ZLMediaKit: Quick Start

What is ZLMediaKit

ZLMediaKit is a high-performance operational-level streaming service framework based on C++11. It supports multiple protocols and supports protocol transfer. It connects the video surveillance protocol stack and live broadcast protocol stack. It supports cluster, on-demand transfer protocol, on-demand push-pull streaming, first broadcast and then push-out, and interrupt continuous push-out and other functions. It supports multi-track mode (multiple video/audio in one stream).
Its Gitee address:/xia-chu/ZLMediaKit

Compilation

Pull ZLMediaKit.

git clone git@:xia-chu/

Install the dependency library

• Install FFmpeg: Used to process multimedia data, executed under Ubuntusudo apt-get install ffmpeg。

Build a project

Create the build directory under the ZLMediaKit directory and enter, executecmake.., and then executemake -j4Compile.

cd ZLMediaKit
mkdir build
cd build
cmake ..
make -j4

Problem handling

Question 1: srtp not found, WebRTC related functions failed to open

I encountered the following error while cmake
Error 1:

-- srt function is enabled
 CMake Warning at webrtc/:28 (message):
 srtp not found, WebRTC related functions failed to open

Solution: Install the SRTP library

sudo apt-get install libsrtp2-dev

Question 2: Dependency library issue

-- Configuring done (2.7s)
CMake Error at 3rdpart/:32 (add_library):
No SOURCES given to target: jsoncpp


CMake Error at 3rdpart/:55 (add_library):
No SOURCES given to target: mov


CMake Error at 3rdpart/:68 (add_library):
No SOURCES given to target: flv


CMake Error at 3rdpart/:91 (add_library):
No SOURCES given to target: mpeg


CMake Error at 3rdpart/:201 (add_library):
No SOURCES given to target: zltoolkit

There are some dependency libraries in the ZLMediaKit project that are managed through Git submodules. You need to ensure that all submodules are initialized and updated correctly. Execute the following command in the project root directory:

git submodule update --init --recursive

Install

If you need to install it into the system, executesudo make install。

Configure and run

• Modify the configuration file: The configuration file is located in the conf directory and can be modified as needed. If modifiedIn-houseapiDebugetc.
• Start ZLMediaKit:existZLMediaKit/release/linux/DebugIn the directory, it can be executed./MediaServer -hCheck the startup parameters,

./MediaServer -h
 2025-03-03 21:15:10.198 I [MediaServer] [5747-MediaServer] :35 registerPlugin | Load codec: H264
 2025-03-03 21:15:10.219 I [MediaServer] [5747-MediaServer] :35 registerPlugin | Load codec: H265
 2025-03-03 21:15:10.223 I [MediaServer] [5747-MediaServer] :35 registerPlugin | Load codec: JPEG
 2025-03-03 21:15:10.228 I [MediaServer] [5747-MediaServer] :35 registerPlugin | Load codec: mpeg4-generic
 2025-03-03 21:15:10.228 I [MediaServer] [5747-MediaServer] :35 registerPlugin | Load codec: opus
 2025-03-03 21:15:10.228 I [MediaServer] [5747-MediaServer] :35 registerPlugin | Load codec: PCMA
 2025-03-03 21:15:10.228 I [MediaServer] [5747-MediaServer] :35 registerPlugin | Load codec: PCMU
 2025-03-03 21:15:10.228 I [MediaServer] [5747-MediaServer] :35 registerPlugin | Load codec: L16
 2025-03-03 21:15:10.236 I [MediaServer] [5747-MediaServer] :35 registerPlugin | Load codec: MP3
 -h --help No parameter Default: null Optional Print this information
 -d --daemon No parameter Default: null Optional Whether to start in Daemon mode
 -l --level There are parameters Default: 1 Optional Log level, LTrace~LError(0~4)
 -m --max_day with parameters Default: 7 Optional Log maximum number of days to save
 -c --config with parameters Default: /mnt/d/ubunt/xmr/program/cpp/ZLMediaKit/release/linux/Debug/ Optional Configuration file path
 -s --ssl parameter Default: /mnt/d/ubunt/xmr/program/cpp/ZLMediaKit/release/linux/Debug/ Optional ssl certificate file or folder, support p12/pem type
 -t --threads with parameter Default: 16 Optional Start event trigger number of threads
 --affinity parameter Default: 1 Optional Whether to start the CPU affinity setting
 -v --version No parameter Default: null Optional Display version number
 --log-slice with parameters Default: 100 Optional Maximum number of saved log slices
 --log-size parameter Default: 256 Optional Single log slice Maximum capacity, unit MB
 --log-dir parameter Default: /mnt/d/ubunt/xmr/program/cpp/ZLMediaKit/release/linux/Debug/log/ Optional Log save folder path

 2025-03-03 21:15:10.441 I [MediaServer] [5747-MediaServer] :91 ~Logger |

or./MediaServer -d &Start in daemon mode.

sudo ./MediaServer -d &

Problem handling

Question 1: No permission to listen to port 554

When starting ./MediaServer -d, it displays unauthorized listening port 554

2025-03-03 21:41:18.193 W [MediaServer] [5879-MediaServer] :433 bind_sock6 | Bind socket failed: permission denied
 2025-03-03 21:41:18.227 E [MediaServer] [5879-MediaServer] :448 start_main | Start server failed: Listen on :: 554 failed: permission denied
 2025-03-03 21:41:19.241 W [MediaServer] [5876-MediaServer] :153 operator() | Received an active exit signal, closing the parent and child processes
 2025-03-03 21:41:19.249 I [MediaServer] [5876-MediaServer] :91 ~Logger |

Execute using sudo.

Question 2: Port 80 has been used

2025-03-03 21:41:28.908 W [MediaServer] [5906-MediaServer] :433 bind_sock6 | Bind socket failed: address already in use
 2025-03-03 21:41:28.967 E [MediaServer] [5906-MediaServer] :448 start_main | Start server failed: Listen on :: 80 failed: address already in use
 2025-03-03 21:41:29.973 W [MediaServer] [5903-MediaServer] :153 operator() | Received an active exit signal, closing the parent and child processes
 2025-03-03 21:41:29.985 I [MediaServer] [5903-MediaServer] :91 ~Logger |

• deal with
  The 80 port is occupied because MediaServer uses 80 port when processing http. I use the solution to not handle http.
  Turn on MediaServer (in the same directory as MediaServer), and turn off the http function.
  Change the port under http from 80 to -1

[http]
port=-1

Restart MediaServer to see if it is started successfully (554 is listening)

sudo ./MediaServer -d &
netstat -ant | grep 554
tcp6 0 0 :::554 :::* LISTEN

Push flow test

RTSP streaming

Prepare

Prepare video files

Find an mp4 video and put it in a specific directory, for example: /path/to/test.mp4, and use ffmpeg to push the video later.

Install VLC

Install VL to pull the data stream forwarded by ZLMediaKit

Pushing

Execute the following push flow command to push test.mp4 to rtsp://127.0.0.1/live/test

ffmpeg -re -i "/path/to/test.mp4" -vcodec h264 -acodec aac -f rtsp -rtsp_transport tcp rtsp://127.0.0.1/live/test

• -re: Read input files at local frame rate to simulate real-time streaming.
• -i "/path/to/test.mp4": Specify the input video file path.
• -vcodec h264: Set the video encoding format to H.264.
• -acodec aac: Set the audio encoding format to AAC.
• -f rtsp: Specify the output format to be RTSP.
• -rtsp_transport tcp: Use TCP as the RTSP transport protocol.
• rtsp://127.0.0.1/live/test: The target address of the push stream,127.0.0.1It is the IP address of the ZLMediaKit server.liveIt's the application name,testis the stream name.

• It is recommended to add the -stream_loop -1 parameter to realize loop push flow. Otherwise, if test.mp4 is smaller, the push flow will end soon.

ffmpeg -stream_loop -1 -re -i "/path/to/test.mp4" -vcodec h264 -acodec aac -f rtsp -rtsp_transport tcp rtsp://127.0.0.1/live/test

Pull stream verification

Use a player such as VLC to perform stream pull verification. Select "Media" -> "Open Network Streaming" in VLC and enter the push streaming addressrtsp://127.0.0.1/live/testYou can watch the video.

Problem: Failed to pull the stolen

If it is under Windows, usewsl+ubuntu,existubunutStart MediaServer and push streaming in an environment, but cannot be usedrtsp://127.0.0.1/live/testThe address is used to pull the stream.
Start MediaServer in Ubuntu in WSL (Windows Subsystem for Linux) and push RTSP to rtsp://127.0.0.1/live/test through FFmpeg. When using VLC to play under Windows, you need to pay attention to the network communication between WSL and Windows.

• Get the IP address of the WSL
  In a WSL Ubuntu terminal, use the following command to obtain the IP address of the WSL:

ip addr show eth0 | grep -oP '(?<=inet\s)\d+(\.\d+){3}'

This command outputs the IP address of the WSL, such as 172.28.224.1.

• Setting up RTSP path in VLC
  Open the VLC player under Windows, select Media -> Open Network Streaming, enter the RTSP path in the input box, the format is:
  plaintext
  rtsp://<WSL's IP address>/live/test

For example, if the IP address of WSL is 172.28.224.1, enter rtsp://172.28.224.1/live/test and click the Play button.

The role of ZLMediaKit in RTSP streaming testing

Receive push streaming data

ZLMediaKit asRTSP Server, listen for specifiedPort (default 554), waiting for the RTSP push request initiated by the client (such as FFmpeg). When the request is received, itEstablish an RTSP session with the client,andReceive audio and video stream data sent by the client。

Protocol processing

• RTSP protocol analysis: ZLMediaKit will parse the RTSP protocol and process various RTSP requests sent by the client, such as OPTIONS, DESCRIBE, SETUP, PLAY, etc., to ensure the normal establishment of the session and the correct transmission of data.
• RTP/RTCP processing: RTSP is usually used with RTP (Real-time Transport Protocol) and RTCP (Real-time Transport Control Protocol). ZLMediaKit processes RTP packets, restores them to audio and video streams, and controls and feedbacks the streams through the RTCP protocol.

Flow Management

• Stream Registration: When a new push stream is received, ZLMediaKit will register the stream and record the relevant information of the stream, such as the flow name, application name, encoding format, etc.
• Stream distribution:ZLMediaKit can distribute received streams to multiple stream pull clients. When there is a stream pull request, it will send the corresponding stream data to the stream pull client based on the stream registration information.

Storage and forwarding

• storage: ZLMediaKit supports storing received streaming data, such as saving as local files or writing to a database, for convenient subsequent playback and analysis.
• Forward: The received stream can be forwarded to other servers, realizing multi-level distribution of streams and cross-network transmission.

The flow process

Stream stage

1. Client initiates a request:FFmpeg, as a streaming client, sends an RTSP OPTIONS request to the ZLMediaKit server and asks the RTSP method supported by the server.
2. Server Response: After the ZLMediaKit server receives an OPTIONS request, it returns a list of supported RTSP methods.
3. Client sends DESCRIBE request: FFmpeg sends a DESCRIBE request to obtain media description information (SDP, Session Description Protocol) on the server.
4. Server returns SDP: The ZLMediaKit server returns SDP information, including the encoding format, transmission address and other information of the audio and video stream.
5. Client sends SETUP request:FFmpeg sends SETUP requests according to SDP information, and sets transmission channels and parameters.
6. Server Response SETUP: The ZLMediaKit server responds to the SETUP request and confirms the transmission channel and parameters.
7. Client sends PLAY request:FFmpeg sends a PLAY request and starts pushing.
8. Data transmission:FFmpeg encapsulates audio and video data into RTP packets and sends it to the ZLMediaKit server via TCP or UDP.

Stream pulling stage

1. The stream pull client initiates a request: VLC and other stream pull clients send RTSP OPTIONS request to the ZLMediaKit server.
2. Server Response: The ZLMediaKit server returns a list of supported RTSP methods.
3. The stream pull client sends a DESCRIBE request: Obtain media description information.
4. Server returns SDP: The ZLMediaKit server returns SDP information.
5. The stream pull client sends SETUP request: Set the transmission channel and parameters.
6. Server Response SETUP: Confirm the transmission channel and parameters.
7. Pull the stream client sends PLAY request: Start pulling the flow.
8. Data transmission: The ZLMediaKit server encapsulates the received audio and video stream data into RTP packets and sends it to the stream pulling client.