webrtc/media/base/rtputils.h

/*
 * libjingle
 * Copyright 2011 Google Inc.
 *
 * 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. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

#ifndef WEBRTC_MEDIA_BASE_RTPUTILS_H_
#define WEBRTC_MEDIA_BASE_RTPUTILS_H_

#include "webrtc/base/byteorder.h"

namespace rtc {
struct PacketTimeUpdateParams;
}  // namespace rtc

namespace cricket {

const size_t kMinRtpPacketLen = 12;
const size_t kMaxRtpPacketLen = 2048;
const size_t kMinRtcpPacketLen = 4;

struct RtpHeader {
  int payload_type;
  int seq_num;
  uint32_t timestamp;
  uint32_t ssrc;
};

enum RtcpTypes {
  kRtcpTypeSR = 200,      // Sender report payload type.
  kRtcpTypeRR = 201,      // Receiver report payload type.
  kRtcpTypeSDES = 202,    // SDES payload type.
  kRtcpTypeBye = 203,     // BYE payload type.
  kRtcpTypeApp = 204,     // APP payload type.
  kRtcpTypeRTPFB = 205,   // Transport layer Feedback message payload type.
  kRtcpTypePSFB = 206,    // Payload-specific Feedback message payload type.
};

bool GetRtpPayloadType(const void* data, size_t len, int* value);
bool GetRtpSeqNum(const void* data, size_t len, int* value);
bool GetRtpTimestamp(const void* data, size_t len, uint32_t* value);
bool GetRtpSsrc(const void* data, size_t len, uint32_t* value);
bool GetRtpHeaderLen(const void* data, size_t len, size_t* value);
bool GetRtcpType(const void* data, size_t len, int* value);
bool GetRtcpSsrc(const void* data, size_t len, uint32_t* value);
bool GetRtpHeader(const void* data, size_t len, RtpHeader* header);

bool SetRtpSsrc(void* data, size_t len, uint32_t value);
// Assumes version 2, no padding, no extensions, no csrcs.
bool SetRtpHeader(void* data, size_t len, const RtpHeader& header);

bool IsRtpPacket(const void* data, size_t len);

// True if |payload type| is 0-127.
bool IsValidRtpPayloadType(int payload_type);

// Verifies that a packet has a valid RTP header.
bool ValidateRtpHeader(const uint8_t* rtp,
                       size_t length,
                       size_t* header_length);

// Helper method which updates the absolute send time extension if present.
bool UpdateRtpAbsSendTimeExtension(uint8_t* rtp,
                                   size_t length,
                                   int extension_id,
                                   uint64_t time_us);

// Applies specified |options| to the packet. It updates the absolute send time
// extension header if it is present present then updates HMAC.
bool ApplyPacketOptions(uint8_t* data,
                        size_t length,
                        const rtc::PacketTimeUpdateParams& packet_time_params,
                        uint64_t time_us);


}  // namespace cricket

#endif  // WEBRTC_MEDIA_BASE_RTPUTILS_H_