视频直播：libx264编码一帧图片+live555搭建RTSP流媒体服务器

 

最近又复习了一下live555的源代码，并在VS2013下编译了视频直播程序。

从视频读取一帧后x264编码，用live555的RTSP传输流媒体。

效果清晰流畅（640*480+40帧每秒），很满意。

附上主要的cpp代码

/* H264FramedLiveSource.cpp By Chain_Gank */

#include <highgui.h>
#include <cv.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdint.h>
//#include <unistd.h>
#include <fcntl.h>
#include "H264FramedLiveSource.hh"
#pragma comment(lib,"libx264.lib")
#define ENCODER_TUNE   "zerolatency"
#define ENCODER_PROFILE  "baseline"
#define ENCODER_PRESET "veryfast"
#define ENCODER_COLORSPACE X264_CSP_I420
#define CLEAR(x) (memset((&x),0,sizeof(x)))

int FPS, WIDTH, HEIGHT, widthStep;  //这些是视频的参数，用来初始化编码器 和 图片格式转换

//这个函数把RGB24图片转换为YUV420格式图片
void Convert(unsigned char *RGB, unsigned char *YUV, unsigned int width, unsigned int height);

extern class F f; //包含编码器和图片缓冲的各种指针变量和函数。因为一直都要用，所以在一开始就声明的全局变量，到程序结束一直存在

//初始化全局变量f中的各个成员，给指针分配相应的内存空间，并初始化摄像头和264编码器
void F::init()
{
    int ret, frames_total;  //ret是临时变量作用不大，frames_total存储视频总帧数，用于初始化编码器

    cap = cvCaptureFromFile("test.mp4"); 
    //cap = cvCaptureFromAVI("4.avi");
    //cap = cvCaptureFromCAM(0);  //camera
    img = cvQueryFrame(cap);

    //获取视频文件属性
    FPS =  (int)cvGetCaptureProperty(cap, CV_CAP_PROP_FPS);
    frames_total = (int)cvGetCaptureProperty(cap, CV_CAP_PROP_FRAME_COUNT) - 1;
    //cvSetCaptureProperty(cap, CV_CAP_PROP_FRAME_WIDTH, 320);   //camera
    //cvSetCaptureProperty(cap, CV_CAP_PROP_FRAME_HEIGHT, 240);  //camera
    HEIGHT = (int)cvGetCaptureProperty(cap, CV_CAP_PROP_FRAME_HEIGHT) ;
    WIDTH = (int)cvGetCaptureProperty(cap, CV_CAP_PROP_FRAME_WIDTH) ;

    //调节视频的分辨率
    while (WIDTH > 480 || HEIGHT > 270)
    {
        HEIGHT /= 2;
        WIDTH /= 2;
    }

    widthStep = WIDTH * 3; //固定为3倍，用于提取IplImage中的RGB数据
    printf("fps: %d\twidth: %d\theight: %d\n", FPS, WIDTH, HEIGHT);

    //这个是修改分辨率后的图片缓冲区
    img2 = cvCreateImage(cvSize(WIDTH, HEIGHT), img->depth, img->nChannels);

    if (!cap)
    {
        fprintf(stderr, "Can not open file.\n");
        exit(-1);
    }

    //encoder结构体包含了编码器需要的变量
    encoder = (my_x264_encoder *)malloc(sizeof(my_x264_encoder));
    if (!encoder){
        printf("cannot malloc my_x264_encoder !\n");
        exit(EXIT_FAILURE);
    }
    CLEAR(*encoder);
    //初始化encoder的成员
    strcpy(encoder->parameter_preset, ENCODER_PRESET);
    strcpy(encoder->parameter_tune, ENCODER_TUNE);
    encoder->x264_parameter = (x264_param_t *)malloc(sizeof(x264_param_t));
    if (!encoder->x264_parameter){
        printf("malloc x264_parameter error!\n");
        exit(EXIT_FAILURE);
    }


    CLEAR(*(encoder->x264_parameter));
    x264_param_default(encoder->x264_parameter);

    //设置编码器参数状态为： 修改后立刻生效
    if ((ret = x264_param_default_preset(encoder->x264_parameter, encoder->parameter_preset, encoder->parameter_tune))<0){
        printf("x264_param_default_preset error!\n");
        exit(EXIT_FAILURE);
    }

    /*cpuFlags 去空缓冲区继续使用不死锁保证*/
    encoder->x264_parameter->i_threads = X264_SYNC_LOOKAHEAD_AUTO;
    /*视频选项*/
    encoder->x264_parameter->i_width = WIDTH;//要编码的图像的宽度
    encoder->x264_parameter->i_height = HEIGHT;//要编码的图像的高度
    encoder->x264_parameter->i_frame_total = frames_total;// frames_total;//要编码的总帧数，不知道用0
    encoder->x264_parameter->i_keyint_max = 10 * FPS; //关键帧出现间隔，如果视频动作变化较大，可调小到2-4
    /*流参数*///下面四个参数不怎么影响，不过也初始化了吧
    encoder->x264_parameter->i_bframe = 5; 
    encoder->x264_parameter->b_open_gop = 0;
    encoder->x264_parameter->i_bframe_pyramid = 0; //禁止B帧
    encoder->x264_parameter->i_bframe_adaptive = X264_B_ADAPT_TRELLIS; //B帧出现率

    /*log参数，不需要打印编码信息时直接注释掉*/
    //encoder->x264_parameter->i_log_level = X264_LOG_DEBUG;

    encoder->x264_parameter->i_fps_num = FPS;//码率分子
    encoder->x264_parameter->i_fps_den = 1;//码率分母

    //下面两个挺重要
    encoder->x264_parameter->b_intra_refresh = 1;  
    encoder->x264_parameter->b_annexb = 1; 

    strcpy(encoder->parameter_profile, ENCODER_PROFILE);
    if ((ret = x264_param_apply_profile(encoder->x264_parameter, encoder->parameter_profile))<0){
        printf("x264_param_apply_profile error!\n");
        exit(EXIT_FAILURE);
    }

    /*打开编码器*/
    encoder->x264_encoder = x264_encoder_open(encoder->x264_parameter);
    encoder->colorspace = ENCODER_COLORSPACE;

    /*初始化pic*/
    encoder->yuv420p_picture = (x264_picture_t *)malloc(sizeof(x264_picture_t));
    if (!encoder->yuv420p_picture){
        printf("malloc encoder->yuv420p_picture error!\n");
        exit(EXIT_FAILURE);
    }
    if ((ret = x264_picture_alloc(encoder->yuv420p_picture, encoder->colorspace, WIDTH, HEIGHT))<0){
        printf("ret=%d\n", ret);
        printf("x264_picture_alloc error!\n");
        exit(EXIT_FAILURE);
    }

    //设置264的输入图片格式
    encoder->yuv420p_picture->img.i_csp = encoder->colorspace;
    encoder->yuv420p_picture->img.i_plane = 3;  //plane格式存储
    encoder->yuv420p_picture->i_type = X264_TYPE_AUTO;

    /*申请YUV buffer*///这个YUV缓冲区的数据就是264需要的图片数据
    encoder->yuv = (uint8_t *)malloc(WIDTH*HEIGHT * 3 / 2);
    if (!encoder->yuv){
        printf("malloc yuv error!\n");
        exit(EXIT_FAILURE);
    }
    CLEAR(*(encoder->yuv));
    encoder->yuv420p_picture->img.plane[0] = encoder->yuv;
    encoder->yuv420p_picture->img.plane[1] = encoder->yuv + WIDTH*HEIGHT;
    encoder->yuv420p_picture->img.plane[2] = encoder->yuv + WIDTH*HEIGHT + WIDTH*HEIGHT / 4;

    n_nal = 0;//初始化为0，之后用于保存每帧的NALU数量
    //每个NALU的数据都存在这里，一般一帧编码为1个（最多3个）NALU，分辨率较大时也许会更多
    encoder->nal = (x264_nal_t *)malloc(3 * sizeof(x264_nal_t));
    if (!encoder->nal){
        printf("malloc x264_nal_t error!\n");
        exit(EXIT_FAILURE);
    }
    CLEAR(*(encoder->nal));

    //用于提取IplImage中的图片数据
    RGB1 = (unsigned char *)malloc(HEIGHT * WIDTH * 3);
    /**************************************************************************************************************************************/
    /************************************************* 初始化完毕 *********************************************************************/
    /**************************************************************************************************************************************/
}

H264FramedLiveSource::H264FramedLiveSource(UsageEnvironment& env, unsigned preferredFrameSize, unsigned playTimePerFrame)
    : FramedSource(env)
{

}

H264FramedLiveSource* H264FramedLiveSource::createNew(UsageEnvironment& env, unsigned preferredFrameSize, unsigned playTimePerFrame)
{
    H264FramedLiveSource* newSource = new H264FramedLiveSource(env, preferredFrameSize, playTimePerFrame);
    return newSource;
}

H264FramedLiveSource::~H264FramedLiveSource()
{
    printf("~~~~~~~~~~~~~~~\n");
    /*free(RGB1);
    cvReleaseCapture(&cap);
    free(encoder->yuv);
    free(encoder->yuv420p_picture);
    free(encoder->x264_parameter);
    x264_encoder_close(encoder->x264_encoder);
    free(encoder);*/
}

void F::getframe()
{
    printf("#");
    img = cvQueryFrame(cap);
    cvResize(img, img2); //把图片转换为img2的分辨率大小，在上面的函数中有写到img2初始化的大小，可自行调整
    /*for循环：从IplImage格式中获取RGB格式图片*/
    for (int i = 0; i< HEIGHT; i++)
    {
        for (int j = 0; j< WIDTH; j++)
        {
            RGB1[(i*WIDTH + j) * 3] = img2->imageData[i * widthStep + j * 3 + 2];;
            RGB1[(i*WIDTH + j) * 3 + 1] = img2->imageData[i * widthStep + j * 3 + 1];
            RGB1[(i*WIDTH + j) * 3 + 2] = img2->imageData[i * widthStep + j * 3];
        }
    }
    //把RGB格式图片转换为YUV格式图片
    Convert(RGB1, encoder->yuv, WIDTH, HEIGHT);

    
    encoder->yuv420p_picture->i_pts++; //每帧图片序列号，要保持递增
    //编码YUV格式图片，编码后的数据放在encoder->nal中
    if (x264_encoder_encode(encoder->x264_encoder, &encoder->nal, &n_nal, encoder->yuv420p_picture, &pic_out) < 0)
    {
        printf("x264_encoder_encode error!\n");
        exit(EXIT_FAILURE);
    }
}

void H264FramedLiveSource::doGetNextFrame()
{

    fFrameSize = 0;
    f.getframe();

    //把编码后的H264数据（即所有NALU）放到fTo，fTo会被live555的某些函数使用并发送
    for (f.my_nal = f.encoder->nal; f.my_nal < f.encoder->nal + f.n_nal; ++(f.my_nal))
    {
        //判断NALU是否大于fTo输入缓冲区
        if (fFrameSize + f.my_nal->i_payload > fMaxSize)
        {
            printf("fMaxSize!!!!!!!!!!!!\n");
            break;
        }
        //p_payload存放NALU数据，i_payload存放NALU字节大小
        memcpy((unsigned char*)fTo + fFrameSize, f.my_nal->p_payload, f.my_nal->i_payload);
        fFrameSize += f.my_nal->i_payload;
    }

    //将会判断数据是否存满，Parser缓冲区（一共两个）互换。
    //然后提取有效数据，continueReadingFrame，读完有效数据后由调用回doGetNextFrame
    nextTask() = envir().taskScheduler().scheduleDelayedTask(0, (TaskFunc*)FramedSource::afterGetting, this);
    return;
}