技術標籤：webrtc 渲染

此部分為webrtc視訊渲染顯示，程式碼結構如下：

其實此部分程式碼與《webrtc視訊引擎之vedio_capture_module介紹》的程式碼結構一樣

1，圖中能夠直接看到的.h和.cc檔案也是一個適配作用，用於根據系統平臺適配採用某部分進行視訊渲染；

2， android資料夾用於在android平臺渲染顯示視訊影象；

3， IOS資料夾用於在IOS平臺渲染顯示視訊影象；

4， linux資料夾用於在linux平臺渲染顯示視訊影象；

5， mac資料夾用於在mac平臺渲染顯示視訊影象；

6，windows資料夾用於在windows平臺渲染顯示視訊影象；

render影象顯示模組的介面類：

在呼叫該介面類建立例項物件的時候需要從建構函式傳入 相關的顯示引數， 如下：

const int32_t id, //本路顯示視訊的ID，使用者自定義，用於唯一區分本路視訊即可

const VideoRenderType videoRenderType, // 此定於如下列舉

enum VideoRenderType

{

kRenderExternal = 0, // External

kRenderWindows = 1, // Windows

kRenderCocoa = 2, // Mac

kRenderCarbon = 3,

kRenderiOS = 4, // iPhone

kRenderAndroid = 5, // Android

kRenderX11 = 6, // Linux

kRenderDefault

};

void* window, //用於顯示視訊的視窗物件指標

const bool fullscreen //是否需要全屏顯示

ModuleVideoRenderImpl(const int32_t id, const VideoRenderType videoRenderType, void* window, const bool fullscreen);

該介面還是StartRender 、StopRender等介面供外部呼叫控制視訊渲染

class ModuleVideoRenderImpl: public VideoRender

{

public:

/*

* VideoRenderer constructor/destructor

*/

ModuleVideoRenderImpl(const int32_t id,

const VideoRenderType videoRenderType,

void* window, const bool fullscreen);

virtual ~ModuleVideoRenderImpl();

/*

* Change the unique identifier of this object

*/

virtual int32_t ChangeUniqueId(const int32_t id);

virtual int32_t TimeUntilNextProcess();

virtual int32_t Process();

/*

* Returns the render window

*/

virtual void* Window();

/*

* Change render window

*/

virtual int32_t ChangeWindow(void* window);

/*

* Returns module id

*/

int32_t Id();

/**************************************************************************

*

* Incoming Streams

*

***************************************************************************/

/*

* Add incoming render stream

*/

virtual VideoRenderCallback

* AddIncomingRenderStream(const uint32_t streamId,

const uint32_t zOrder,

const float left, const float top,

const float right, const float bottom);

/*

* Delete incoming render stream

*/

virtual int32_t

DeleteIncomingRenderStream(const uint32_t streamId);

/*

* Add incoming render callback, used for external rendering

*/

virtual int32_t

AddExternalRenderCallback(const uint32_t streamId,

VideoRenderCallback* renderObject);

/*

* Get the porperties for an incoming render stream

*/

virtual int32_t

GetIncomingRenderStreamProperties(const uint32_t streamId,

uint32_t& zOrder,

float& left, float& top,

float& right, float& bottom) const;

/*

* Incoming frame rate for the specified stream.

*/

virtual uint32_t GetIncomingFrameRate(const uint32_t streamId);

/*

* Returns the number of incoming streams added to this render module

*/

virtual uint32_t GetNumIncomingRenderStreams() const;

/*

* Returns true if this render module has the streamId added, false otherwise.

*/

virtual bool HasIncomingRenderStream(const uint32_t streamId) const;

/*

*

*/

virtual int32_t

RegisterRawFrameCallback(const uint32_t streamId,

VideoRenderCallback* callbackObj);

virtual int32_t GetLastRenderedFrame(const uint32_t streamId,

I420VideoFrame &frame) const;

virtual int32_t SetExpectedRenderDelay(uint32_t stream_id,

int32_t delay_ms);

/**************************************************************************

*

* Start/Stop

*

***************************************************************************/

/*

* Starts rendering the specified stream

*/

virtual int32_t StartRender(const uint32_t streamId);

/*

* Stops the renderer

*/

virtual int32_t StopRender(const uint32_t streamId);

/*

* Sets the renderer in start state, no streams removed.

*/

virtual int32_t ResetRender();

/**************************************************************************

*

* Properties

*

***************************************************************************/

/*

* Returns the prefered render video type

*/

virtual RawVideoType PreferredVideoType() const;

/*

* Returns true if the renderer is in fullscreen mode, otherwise false.

*/

virtual bool IsFullScreen();

/*

* Gets screen resolution in pixels

*/

virtual int32_t

GetScreenResolution(uint32_t& screenWidth,

uint32_t& screenHeight) const;

/*

* Get the actual render rate for this stream. I.e rendered frame rate,

* not frames delivered to the renderer.

*/

virtual uint32_t RenderFrameRate(const uint32_t streamId);

/*

* Set cropping of incoming stream

*/

virtual int32_t SetStreamCropping(const uint32_t streamId,

const float left, const float top,

const float right, const float bottom);

virtual int32_t ConfigureRenderer(const uint32_t streamId,

const unsigned int zOrder,

const float left, const float top,

const float right, const float bottom);

virtual int32_t SetTransparentBackground(const bool enable);

virtual int32_t FullScreenRender(void* window, const bool enable);

virtual int32_t SetBitmap(const void* bitMap,

const uint8_t pictureId,

const void* colorKey,

const float left, const float top,

const float right, const float bottom);

virtual int32_t SetText(const uint8_t textId,

const uint8_t* text,

const int32_t textLength,

const uint32_t textColorRef,

const uint32_t backgroundColorRef,

const float left, const float top,

const float right, const float bottom);

virtual int32_t SetStartImage(const uint32_t streamId,

const I420VideoFrame& videoFrame);

virtual int32_t SetTimeoutImage(const uint32_t streamId,

const I420VideoFrame& videoFrame,

const uint32_t timeout);

virtual int32_t MirrorRenderStream(const int renderId,

const bool enable,

const bool mirrorXAxis,

const bool mirrorYAxis);

private:

int32_t _id;

CriticalSectionWrapper& _moduleCrit;

void* _ptrWindow;

bool _fullScreen;

IVideoRender* _ptrRenderer;

typedef std::map IncomingVideoStreamMap;

IncomingVideoStreamMap _streamRenderMap;

}; 有興趣的同學朋友可以自行去研究每個裝置是怎麼顯示視訊， 至於每個裝置如何顯示視訊這個後面都單獨介紹，這裡只做個整體的介紹。