| /* |
| * 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. |
| */ |
| |
| #include "talk/media/base/rtputils.h" |
| |
| namespace cricket { |
| |
| static const int kRtpVersion = 2; |
| static const size_t kRtpFlagsOffset = 0; |
| static const size_t kRtpPayloadTypeOffset = 1; |
| static const size_t kRtpSeqNumOffset = 2; |
| static const size_t kRtpTimestampOffset = 4; |
| static const size_t kRtpSsrcOffset = 8; |
| static const size_t kRtcpPayloadTypeOffset = 1; |
| |
| bool GetUint8(const void* data, size_t offset, int* value) { |
| if (!data || !value) { |
| return false; |
| } |
| *value = *(static_cast<const uint8*>(data) + offset); |
| return true; |
| } |
| |
| bool GetUint16(const void* data, size_t offset, int* value) { |
| if (!data || !value) { |
| return false; |
| } |
| *value = static_cast<int>( |
| talk_base::GetBE16(static_cast<const uint8*>(data) + offset)); |
| return true; |
| } |
| |
| bool GetUint32(const void* data, size_t offset, uint32* value) { |
| if (!data || !value) { |
| return false; |
| } |
| *value = talk_base::GetBE32(static_cast<const uint8*>(data) + offset); |
| return true; |
| } |
| |
| bool SetUint8(void* data, size_t offset, int value) { |
| if (!data) { |
| return false; |
| } |
| talk_base::Set8(data, offset, value); |
| return true; |
| } |
| |
| bool SetUint16(void* data, size_t offset, int value) { |
| if (!data) { |
| return false; |
| } |
| talk_base::SetBE16(static_cast<uint8*>(data) + offset, value); |
| return true; |
| } |
| |
| bool SetUint32(void* data, size_t offset, uint32 value) { |
| if (!data) { |
| return false; |
| } |
| talk_base::SetBE32(static_cast<uint8*>(data) + offset, value); |
| return true; |
| } |
| |
| bool GetRtpFlags(const void* data, size_t len, int* value) { |
| if (len < kMinRtpPacketLen) { |
| return false; |
| } |
| return GetUint8(data, kRtpFlagsOffset, value); |
| } |
| |
| bool GetRtpPayloadType(const void* data, size_t len, int* value) { |
| if (len < kMinRtpPacketLen) { |
| return false; |
| } |
| if (!GetUint8(data, kRtpPayloadTypeOffset, value)) { |
| return false; |
| } |
| *value &= 0x7F; |
| return true; |
| } |
| |
| bool GetRtpSeqNum(const void* data, size_t len, int* value) { |
| if (len < kMinRtpPacketLen) { |
| return false; |
| } |
| return GetUint16(data, kRtpSeqNumOffset, value); |
| } |
| |
| bool GetRtpTimestamp(const void* data, size_t len, uint32* value) { |
| if (len < kMinRtpPacketLen) { |
| return false; |
| } |
| return GetUint32(data, kRtpTimestampOffset, value); |
| } |
| |
| bool GetRtpSsrc(const void* data, size_t len, uint32* value) { |
| if (len < kMinRtpPacketLen) { |
| return false; |
| } |
| return GetUint32(data, kRtpSsrcOffset, value); |
| } |
| |
| bool GetRtpHeaderLen(const void* data, size_t len, size_t* value) { |
| if (!data || len < kMinRtpPacketLen || !value) return false; |
| const uint8* header = static_cast<const uint8*>(data); |
| // Get base header size + length of CSRCs (not counting extension yet). |
| size_t header_size = kMinRtpPacketLen + (header[0] & 0xF) * sizeof(uint32); |
| if (len < header_size) return false; |
| // If there's an extension, read and add in the extension size. |
| if (header[0] & 0x10) { |
| if (len < header_size + sizeof(uint32)) return false; |
| header_size += ((talk_base::GetBE16(header + header_size + 2) + 1) * |
| sizeof(uint32)); |
| if (len < header_size) return false; |
| } |
| *value = header_size; |
| return true; |
| } |
| |
| bool GetRtpVersion(const void* data, size_t len, int* version) { |
| if (len == 0) { |
| return false; |
| } |
| |
| const uint8 first = static_cast<const uint8*>(data)[0]; |
| *version = static_cast<int>((first >> 6) & 0x3); |
| return true; |
| } |
| |
| bool GetRtpHeader(const void* data, size_t len, RtpHeader* header) { |
| return (GetRtpPayloadType(data, len, &(header->payload_type)) && |
| GetRtpSeqNum(data, len, &(header->seq_num)) && |
| GetRtpTimestamp(data, len, &(header->timestamp)) && |
| GetRtpSsrc(data, len, &(header->ssrc))); |
| } |
| |
| bool GetRtcpType(const void* data, size_t len, int* value) { |
| if (len < kMinRtcpPacketLen) { |
| return false; |
| } |
| return GetUint8(data, kRtcpPayloadTypeOffset, value); |
| } |
| |
| // This method returns SSRC first of RTCP packet, except if packet is SDES. |
| // TODO(mallinath) - Fully implement RFC 5506. This standard doesn't restrict |
| // to send non-compound packets only to feedback messages. |
| bool GetRtcpSsrc(const void* data, size_t len, uint32* value) { |
| // Packet should be at least of 8 bytes, to get SSRC from a RTCP packet. |
| if (!data || len < kMinRtcpPacketLen + 4 || !value) return false; |
| int pl_type; |
| if (!GetRtcpType(data, len, &pl_type)) return false; |
| // SDES packet parsing is not supported. |
| if (pl_type == kRtcpTypeSDES) return false; |
| *value = talk_base::GetBE32(static_cast<const uint8*>(data) + 4); |
| return true; |
| } |
| |
| bool SetRtpHeaderFlags( |
| void* data, size_t len, |
| bool padding, bool extension, int csrc_count) { |
| if (csrc_count > 0x0F) { |
| return false; |
| } |
| int flags = 0; |
| flags |= (kRtpVersion << 6); |
| flags |= ((padding ? 1 : 0) << 5); |
| flags |= ((extension ? 1 : 0) << 4); |
| flags |= csrc_count; |
| return SetUint8(data, kRtpFlagsOffset, flags); |
| } |
| |
| // Assumes marker bit is 0. |
| bool SetRtpPayloadType(void* data, size_t len, int value) { |
| if (value >= 0x7F) { |
| return false; |
| } |
| return SetUint8(data, kRtpPayloadTypeOffset, value & 0x7F); |
| } |
| |
| bool SetRtpSeqNum(void* data, size_t len, int value) { |
| return SetUint16(data, kRtpSeqNumOffset, value); |
| } |
| |
| bool SetRtpTimestamp(void* data, size_t len, uint32 value) { |
| return SetUint32(data, kRtpTimestampOffset, value); |
| } |
| |
| bool SetRtpSsrc(void* data, size_t len, uint32 value) { |
| return SetUint32(data, kRtpSsrcOffset, value); |
| } |
| |
| // Assumes version 2, no padding, no extensions, no csrcs. |
| bool SetRtpHeader(void* data, size_t len, const RtpHeader& header) { |
| return (SetRtpHeaderFlags(data, len, false, false, 0) && |
| SetRtpPayloadType(data, len, header.payload_type) && |
| SetRtpSeqNum(data, len, header.seq_num) && |
| SetRtpTimestamp(data, len, header.timestamp) && |
| SetRtpSsrc(data, len, header.ssrc)); |
| } |
| |
| } // namespace cricket |