webrtc之视频显示模块--video_render

在上一篇博文中，简单介绍了webrtc为我们提供了跨平台的视频采集模块，这篇博文也简单介绍下webrtc为我们提供的跨平台的视频显示模块：video_render。 该模块的源码结构如下：

如上图，我们也可以看到webrtc提供的视频显示模块video_render模块支持android、IOS、linux、mac和windows平台。我们在使用的时候只用单独编译该模块或者从webrtc中提取出该模块即可。

video_render模块的头文件内容为：

// Class definitions
class VideoRender: public Module
{
public:
    /*
     *   Create a video render module object
     *
     *   id              - unique identifier of this video render module object
     *   window          - pointer to the window to render to
     *   fullscreen      - true if this is a fullscreen renderer
     *   videoRenderType - type of renderer to create
     */
    static VideoRender
            * CreateVideoRender(
                                          const int32_t id,
                                          void* window,
                                          const bool fullscreen,
                                          const VideoRenderType videoRenderType =
                                                  kRenderDefault);

    /*
     *   Destroy a video render module object
     *
     *   module  - object to destroy
     */
    static void DestroyVideoRender(VideoRender* module);

    /*
     *   Change the unique identifier of this object
     *
     *   id      - new unique identifier of this video render module object
     */
    virtual int32_t ChangeUniqueId(const int32_t id) = ;

    virtual int32_t TimeUntilNextProcess() = ;
    virtual int32_t Process() = ;

    /**************************************************************************
     *
     *   Window functions
     *
     ***************************************************************************/

    /*
     *   Get window for this renderer
     */
    virtual void* Window() = ;

    /*
     *   Change render window
     *
     *   window      - the new render window, assuming same type as originally created.
     */
    virtual int32_t ChangeWindow(void* window) = ;

    /**************************************************************************
     *
     *   Incoming Streams
     *
     ***************************************************************************/

    /*
     *   Add incoming render stream
     *
     *   streamID    - id of the stream to add
     *   zOrder      - relative render order for the streams, 0 = on top
     *   left        - position of the stream in the window, [0.0f, 1.0f]
     *   top         - position of the stream in the window, [0.0f, 1.0f]
     *   right       - position of the stream in the window, [0.0f, 1.0f]
     *   bottom      - position of the stream in the window, [0.0f, 1.0f]
     *
     *   Return      - callback class to use for delivering new frames to render.
     */
    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
     *
     *   streamID    - id of the stream to add
     */
    virtual int32_t
            DeleteIncomingRenderStream(const uint32_t streamId) = ;

    /*
     *   Add incoming render callback, used for external rendering
     *
     *   streamID     - id of the stream the callback is used for
     *   renderObject - the VideoRenderCallback to use for this stream, NULL to remove
     *
     *   Return      - callback class to use for delivering new frames to render.
     */
    virtual int32_t
            AddExternalRenderCallback(const uint32_t streamId,
                                      VideoRenderCallback* renderObject) = ;

    /*
     *   Get the porperties for an incoming render stream
     *
     *   streamID    - [in] id of the stream to get properties for
     *   zOrder      - [out] relative render order for the streams, 0 = on top
     *   left        - [out] position of the stream in the window, [0.0f, 1.0f]
     *   top         - [out] position of the stream in the window, [0.0f, 1.0f]
     *   right       - [out] position of the stream in the window, [0.0f, 1.0f]
     *   bottom      - [out] position of the stream in the window, [0.0f, 1.0f]
     */
    virtual int32_t
            GetIncomingRenderStreamProperties(const uint32_t streamId,
                                              uint32_t& zOrder,
                                              float& left, float& top,
                                              float& right, float& bottom) const = ;
    /*
     *   The incoming frame rate to the module, not the rate rendered in the window.
     */
    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 = ;

    /*
     *   Registers a callback to get raw images in the same time as sent
     *   to the renderer. To be used for external rendering.
     */
    virtual int32_t
            RegisterRawFrameCallback(const uint32_t streamId,
                                     VideoRenderCallback* callbackObj) = ;

    /*
     * This method is usefull to get last rendered frame for the stream specified
     */
    virtual int32_t
            GetLastRenderedFrame(const uint32_t streamId,
                                 I420VideoFrame &frame) const = ;

    /**************************************************************************
     *
     *   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) = ;

    /*
     *   Resets the renderer
     *   No streams are removed. The state should be as after AddStream was called.
     */
    virtual int32_t ResetRender() = ;

    /**************************************************************************
     *
     *   Properties
     *
     ***************************************************************************/

    /*
     *   Returns the preferred 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) = ;

    /*
     * re-configure renderer
     */

    // Set the expected time needed by the graphics card or external renderer,
    // i.e. frames will be released for rendering |delay_ms| before set render
    // time in the video frame.
    virtual int32_t SetExpectedRenderDelay(uint32_t stream_id,
                                           int32_t delay_ms) = ;

    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) = ;

    /*
     * Set a start image. The image is rendered before the first image has been delivered
     */
    virtual int32_t
            SetStartImage(const uint32_t streamId,
                          const I420VideoFrame& videoFrame) = ;

    /*
     * Set a timout image. The image is rendered if no videoframe has been delivered
     */
    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) = ;
};

1，在显示前需要向该模块传入一个windows窗口对象的指针，理由如下函数：

static VideoRender
            * CreateVideoRender(
                                          const int32_t id,
                                          void* window,
                                          const bool fullscreen,
                                          const VideoRenderType videoRenderType =
                                                  kRenderDefault);,

2，

以下两个函数主要用于开始显示和结束显示。

 /*
     *   Starts rendering the specified stream
     */
    virtual int32_t StartRender(const uint32_t streamId) = 0;

    /*
     *   Stops the renderer
     */
    virtual int32_t StopRender(const uint32_t streamId) = 0;

另：
webrtc也有自带调用video_render的例程： 如下图

该例程包含 直接c++调用（主要针对windows系统）和android版本（其实android版本是没有实际源码，但是我们能仿照windows的调用方式写出来）和ios的调用，下面只列出直接C++调用的程序

头文件为：

/*
 *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#ifndef WEBRTC_MODULES_VIDEO_RENDER_MAIN_TEST_TESTAPI_TESTAPI_H
#define WEBRTC_MODULES_VIDEO_RENDER_MAIN_TEST_TESTAPI_TESTAPI_H

#include "webrtc/modules/video_render/include/video_render_defines.h"

void RunVideoRenderTests(void* window, webrtc::VideoRenderType windowType);

#endif  // WEBRTC_MODULES_VIDEO_RENDER_MAIN_TEST_TESTAPI_TESTAPI_H

源码文件为：

/*
 *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#include "webrtc/modules/video_render/test/testAPI/testAPI.h"

#include <stdio.h>

#if defined(_WIN32)
#include <tchar.h>
#include <windows.h>
#include <assert.h>
#include <fstream>
#include <iostream>
#include <string>
#include <windows.h>
#include <ddraw.h>

#elif defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID)

#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <iostream>
#include <sys/time.h>

#endif

#include "webrtc/common_types.h"
#include "webrtc/modules/interface/module_common_types.h"
#include "webrtc/modules/utility/interface/process_thread.h"
#include "webrtc/modules/video_render/include/video_render.h"
#include "webrtc/modules/video_render/include/video_render_defines.h"
#include "webrtc/system_wrappers/interface/sleep.h"
#include "webrtc/system_wrappers/interface/tick_util.h"
#include "webrtc/system_wrappers/interface/trace.h"

using namespace webrtc;

void GetTestVideoFrame(I420VideoFrame* frame,
                       uint8_t startColor);
int TestSingleStream(VideoRender* renderModule);
int TestFullscreenStream(VideoRender* &renderModule,
                         void* window,
                         const VideoRenderType videoRenderType);
int TestBitmapText(VideoRender* renderModule);
int TestMultipleStreams(VideoRender* renderModule);
int TestExternalRender(VideoRender* renderModule);

#define TEST_FRAME_RATE 30
#define TEST_TIME_SECOND 5
#define TEST_FRAME_NUM (TEST_FRAME_RATE*TEST_TIME_SECOND)
#define TEST_STREAM0_START_COLOR 0
#define TEST_STREAM1_START_COLOR 64
#define TEST_STREAM2_START_COLOR 128
#define TEST_STREAM3_START_COLOR 192

#if defined(WEBRTC_LINUX)

#define GET_TIME_IN_MS timeGetTime()

unsigned long timeGetTime()
{
    struct timeval tv;
    struct timezone tz;
    unsigned long val;

    gettimeofday(&tv, &tz);
    val= tv.tv_sec*+ tv.tv_usec/;
    return(val);
}

#elif defined(WEBRTC_MAC)

#include <unistd.h>

#define GET_TIME_IN_MS timeGetTime()

unsigned long timeGetTime()
{
    return ;
}

#else

#define GET_TIME_IN_MS ::timeGetTime()

#endif

using namespace std;

#if defined(_WIN32)
LRESULT CALLBACK WebRtcWinProc( HWND hWnd,UINT uMsg,WPARAM wParam,LPARAM lParam)
{
    switch(uMsg)
    {
        case WM_DESTROY:
        break;
        case WM_COMMAND:
        break;
    }
    return DefWindowProc(hWnd,uMsg,wParam,lParam);
}

int WebRtcCreateWindow(HWND &hwndMain,int winNum, int width, int height)
{
    HINSTANCE hinst = GetModuleHandle();
    WNDCLASSEX wcx;
    wcx.hInstance = hinst;
    wcx.lpszClassName = TEXT("VideoRenderTest");
    wcx.lpfnWndProc = (WNDPROC)WebRtcWinProc;
    wcx.style = CS_DBLCLKS;
    wcx.hIcon = LoadIcon (NULL, IDI_APPLICATION);
    wcx.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
    wcx.hCursor = LoadCursor (NULL, IDC_ARROW);
    wcx.lpszMenuName = NULL;
    wcx.cbSize = sizeof (WNDCLASSEX);
    wcx.cbClsExtra = ;
    wcx.cbWndExtra = ;
    wcx.hbrBackground = GetSysColorBrush(COLOR_3DFACE);

    // Register our window class with the operating system.
    // If there is an error, exit program.
    if ( !RegisterClassEx (&wcx) )
    {
        MessageBox( , TEXT("Failed to register window class!"),TEXT("Error!"), MB_OK|MB_ICONERROR );
        return ;
    }

    // Create the main window.
    hwndMain = CreateWindowEx(
            , // no extended styles
            TEXT("VideoRenderTest"), // class name
            TEXT("VideoRenderTest Window"), // window name
            WS_OVERLAPPED |WS_THICKFRAME, // overlapped window
            , // horizontal position
            , // vertical position
            width, // width
            height, // height
            (HWND) NULL, // no parent or owner window
            (HMENU) NULL, // class menu used
            hinst, // instance handle
            NULL); // no window creation data

    if (!hwndMain)
        return -;

    // Show the window using the flag specified by the program
    // that started the application, and send the application
    // a WM_PAINT message.

    ShowWindow(hwndMain, SW_SHOWDEFAULT);
    UpdateWindow(hwndMain);
    return ;
}

#elif defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID)

int WebRtcCreateWindow(Window *outWindow, Display **outDisplay, int winNum, int width, int height) // unsigned char* title, int titleLength)

{
    int screen, xpos = , ypos = ;
    XEvent evnt;
    XSetWindowAttributes xswa; // window attribute struct
    XVisualInfo vinfo; // screen visual info struct
    unsigned long mask; // attribute mask

    // get connection handle to xserver
    Display* _display = XOpenDisplay( NULL );

    // get screen number
    screen = DefaultScreen(_display);

    // put desired visual info for the screen in vinfo
    if( XMatchVisualInfo(_display, screen, , TrueColor, &vinfo) !=  )
    {
        //printf( "Screen visual info match!\n" );
    }

    // set window attributes
    xswa.colormap = XCreateColormap(_display, DefaultRootWindow(_display), vinfo.visual, AllocNone);
    xswa.event_mask = StructureNotifyMask | ExposureMask;
    xswa.background_pixel = ;
    xswa.border_pixel = ;

    // value mask for attributes
    mask = CWBackPixel | CWBorderPixel | CWColormap | CWEventMask;

    switch( winNum )
    {
        case :
        xpos = ;
        ypos = ;
        break;
        case :
        xpos = ;
        ypos = ;
        break;
        default:
        break;
    }

    // create a subwindow for parent (defroot)
    Window _window = XCreateWindow(_display, DefaultRootWindow(_display),
            xpos, ypos,
            width,
            height,
            , vinfo.depth,
            InputOutput,
            vinfo.visual,
            mask, &xswa);

    // Set window name
    if( winNum ==  )
    {
        XStoreName(_display, _window, "VE MM Local Window");
        XSetIconName(_display, _window, "VE MM Local Window");
    }
    else if( winNum ==  )
    {
        XStoreName(_display, _window, "VE MM Remote Window");
        XSetIconName(_display, _window, "VE MM Remote Window");
    }

    // make x report events for mask
    XSelectInput(_display, _window, StructureNotifyMask);

    // map the window to the display
    XMapWindow(_display, _window);

    // wait for map event
    do
    {
        XNextEvent(_display, &evnt);
    }
    while (evnt.type != MapNotify || evnt.xmap.event != _window);

    *outWindow = _window;
    *outDisplay = _display;

    return ;
}
#endif  // LINUX

// Note: Mac code is in testApi_mac.mm.

class MyRenderCallback: public VideoRenderCallback
{
public:
    MyRenderCallback() :
        _cnt()
    {
    }
    ;
    ~MyRenderCallback()
    {
    }
    ;
    virtual int32_t RenderFrame(const uint32_t streamId,
                                I420VideoFrame& videoFrame)
    {
        _cnt++;
        if (_cnt %  == )
        {
            printf("Render callback %d \n",_cnt);
        }
        return ;
    }
    int32_t _cnt;
};

void GetTestVideoFrame(I420VideoFrame* frame,
                       uint8_t startColor) {
    // changing color
    static uint8_t color = startColor;

    memset(frame->buffer(kYPlane), color, frame->allocated_size(kYPlane));
    memset(frame->buffer(kUPlane), color, frame->allocated_size(kUPlane));
    memset(frame->buffer(kVPlane), color, frame->allocated_size(kVPlane));

    ++color;
}

int TestSingleStream(VideoRender* renderModule) {
    int error = ;
    // Add settings for a stream to render
    printf("Add stream 0 to entire window\n");
    const int streamId0 = ;
    VideoRenderCallback* renderCallback0 = renderModule->AddIncomingRenderStream(streamId0, , 0.0f, 0.0f, 1.0f, 1.0f);
    assert(renderCallback0 != NULL);

#ifndef WEBRTC_INCLUDE_INTERNAL_VIDEO_RENDER
    MyRenderCallback externalRender;
    renderModule->AddExternalRenderCallback(streamId0, &externalRender);
#endif

    printf("Start render\n");
    error = renderModule->StartRender(streamId0);
    if (error != ) {
      // TODO(phoglund): This test will not work if compiled in release mode.
      // This rather silly construct here is to avoid compilation errors when
      // compiling in release. Release => no asserts => unused 'error' variable.
      assert(false);
    }

    // Loop through an I420 file and render each frame
    const int width = ;
    const int half_width = (width + ) / ;
    const int height = ;

    I420VideoFrame videoFrame0;
    videoFrame0.CreateEmptyFrame(width, height, width, half_width, half_width);

    const uint32_t renderDelayMs = ;

    for (int i=; i<TEST_FRAME_NUM; i++) {
        GetTestVideoFrame(&videoFrame0, TEST_STREAM0_START_COLOR);
        // Render this frame with the specified delay
        videoFrame0.set_render_time_ms(TickTime::MillisecondTimestamp()
                                       + renderDelayMs);
        renderCallback0->RenderFrame(streamId0, videoFrame0);
        SleepMs(/TEST_FRAME_RATE);
    }

    // Shut down
    printf("Closing...\n");
    error = renderModule->StopRender(streamId0);
    assert(error == );

    error = renderModule->DeleteIncomingRenderStream(streamId0);
    assert(error == );

    return ;
}

int TestFullscreenStream(VideoRender* &renderModule,
                         void* window,
                         const VideoRenderType videoRenderType) {
    VideoRender::DestroyVideoRender(renderModule);
    renderModule = VideoRender::CreateVideoRender(, window, true, videoRenderType);

    TestSingleStream(renderModule);

    VideoRender::DestroyVideoRender(renderModule);
    renderModule = VideoRender::CreateVideoRender(, window, false, videoRenderType);

    return ;
}

int TestBitmapText(VideoRender* renderModule) {
#if defined(WIN32)

    int error = ;
    // Add settings for a stream to render
    printf("Add stream 0 to entire window\n");
    const int streamId0 = ;
    VideoRenderCallback* renderCallback0 = renderModule->AddIncomingRenderStream(streamId0, , 0.0f, 0.0f, 1.0f, 1.0f);
    assert(renderCallback0 != NULL);

    printf("Adding Bitmap\n");
    DDCOLORKEY ColorKey; // black
    ColorKey.dwColorSpaceHighValue = RGB(, , );
    ColorKey.dwColorSpaceLowValue = RGB(, , );
    HBITMAP hbm = (HBITMAP)LoadImage(NULL,
                                     (LPCTSTR)_T("renderStartImage.bmp"),
                                     IMAGE_BITMAP, , , LR_LOADFROMFILE);
    renderModule->SetBitmap(hbm, , &ColorKey, 0.0f, 0.0f, 0.3f,
                             0.3f);

    printf("Adding Text\n");
    renderModule->SetText(, (uint8_t*) "WebRtc Render Demo App", ,
                           RGB(, , ), RGB(, , ), 0.25f, 0.1f, 1.0f,
                           1.0f);

    printf("Start render\n");
    error = renderModule->StartRender(streamId0);
    assert(error == );

    // Loop through an I420 file and render each frame
    const int width = ;
    const int half_width = (width + ) / ;
    const int height = ;

    I420VideoFrame videoFrame0;
    videoFrame0.CreateEmptyFrame(width, height, width, half_width, half_width);

    const uint32_t renderDelayMs = ;

    for (int i=; i<TEST_FRAME_NUM; i++) {
        GetTestVideoFrame(&videoFrame0, TEST_STREAM0_START_COLOR);
        // Render this frame with the specified delay
        videoFrame0.set_render_time_ms(TickTime::MillisecondTimestamp() +
                                       renderDelayMs);
        renderCallback0->RenderFrame(streamId0, videoFrame0);
        SleepMs(/TEST_FRAME_RATE);
    }
    // Sleep and let all frames be rendered before closing
    SleepMs(renderDelayMs*);

    // Shut down
    printf("Closing...\n");
    ColorKey.dwColorSpaceHighValue = RGB(,,);
    ColorKey.dwColorSpaceLowValue = RGB(,,);
    renderModule->SetBitmap(NULL, , &ColorKey, 0.0f, 0.0f, 0.0f, 0.0f);
    renderModule->SetText(, NULL, , RGB(,,),
                    RGB(,,), 0.0f, 0.0f, 0.0f, 0.0f);

    error = renderModule->StopRender(streamId0);
    assert(error == );

    error = renderModule->DeleteIncomingRenderStream(streamId0);
    assert(error == );
#endif

    return ;
}

int TestMultipleStreams(VideoRender* renderModule) {
    // Add settings for a stream to render
    printf("Add stream 0\n");
    const int streamId0 = ;
    VideoRenderCallback* renderCallback0 =
        renderModule->AddIncomingRenderStream(streamId0, , 0.0f, 0.0f, 0.45f, 0.45f);
    assert(renderCallback0 != NULL);
    printf("Add stream 1\n");
    const int streamId1 = ;
    VideoRenderCallback* renderCallback1 =
        renderModule->AddIncomingRenderStream(streamId1, , 0.55f, 0.0f, 1.0f, 0.45f);
    assert(renderCallback1 != NULL);
    printf("Add stream 2\n");
    const int streamId2 = ;
    VideoRenderCallback* renderCallback2 =
        renderModule->AddIncomingRenderStream(streamId2, , 0.0f, 0.55f, 0.45f, 1.0f);
    assert(renderCallback2 != NULL);
    printf("Add stream 3\n");
    const int streamId3 = ;
    VideoRenderCallback* renderCallback3 =
        renderModule->AddIncomingRenderStream(streamId3, , 0.55f, 0.55f, 1.0f, 1.0f);
    assert(renderCallback3 != NULL);
    assert(renderModule->StartRender(streamId0) == );
    assert(renderModule->StartRender(streamId1) == );
    assert(renderModule->StartRender(streamId2) == );
    assert(renderModule->StartRender(streamId3) == );

    // Loop through an I420 file and render each frame
    const int width = ;
    const int half_width = (width + ) / ;
    const int height = ;

    I420VideoFrame videoFrame0;
    videoFrame0.CreateEmptyFrame(width, height, width, half_width, half_width);
    I420VideoFrame videoFrame1;
    videoFrame1.CreateEmptyFrame(width, height, width, half_width, half_width);
    I420VideoFrame videoFrame2;
    videoFrame2.CreateEmptyFrame(width, height, width, half_width, half_width);
    I420VideoFrame videoFrame3;
    videoFrame3.CreateEmptyFrame(width, height, width, half_width, half_width);

    const uint32_t renderDelayMs = ;

    // Render frames with the specified delay.
    for (int i=; i<TEST_FRAME_NUM; i++) {
      GetTestVideoFrame(&videoFrame0, TEST_STREAM0_START_COLOR);

      videoFrame0.set_render_time_ms(TickTime::MillisecondTimestamp() +
                                     renderDelayMs);
      renderCallback0->RenderFrame(streamId0, videoFrame0);

      GetTestVideoFrame(&videoFrame1, TEST_STREAM1_START_COLOR);
      videoFrame1.set_render_time_ms(TickTime::MillisecondTimestamp() +
                                     renderDelayMs);
      renderCallback1->RenderFrame(streamId1, videoFrame1);

      GetTestVideoFrame(&videoFrame2,  TEST_STREAM2_START_COLOR);
      videoFrame2.set_render_time_ms(TickTime::MillisecondTimestamp() +
                                     renderDelayMs);
      renderCallback2->RenderFrame(streamId2, videoFrame2);

      GetTestVideoFrame(&videoFrame3, TEST_STREAM3_START_COLOR);
      videoFrame3.set_render_time_ms(TickTime::MillisecondTimestamp() +
                                     renderDelayMs);
      renderCallback3->RenderFrame(streamId3, videoFrame3);

      SleepMs(/TEST_FRAME_RATE);
    }

    // Shut down
    printf("Closing...\n");
    assert(renderModule->StopRender(streamId0) == );
    assert(renderModule->DeleteIncomingRenderStream(streamId0) == );
    assert(renderModule->StopRender(streamId1) == );
    assert(renderModule->DeleteIncomingRenderStream(streamId1) == );
    assert(renderModule->StopRender(streamId2) == );
    assert(renderModule->DeleteIncomingRenderStream(streamId2) == );
    assert(renderModule->StopRender(streamId3) == );
    assert(renderModule->DeleteIncomingRenderStream(streamId3) == );

    return ;
}

int TestExternalRender(VideoRender* renderModule) {
    MyRenderCallback *externalRender = new MyRenderCallback();

    const int streamId0 = ;
    VideoRenderCallback* renderCallback0 =
        renderModule->AddIncomingRenderStream(streamId0, , 0.0f, 0.0f,
                                                   1.0f, 1.0f);
    assert(renderCallback0 != NULL);
    assert(renderModule->AddExternalRenderCallback(streamId0,
                                                   externalRender) == );

    assert(renderModule->StartRender(streamId0) == );

    const int width = ;
    const int half_width = (width + ) / ;
    const int height = ;
    I420VideoFrame videoFrame0;
    videoFrame0.CreateEmptyFrame(width, height, width, half_width, half_width);

    const uint32_t renderDelayMs = ;
    int frameCount = TEST_FRAME_NUM;
    for (int i=; i<frameCount; i++) {
        videoFrame0.set_render_time_ms(TickTime::MillisecondTimestamp() +
                                       renderDelayMs);
        renderCallback0->RenderFrame(streamId0, videoFrame0);
        SleepMs();
    }

    // Sleep and let all frames be rendered before closing
    SleepMs(*renderDelayMs);

    assert(renderModule->StopRender(streamId0) == );
    assert(renderModule->DeleteIncomingRenderStream(streamId0) == );
    assert(frameCount == externalRender->_cnt);

    delete externalRender;
    externalRender = NULL;

    return ;
}

void RunVideoRenderTests(void* window, VideoRenderType windowType) {
#ifndef WEBRTC_INCLUDE_INTERNAL_VIDEO_RENDER
    windowType = kRenderExternal;
#endif

    int myId = ;

    // Create the render module
    printf("Create render module\n");
    VideoRender* renderModule = NULL;
    renderModule = VideoRender::CreateVideoRender(myId,
                                                  window,
                                                  false,
                                                  windowType);
    assert(renderModule != NULL);

    // ##### Test single stream rendering ####
    printf("#### TestSingleStream ####\n");
    if (TestSingleStream(renderModule) != ) {
        printf ("TestSingleStream failed\n");
    }

    // ##### Test fullscreen rendering ####
    printf("#### TestFullscreenStream ####\n");
    if (TestFullscreenStream(renderModule, window, windowType) != ) {
        printf ("TestFullscreenStream failed\n");
    }

    // ##### Test bitmap and text ####
    printf("#### TestBitmapText ####\n");
    if (TestBitmapText(renderModule) != ) {
        printf ("TestBitmapText failed\n");
    }

    // ##### Test multiple streams ####
    printf("#### TestMultipleStreams ####\n");
    if (TestMultipleStreams(renderModule) != ) {
        printf ("TestMultipleStreams failed\n");
    }

    // ##### Test multiple streams ####
    printf("#### TestExternalRender ####\n");
    if (TestExternalRender(renderModule) != ) {
        printf ("TestExternalRender failed\n");
    }

    delete renderModule;
    renderModule = NULL;

    printf("VideoRender unit tests passed.\n");
}

// Note: The Mac main is implemented in testApi_mac.mm.
#if defined(_WIN32)
int _tmain(int argc, _TCHAR* argv[])
#elif defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID)
int main(int argc, char* argv[])
#endif
#if !defined(WEBRTC_MAC) && !defined(WEBRTC_ANDROID)
{
    // Create a window for testing.
    void* window = NULL;
#if defined (_WIN32)
    HWND testHwnd;
    WebRtcCreateWindow(testHwnd, , , );
    window = (void*)testHwnd;
    VideoRenderType windowType = kRenderWindows;
#elif defined(WEBRTC_LINUX)
    Window testWindow;
    Display* display;
    WebRtcCreateWindow(&testWindow, &display, , , );
    VideoRenderType windowType = kRenderX11;
    window = (void*)testWindow;
#endif // WEBRTC_LINUX

    RunVideoRenderTests(window, windowType);
    return ;
}
#endif  // !WEBRTC_MAC