93 lines
3.4 KiB
Objective-C
93 lines
3.4 KiB
Objective-C
/*
|
|
* Copyright 2015 The WebRTC Project Authors. All rights reserved.
|
|
*
|
|
* Use of this source code is governed by a BSD-style license
|
|
* that can be found in the LICENSE file in the root of the source
|
|
* tree. An additional intellectual property rights grant can be found
|
|
* in the file PATENTS. All contributing project authors may
|
|
* be found in the AUTHORS file in the root of the source tree.
|
|
*/
|
|
|
|
#import "ARDSDPUtils.h"
|
|
|
|
#import "WebRTC/RTCLogging.h"
|
|
#import "WebRTC/RTCSessionDescription.h"
|
|
|
|
@implementation ARDSDPUtils
|
|
|
|
+ (RTCSessionDescription *)
|
|
descriptionForDescription:(RTCSessionDescription *)description
|
|
preferredVideoCodec:(NSString *)codec {
|
|
NSString *sdpString = description.sdp;
|
|
NSString *lineSeparator = @"\n";
|
|
NSString *mLineSeparator = @" ";
|
|
// Copied from PeerConnectionClient.java.
|
|
// TODO(tkchin): Move this to a shared C++ file.
|
|
NSMutableArray *lines =
|
|
[NSMutableArray arrayWithArray:
|
|
[sdpString componentsSeparatedByString:lineSeparator]];
|
|
NSInteger mLineIndex = -1;
|
|
NSString *codecRtpMap = nil;
|
|
// a=rtpmap:<payload type> <encoding name>/<clock rate>
|
|
// [/<encoding parameters>]
|
|
NSString *pattern =
|
|
[NSString stringWithFormat:@"^a=rtpmap:(\\d+) %@(/\\d+)+[\r]?$", codec];
|
|
NSRegularExpression *regex =
|
|
[NSRegularExpression regularExpressionWithPattern:pattern
|
|
options:0
|
|
error:nil];
|
|
for (NSInteger i = 0; (i < lines.count) && (mLineIndex == -1 || !codecRtpMap);
|
|
++i) {
|
|
NSString *line = lines[i];
|
|
if ([line hasPrefix:@"m=video"]) {
|
|
mLineIndex = i;
|
|
continue;
|
|
}
|
|
NSTextCheckingResult *codecMatches =
|
|
[regex firstMatchInString:line
|
|
options:0
|
|
range:NSMakeRange(0, line.length)];
|
|
if (codecMatches) {
|
|
codecRtpMap =
|
|
[line substringWithRange:[codecMatches rangeAtIndex:1]];
|
|
continue;
|
|
}
|
|
}
|
|
if (mLineIndex == -1) {
|
|
RTCLog(@"No m=video line, so can't prefer %@", codec);
|
|
return description;
|
|
}
|
|
if (!codecRtpMap) {
|
|
RTCLog(@"No rtpmap for %@", codec);
|
|
return description;
|
|
}
|
|
NSArray *origMLineParts =
|
|
[lines[mLineIndex] componentsSeparatedByString:mLineSeparator];
|
|
if (origMLineParts.count > 3) {
|
|
NSMutableArray *newMLineParts =
|
|
[NSMutableArray arrayWithCapacity:origMLineParts.count];
|
|
NSInteger origPartIndex = 0;
|
|
// Format is: m=<media> <port> <proto> <fmt> ...
|
|
[newMLineParts addObject:origMLineParts[origPartIndex++]];
|
|
[newMLineParts addObject:origMLineParts[origPartIndex++]];
|
|
[newMLineParts addObject:origMLineParts[origPartIndex++]];
|
|
[newMLineParts addObject:codecRtpMap];
|
|
for (; origPartIndex < origMLineParts.count; ++origPartIndex) {
|
|
if (![codecRtpMap isEqualToString:origMLineParts[origPartIndex]]) {
|
|
[newMLineParts addObject:origMLineParts[origPartIndex]];
|
|
}
|
|
}
|
|
NSString *newMLine =
|
|
[newMLineParts componentsJoinedByString:mLineSeparator];
|
|
[lines replaceObjectAtIndex:mLineIndex
|
|
withObject:newMLine];
|
|
} else {
|
|
RTCLogWarning(@"Wrong SDP media description format: %@", lines[mLineIndex]);
|
|
}
|
|
NSString *mangledSdpString = [lines componentsJoinedByString:lineSeparator];
|
|
return [[RTCSessionDescription alloc] initWithType:description.type
|
|
sdp:mangledSdpString];
|
|
}
|
|
|
|
@end
|