C# 使用SDL2進行視訊播放視窗截圖和字幕新增
阿新 • • 發佈:2018-12-30
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。