msf-rtp 0.4.1

Real-time Transport Protocol (RTP) for Rust.
Documentation 
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
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141

//! Opus audio (de)packetizer.

use std::convert::Infallible;

use bytes::Bytes;

use crate::{depacketizer::Depacketizer, packetizer::Packetizer, rtp::RtpPacket};

/// Opus audio frame.
#[derive(Clone)]
pub struct AudioFrame {
    data: Bytes,
    timestamp: u32,
}

impl AudioFrame {
    /// Create a new audio frame with a given RTP timestamp.
    #[inline]
    pub const fn new(timestamp: u32, data: Bytes) -> Self {
        Self { data, timestamp }
    }

    /// Get the frame RTP timestamp.
    #[inline]
    pub fn timestamp(&self) -> u32 {
        self.timestamp
    }

    /// Get the frame data containing encoded audio samples.
    #[inline]
    pub fn data(&self) -> &Bytes {
        &self.data
    }

    /// Take the frame data.
    #[inline]
    pub fn into_data(self) -> Bytes {
        self.data
    }
}

/// Opus depacketizer.
pub struct OpusDepacketizer {
    payload_type: u8,
    frame: Option<AudioFrame>,
}

impl OpusDepacketizer {
    /// Create a new Opus depacketizer.
    #[inline]
    pub const fn new(payload_type: u8) -> Self {
        Self {
            payload_type,
            frame: None,
        }
    }
}

impl Depacketizer for OpusDepacketizer {
    type Frame = AudioFrame;
    type Error = Infallible;

    fn push(&mut self, packet: RtpPacket) -> Result<(), Self::Error> {
        if packet.payload_type() != self.payload_type {
            return Ok(());
        }

        assert!(self.frame.is_none());

        let timestamp = packet.timestamp();
        let data = packet.stripped_payload();

        self.frame = Some(AudioFrame::new(timestamp, data));

        Ok(())
    }

    #[inline]
    fn flush(&mut self) -> Result<(), Self::Error> {
        Ok(())
    }

    #[inline]
    fn take(&mut self) -> Result<Option<Self::Frame>, Self::Error> {
        Ok(self.frame.take())
    }
}

/// Opus packetizer.
pub struct OpusPacketizer {
    payload_type: u8,
    ssrc: u32,
    sequence_number: u16,
    packet: Option<RtpPacket>,
}

impl OpusPacketizer {
    /// Create a new Opus packetizer.
    #[inline]
    pub const fn new(payload_type: u8, ssrc: u32) -> Self {
        Self {
            payload_type,
            ssrc,
            sequence_number: 0,
            packet: None,
        }
    }
}

impl Packetizer for OpusPacketizer {
    type Frame = AudioFrame;
    type Error = Infallible;

    fn push(&mut self, frame: Self::Frame) -> Result<(), Self::Error> {
        assert!(self.packet.is_none());

        let packet = RtpPacket::new()
            .with_payload_type(self.payload_type)
            .with_ssrc(self.ssrc)
            .with_sequence_number(self.sequence_number)
            .with_timestamp(frame.timestamp())
            .with_marker(true)
            .with_payload(frame.into_data(), 0);

        self.sequence_number = self.sequence_number.wrapping_add(1);

        self.packet = Some(packet);

        Ok(())
    }

    #[inline]
    fn flush(&mut self) -> Result<(), Self::Error> {
        Ok(())
    }

    #[inline]
    fn take(&mut self) -> Result<Option<RtpPacket>, Self::Error> {
        Ok(self.packet.take())
    }
}