Audio and video project—Audio and video player analysis based on FFmpeg and SDL (22)

introduce

In this series, I plan to spend a lot of time explaining my gitee project audio and video player. In this project, you can learn audio and video decapsulation, decoding, and SDL rendering related knowledge. If you are interested in the source code, please check out the audio and video player based on FFmpeg and SDL

If you don’t understand this article, you can refer to my previous article Audio and Video Project— Audio and Video Player Analysis Based on FFmpeg and SDL (21)

parse

All the classes of our player have been parsed. Let's take a look at how the main function uses functions to implement audio and video playback.

#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();
    // queue
    AVPacketQueue 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;
}

The basic process is demultiplexing -> decoding -> output audio/output video

Okay, if necessary, I will analyze this main in depth in the future. Now this project comes to an end.