1. 程式人生 > >C# 使用SDL2進行視訊播放視窗截圖和字幕新增

C# 使用SDL2進行視訊播放視窗截圖和字幕新增

使用SDL2進行視訊播放視窗截圖和字幕新增

視訊截圖

   


    /// <summary>
    /// SDL2截圖操作類
    /// </summary>
    public unsafe class SDLScreenshot
    {
        IntPtr window;// 視窗物件
        IntPtr renderer;// 播放視窗的渲染器(來自於已初始化的播放視窗渲染器)


        public SDLScreenshot(IntPtr window, IntPtr renderer)
        {
            this.window = window;
            this.renderer = renderer;
        }


        /// <summary>
        /// 儲存截圖
        /// </summary>
        /// <param name="width"></param>
        /// <param name="height"></param>
        /// <param name="path"></param>
        public void SaveBMP(int width, int height,string path)
        {
            // 判斷渲染器是否初始化
            if (renderer == IntPtr.Zero)
            {
                Console.WriteLine("renderer is null ,please call Init() method.");
                return;
            }
            uint Rmask=0x00FF0000, Gmask = 0x0000FF00, Bmask = 0x000000FF, Amask = 0x00000000;
            // 獲取影象資料
            SDL.SDL_Surface* surface= (SDL.SDL_Surface*)SDL.SDL_CreateRGBSurface(0, width, height, 32, Rmask, Gmask, Bmask, Amask);
            //設定紋理的資料
            SDL.SDL_Rect destrect;
            destrect.x = 0;
            destrect.y = 0;
            destrect.w = width;
            destrect.h = height;


            // 讀取並渲染影象資料
            SDL.SDL_RenderReadPixels(renderer, ref destrect, SDL.SDL_PIXELFORMAT_ARGB8888, surface->pixels, surface->pitch);


            //儲存圖片
            int i = SDL.SDL_SaveBMP((IntPtr)surface, path);
            if (i != 0)
            {
                Console.WriteLine("screenshot failed." + SDL.SDL_GetError());
            }


            SDL.SDL_FreeSurface((IntPtr)surface);
            //SDL.SDL_RenderClear(renderer);
            //SDL.SDL_DestroyRenderer(renderer);


        }


        /// <summary>
        /// 載入截圖
        /// </summary>
        /// <param name="width"></param>
        /// <param name="height"></param>
        /// <param name="path"></param>
        public void LoadBMP(int width, int height, string path)
        {
            // 判斷渲染器是否初始化
            if (renderer == IntPtr.Zero)
            {
                Console.WriteLine("renderer is null ,please call Init() method.");
                return;
            }
            // 載入圖片
            IntPtr surface = SDL.SDL_LoadBMP(path);
            if (surface == IntPtr.Zero)
            {
                Console.WriteLine("load bmp failed." + SDL.SDL_GetError());
                return;
            }
            IntPtr texture = SDL.SDL_CreateTextureFromSurface(renderer, surface);
            if (texture == IntPtr.Zero)
            {
                Console.WriteLine("create texture failed." + SDL.SDL_GetError());
                return;
            }
            SDL.SDL_FreeSurface(surface);


            //設定紋理的資料
            SDL.SDL_Rect destrect;
            destrect.x = 0;
            destrect.y = 0;
            destrect.w = width;
            destrect.h = height;


            SDL.SDL_Rect srcrect = destrect;


            //SDL.SDL_RenderClear(renderer);
            SDL.SDL_RenderCopy(renderer, texture, ref srcrect, ref destrect);
            SDL.SDL_RenderPresent(renderer);


            //SDL.SDL_Delay(20);


            SDL.SDL_DestroyTexture(texture);
            //SDL.SDL_DestroyRenderer(renderer);
            //SDL.SDL_DestroyWindow(screen);
            //Quit SDL    
            //SDL.SDL_Quit();
        }
    }

播放測試程式碼:

   if (isSaveScreenshot)
                            {
                                SDLScreenshot screenshot = new SDLScreenshot(sdlVideo.window, sdlVideo.sdlrenderer);
                                screenshot.SaveBMP(nvVideoframe.VideoFrame->width, nvVideoframe.VideoFrame->height, "screenshot.bmp");
                                isSaveScreenshot = false;
                 }

測試效果圖:


注:此處截圖是直接獲取的播放視窗的影象畫素來實現的。

視訊字幕

 /// <summary>
    /// SDL2字幕顯示類
    /// </summary>
    public unsafe class SDLTTF
    {
        IntPtr renderer;// 播放視窗的渲染器(來自於已初始化的播放視窗渲染器)

        public SDLTTF(IntPtr renderer)
        {
            this.renderer = renderer;
        }

        /// <summary>
        /// 展示字幕文字
        /// </summary>
        /// <param name="text"></param>
        public void ShowText(string ttfPath, int fontSize,string text)
        {
            // 初始化 ttf
            if (SDL_ttf.TTF_Init() < 0)
            {
                Console.WriteLine("SDL_ttf.TTF_Init() failed.");
                return;
            }
            // 是否初始化完成
            int was_init = SDL_ttf.TTF_WasInit();

            if (was_init == 1)
                // SDL_ttf was already initialized
                Console.WriteLine("SDL_ttf was already initialized");
            else if (was_init == 0)
                // SDL_ttf was not already initialized
                Console.WriteLine("SDL_ttf was not already initialized");

            // 判斷是否初始化
            if (renderer == IntPtr.Zero)
            {
                Console.WriteLine("Not initialized by  SDL_ttf.TTF_Init() ,please call Init() method.");
                return;
            }

            //如:開啟ttfPath=simfang.ttf 字型檔,設字型為fontSize=20號
            IntPtr font = SDL_ttf.TTF_OpenFont(ttfPath, fontSize);
            if (font == IntPtr.Zero)
            {
                Console.WriteLine("open font failed." + SDL.SDL_GetError());
                return;
            }

            // 設定文字顏色
            SDL.SDL_Color color;
            color.a = 255;
            color.r = 255;
            color.g = 255;
            color.b = 255;

            // 渲染文字效果
            //IntPtr surface = SDL_ttf.TTF_RenderUTF8_Blended(font, text, color);
            IntPtr surface = SDL_ttf.TTF_RenderUNICODE_Blended(font, text, color);
            if (surface == IntPtr.Zero)
            {
                Console.WriteLine("show surface failed." + SDL.SDL_GetError());
            }
            IntPtr texture = SDL.SDL_CreateTextureFromSurface(renderer, surface);
            if (texture == IntPtr.Zero)
            {
                Console.WriteLine("create texture failed." + SDL.SDL_GetError());
            }
            SDL.SDL_FreeSurface(surface);
            // 關閉字型
            SDL_ttf.TTF_CloseFont(font);

            // 停止顯示
            SDL_ttf.TTF_Quit();

            //設定紋理的資料
            SDL.SDL_Rect destrect;
            destrect.x = 0;
            destrect.y = 0;
            destrect.w = text.Length * 20;
            destrect.h = 20;

            SDL.SDL_Rect srcrect = destrect;

            SDL.SDL_RenderClear(renderer);
            SDL.SDL_RenderCopy(renderer, texture, ref srcrect, ref destrect);
            SDL.SDL_RenderPresent(renderer);
            SDL.SDL_DestroyTexture(texture);
            SDL.SDL_DestroyRenderer(renderer);
        }
    }

事件測試字幕新增:

  /// <summary>
        /// 字幕疊加****需要新增三個dll庫:SDL2_ttf.dll 、libfreetype-6.dll 、zlib1.dll
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void mbtnAddFontText_Click(object sender, EventArgs e)
        {
            Console.WriteLine("疊加字幕...............");

            sdlTTF = new SDLTTF(sdlVideo.sdlrenderer);
            // 中英文都需要相容
            string text = "Hello 世界!";
            // 設定一個字型庫並設定字型大小和顯示文字內容
            sdlTTF.ShowText("simkai.ttf",12, text);
        }

測試效果圖:


如果是播放過程中顯示字幕一定要在視訊渲染完成後渲染字幕,如下面工具類的方法:

/// <summary>
        /// 播放視訊
        /// </summary>
        /// <param name="width"></param>
        /// <param name="height"></param>
        /// <param name="pixels"></param>
        /// <param name="pixelsSize"></param>
        /// <param name="pitch"></param>
        /// <returns></returns>
        public int SDL_Display(int width, int height, IntPtr pixels, int pixelsSize,
            int pitch)
        {
            lock (this)
            {
                while (isPause)
                {
                    SDL.SDL_Delay(20);//延遲播放
                }

                #region SDL 視訊資料渲染播放
                //設定紋理的資料
                sdlrect.x = 0;
                sdlrect.y = 0;
                sdlrect.w = width;
                sdlrect.h = height;
                SDL.SDL_UpdateTexture(sdltexture, ref sdlrect, pixels, pitch);
                //SDL.SDL_UpdateTexture(sdltexture, IntPtr.Zero, pixels, pitch);//此處程式碼導致播放視窗綠色陰影
                //複製紋理資訊到渲染器目標
                SDL.SDL_RenderClear(sdltexture);
                //SDL.SDL_Rect srcRect = sdlrect;
                //SDL.SDL_RenderCopy(sdlrenderer, sdltexture, ref srcRect, ref sdlrect);

                SDL.SDL_RenderCopy(sdlrenderer, sdltexture, IntPtr.Zero, IntPtr.Zero);
                //字幕渲染顯示-特別提醒:此處必須放置於視訊渲染之後,否則字幕不會顯示
                if (ttfText!=null&&!ttfText.Equals(""))
                {
                    RenderToShowTTF(ttfText);
                }
                //else
                //{
                //    RenderToShowTTF( "未設定字幕內容");
                //}
                //視訊渲染顯示
                SDL.SDL_RenderPresent(sdlrenderer);
                //SDL.SDL_Delay(40);
                //SDL.SDL_PollEvent(out sdlevent);
                //switch (sdlevent.type)
                //{
                //    case SDL.SDL_EventType.SDL_QUIT:
                //        SDL.SDL_Quit();
                //        return -1;
                //    default:
                //        break;
                //}
                return 0;
            }


            //SDL.SDL_RenderClear(sdlrenderer);
            //SDL.SDL_RenderCopy(sdlrenderer, sdltexture, ref srcRect, ref sdlrect);
            //SDL.SDL_RenderPresent(sdlrenderer);
            ////Delay 40ms  
            //SDL.SDL_Delay(40);
            #endregion


            //#region SDL 視訊資料渲染播放
            //////設定紋理的資料
            ////sdlrect.x = 0;
            ////sdlrect.y = 0;
            ////sdlrect.w = width;
            ////sdlrect.h = height;
            ////SDL.SDL_UpdateTexture(sdltexture, ref sdlrect, pixels, pitch);
            //////複製紋理資訊到渲染器目標
            ////SDL.SDL_Rect srcRect = sdlrect;
            ////SDL.SDL_RenderCopy(sdlrenderer, sdltexture, ref srcRect, ref sdlrect);
            //////視訊渲染顯示
            ////SDL.SDL_RenderPresent(sdlrenderer);
            //////SDL.SDL_Delay(40);
            ////SDL.SDL_PollEvent(out sdlevent);
            ////switch (sdlevent.type)
            ////{
            ////    case SDL.SDL_EventType.SDL_QUIT:
            ////        SDL.SDL_Quit();
            ////        return -1;
            ////    default:
            ////        break;
            ////}
            ////return 0;
            //#endregion
        }

        /// <summary>
        ///  設定字幕顯示內容
        /// </summary>
        /// <param name="ttfPath"></param>
        /// <param name="fontSize"></param>
        public void SDL_TTF_TEXT(string ttfPath, string text, int fontSize)
        {
            this.ttfPath = ttfPath;
            this.ttfText = text;
            this.ttfFontSize = fontSize;
        }

        /// <summary>
        /// 渲染字幕
        /// </summary>
        /// <param name="text"></param>
        private void RenderToShowTTF(string text)
        {
            // 初始化 ttf
            if (SDL_ttf.TTF_Init() < 0)
            {
                Console.WriteLine("SDL_ttf.TTF_Init() failed.");
                return;
            }
            // 是否初始化完成
            int was_init = SDL_ttf.TTF_WasInit();

            if (was_init == 1)
                // SDL_ttf was already initialized
                Console.WriteLine("SDL_ttf was already initialized");
            else if (was_init == 0)
                // SDL_ttf was not already initialized
                Console.WriteLine("SDL_ttf was not already initialized");

            //如:開啟ttfPath=simfang.ttf 字型檔,設字型為fontSize=20號
            IntPtr font = SDL_ttf.TTF_OpenFont(ttfPath, ttfFontSize);
            if (font == IntPtr.Zero)
            {
                Console.WriteLine("open font failed." + SDL.SDL_GetError());
                return;
            }

            // 設定文字字型
            SDL_ttf.TTF_SetFontStyle(font, SDL_ttf.TTF_STYLE_BOLD);

            // 設定文字顏色
            SDL.SDL_Color color;
            color.a = 255;
            color.r = 255;
            color.g = 255;
            color.b = 255;

            // 渲染文字效果
            //IntPtr surface = SDL_ttf.TTF_RenderText_Blended(font, text, color);
            IntPtr surface = SDL_ttf.TTF_RenderUTF8_Blended(font, text, color);
            //IntPtr surface = SDL_ttf.TTF_RenderUNICODE_Blended(font, text, color);
            if (surface == IntPtr.Zero)
            {
                Console.WriteLine("show surface failed." + SDL.SDL_GetError());
            }
            IntPtr texture = SDL.SDL_CreateTextureFromSurface(sdlrenderer, surface);
            if (texture == IntPtr.Zero)
            {
                Console.WriteLine("create texture failed." + SDL.SDL_GetError());
            }

            SDL.SDL_FreeSurface(surface);
            // 關閉字型
            SDL_ttf.TTF_CloseFont(font);

            // 停止顯示
            SDL_ttf.TTF_Quit();

            // 計算合適的寬度和高度
            int texWidth = 0;
            int texHeight = 0;
            uint format = 0;
            int access = 0;
            // 下面這行程式碼解決字型虛浮不清問題
            SDL.SDL_QueryTexture(texture, out format, out access, out texWidth, out texHeight);
            //設定紋理的資料
            SDL.SDL_Rect destrect;
            destrect.x = 0;
            destrect.y = 0;
            destrect.w = texWidth;
            destrect.h = texHeight;

            SDL.SDL_Rect srcrect = destrect;
            SDL.SDL_RenderCopy(sdlrenderer, texture, ref srcrect, ref destrect);
        }

效果就會好很多:

,請看這裡的“中華人民共和國”

注意:常用中英文ttf字型包中包含了:times new roman,中山行書百年紀念版,calibri,Christopherhand,DejaVuSansMono,方正蘭亭黑,James Fajardo,Monaco,微軟雅黑,仿宋,黑體,楷體,宋體,yahei_mono,仿宋_GB2312,楷體_GB2312,迷你簡行楷碑等。本文使用的是simkai.ttf。下面是部分字型檔名:

bb1550.ttf
calibri.ttf
calibrib.ttf
calibrii.ttf
calibriz.ttf
comesinhandy.ttf
DejaVuSansMono-Bold.ttf
DejaVuSansMono-BoldOblique.ttf
DejaVuSansMono-Oblique.ttf
DejaVuSansMono.ttf
DroidSansFallback.ttf
James_Fajardo.ttf
Monaco.ttf
msyh.ttf
msyhbd.ttf
simfang.ttf
simhei.ttf
simkai.ttf
simsun.ttc
times.ttf
timesbd.ttf
timesbi.ttf
timesi.ttf
yahei_mono.ttf

如果懶得下載,Windows裡面有字型,在C:\Windows\Fonts目錄下。

參考資料