Take the body of msg and store it in buffer. After this method,
the body and size of msg will be set to null and 0 respectively.
If body data was set from raw memory instead of a #GstBuffer this function
will always return null. The caller can check if there is a body buffer by
calling gstrtsp.rtspmessage.RTSPMessage.hasBodyBuffer.
Take the body of msg and store it in buffer. After this method, the body and size of msg will be set to null and 0 respectively.
If body data was set from raw memory instead of a #GstBuffer this function will always return null. The caller can check if there is a body buffer by calling gstrtsp.rtspmessage.RTSPMessage.hasBodyBuffer.