说明
这里的需求是要往生成的录像文件中添加显示时间，实际上也就是海思的VENC与OSD的绑定。
在上一篇博客海思平台freetype、SDL、SDL_TTL的编译编译出三个库之后，又提供了例程生成一个bmp图片，但是实际上我们每次往海思通道贴图，不可能说都像例程一样保存成bmp图片再贴图，这样会造成资源的浪费。
所以这里进行了进一步的修改，让我们能够直接拿到bmp图片的位图数据，而不需要生成bmp图片。
一、bmp位图数据的获取
/* getVencOsd 获取生成的位图数据 bitmap 海思 BITMAP_S 位图数据结构体指针 */ static SV_S32 getVencOsd(BITMAP_S *bitmap) { if( bitmap == NULL || bitmap->pData == NULL ) { LOG(ERROR)<<“bitmap or pData is NULL”; return SV_FAILURE; } //初始化字库 if ( TTF_Init() < 0 ) { SDL_Quit(); return SV_FAILURE; } //打开字库 font = TTF_OpenFont(“/root/res/wqy-microhei.ttc”, 48); if ( font == NULL ) { fprintf(stderr, “Couldnt load %d pt font from %s: %s\n”, 18, “ptsize”, SDL_GetError()); SDL_Quit(); return SV_FAILURE; } //生成显示时间 std::string time(“2019-10-10 10:10:10”); SDL_Color forecol = { 0xff, 0xff, 0xff, 0xff }; SDL_Surface *text = TTF_RenderUTF8_Solid(font, time.c_str(), forecol); if ( text == NULL ) { LOG(ERROR)<<“temp is NULL”; return SV_FAILURE; } SDL_PixelFormat fmt; memset(&fmt, 0, sizeof(SDL_PixelFormat)); fmt.BitsPerPixel = 16; fmt.BytesPerPixel = 2; fmt.colorkey = 0xffffffff; fmt.alpha = 0xff; fmt.Rmask = 0xff000000;//0x00FF0000 fmt.Gmask = 0x0000ff00;//0x0000FF00 fmt.Bmask = 0x000000ff;//0x000000FF fmt.Amask = 0; SDL_Surface *temp = SDL_ConvertSurface(text, &fmt, 0); if ( temp == NULL ) { LOG(ERROR)<<“temp is NULL”; SDL_FreeSurface(text); return SV_FAILURE; } memset(bitmap->pData, 0, DATA_BUFF); memcpy(bitmap->pData, temp->pixels, (2*(temp->w)*(temp->h))); bitmap->u32Width = temp->w; bitmap->u32Height = temp->h; bitmap->enPixelFormat = PIXEL_FORMAT_RGB_1555 ; SDL_FreeSurface(text); SDL_FreeSurface(temp); return SV_SUCCEED;<
}
二、创建RGN区域
/* * s32CreateRgnAndAttachVencChn 创建贴图区域并绑定到编码通道 * OsdRGBAs 海思 SV_OSD_RGBA_S 结构体对象 * s32VencChn 编码通道号 * s32RgnHandle 通道句柄 注意：海思的编码通道位图只支持PIXEL_FORMAT_RGB_1555或PIXEL_FORMAT_RGB_4444这里用的是1555 */ static SV_S32 s32CreateRgnAndAttachVencChn(const SV_OSD_RGBA_S OsdRGBAs, const SV_S32 s32VencChn, const SV_S32 s32RgnHandle) { MPP_CHN_S stChn; //RGN 区域绑定到对应VENC stChn.enModId = HI_ID_VENC; stChn.s32DevId = 0; stChn.s32ChnId = s32VencChn; //创建RGN区域 RGN_ATTR_S stRgnAttrSet; stRgnAttrSet.enType = OVERLAY_RGN; stRgnAttrSet.unAttr.stOverlay.enPixelFmt = PIXEL_FORMAT_RGB_1555; stRgnAttrSet.unAttr.stOverlay.stSize.u32Width = std::max(2, ALIGN_BACK(OsdRGBAs.stPixRect.stRectSize.s32Width, 2)); stRgnAttrSet.unAttr.stOverlay.stSize.u32Height = std::max(2, ALIGN_BACK(OsdRGBAs.stPixRect.stRectSize.s32Height, 2)); stRgnAttrSet.unAttr.stOverlay.u32BgColor = 0; HI_MPI_RGN_DetachFromChn(s32RgnHandle, &stChn); HI_MPI_RGN_Destroy(s32RgnHandle); SV_S32 s32Ret = HI_MPI_RGN_Create(s32RgnHandle, &stRgnAttrSet); if(s32Ret != SV_SUCCEED) { LOG(ERROR)<<“HI_MPI_RGN_Create failed with 0x”<<std::hex<<s32Ret; return SV_FAILURE; } RGN_CHN_ATTR_S stChnAttr; memset(&stChnAttr, 0, sizeof(stChnAttr)); stChnAttr.bShow = HI_TRUE; stChnAttr.enType = OVERLAY_RGN; stChnAttr.unChnAttr.stOverlayChn.stPoint.s32X = ALIGN_BACK(OsdRGBAs.stPixRect.stStartPoint.s32X, 2); stChnAttr.unChnAttr.stOverlayChn.stPoint.s32Y = ALIGN_BACK(OsdRGBAs.stPixRect.stStartPoint.s32Y, 2); stChnAttr.unChnAttr.stOverlayChn.u32BgAlpha = 0; stChnAttr.unChnAttr.stOverlayChn.u32FgAlpha = 128; stChnAttr.unChnAttr.stOverlayChn.u32Layer = 0; s32Ret = HI_MPI_RGN_AttachToChn(s32RgnHandle, &stChn, &stChnAttr); if(s32Ret != SV_SUCCEED) { LOG(ERROR)<<“HI_MPI_RGN_AttachToChn failed with 0x”<<std::hex<<s32Ret; HI_MPI_RGN_Destroy(s32RgnHandle); return SV_FAILURE; } return SV_SUCCEED; }<
三、加载bmp位图
/* s32LoadBmp 加载显示bmp pData 用来存放位图的buffer */ SV_S32 s32LoadBmp(SV_VOID *pData) { BITMAP_S bitmap; bitmap.pData = pData; SV_S32 s32VencChn = 0; SV_S32 s32Ret = getVencOsd(s32VencChn, &bitmap); if( s32Ret == SV_FAILURE ) { LOG(ERROR)<<“getVencOsd is failed!”; return SV_FAILURE; } SV_OSD_RGBA_S pOsd; pOsd.stPixRect.stStartPoint.s32X = 0; pOsd.stPixRect.stStartPoint.s32Y = 0; pOsd.stPixRect.stRectSize.s32Width = bitmap.u32Width; pOsd.stPixRect.stRectSize.s32Height = bitmap.u32Height; SV_S32 s32RgnHandle = 0; s32Ret = this->s32CreateRgnAndAttachVencChn(pOsd, s32VencChn, s32RgnHandle); if( s32Ret == SV_FAILURE ) { LOG(ERROR)<<“s32CreateRgnAndAttachVencChn failed with “<<s32Ret; return SV_FAILURE; } //设定相应位图显示 s32Ret = HI_MPI_RGN_SetBitMap(s32RgnHandle, &bitmap); if( s32Ret != SV_SUCCEED ) { LOG(ERROR)<<“sv_updateRgnChannals : HI_MPI_RGN_SetBitMap failed with 0x”<<std::hex<<s32Ret; HI_MPI_RGN_Destroy(s32RgnHandle); return SV_FAILURE; } return SV_SUCCEED; }<
四、主函数
int main (void) { char *pData = (char *)malloc(1024 * 512); s32LoadBmp( pData ); return 0; }原文连接：https://blog.csdn.net/weixin_44362642/article/details/103469479
