How to save rtsp stream without packet loss by using FFMPEG

To save RTSP streams using FFMPEG without losing data packets, follow these steps and apply specific configurations to optimize packet reception and recording. Here is a detailed guide on the steps and parameter configurations:

1. Basic Command Structure

First, the basic FFMPEG command for capturing a stream from an RTSP source and saving it to a file is:

bash
ffmpeg -i rtsp://your_rtsp_stream_url -c copy output_file.mp4

This command includes:

• -i rtsp://your_rtsp_stream_url specifies the RTSP stream URL.
• -c copy uses the "copy" parameter to avoid re-encoding video and audio data, which reduces processing time and potential data loss.
• output_file.mp4 specifies the output file name and format.

2. Optimizing Network Buffering

To reduce data packet loss, adjust FFMPEG's buffering settings:

bash
ffmpeg -rtsp_transport tcp -buffer_size 1024000 -i rtsp://your_rtsp_stream_url -c copy output_file.mp4

Parameter explanations:

• -rtsp_transport tcp forces FFMPEG to receive the RTSP stream via TCP instead of the default UDP. TCP is more reliable than UDP in network transmission because it provides packet acknowledgment and retransmission mechanisms.
• -buffer_size 1024000 sets the buffer size, which can be adjusted based on network conditions. This helps manage large data streams and network latency.

3. Using a More Stable Output Container Format

Choose a container format that supports long-duration recording, such as Matroska (MKV):

bash
ffmpeg -rtsp_transport tcp -buffer_size 1024000 -i rtsp://your_rtsp_stream_url -c copy output_file.mkv

4. Network and System Monitoring

Monitor network connections and system resources continuously during recording to ensure no network congestion or system overload. If network issues arise, consider increasing buffer size or optimizing the network.

Practical Example

Assume an RTSP stream URL is rtsp://192.168.1.10/stream, and you want to save it to stream_record.mkv. Use the following command:

bash
ffmpeg -rtsp_transport tcp -buffer_size 1024000 -i rtsp://192.168.1.10/stream -c copy stream_record.mkv

By following these steps and configurations, you can significantly ensure that data packets are not lost during RTSP stream capture, thereby improving the reliability and integrity of the recorded video.