1- var codecs = { } ;
2-
3- /* this function credit goes to Google Chrome WebRTC team! */
4- codecs . opus = function ( sessionDescription ) {
5-
6- /* no opus? use other codec! */
7- if ( ! isopus ) return sessionDescription ;
8-
9- var sdp = sessionDescription . sdp ;
10-
11- /* Opus? use it! */
12- function preferOpus ( ) {
13- var sdpLines = sdp . split ( '\r\n' ) ;
14-
15- // Search for m line.
16- for ( var i = 0 ; i < sdpLines . length ; i ++ ) {
17- if ( sdpLines [ i ] . search ( 'm=audio' ) !== - 1 ) {
18- var mLineIndex = i ;
19- break ;
20- }
21- }
22- if ( mLineIndex === null )
23- return sdp ;
24-
25- // If Opus is available, set it as the default in m line.
26- for ( i = 0 ; i < sdpLines . length ; i ++ ) {
27- if ( sdpLines [ i ] . search ( 'opus/48000' ) !== - 1 ) {
28- var opusPayload = extractSdp ( sdpLines [ i ] , / : ( \d + ) o p u s \/ 4 8 0 0 0 / i) ;
29- if ( opusPayload )
30- sdpLines [ mLineIndex ] = setDefaultCodec ( sdpLines [ mLineIndex ] , opusPayload ) ;
31- break ;
32- }
33- }
34-
35- // Remove CN in m line and sdp.
36- sdpLines = removeCN ( sdpLines , mLineIndex ) ;
37-
38- sdp = sdpLines . join ( '\r\n' ) ;
39- return sdp ;
40- }
41-
42- function extractSdp ( sdpLine , pattern ) {
43- var _result = sdpLine . match ( pattern ) ;
44- return ( _result && _result . length == 2 ) ? _result [ 1 ] : null ;
45- }
46-
47- // Set the selected codec to the first in m line.
48- function setDefaultCodec ( mLine , payload ) {
49- var elements = mLine . split ( ' ' ) ;
50- var newLine = new Array ( ) ;
51- var index = 0 ;
52- for ( var i = 0 ; i < elements . length ; i ++ ) {
53- if ( index === 3 ) // Format of media starts from the fourth.
54- newLine [ index ++ ] = payload ; // Put target payload to the first.
55- if ( elements [ i ] !== payload )
56- newLine [ index ++ ] = elements [ i ] ;
57- }
58- return newLine . join ( ' ' ) ;
59- }
60-
61- // Strip CN from sdp before CN constraints is ready.
62- function removeCN ( sdpLines , mLineIndex ) {
63- var mLineElements = sdpLines [ mLineIndex ] . split ( ' ' ) ;
64- // Scan from end for the convenience of removing an item.
65- for ( var i = sdpLines . length - 1 ; i >= 0 ; i -- ) {
66- var payload = extractSdp ( sdpLines [ i ] , / a = r t p m a p : ( \d + ) C N \/ \d + / i) ;
67- if ( payload ) {
68- var cnPos = mLineElements . indexOf ( payload ) ;
69- if ( cnPos !== - 1 ) {
70- // Remove CN payload from m line.
71- mLineElements . splice ( cnPos , 1 ) ;
72- }
73- // Remove CN line in sdp
74- sdpLines . splice ( i , 1 ) ;
75- }
76- }
77-
78- sdpLines [ mLineIndex ] = mLineElements . join ( ' ' ) ;
79- return sdpLines ;
80- }
81-
82-
83- var result ;
84-
85- /* in case of error; use default codec; otherwise use opus */
86- try {
87- result = preferOpus ( ) ;
88- console . log ( 'using opus codec!' ) ;
89- }
90- catch ( e ) {
91- console . error ( e ) ;
92- result = sessionDescription . sdp ;
93-
94- window . messenger && window . messenger . deliver ( e . stack + '\n\n Location: ' + location . href + '\n UserAgen: ' + navigator . userAgent ) ;
95- }
96-
97- return new window . SessionDescription ( {
98- sdp : result ,
99- type : sessionDescription . type
100- } ) ;
101- } ;
102-
103- /* check support of opus codec */
104- codecs . isopus = function ( ) {
105- var result = true ;
106- new PeerConnection ( defaults . iceServers ) . createOffer ( function ( sessionDescription ) {
107- result = sessionDescription . sdp . indexOf ( 'opus' ) !== - 1 ;
108- } , null , defaults . constraints ) ;
109- return result ;
110- } ;
111-
112- /* used to know opus codec support */
1+ /* MIT License: https://webrtc-experiment.appspot.com/licence/ */
2+
3+ var codecs = { } ;
4+
5+ /* this function credit goes to Google Chrome WebRTC team! */
6+ codecs . opus = function ( sessionDescription ) {
7+
8+ /* no opus? use other codec! */
9+ if ( ! isopus ) return sessionDescription ;
10+
11+ var sdp = sessionDescription . sdp ;
12+
13+ /* Opus? use it! */
14+ function preferOpus ( ) {
15+ var sdpLines = sdp . split ( '\r\n' ) ;
16+
17+ // Search for m line.
18+ for ( var i = 0 ; i < sdpLines . length ; i ++ ) {
19+ if ( sdpLines [ i ] . search ( 'm=audio' ) !== - 1 ) {
20+ var mLineIndex = i ;
21+ break ;
22+ }
23+ }
24+ if ( mLineIndex === null )
25+ return sdp ;
26+
27+ // If Opus is available, set it as the default in m line.
28+ for ( i = 0 ; i < sdpLines . length ; i ++ ) {
29+ if ( sdpLines [ i ] . search ( 'opus/48000' ) !== - 1 ) {
30+ var opusPayload = extractSdp ( sdpLines [ i ] , / : ( \d + ) o p u s \/ 4 8 0 0 0 / i) ;
31+ if ( opusPayload )
32+ sdpLines [ mLineIndex ] = setDefaultCodec ( sdpLines [ mLineIndex ] , opusPayload ) ;
33+ break ;
34+ }
35+ }
36+
37+ // Remove CN in m line and sdp.
38+ sdpLines = removeCN ( sdpLines , mLineIndex ) ;
39+
40+ sdp = sdpLines . join ( '\r\n' ) ;
41+ return sdp ;
42+ }
43+
44+ function extractSdp ( sdpLine , pattern ) {
45+ var _result = sdpLine . match ( pattern ) ;
46+ return ( _result && _result . length == 2 ) ? _result [ 1 ] : null ;
47+ }
48+
49+ // Set the selected codec to the first in m line.
50+ function setDefaultCodec ( mLine , payload ) {
51+ var elements = mLine . split ( ' ' ) ;
52+ var newLine = new Array ( ) ;
53+ var index = 0 ;
54+ for ( var i = 0 ; i < elements . length ; i ++ ) {
55+ if ( index === 3 ) // Format of media starts from the fourth.
56+ newLine [ index ++ ] = payload ; // Put target payload to the first.
57+ if ( elements [ i ] !== payload )
58+ newLine [ index ++ ] = elements [ i ] ;
59+ }
60+ return newLine . join ( ' ' ) ;
61+ }
62+
63+ // Strip CN from sdp before CN constraints is ready.
64+ function removeCN ( sdpLines , mLineIndex ) {
65+ var mLineElements = sdpLines [ mLineIndex ] . split ( ' ' ) ;
66+ // Scan from end for the convenience of removing an item.
67+ for ( var i = sdpLines . length - 1 ; i >= 0 ; i -- ) {
68+ var payload = extractSdp ( sdpLines [ i ] , / a = r t p m a p : ( \d + ) C N \/ \d + / i) ;
69+ if ( payload ) {
70+ var cnPos = mLineElements . indexOf ( payload ) ;
71+ if ( cnPos !== - 1 ) {
72+ // Remove CN payload from m line.
73+ mLineElements . splice ( cnPos , 1 ) ;
74+ }
75+ // Remove CN line in sdp
76+ sdpLines . splice ( i , 1 ) ;
77+ }
78+ }
79+
80+ sdpLines [ mLineIndex ] = mLineElements . join ( ' ' ) ;
81+ return sdpLines ;
82+ }
83+
84+
85+ var result ;
86+
87+ /* in case of error; use default codec; otherwise use opus */
88+ try {
89+ result = preferOpus ( ) ;
90+ console . log ( 'using opus codec!' ) ;
91+ }
92+ catch ( e ) {
93+ console . error ( e ) ;
94+ result = sessionDescription . sdp ;
95+
96+ window . messenger && window . messenger . deliver ( e . stack + '\n\n Location: ' + location . href + '\n UserAgen: ' + navigator . userAgent ) ;
97+ }
98+
99+ return new window . SessionDescription ( {
100+ sdp : result ,
101+ type : sessionDescription . type
102+ } ) ;
103+ } ;
104+
105+ /* check support of opus codec */
106+ codecs . isopus = function ( ) {
107+ var result = true ;
108+ new PeerConnection ( defaults . iceServers ) . createOffer ( function ( sessionDescription ) {
109+ result = sessionDescription . sdp . indexOf ( 'opus' ) !== - 1 ;
110+ } , null , defaults . constraints ) ;
111+ return result ;
112+ } ;
113+
114+ /* used to know opus codec support */
113115var isopus = ! ! codecs . isopus ( ) ;
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