blob: f2f7fa804246078563e0bd1738e6de5c16e4de6a [file] [log] [blame]
// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <map>
#include <string>
#include <vector>
namespace remoting {
namespace protocol {
// SdpMessage is used to process session descriptions messages in SDP format
// generated by WebRTC (see RFC 4566). In particularly it allows configuring
// video and audio codecs.
// It also normalizes the SDP message to make sure the text used for HMAC
// signature verification is the same that was signed on the sending side.
// This is necessary because WebRTC generates SDP with CRLF line endings which
// are sometimes converted to LF after passing the signaling channel.
class SdpMessage {
explicit SdpMessage(const std::string& sdp);
bool has_audio() const { return has_audio_; }
bool has_video() const { return has_video_; }
// Returns string representation of the SDP message. The result always has
// line-endings normalized to CR+LF and empty lines removed.
std::string ToString() const;
// Returns string representation of the SDP message for the purpose of
// computing or verifying its signature, which is transmitted along with the
// SDP over signaling channel. This must be implemented in exactly the same
// way at each end of the connection.
std::string NormalizedForSignature() const;
// Adds specified parameters for the |codec|. Returns false if the |codec| is
// not listed anywhere in the SDP message.
bool AddCodecParameter(const std::string& codec,
const std::string& parameters_to_add);
// Prefers |codec| in current session description. Returns false if |codec| is
// not found.
bool PreferVideoCodec(const std::string& codec);
// Finds the lines of the form "a=rtpmap:<payload_type> <codec>/.." with the
// specified |codec| and returns a list of the matching payload types with
// their line numbers.
std::vector<std::pair<int, std::string>> FindCodec(
const std::string& codec) const;
std::vector<std::string> sdp_lines_;
bool has_audio_ = false;
bool has_video_ = false;
} // namespace protocol
} // namespace remoting