM_PIXEL_FORMAT_YVU_SEMIPLANAR_420 || pConfig->mPicFormat == MM_PIXEL_FORMAT_YUV_SEMIPLANAR_420)
  {
    p_g2d_ctx->src_frm_info.p_vir_addr[0] = (void *)g2d_allocMem(size);
    if(NULL == p_g2d_ctx->src_frm_info.p_vir_addr[0])
    {
      aloge("malloc_src_frm_y_mem_failed");
      return -1;
    }


    p_g2d_ctx->src_frm_info.p_vir_addr[1] = (void *)g2d_allocMem(size/2);
    if(NULL == p_g2d_ctx->src_frm_info.p_vir_addr[1])
    {
      g2d_freeMem(p_g2d_ctx->src_frm_info.p_vir_addr[0]);
      aloge("malloc_src_frm_c_mem_failed");  
      return -1;
    }


    p_g2d_ctx->src_frm_info.p_phy_addr[0] = (void *)g2d_getPhyAddrByVirAddr(p_g2d_ctx->src_frm_info.p_vir_addr[0]); 
    p_g2d_ctx->src_frm_info.p_phy_addr[1] = (void *)g2d_getPhyAddrByVirAddr(p_g2d_ctx->src_frm_info.p_vir_addr[1]);
  }


 if(pConfig->mDstPicFormat == MM_PIXEL_FORMAT_RGB_888)
 {
  size = p_g2d_ctx->dst_frm_info.frm_width * p_g2d_ctx->dst_frm_info.frm_height * 3;
  p_g2d_ctx->dst_frm_info.p_vir_addr[0] = (void *)g2d_allocMem(size);
  if(NULL == p_g2d_ctx->dst_frm_info.p_vir_addr[0])
  {
   if(p_g2d_ctx->src_frm_info.p_vir_addr[0] != NULL)
   {
    g2d_freeMem(p_g2d_ctx->src_frm_info.p_vir_addr[0]); 
   }
   if(p_g2d_ctx->src_frm_info.p_vir_addr[1] != NULL)
   {
    g2d_freeMem(p_g2d_ctx->src_frm_info.p_vir_addr[1]);
   }
   aloge("malloc_dst_frm_y_mem_failed");
   return -1;
  }
  p_g2d_ctx->dst_frm_info.p_phy_addr[0] = (void *)g2d_getPhyAddrByVirAddr(p_g2d_ctx->dst_frm_info.p_vir_addr[0]); 
 }


  return 0; 
}

通过fopen 传菜间两个文件句柄，fd_in fd_out 用来操作输入输出两个文件资源。

    p_g2d_ctx->fd_in = fopen(p_g2d_ctx->mConfigPara.SrcFile,"r");
    if(NULL == p_g2d_ctx->fd_in)
    {
      aloge("open src file failed");
      ret = -1;
      goto _err2;
    }
    fseek(p_g2d_ctx->fd_in, 0, SEEK_SET);


      p_g2d_ctx->fd_out = fopen(p_g2d_ctx->mConfigPara.DstFile, "wb");
      if (NULL == p_g2d_ctx->fd_out)
      {
        aloge("open out file failed");
        ret = -1;
        goto _err2;
      }
      fseek(p_g2d_ctx->fd_out, 0, SEEK_SET);

读出 1920x1080 nv21 图资放入 虚拟空间

read_len = p_g2d_ctx->src_frm_info.frm_width * p_g2d_ctx->src_frm_info.frm_height;
    if(pConfig->mPicFormat == MM_PIXEL_FORMAT_YVU_SEMIPLANAR_420|| pConfig->mPicFormat == MM_PIXEL_FORMAT_YUV_SEMIPLANAR_420)
    {
      size1 = fread(p_g2d_ctx->src_frm_info.p_vir_addr[0] , 1, read_len, p_g2d_ctx->fd_in);
      if(size1 != read_len)
      {
        aloge("read_y_data_frm_src_file_invalid");
      }
      size2 = fread(p_g2d_ctx->src_frm_info.p_vir_addr[1], 1, read_len /2, p_g2d_ctx->fd_in);
      if(size2 != read_len/2)
      {
        aloge("read_c_data_frm_src_file_invalid");
      }


      fclose(p_g2d_ctx->fd_in);


      g2d_flushCache((void *)p_g2d_ctx->src_frm_info.p_vir_addr[0], read_len);
      g2d_flushCache((void *)p_g2d_ctx->src_frm_info.p_vir_addr[1], read_len/2);
    }

打开g2d 初始化，并开始转换

ret = SampleG2d_G2dOpen(p_g2d_ctx);
  if (ret < 0)
    {
        aloge("fatal error! open /dev/g2d fail!");
        goto _err2;
    }
    ret = SampleG2d_G2dConvert(p_g2d_ctx);
    if (ret < 0)
    {
        aloge("fatal error! g2d convert fail!");
        goto _close_g2d;
    }
//具体转化函数：


static int SampleG2d_G2dConvert_scale(SAMPLE_G2D_CTX *p_g2d_ctx)
{
    int ret = 0;
    g2d_blt_h blit;
    g2d_fmt_enh eSrcFormat, eDstFormat; 
    SampleG2dConfig *pConfig = NULL;


    pConfig = &p_g2d_ctx->mConfigPara;


  ret = convert_PIXEL_FORMAT_E_to_g2d_fmt_enh(pConfig->mPicFormat, &eSrcFormat);
  if(ret!=SUCCESS)
  {
    aloge("fatal error! src pixel format[0x%x] is invalid!", pConfig->mPicFormat);
    return -1;
  }
  ret = convert_PIXEL_FORMAT_E_to_g2d_fmt_enh(pConfig->mDstPicFormat, &eDstFormat);
  if(ret!=SUCCESS)
  {
    aloge("fatal error! dst pixel format[0x%x] is invalid!", pConfig->mPicFormat);
    return -1;
  }


  //config blit
  memset(&blit, 0, sizeof(g2d_blt_h));


  if(0 != pConfig->mDstRotate)
  {
    aloge("fatal_err: rotation can't be performed when do scaling");
  }


  blit.flag_h = G2D_BLT_NONE_H;    // angle rotation used
//  switch(pConfig->mDstRotate)
//  {
//    case 0:
//      blit.flag_h = G2D_BLT_NONE_H;  //G2D_ROT_0, G2D_BLT_NONE_H
//      break;
//    case 90:
//      blit.flag_h = G2D_ROT_90;
//      break;
//    case 180:
//      blit.flag_h = G2D_ROT_180;
//      break;
//    case 270:
//      blit.flag_h = G2D_ROT_270;
//      break;
//    default:
//      aloge("fatal error! rotation[%d] is invalid!", pConfig->mDstRotate);
//      blit.flag_h = G2D_BLT_NONE_H;
//      break;
//  }
  //blit.src_image_h.bbuff = 1;
  //blit.src_image_h.color = 0xff;
  blit.src_image_h.format = eSrcFormat;
  blit.src_image_h.laddr[0] = (unsigned int)p_g2d_ctx->src_frm_info.p_phy_addr[0];
  blit.src_image_h.laddr[1] = (unsigned int)p_g2d_ctx->src_frm_info.p_phy_addr[1];
  blit.src_image_h.laddr[2] = (unsigned int)p_g2d_ctx->src_frm_info.p_phy_addr[2];
  //blit.src_image_h.haddr[] = 
  blit.src_image_h.width = p_g2d_ctx->src_frm_info.frm_width;
  blit.src_image_h.height = p_g2d_ctx->src_frm_info.frm_height;
  blit.src_image_h.align[0] = 0;
  blit.src_image_h.align[1] = 0;
  blit.src_image_h.align[2] = 0;
  blit.src_image_h.clip_rect.x = pConfig->mSrcRectX;
  blit.src_image_h.clip_rect.y = pConfig->mSrcRectY;
  blit.src_image_h.clip_rect.w = pConfig->mSrcRectW;
  blit.src_image_h.clip_rect.h = pConfig->mSrcRectH;
  blit.src_image_h.gamut = G2D_BT601;
  blit.src_image_h.bpremul = 0;
  //blit.src_image_h.alpha = 0xff;
  blit.src_image_h.mode = G2D_PIXEL_ALPHA;  //G2D_PIXEL_ALPHA, G2D_GLOBAL_ALPHA
  blit.src_image_h.fd = -1;
  blit.src_image_h.use_phy_addr = 1;


  //blit.dst_image_h.bbuff = 1;
  //blit.dst_image_h.color = 0xff;
  blit.dst_image_h.format = eDstFormat;
  blit.dst_image_h.laddr[0] = (unsigned int)p_g2d_ctx->dst_frm_info.p_phy_addr[0];
  blit.dst_image_h.laddr[1] = (unsigned int)p_g2d_ctx->dst_frm_info.p_phy_addr[1];
  blit.dst_image_h.laddr[2] = (unsigned int)p_g2d_ctx->dst_frm_info.p_phy_addr[2];
  //blit.dst_image_h.haddr[] = 
  blit.dst_image_h.width = p_g2d_ctx->dst_frm_info.frm_width;
  blit.dst_image_h.height = p_g2d_ctx->dst_frm_info.frm_height;
  blit.dst_image_h.align[0] = 0;
  blit.dst_image_h.align[1] = 0;
  blit.dst_image_h.align[2] = 0;
  blit.dst_image_h.clip_rect.x = pConfig->mDstRectX;
  blit.dst_image_h.clip_rect.y = pConfig->mDstRectY;
  blit.dst_image_h.clip_rect.w = pConfig->mDstRectW;
  blit.dst_image_h.clip_rect.h = pConfig->mDstRectH;
  blit.dst_image_h.gamut = G2D_BT601;
  blit.dst_image_h.bpremul = 0;
  //blit.dst_image_h.alpha = 0xff;
  blit.dst_image_h.mode = G2D_PIXEL_ALPHA;  //G2D_PIXEL_ALPHA, G2D_GLOBAL_ALPHA
  blit.dst_image_h.fd = -1;
  blit.dst_image_h.use_phy_addr = 1;


  ret = ioctl(p_g2d_ctx->mG2dFd, G2D_CMD_BITBLT_H, (unsigned long)&blit);
  if(ret < 0)
    {
        aloge("fatal error! bit-block(image) transfer failed[%d]", ret);
        system("cd /sys/class/sunxi_dump;echo 0x14A8000,0x14A8100 > dump;cat dump");
  }


  return ret;
}

转化完成后将640x360 rgb888 图资通过fd_out句柄存储起来

if(pConfig->mDstPicFormat == MM_PIXEL_FORMAT_RGB_888)
    {
      out_len = p_g2d_ctx->dst_frm_info.frm_width * p_g2d_ctx->dst_frm_info.frm_height *3;
      g2d_flushCache((void *)p_g2d_ctx->dst_frm_info.p_vir_addr[0], out_len);


      fwrite(p_g2d_ctx->dst_frm_info.p_vir_addr[0], 1, out_len, p_g2d_ctx->fd_out);
    }

转化步骤总结

通过步骤3中的模块化分析，可以看出g2d 转化大概分为一下步骤：

为打开 iomen 初始化；

为src以及dst图资申请虚拟地址空间并转换成物理地址空间；

将src图资放入虚拟地址空间，然后自动映射到物理地址空间；

打开g2d 设备节点进行转换（最重要的一环，可以通过手册分析具体怎么转换的）；

将转换好的dst图资保存起来；

审核编辑：刘清