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28 #include "talk/media/base/rtputils.h"
32 static const int kRtpVersion = 2;
33 static const size_t kRtpFlagsOffset = 0;
34 static const size_t kRtpPayloadTypeOffset = 1;
35 static const size_t kRtpSeqNumOffset = 2;
36 static const size_t kRtpTimestampOffset = 4;
37 static const size_t kRtpSsrcOffset = 8;
38 static const size_t kRtcpPayloadTypeOffset = 1;
40 bool GetUint8(const void* data, size_t offset, int* value) {
41 if (!data || !value) {
44 *value = *(static_cast<const uint8*>(data) + offset);
48 bool GetUint16(const void* data, size_t offset, int* value) {
49 if (!data || !value) {
52 *value = static_cast<int>(
53 rtc::GetBE16(static_cast<const uint8*>(data) + offset));
57 bool GetUint32(const void* data, size_t offset, uint32* value) {
58 if (!data || !value) {
61 *value = rtc::GetBE32(static_cast<const uint8*>(data) + offset);
65 bool SetUint8(void* data, size_t offset, int value) {
69 rtc::Set8(data, offset, value);
73 bool SetUint16(void* data, size_t offset, int value) {
77 rtc::SetBE16(static_cast<uint8*>(data) + offset, value);
81 bool SetUint32(void* data, size_t offset, uint32 value) {
85 rtc::SetBE32(static_cast<uint8*>(data) + offset, value);
89 bool GetRtpFlags(const void* data, size_t len, int* value) {
90 if (len < kMinRtpPacketLen) {
93 return GetUint8(data, kRtpFlagsOffset, value);
96 bool GetRtpPayloadType(const void* data, size_t len, int* value) {
97 if (len < kMinRtpPacketLen) {
100 if (!GetUint8(data, kRtpPayloadTypeOffset, value)) {
107 bool GetRtpSeqNum(const void* data, size_t len, int* value) {
108 if (len < kMinRtpPacketLen) {
111 return GetUint16(data, kRtpSeqNumOffset, value);
114 bool GetRtpTimestamp(const void* data, size_t len, uint32* value) {
115 if (len < kMinRtpPacketLen) {
118 return GetUint32(data, kRtpTimestampOffset, value);
121 bool GetRtpSsrc(const void* data, size_t len, uint32* value) {
122 if (len < kMinRtpPacketLen) {
125 return GetUint32(data, kRtpSsrcOffset, value);
128 bool GetRtpHeaderLen(const void* data, size_t len, size_t* value) {
129 if (!data || len < kMinRtpPacketLen || !value) return false;
130 const uint8* header = static_cast<const uint8*>(data);
131 // Get base header size + length of CSRCs (not counting extension yet).
132 size_t header_size = kMinRtpPacketLen + (header[0] & 0xF) * sizeof(uint32);
133 if (len < header_size) return false;
134 // If there's an extension, read and add in the extension size.
135 if (header[0] & 0x10) {
136 if (len < header_size + sizeof(uint32)) return false;
137 header_size += ((rtc::GetBE16(header + header_size + 2) + 1) *
139 if (len < header_size) return false;
141 *value = header_size;
145 bool GetRtpVersion(const void* data, size_t len, int* version) {
150 const uint8 first = static_cast<const uint8*>(data)[0];
151 *version = static_cast<int>((first >> 6) & 0x3);
155 bool GetRtpHeader(const void* data, size_t len, RtpHeader* header) {
156 return (GetRtpPayloadType(data, len, &(header->payload_type)) &&
157 GetRtpSeqNum(data, len, &(header->seq_num)) &&
158 GetRtpTimestamp(data, len, &(header->timestamp)) &&
159 GetRtpSsrc(data, len, &(header->ssrc)));
162 bool GetRtcpType(const void* data, size_t len, int* value) {
163 if (len < kMinRtcpPacketLen) {
166 return GetUint8(data, kRtcpPayloadTypeOffset, value);
169 // This method returns SSRC first of RTCP packet, except if packet is SDES.
170 // TODO(mallinath) - Fully implement RFC 5506. This standard doesn't restrict
171 // to send non-compound packets only to feedback messages.
172 bool GetRtcpSsrc(const void* data, size_t len, uint32* value) {
173 // Packet should be at least of 8 bytes, to get SSRC from a RTCP packet.
174 if (!data || len < kMinRtcpPacketLen + 4 || !value) return false;
176 if (!GetRtcpType(data, len, &pl_type)) return false;
177 // SDES packet parsing is not supported.
178 if (pl_type == kRtcpTypeSDES) return false;
179 *value = rtc::GetBE32(static_cast<const uint8*>(data) + 4);
183 bool SetRtpHeaderFlags(
184 void* data, size_t len,
185 bool padding, bool extension, int csrc_count) {
186 if (csrc_count > 0x0F) {
190 flags |= (kRtpVersion << 6);
191 flags |= ((padding ? 1 : 0) << 5);
192 flags |= ((extension ? 1 : 0) << 4);
194 return SetUint8(data, kRtpFlagsOffset, flags);
197 // Assumes marker bit is 0.
198 bool SetRtpPayloadType(void* data, size_t len, int value) {
202 return SetUint8(data, kRtpPayloadTypeOffset, value & 0x7F);
205 bool SetRtpSeqNum(void* data, size_t len, int value) {
206 return SetUint16(data, kRtpSeqNumOffset, value);
209 bool SetRtpTimestamp(void* data, size_t len, uint32 value) {
210 return SetUint32(data, kRtpTimestampOffset, value);
213 bool SetRtpSsrc(void* data, size_t len, uint32 value) {
214 return SetUint32(data, kRtpSsrcOffset, value);
217 // Assumes version 2, no padding, no extensions, no csrcs.
218 bool SetRtpHeader(void* data, size_t len, const RtpHeader& header) {
219 return (SetRtpHeaderFlags(data, len, false, false, 0) &&
220 SetRtpPayloadType(data, len, header.payload_type) &&
221 SetRtpSeqNum(data, len, header.seq_num) &&
222 SetRtpTimestamp(data, len, header.timestamp) &&
223 SetRtpSsrc(data, len, header.ssrc));
226 bool IsRtpPacket(const void* data, size_t len) {
227 if (len < kMinRtpPacketLen)
231 if (!GetRtpVersion(data, len, &version))
234 return version == kRtpVersion;
237 } // namespace cricket