These is a brief description of the changes that I have made to
implement the RECORD functionality of RTSP.  As you recommended, I have
tried using the rat program on UNIX to test the changes I have made. 
Unfortunately, I was not able to get that audio program working with
RTSP.  However, from my point of view, the changes I have made are very
naturally built in the previous code, so no problems should be arising.

Changes returned by CVS history:

M 08/18 01:42 +0000 am435 1.17 Makefile        rtsp/src == <remote>
M 08/18 01:42 +0000 am435 1.4  recordservice.c rtsp/src == <remote>
M 08/18 01:42 +0000 am435 1.11 request.c       rtsp/src == <remote>
M 08/18 01:42 +0000 am435 1.7  response.c      rtsp/src == <remote>
M 08/18 01:42 +0000 am435 1.4  rtsp.c          rtsp/src == <remote>
M 08/18 01:42 +0000 am435 1.3  rtsp.h          rtsp/src == <remote>
M 08/18 01:42 +0000 am435 1.3  rtspd.conf      rtsp/src == <remote>

1. recordservice.c

Open file with name r->path (r is the procedure input parameter of the
data type request_t); Check if the corresponded file could not be
created; In the loop for packet receiving:  read buffers from the
incoming stream and Write them into the opened file until reach the end
of the stream.

2. request.c

Implemented Error status 201 to diagnose if file could not be opened for
the method r->p.method = "RECORD" implemented.

3. response.c

The Error message "File can not be created" was defined to be used in
error checking routines of the RECORD.

4.  rtsp.c

For the HTTP_Method(p) = "RECORD", the T_RECORD mode was defined in
addition to the T_PLAY defined before.

5.  rtsp.h

Second enum value T_RECORD was defined:

enum {T_PLAY = 1, T_RECORD = 2};