C# 實現SDL2進行視訊播放視窗截圖和字幕新增
阿新 • • 發佈：2020-12-09
使用SDL2進行視訊播放視窗截圖和字幕新增操作
SDL API檢視：https://wiki.libsdl.org/APIByCategory
視訊截圖
我就廢話不多說了，大家還是直接看程式碼吧~
/// <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,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,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,ref destrect);
SDL.SDL_RenderPresent(renderer);
SDL.SDL_DestroyTexture(texture);
SDL.SDL_DestroyRenderer(renderer);
}
}事件測試字幕新增：
需要的引用庫下載：https://www.libsdl.org/projects/SDL_ttf/
/// <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,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,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,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,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,pitch);
//複製紋理資訊到渲染器目標
SDL.SDL_Rect srcRect = sdlrect;
SDL.SDL_RenderCopy(sdlrenderer,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,color);
IntPtr surface = SDL_ttf.TTF_RenderUTF8_Blended(font,color);
//IntPtr surface = SDL_ttf.TTF_RenderUNICODE_Blended(font,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,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。
以上這篇C# 實現SDL2進行視訊播放視窗截圖和字幕新增就是小編分享給大家的全部內容了，希望能給大家一個參考，也希望大家多多支援我們。