RTSP downmix: (4)in, (1)out. 2x2 grid. Labels outbound stream, records unlabeled local file. Bash.
This script contains a command for FFmpeg, a popular open-source multimedia framework that allows users to encode, decode, transcode, and stream audio and video files.
The command takes four input video streams using RTSP protocol and applies a complex filter to combine them into a single output stream. The filter complex uses various scaling and overlay techniques to combine the input streams in a specific layout, with each stream labeled with text indicating its source. The output stream is then encoded using the libx264 codec with certain parameters and is simultaneously written to an RTSP output stream and a MPEG-TS file on disk.
Here is a brief breakdown of the different components of the FFmpeg command:
The -i flag is used to specify the input streams.
The -filter_complex flag is used to specify the complex filtergraph that processes the input streams and produces the output stream.
The -map flag is used to specify which streams should be included in the output.
The -c:v flag is used to specify the video codec for encoding the output.
The -crf flag is used to specify the Constant Rate Factor for the output video, which controls the quality/file size tradeoff.
The -preset flag is used to specify the encoding speed preset, with veryfast being a faster preset that sacrifices some quality.
The -tune flag is used to specify a preset optimization for certain types of input streams, with zerolatency being optimized for low-latency streaming.
The -f flag is used to specify the output format and destination, with [f=rtsp]rtsp://output_stream specifying an RTSP output stream and [f=mpegts]disk_file.ts specifying a MPEG-TS file on disk.
The -loglevel and -report flags are used to specify the logging verbosity level and to generate a report file, respectively.
To run this script, you will need to install FFmpeg if it is not already installed on your system. You can install FFmpeg by opening a terminal window and running the following command:
sudo apt install ffmpegThis will install FFmpeg along with all of its dependencies on your system.
Once FFmpeg is installed, you can save the script to a file (for example, "script.sh") and then make it executable by running the following command:
chmod +x script.shFinally, you can run the script by typing its filename in the terminal and pressing Enter:
./script.shPlease note that you need to modify the script to match the specific RTSP input streams, output destinations, and font files that you are using. You can refer to the FFmpeg documentation for more information on the various options and settings available in the command.
This script provides a flexible and powerful way to combine multiple video streams with custom text overlays and write the output to multiple destinations, making it suitable for a variety of applications, such as:
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Surveillance systems: This script can be used to merge multiple video streams from surveillance cameras into a single output stream that can be easily monitored and recorded.
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Live events: This script can be used to merge multiple video feeds from different cameras at a live event (e.g. sports, concerts) into a single output stream that can be broadcasted to a remote audience.
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Video conferencing: This script can be used to merge multiple video streams from different participants in a video conference into a single output stream that can be shared with other participants or recorded for later viewing.
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Broadcasting: This script can be used to merge multiple video feeds from different sources (e.g. studio cameras, remote cameras) into a single output stream that can be broadcasted to a wider audience.
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Video production: This script can be used during video production to monitor multiple camera angles at once and create a single output stream for editing and post-production.
In the script, the backslash \ is used as an escape character to split long commands across multiple lines. When a backslash is used at the end of a line, it tells the shell to ignore the line break and treat the command as a single line.
This technique of using backslashes to split long commands across multiple lines is known as line continuation or line wrapping. It is often used to improve the readability and maintainability of complex shell scripts.
In the script, the backslashes are used to split the -filter_complex option into multiple lines for better readability. This option specifies the filtergraph that is used to process the input video streams and generate the output stream. The filtergraph consists of a series of filterchains, each of which contains one or more filter operations separated by semicolons.
By using backslashes to split the -filter_complex option into multiple lines, it is easier to understand the filtergraph and modify it if needed.
This software is provided "as is" and without warranty of any kind, express or implied, including but not limited to the warranties of merchantability, fitness for a particular purpose and noninfringement. In no event shall the authors or copyright holders be liable for any claim, damages or other liability, whether in an action of contract, tort or otherwise, arising from, out of or in connection with the software or the use or other dealings in the software.
The authors do not endorse or support any harmful or malicious activities that may be carried out with the software. It is the user's responsibility to ensure that their use of the software complies with all applicable laws and regulations.
These files released under the MIT License.