介绍
在本系列,我打算花大篇幅讲解我的 gitee 项目音视频播放器,在这个项目,您可以学到音视频解封装,解码,SDL渲染相关的知识。您对源代码感兴趣的话,请查看基于FFmpeg和SDL的音视频播放器
如果您不理解本文,可参考我的前一篇文章音视频项目—基于FFmpeg和SDL的音视频播放器解析(二十一)
解析
我们播放器所有的类已经解析完了,我们来看一下 main 函数如何使用函数,实现音视频的播放。
#include <iostream>
#include "log.h"
#include "demuxthread.h"
#include "avframequeue.h"
#include "decodethread.h"
#include "audiooutput.h"
#include "videooutput.h"
using namespace std;#undef main
int main(int argc, char *argv[])
{int ret = 0;cout << "Hello World!" << endl;LogInit();// queueAVPacketQueue audio_packet_queue;AVPacketQueue video_packet_queue;AVFrameQueue audio_frame_queue;AVFrameQueue video_frame_queue;AVSync avsync;avsync.InitClock();//1 .解复用DemuxThread *demux_thread = new DemuxThread(&audio_packet_queue, &video_packet_queue);ret = demux_thread->Init(argv[1]);if(ret < 0) {LogError("demux_thread.Init failed");return -1;}ret = demux_thread->Start();if(ret < 0) {LogError("demux_thread.Start() failed");return -1;}// 解码线程初始化DecodeThread *audio_decode_thread = new DecodeThread(&audio_packet_queue, &audio_frame_queue);ret = audio_decode_thread->Init(demux_thread->AudioCodecParameters());if(ret < 0) {LogError("audio_decode_thread->Init() failed");return -1;}ret = audio_decode_thread->Start();if(ret < 0) {LogError("audio_decode_thread->Start() failed");return -1;}DecodeThread *video_decode_thread = new DecodeThread(&video_packet_queue, &video_frame_queue);ret = video_decode_thread->Init(demux_thread->VideoCodecParameters());if(ret < 0) {LogError("video_decode_thread->Init() failed");return -1;}ret = video_decode_thread->Start();if(ret < 0) {LogError("video_decode_thread->Start() failed");return -1;}// 初始化audio输出AudioParams audio_params = {0};memset(&audio_params, 0, sizeof(AudioParams));audio_params.channels = demux_thread->AudioCodecParameters()->channels;audio_params.channel_layout = demux_thread->AudioCodecParameters()->channel_layout;audio_params.fmt = (enum AVSampleFormat) demux_thread->AudioCodecParameters()->format;audio_params.freq = demux_thread->AudioCodecParameters()->sample_rate;audio_params.frame_size =demux_thread->AudioCodecParameters()->frame_size;AudioOutput *audio_output = new AudioOutput(&avsync, demux_thread->AudioStreamTimebase(), audio_params, &audio_frame_queue);ret = audio_output->Init();if(ret < 0) {LogError("audio_output->Init() failed");return -1;}VideoOutput *video_output = new VideoOutput(&avsync, demux_thread->VideoStreamTimebase(),&video_frame_queue, demux_thread->VideoCodecParameters()->width,demux_thread->VideoCodecParameters()->height);ret = video_output->Init();if(ret < 0) {LogError("video_output->Init() failed");return -1;}video_output->MainLoop();// 休眠120秒
// std::this_thread::sleep_for(std::chrono::milliseconds(120*1000));LogInfo("demux_thread->Stop");demux_thread->Stop();LogInfo("delete demux_thread");delete demux_thread;LogInfo("audio_decode_thread->Stop()");audio_decode_thread->Stop();LogInfo("delete audio_decode_thread");delete audio_decode_thread;LogInfo("video_decode_thread->Stop()");video_decode_thread->Stop();LogInfo("delete video_decode_thread");delete video_decode_thread;LogInfo("main finish");return 0;
}
基本流程就是解复用——》解码——》输出音频 / 输出视频
好了,未来如果有需要的再深入解析这个 main,现在这个项目先告一段落。