Recording Video from RTSP/H.265 Camera using FFmpeg: Overcoming Common Issues

FFmpeg is a powerful, open-source media processing tool that enables users to record and convert video streams. When working with RTSP (Real-Time Streaming Protocol) cameras, particularly those transmitting H.265 encoded video over TCP, users may encounter issues while recording the stream. In this article, we'll discuss one such common problem: obtaining incorrect codec parameters, and explore a solution to overcome it.

Incorrect Codec Parameters

When attempting to record an RTSP/H.265 video stream using FFmpeg, you might encounter an error message indicating that 'dimensions not set' or 'could not write header for output file #0 (incorrect codec parameters ?): Invalid argument.' This issue occurs when FFmpeg is unable to determine the correct dimensions of the input video stream.

The problem is often caused by the lack of dimension information in the RTSP stream, which can happen when using an RTSP/H.265 camera that only supports RTSP over TCP. In such cases, forcing the use of RTSP/TCP transport protocol using the `-rtsp_transport tcp` option may resolve the issue.

Method PAUSE Failed

Another common error that users might encounter while recording RTSP streams with FFmpeg is a 'method PAUSE failed' error, often accompanied by an HTTP status code 455. This error typically occurs when attempting to pause or seek within the stream using the `pause` method.

The root cause of this issue is usually related to the camera's RTSP implementation, which may not support the `PAUSE` method in certain states. In such cases, users can try using alternative methods, such as `seek` or `stop`, to control the stream playback.

Solutions and Workarounds

To overcome the issues mentioned above, you can try the following solutions:

1. Force RTSP/TCP transport protocol: Use the `-rtsp_transport tcp` option when launching FFmpeg to ensure that it uses TCP transport protocol for the RTSP connection.

2. Increase analyzeduration and probesize options: Adjusting these options can help FFmpeg gather more information about the input stream, which may resolve issues with incorrect codec parameters.

Example FFmpeg command:

```bash

ffmpeg -rtsp_transport tcp -i rtsp://:554/ -analyzeduration 10000000 -probesize 10000000 output.mp4

```

In conclusion, recording video from RTSP/H.265 cameras using FFmpeg can be challenging due to the complexities of RTSP protocol and H.265 encoding. By understanding the common issues that may arise, such as incorrect codec parameters and method PAUSE failed errors, users can take steps to overcome these problems and successfully record their desired video streams.

Ffmpeg rtsp pause