28e2075280
trunk/talk git-svn-id: http://webrtc.googlecode.com/svn/trunk@4318 4adac7df-926f-26a2-2b94-8c16560cd09d
227 lines
7.1 KiB
C++
227 lines
7.1 KiB
C++
/*
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* libjingle
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* Copyright 2011 Google Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
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* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
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* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "talk/media/base/rtputils.h"
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namespace cricket {
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static const int kRtpVersion = 2;
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static const size_t kRtpFlagsOffset = 0;
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static const size_t kRtpPayloadTypeOffset = 1;
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static const size_t kRtpSeqNumOffset = 2;
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static const size_t kRtpTimestampOffset = 4;
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static const size_t kRtpSsrcOffset = 8;
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static const size_t kRtcpPayloadTypeOffset = 1;
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bool GetUint8(const void* data, size_t offset, int* value) {
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if (!data || !value) {
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return false;
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}
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*value = *(static_cast<const uint8*>(data) + offset);
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return true;
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}
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bool GetUint16(const void* data, size_t offset, int* value) {
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if (!data || !value) {
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return false;
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}
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*value = static_cast<int>(
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talk_base::GetBE16(static_cast<const uint8*>(data) + offset));
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return true;
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}
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bool GetUint32(const void* data, size_t offset, uint32* value) {
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if (!data || !value) {
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return false;
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}
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*value = talk_base::GetBE32(static_cast<const uint8*>(data) + offset);
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return true;
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}
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bool SetUint8(void* data, size_t offset, int value) {
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if (!data) {
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return false;
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}
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talk_base::Set8(data, offset, value);
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return true;
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}
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bool SetUint16(void* data, size_t offset, int value) {
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if (!data) {
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return false;
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}
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talk_base::SetBE16(static_cast<uint8*>(data) + offset, value);
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return true;
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}
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bool SetUint32(void* data, size_t offset, uint32 value) {
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if (!data) {
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return false;
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}
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talk_base::SetBE32(static_cast<uint8*>(data) + offset, value);
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return true;
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}
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bool GetRtpFlags(const void* data, size_t len, int* value) {
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if (len < kMinRtpPacketLen) {
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return false;
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}
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return GetUint8(data, kRtpFlagsOffset, value);
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}
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bool GetRtpPayloadType(const void* data, size_t len, int* value) {
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if (len < kMinRtpPacketLen) {
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return false;
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}
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if (!GetUint8(data, kRtpPayloadTypeOffset, value)) {
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return false;
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}
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*value &= 0x7F;
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return true;
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}
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bool GetRtpSeqNum(const void* data, size_t len, int* value) {
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if (len < kMinRtpPacketLen) {
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return false;
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}
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return GetUint16(data, kRtpSeqNumOffset, value);
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}
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bool GetRtpTimestamp(const void* data, size_t len, uint32* value) {
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if (len < kMinRtpPacketLen) {
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return false;
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}
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return GetUint32(data, kRtpTimestampOffset, value);
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}
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bool GetRtpSsrc(const void* data, size_t len, uint32* value) {
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if (len < kMinRtpPacketLen) {
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return false;
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}
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return GetUint32(data, kRtpSsrcOffset, value);
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}
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bool GetRtpHeaderLen(const void* data, size_t len, size_t* value) {
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if (!data || len < kMinRtpPacketLen || !value) return false;
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const uint8* header = static_cast<const uint8*>(data);
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// Get base header size + length of CSRCs (not counting extension yet).
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size_t header_size = kMinRtpPacketLen + (header[0] & 0xF) * sizeof(uint32);
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if (len < header_size) return false;
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// If there's an extension, read and add in the extension size.
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if (header[0] & 0x10) {
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if (len < header_size + sizeof(uint32)) return false;
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header_size += ((talk_base::GetBE16(header + header_size + 2) + 1) *
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sizeof(uint32));
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if (len < header_size) return false;
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}
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*value = header_size;
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return true;
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}
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bool GetRtpVersion(const void* data, size_t len, int* version) {
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if (len == 0) {
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return false;
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}
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const uint8 first = static_cast<const uint8*>(data)[0];
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*version = static_cast<int>((first >> 6) & 0x3);
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return true;
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}
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bool GetRtpHeader(const void* data, size_t len, RtpHeader* header) {
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return (GetRtpPayloadType(data, len, &(header->payload_type)) &&
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GetRtpSeqNum(data, len, &(header->seq_num)) &&
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GetRtpTimestamp(data, len, &(header->timestamp)) &&
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GetRtpSsrc(data, len, &(header->ssrc)));
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}
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bool GetRtcpType(const void* data, size_t len, int* value) {
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if (len < kMinRtcpPacketLen) {
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return false;
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}
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return GetUint8(data, kRtcpPayloadTypeOffset, value);
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}
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// This method returns SSRC first of RTCP packet, except if packet is SDES.
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// TODO(mallinath) - Fully implement RFC 5506. This standard doesn't restrict
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// to send non-compound packets only to feedback messages.
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bool GetRtcpSsrc(const void* data, size_t len, uint32* value) {
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// Packet should be at least of 8 bytes, to get SSRC from a RTCP packet.
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if (!data || len < kMinRtcpPacketLen + 4 || !value) return false;
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int pl_type;
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if (!GetRtcpType(data, len, &pl_type)) return false;
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// SDES packet parsing is not supported.
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if (pl_type == kRtcpTypeSDES) return false;
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*value = talk_base::GetBE32(static_cast<const uint8*>(data) + 4);
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return true;
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}
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bool SetRtpHeaderFlags(
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void* data, size_t len,
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bool padding, bool extension, int csrc_count) {
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if (csrc_count > 0x0F) {
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return false;
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}
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int flags = 0;
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flags |= (kRtpVersion << 6);
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flags |= ((padding ? 1 : 0) << 5);
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flags |= ((extension ? 1 : 0) << 4);
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flags |= csrc_count;
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return SetUint8(data, kRtpFlagsOffset, flags);
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}
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// Assumes marker bit is 0.
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bool SetRtpPayloadType(void* data, size_t len, int value) {
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if (value >= 0x7F) {
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return false;
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}
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return SetUint8(data, kRtpPayloadTypeOffset, value & 0x7F);
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}
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bool SetRtpSeqNum(void* data, size_t len, int value) {
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return SetUint16(data, kRtpSeqNumOffset, value);
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}
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bool SetRtpTimestamp(void* data, size_t len, uint32 value) {
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return SetUint32(data, kRtpTimestampOffset, value);
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}
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bool SetRtpSsrc(void* data, size_t len, uint32 value) {
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return SetUint32(data, kRtpSsrcOffset, value);
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}
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// Assumes version 2, no padding, no extensions, no csrcs.
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bool SetRtpHeader(void* data, size_t len, const RtpHeader& header) {
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return (SetRtpHeaderFlags(data, len, false, false, 0) &&
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SetRtpPayloadType(data, len, header.payload_type) &&
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SetRtpSeqNum(data, len, header.seq_num) &&
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SetRtpTimestamp(data, len, header.timestamp) &&
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SetRtpSsrc(data, len, header.ssrc));
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}
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} // namespace cricket
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