視頻直播：libx264編碼一幀圖片+live555搭建RTSP流媒體服務器

 

最近又複習了一下live555的源代碼，並在VS2013下編譯了視頻直播程序。

從視頻讀取一幀後x264編碼，用live555的RTSP傳輸流媒體。

效果清晰流暢（640*480+40幀每秒），很滿意。

附上主要的cpp代碼

/* 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;  //這些是視頻的參數，用來初始化編碼器 和 圖片格式轉換

//這個函數把RGB24圖片轉換爲YUV420格式圖片
void Convert(unsigned char *RGB, unsigned char *YUV, unsigned int width, unsigned int height);

extern class F f; //包含編碼器和圖片緩衝的各類指針變量和函數。由於一直都要用，因此在一開始就聲明的全局變量，到程序結束一直存在

//初始化全局變量f中的各個成員，給指針分配相應的內存空間，並初始化攝像頭和264編碼器
void F::init()
{
    int ret, frames_total;  //ret是臨時變量做用不大，frames_total存儲視頻總幀數，用於初始化編碼器

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

    //獲取視頻文件屬性
    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) ;

    //調節視頻的分辨率
    while (WIDTH > 480 || HEIGHT > 270)
    {
        HEIGHT /= 2;
        WIDTH /= 2;
    }

    widthStep = WIDTH * 3; //固定爲3倍，用於提取IplImage中的RGB數據
    printf("fps: %d\twidth: %d\theight: %d\n", FPS, WIDTH, HEIGHT);

    //這個是修改分辨率後的圖片緩衝區
    img2 = cvCreateImage(cvSize(WIDTH, HEIGHT), img->depth, img->nChannels);

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

    //encoder結構體包含了編碼器須要的變量
    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的成員
    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);

    //設置編碼器參數狀態爲： 修改後馬上生效
    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 去空緩衝區繼續使用不死鎖保證*/
    encoder->x264_parameter->i_threads = X264_SYNC_LOOKAHEAD_AUTO;
    /*視頻選項*/
    encoder->x264_parameter->i_width = WIDTH;//要編碼的圖像的寬度
    encoder->x264_parameter->i_height = HEIGHT;//要編碼的圖像的高度
    encoder->x264_parameter->i_frame_total = frames_total;// frames_total;//要編碼的總幀數，不知道用0
    encoder->x264_parameter->i_keyint_max = 10 * FPS; //關鍵幀出現間隔，若是視頻動做變化較大，可調小到2-4
    /*流參數*///下面四個參數不怎麼影響，不過也初始化了吧
    encoder->x264_parameter->i_bframe = 5; 
    encoder->x264_parameter->b_open_gop = 0;
    encoder->x264_parameter->i_bframe_pyramid = 0; //禁止B幀
    encoder->x264_parameter->i_bframe_adaptive = X264_B_ADAPT_TRELLIS; //B幀出現率

    /*log參數，不須要打印編碼信息時直接註釋掉*/
    //encoder->x264_parameter->i_log_level = X264_LOG_DEBUG;

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

    //下面兩個挺重要
    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);
    }

    /*打開編碼器*/
    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);
    }

    //設置264的輸入圖片格式
    encoder->yuv420p_picture->img.i_csp = encoder->colorspace;
    encoder->yuv420p_picture->img.i_plane = 3;  //plane格式存儲
    encoder->yuv420p_picture->i_type = X264_TYPE_AUTO;

    /*申請YUV buffer*///這個YUV緩衝區的數據就是264須要的圖片數據
    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;//初始化爲0，以後用於保存每幀的NALU數量
    //每一個NALU的數據都存在這裏，通常一幀編碼爲1個（最多3個）NALU，分辨率較大時也許會更多
    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));

    //用於提取IplImage中的圖片數據
    RGB1 = (unsigned char *)malloc(HEIGHT * WIDTH * 3);
    /**************************************************************************************************************************************/
    /************************************************* 初始化完畢 *********************************************************************/
    /**************************************************************************************************************************************/
}

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); //把圖片轉換爲img2的分辨率大小，在上面的函數中有寫到img2初始化的大小，可自行調整
    /*for循環：從IplImage格式中獲取RGB格式圖片*/
    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格式圖片轉換爲YUV格式圖片
    Convert(RGB1, encoder->yuv, WIDTH, HEIGHT);

    
    encoder->yuv420p_picture->i_pts++; //每幀圖片序列號，要保持遞增
    //編碼YUV格式圖片，編碼後的數據放在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();

    //把編碼後的H264數據（即全部NALU）放到fTo，fTo會被live555的某些函數使用併發送
    for (f.my_nal = f.encoder->nal; f.my_nal < f.encoder->nal + f.n_nal; ++(f.my_nal))
    {
        //判斷NALU是否大於fTo輸入緩衝區
        if (fFrameSize + f.my_nal->i_payload > fMaxSize)
        {
            printf("fMaxSize!!!!!!!!!!!!\n");
            break;
        }
        //p_payload存放NALU數據，i_payload存放NALU字節大小
        memcpy((unsigned char*)fTo + fFrameSize, f.my_nal->p_payload, f.my_nal->i_payload);
        fFrameSize += f.my_nal->i_payload;
    }

    //將會判斷數據是否存滿，Parser緩衝區（一共兩個）互換。
    //而後提取有效數據，continueReadingFrame，讀完有效數據後由調用回doGetNextFrame
    nextTask() = envir().taskScheduler().scheduleDelayedTask(0, (TaskFunc*)FramedSource::afterGetting, this);
    return;
}