RTSP streaming desktop and Android device delay test in FFmpeg

1. FFMPEG streaming:

1.1 FFmpeg source code preparation

Just choose one of the official website, GitHub, and CSDN:

● Official website:

Builds - CODEX FFMPEG @ gyan.dev

Download source code: just choose one

● GitHub：

Releases · BtbN/FFmpeg-Builds (github.com)

● CSDN has uploaded ffmpeg and rtsp servers:

‍FFmpeg RTSP streaming desktop

1.2 RTSP streaming server

● GitHub：

Releases · aler9/mediamtx (github.com)

2. Execution process

​ After decompression:

2.1 Start the server

● ​Double-click to run:

​

● ​This interface pops up:

2.2 Execute desktop streaming

● Open the terminal under the source bin file:

● Run command:

​ffmpeg -f gdigrab -i desktop -s 1280x720 -rtsp_transport tcp -preset ultrafast -acodec libfaac -f rtsp rtsp://127.0.0.1:8554/stream​

Parameter Description:

,-f gdigrab ​ gdigrab is a screen capture device based on Win32 GDI. Can capture the screen image of the display area of ​​the Windows desktop screen

​​​​ :-i desktop Specify the input file. desktop means that the input device is a desktop screen

​​​​:-f rtsp rtsp://127.0.0.1:8554/stream The output format is rtsp stream, and the address is the local machine address

● Start streaming :

● Open to open Beijing time:

Beijing time calibration_Beijing time online calibration display milliseconds - countdown timer (daojishiqi.com)

2.3 play

● vlc playback stream:

​rtsp://127.0.0.1:8554/stream​

● Display:

It can be seen that the delay of vlc is quite large:

3. Android testing

● ipconfig finds that the address of the Windows machine is 192.168.xx.xx

● Android player input rtsp://192.168.xx.xx/streamaddress

安卓采用 FFMPEG 4.4.1版本，使用 QVideoFrame 代替sws方案，VideoOutput 来刷新图片

In addition to image transmission and re-testing, the delay will be increased by about 50~100ms

● Other ways to push streams :

• The desktop push stream introduced in this article:
  ​ffmpeg -f gdigrab -i desktop -s 1280x720 -rtsp_transport tcp -preset ultrafast -acodec libfaac -f rtsp rtsp://127.0.0.1:8554/stream

• UDP streaming:
  ffmpeg -re -i input.mp4 -c copy -f rtsp rtsp://127.0.0.1:8554/stream

• TCP streaming:
  ffmpeg -re -i input.mp4 -c copy -rtsp_transport tcp -f rtsp rtsp://127.0.0.1:8554/stream

• Circular push flow:
  ffmpeg -re -stream_loop -1 -i input.mp4 -c copy -f rtsp rtsp://127.0.0.1:8554/stream

    其中：
    -re 为以流的方式读取；
    -stream_loop 为循环读取视频源的次数，-1为无限循环；
    -i 为输入的文件；
    -f 为格式化输出到哪里