The audio file could not be decoded or its format is not supported.

The 400 status error in the OpenAI API, particularly when dealing with audio files, can be triggered by several factors:

Incorrect or Unsupported File Format

The error can occur if the audio file format is not recognized or supported by the OpenAI API. Even if the file extension appears correct (e.g., .m4a), there might be issues with the actual format or encoding of the file.

Invalid Request Configuration

The request itself might be malformed, such as incorrect or missing headers, especially the Authorization field, or other configuration issues that make the request invalid.

Rate Limiting or Throttling

Exceeding the rate limits set by OpenAI can result in a 400 error. This happens when the API receives too many requests within a short period, violating the rate limits.

Environment Variable or Parameter Issues

Incorrect data types or hidden characters in environment variables or request parameters can cause the API to reject the request, leading to a 400 error. For example, text values where numeric types are expected.

Network or Middleware Issues

Problems with network traffic or middleware configuration, such as Axios settings, can also result in a 400 error. This includes issues with the base URL, headers, or other network-related settings.