一,
cv::Mat 编码h264数据包,并利用websocket发送,html端进行h264解析并使用wegl渲染
二,
三,
#pragma once
#include <opencv2/core/core.hpp>
#include <string>
#include <gst/gst.h>
#include "websocket_server.h"
namespace Transmit
{
class VideoEncode : public std::enable_shared_from_this<VideoEncode>
{
public:
using Ptr = std::shared_ptr<VideoEncode>;
~VideoEncode();
/**
* @brief 初始化编码器
*/
int init(int width, int height, std::pair<int, int> framerate, WebsocketServer::Ptr websocket, int index);
/**
* @brief 写入视频帧
*/
int write(const cv::Mat &frame);
/**
* @brief 获取websocket服务器
*/
WebsocketServer::Ptr GetWebSocket()
{
return websocket_;
}
/**
* @brief 获取当前相机索引
*/
int GetIndex()
{
return index_;
}
private:
int pushData2Pipeline(const cv::Mat &frame);
private:
GstElement *pipeline_;
GstElement *appSrc_;
GstElement *appSink_;
GstElement *encoder_;
GstElement *capsFilter1_;
GstElement *capsFilter2_;
GstElement *parser_;
int width_ = 0;
int height_ = 0;
int bitrate_ = 1;
std::pair<int, int> framerate_{30, 1};
GstClockTime timestamp{0};
// 用于将数据发送给 websocket 服务器
WebsocketServer::Ptr websocket_;
int index_;
};
}
#include <transmit/video_encode.h>
#include <iostream>
#include <stdio.h>
#include <unistd.h>
#include <gst/gst.h>
#include <gst/gstelement.h>
#include <gst/app/gstappsink.h>
using namespace std;
namespace Transmit
{
GstFlowReturn CaptureGstBuffer(GstAppSink *sink, gpointer user_data)
{
VideoEncode *videoEncode = (VideoEncode*)user_data;
if(!videoEncode)
return GST_FLOW_ERROR;
GstSample *sample = gst_app_sink_pull_sample(sink);
if (sample == NULL)
{
return GST_FLOW_ERROR;
}
GstBuffer *buffer = gst_sample_get_buffer(sample);
GstMapInfo map_info;
if (!gst_buffer_map((buffer), &map_info, GST_MAP_READ))
{
gst_buffer_unmap((buffer), &map_info);
gst_sample_unref(sample);
return GST_FLOW_ERROR;
}
// render using map_info.data
// frame = Mat::zeros(1080, 1920, CV_8UC3);
// frame = cv::Mat(1080, 1920, CV_8UC3, (char *)map_info.data, cv::Mat::AUTO_STEP);
// memcpy(frame.data,map_info.data,map_info.size);
// fprintf(stderr, "Got sample no %d %d\n", sampleno++, (int)map_info.size);
videoEncode->GetWebSocket()->sendH264Data(map_info.data,(int)map_info.size,videoEncode->GetIndex());
gst_buffer_unmap((buffer), &map_info);
gst_sample_unref(sample);
return GST_FLOW_OK;
}
VideoEncode::~VideoEncode()
{
if (appSrc_)
{
GstFlowReturn retflow;
g_signal_emit_by_name(appSrc_, "end-of-stream", &retflow);
std::cout << "EOS sended. Writing last several frame..." << std::endl;
g_usleep(1000000); // 等待1s,写数据
std::cout << "Writing Done!" << std::endl;
if (retflow != GST_FLOW_OK)
{
std::cerr << "We got some error when sending eos!" << std::endl;
}
}
if (pipeline_)
{
gst_element_set_state(pipeline_, GST_STATE_NULL);
gst_object_unref(pipeline_);
pipeline_ = nullptr;
}
}
int VideoEncode::init(int width,int height,std::pair<int, int> framerate,WebsocketServer::Ptr websocket,int index)
{
width_ = width;
height_ = height;
framerate_ = framerate;
websocket_ = websocket;
index_ = index;
pipeline_ = gst_pipeline_new("pipeline");
appSrc_ = gst_element_factory_make("appsrc", "AppSrc");
capsFilter1_ = gst_element_factory_make("capsfilter", "Capsfilter");
capsFilter2_ = gst_element_factory_make("capsfilter", "Capsfilter2");
encoder_ = gst_element_factory_make("omxh264enc", "Omxh264enc");
parser_ = gst_element_factory_make("h264parse", "H264parse");
appSink_ = gst_element_factory_make("appsink", "Appsink");
if (!pipeline_ || !appSrc_ || !encoder_ || !parser_ || !capsFilter2_ || !capsFilter1_ || !appSink_)
{
std::cerr << "Not all elements could be created" << std::endl;
return -1;
}
// 设置 src format
std::string srcFmt = "I420";
// Set up appsrc
g_object_set(appSrc_, "format", GST_FORMAT_TIME, NULL);
g_object_set(appSrc_, "stream-type", 0, NULL);
g_object_set(appSrc_, "is-live", TRUE, NULL);
g_object_set(G_OBJECT(capsFilter1_), "caps", gst_caps_new_simple("video/x-raw", "format", G_TYPE_STRING, srcFmt.c_str(), "width", G_TYPE_INT, width_, "height", G_TYPE_INT, height_, "framerate", GST_TYPE_FRACTION, framerate_.first, framerate_.second, nullptr), NULL);
g_object_set(G_OBJECT(capsFilter2_), "caps", gst_caps_new_simple("video/x-h264", "stream-format", G_TYPE_STRING, "byte-stream", nullptr), nullptr);
// Set up omxh264enc
g_object_set(G_OBJECT(encoder_), "bitrate", bitrate_ * 1024 * 1024 * 8, NULL);
g_object_set(G_OBJECT(encoder_), "temporal-tradeoff", 4, NULL);
// Set up appsink
g_object_set(G_OBJECT(appSink_),"emit-signals",TRUE,NULL);
g_object_set(G_OBJECT(appSink_),"sync", FALSE,NULL);
g_object_set(G_OBJECT(appSink_),"drop", TRUE,NULL);
g_signal_connect (appSink_, "new-sample",G_CALLBACK (CaptureGstBuffer), reinterpret_cast<void*> (this));
// BAdd elements to pipeline
gst_bin_add_many(GST_BIN(pipeline_), appSrc_, capsFilter1_, encoder_, capsFilter2_, parser_, appSink_, nullptr);
// Link elements
if (gst_element_link_many(appSrc_, capsFilter1_, encoder_, capsFilter2_, parser_, appSink_, nullptr) != TRUE)
{
std::cerr << "appSrc, capsFilter2, parser, encoder, capsFilter1, appSink_ could not be linked" << std::endl;
return -1;
}
// Start playing
auto ret = gst_element_set_state(pipeline_, GST_STATE_PLAYING);
if (ret == GST_STATE_CHANGE_FAILURE)
{
std::cerr << "Unable to set the pipeline to the playing state" << std::endl;
return -1;
}
return 0;
}
int VideoEncode::pushData2Pipeline(const cv::Mat &frame)
{
GstBuffer *buffer;
GstFlowReturn ret;
GstMapInfo map;
// Create a new empty buffer
uint size = frame.total() * frame.elemSize();
buffer = gst_buffer_new_and_alloc(size);
gst_buffer_map(buffer, &map, GST_MAP_WRITE);
memcpy(map.data, frame.data, size);
// 必须写入时间戳和每帧画面持续时间
gst_buffer_unmap(buffer, &map);
GST_BUFFER_PTS(buffer) = timestamp;
GST_BUFFER_DTS(buffer) = timestamp;
GST_BUFFER_DURATION(buffer) = gst_util_uint64_scale_int(1, GST_SECOND, framerate_.first / framerate_.second);
timestamp += GST_BUFFER_DURATION(buffer);
// std::cout << "GST_BUFFER_DURATION(buffer):" << GST_BUFFER_DURATION(buffer) << std::endl;
// std::cout << "timestamp:" << static_cast<uint64>(_timestamp * GST_SECOND) << std::endl;
// Push the buffer into the appsrc
g_signal_emit_by_name(appSrc_, "push-buffer", buffer, &ret);
// Free the buffer now that we are done with it
gst_buffer_unref(buffer);
if (ret != GST_FLOW_OK)
{
// We got some error, stop sending data
std::cout << "We got some error, stop sending data" << std::endl;
return -1;
}
return 0;
}
int VideoEncode::write(const cv::Mat &frame)
{
return pushData2Pipeline(frame);
}
}