1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
|
/*
* Copyright (c) 2021 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "modules/rtp_rtcp/source/rtp_util.h"
#include <cstddef>
#include <cstdint>
#include "api/array_view.h"
#include "modules/rtp_rtcp/source/byte_io.h"
#include "rtc_base/checks.h"
namespace webrtc {
namespace {
constexpr uint8_t kRtpVersion = 2;
constexpr size_t kMinRtpPacketLen = 12;
constexpr size_t kMinRtcpPacketLen = 4;
bool HasCorrectRtpVersion(ArrayView<const uint8_t> packet) {
return packet[0] >> 6 == kRtpVersion;
}
// For additional details, see http://tools.ietf.org/html/rfc5761#section-4
bool PayloadTypeIsReservedForRtcp(uint8_t payload_type) {
return 64 <= payload_type && payload_type < 96;
}
} // namespace
bool IsRtpPacket(ArrayView<const uint8_t> packet) {
return packet.size() >= kMinRtpPacketLen && HasCorrectRtpVersion(packet) &&
!PayloadTypeIsReservedForRtcp(packet[1] & 0x7F);
}
bool IsRtcpPacket(ArrayView<const uint8_t> packet) {
return packet.size() >= kMinRtcpPacketLen && HasCorrectRtpVersion(packet) &&
PayloadTypeIsReservedForRtcp(packet[1] & 0x7F);
}
int ParseRtpPayloadType(ArrayView<const uint8_t> rtp_packet) {
RTC_DCHECK(IsRtpPacket(rtp_packet));
return rtp_packet[1] & 0x7F;
}
uint16_t ParseRtpSequenceNumber(ArrayView<const uint8_t> rtp_packet) {
RTC_DCHECK(IsRtpPacket(rtp_packet));
return ByteReader<uint16_t>::ReadBigEndian(rtp_packet.data() + 2);
}
uint32_t ParseRtpSsrc(ArrayView<const uint8_t> rtp_packet) {
RTC_DCHECK(IsRtpPacket(rtp_packet));
return ByteReader<uint32_t>::ReadBigEndian(rtp_packet.data() + 8);
}
} // namespace webrtc
|
