C# 實(shí)現(xiàn)SDL2進(jìn)行視頻播放窗口截圖和字幕添加
使用SDL2進(jìn)行視頻播放窗口截圖和字幕添加操作
SDL API查看:https://wiki.libsdl.org/APIByCategory
視頻截圖
我就廢話不多說(shuō)了,大家還是直接看代碼吧~
/// <summary>
/// SDL2截圖操作類
/// </summary>
public unsafe class SDLScreenshot
{
IntPtr window;// 窗口對(duì)象
IntPtr renderer;// 播放窗口的渲染器(來(lái)自于已初始化的播放窗口渲染器)
public SDLScreenshot(IntPtr window, IntPtr renderer)
{
this.window = window;
this.renderer = renderer;
}
/// <summary>
/// 保存截圖
/// </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;
// 獲取圖像數(shù)據(jù)
SDL.SDL_Surface* surface= (SDL.SDL_Surface*)SDL.SDL_CreateRGBSurface(0, width, height, 32, Rmask, Gmask, Bmask, Amask);
//設(shè)置紋理的數(shù)據(jù)
SDL.SDL_Rect destrect;
destrect.x = 0;
destrect.y = 0;
destrect.w = width;
destrect.h = height;
// 讀取并渲染圖像數(shù)據(jù)
SDL.SDL_RenderReadPixels(renderer, ref destrect, SDL.SDL_PIXELFORMAT_ARGB8888, surface->pixels, surface->pitch);
//保存圖片
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>
/// 加載截圖
/// </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;
}
// 加載圖片
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(shè)置紋理的數(shù)據(jù)
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(cè)試代碼:
if (isSaveScreenshot)
{
SDLScreenshot screenshot = new SDLScreenshot(sdlVideo.window, sdlVideo.sdlrenderer);
screenshot.SaveBMP(nvVideoframe.VideoFrame->width, nvVideoframe.VideoFrame->height, "screenshot.bmp");
isSaveScreenshot = false;
}
測(cè)試效果圖:

注:此處截圖是直接獲取的播放窗口的圖像像素來(lái)實(shí)現(xiàn)的。
視頻字幕
/// <summary>
/// SDL2字幕顯示類
/// </summary>
public unsafe class SDLTTF
{
IntPtr renderer;// 播放窗口的渲染器(來(lái)自于已初始化的播放窗口渲染器)
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:打開ttfPath=simfang.ttf 字庫(kù),設(shè)字體為fontSize=20號(hào)
IntPtr font = SDL_ttf.TTF_OpenFont(ttfPath, fontSize);
if (font == IntPtr.Zero)
{
Console.WriteLine("open font failed." + SDL.SDL_GetError());
return;
}
// 設(shè)置文字顏色
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(guān)閉字體
SDL_ttf.TTF_CloseFont(font);
// 停止顯示
SDL_ttf.TTF_Quit();
//設(shè)置紋理的數(shù)據(jù)
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(cè)試字幕添加:
需要的引用庫(kù)下載:https://www.libsdl.org/projects/SDL_ttf/
/// <summary>
/// 字幕疊加****需要添加三個(gè)dll庫(kù):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);
// 中英文都需要兼容
string text = "Hello 世界!";
// 設(shè)置一個(gè)字體庫(kù)并設(shè)置字體大小和顯示文字內(nèi)容
sdlTTF.ShowText("simkai.ttf",12, text);
}
測(cè)試效果圖:

如果是播放過(guò)程中顯示字幕一定要在視頻渲染完成后渲染字幕,如下面工具類的方法:
/// <summary>
/// 播放視頻
/// </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 視頻數(shù)據(jù)渲染播放
//設(shè)置紋理的數(shù)據(jù)
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);//此處代碼導(dǎo)致播放窗口綠色陰影
//復(fù)制紋理信息到渲染器目標(biāo)
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:此處必須放置于視頻渲染之后,否則字幕不會(huì)顯示
if (ttfText!=null&&!ttfText.Equals(""))
{
RenderToShowTTF(ttfText);
}
//else
//{
// RenderToShowTTF( "未設(shè)置字幕內(nèi)容");
//}
//視頻渲染顯示
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 視頻數(shù)據(jù)渲染播放
//設(shè)置紋理的數(shù)據(jù)
sdlrect.x = 0;
sdlrect.y = 0;
sdlrect.w = width;
sdlrect.h = height;
SDL.SDL_UpdateTexture(sdltexture, ref sdlrect, pixels, pitch);
//復(fù)制紋理信息到渲染器目標(biāo)
SDL.SDL_Rect srcRect = sdlrect;
SDL.SDL_RenderCopy(sdlrenderer, sdltexture, ref srcRect, ref sdlrect);
//視頻渲染顯示
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(shè)置字幕顯示內(nèi)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:打開ttfPath=simfang.ttf 字庫(kù),設(shè)字體為fontSize=20號(hào)
IntPtr font = SDL_ttf.TTF_OpenFont(ttfPath, ttfFontSize);
if (font == IntPtr.Zero)
{
Console.WriteLine("open font failed." + SDL.SDL_GetError());
return;
}
// 設(shè)置文字字體
SDL_ttf.TTF_SetFontStyle(font, SDL_ttf.TTF_STYLE_BOLD);
// 設(shè)置文字顏色
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(guān)閉字體
SDL_ttf.TTF_CloseFont(font);
// 停止顯示
SDL_ttf.TTF_Quit();
// 計(jì)算合適的寬度和高度
int texWidth = 0;
int texHeight = 0;
uint format = 0;
int access = 0;
// 下面這行代碼解決字體虛浮不清問題
SDL.SDL_QueryTexture(texture, out format, out access, out texWidth, out texHeight);
//設(shè)置紋理的數(shù)據(jù)
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(huì)好很多:

請(qǐng)看這里的“中華人民共和國(guó)”
注意:
常用中英文ttf字體包中包含了:times new roman,中山行書百年紀(jì)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(jiǎn)行楷碑等。
本文使用的是simkai.ttf。
下面是部分字體文件名:
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里面有字體,在C:\Windows\Fonts目錄下。
以上這篇C# 實(shí)現(xiàn)SDL2進(jìn)行視頻播放窗口截圖和字幕添加就是小編分享給大家的全部?jī)?nèi)容了,希望能給大家一個(gè)參考,也希望大家多多支持腳本之家。
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