protocol/rtsp: working on main.go in rtsp/cmd/stream

Added file header to main.go, and modified rtsp.go to work with cmd/stream/main.go. This change modifies writeRequest, which now takes a *url.URL. This means the Setup() method can parse a new
URL that contains a given track, and then give this to writeRequest.

protocol/rtsp/cmd/stream/main.go

@@ -1,9 +1,63 @@
+/*
+NAME
+  main.go
+
+DESCRIPTION
+  main.go provides a program to connect to an RTSP server and request for an
+  RTP stream.
+
+AUTHORS
+  Saxon A. Nelson-Milton <saxon@ausocean.org>
+
+LICENSE
+  This is Copyright (C) 2019 the Australian Ocean Lab (AusOcean).
+
+  It is free software: you can redistribute it and/or modify them
+  under the terms of the GNU General Public License as published by the
+  Free Software Foundation, either version 3 of the License, or (at your
+  option) any later version.
+
+  It is distributed in the hope that it will be useful, but WITHOUT
+  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+  FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+  for more details.
+
+  You should have received a copy of the GNU General Public License
+  in gpl.txt.  If not, see http://www.gnu.org/licenses.
+
+  Copyright (c) 2015, T. Jameson Little <t.jameson.little@gmail.com>
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without modification,
+  are permitted provided that the following conditions are met:
+
+  1. Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+  2. Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+  3. Neither the name of the copyright holder nor the names of its contributors
+  may be used to endorse or promote products derived from this software without
+  specific prior written permission.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
 package main
 
 import (
 	"flag"
 	"fmt"
-	"io"
 	"log"
 
 	"bitbucket.org/ausocean/av/protocol/rtsp"
@@ -15,28 +69,26 @@ func main() {
 	trackPtr := flag.String("track", "track1", "The track that we would like to receive media from")
 	flag.Parse()
 
-	sess := rtsp.NewSession()
+	sess, err := rtsp.NewSession(*rtspServerPtr)
-	res, err := sess.Options(*rtspServerPtr)
+	if err != nil {
+		panic(fmt.Sprintf("creating RTSP session failed with error: %v", err))
+	}
+
+	res, err := sess.Options()
 	if err != nil {
 		log.Fatalln(err)
 	}
 	fmt.Println("Options:")
 	fmt.Println(res)
 
-	res, err = sess.Describe(*rtspServerPtr)
+	res, err = sess.Describe()
 	if err != nil {
 		log.Fatalln(err)
 	}
 	fmt.Println("Describe:")
 	fmt.Println(res)
 
-	p, err := rtsp.ParseSdp(&io.LimitedReader{R: res.Body, N: res.ContentLength})
+	res, err = sess.Setup(*trackPtr, fmt.Sprintf("RTP/AVP;unicast;client_port=%d-%d", *clientPortPtr, *clientPortPtr+1))
-	if err != nil {
-		log.Fatalln(err)
-	}
-	log.Printf("%+v", p)
-
-	res, err = sess.Setup(*rtspServerPtr+"/"+*trackPtr, fmt.Sprintf("RTP/AVP;unicast;client_port=%d-%d", *clientPortPtr, *clientPortPtr+1))
 	if err != nil {
 		log.Fatalln(err)
 	}

protocol/rtsp/rtsp.go

@@ -78,18 +78,19 @@ const (
 	setup    = "SETUP"
 )
 
-// session describes an RTSP session.
+// Session describes an RTSP Session.
-type session struct {
+type Session struct {
 	cSeq    int
+	urlStr  string
 	url     *url.URL
 	conn    net.Conn
-	session string
+	Session string
 }
 
-// NewSession returns a pointer to a new session. The URL u will be parsed and
+// NewSession returns a pointer to a new Session. The URL u will be parsed and
 // a connection to the RTSP server will be made.
-func NewSession(u string) (*session, error) {
+func NewSession(u string) (*Session, error) {
-	s := &session{}
+	s := &Session{urlStr: u}
 	var err error
 	s.url, err = url.Parse(u)
 	if err != nil {
@@ -103,40 +104,45 @@ func NewSession(u string) (*session, error) {
 }
 
 // Describe forms and sends an RTSP request of method DESCRIBE to the RTSP server.
-func (s *session) Describe() (*Response, error) {
+func (s *Session) Describe() (*Response, error) {
-	return s.writeRequest(describe, func(req *Request) { req.Header.Add("Accept", "application/sdp") }, nil)
+	return s.writeRequest(s.url, describe, func(req *Request) { req.Header.Add("Accept", "application/sdp") }, nil)
 }
 
 // Options forms and sends an RTSP request of method OPTIONS to the RTSP server.
-func (s *session) Options(urlStr string) (*Response, error) {
+func (s *Session) Options() (*Response, error) {
-	return s.writeRequest(options, nil, nil)
+	return s.writeRequest(s.url, options, nil, nil)
 }
 
 // Setup forms and sends an RTSP request of method SETUP to the RTSP server.
-func (s *session) Setup(transport string) (*Response, error) {
+func (s *Session) Setup(track, transport string) (*Response, error) {
+	url, err := url.Parse(s.urlStr + "/" + track)
+	if err != nil {
+		return nil, err
+	}
 	return s.writeRequest(
+		url,
 		setup,
 		func(req *Request) {
 			req.Header.Add("Transport", transport)
 		},
 		func(resp *Response) {
-			s.session = resp.Header.Get("session")
+			s.Session = resp.Header.Get("Session")
 		},
 	)
 }
 
 // Play forms and sends an RTSP request of method PLAY to the RTSP server
-func (s *session) Play() (*Response, error) {
+func (s *Session) Play() (*Response, error) {
-	return s.writeRequest(play, func(req *Request) { req.Header.Add("session", s.session) }, nil)
+	return s.writeRequest(s.url, play, func(req *Request) { req.Header.Add("Session", s.Session) }, nil)
 }
 
 // writeRequest creates an RTSP request of the method given and writes it to the
-// the session connection.
+// the Session connection.
 //
 //headerOp and respOp define any operation that needs
 // to occur to the request or response for the given method.
-func (s *session) writeRequest(method string, headerOp func(*Request), respOp func(*Response)) (*Response, error) {
+func (s *Session) writeRequest(url *url.URL, method string, headerOp func(*Request), respOp func(*Response)) (*Response, error) {
-	req, err := NewRequest(method, s.nextCSeq(), s.url, nil)
+	req, err := NewRequest(method, s.nextCSeq(), url, nil)
 	if err != nil {
 		return nil, err
 	}
@@ -161,7 +167,7 @@ func (s *session) writeRequest(method string, headerOp func(*Request), respOp fu
 	return res, nil
 }
 
-func (s *session) nextCSeq() string {
+func (s *Session) nextCSeq() string {
 	s.cSeq++
 	return strconv.Itoa(s.cSeq)
 }