mp4_atom/
emsg.rs

1use crate::*;
2
3ext! {
4    name: Emsg,
5    versions: [0, 1],
6    flags: {}
7}
8
9#[derive(Debug, Clone, PartialEq, Eq)]
10#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
11pub enum EmsgTimestamp {
12    Relative(u32),
13    Absolute(u64),
14}
15
16#[derive(Debug, Clone, PartialEq, Eq)]
17#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
18pub struct Emsg {
19    pub timescale: u32,
20    pub presentation_time: EmsgTimestamp,
21    pub event_duration: u32,
22    pub id: u32,
23    pub scheme_id_uri: String,
24    pub value: String,
25    pub message_data: Vec<u8>,
26}
27
28impl AtomExt for Emsg {
29    const KIND_EXT: FourCC = FourCC::new(b"emsg");
30
31    type Ext = EmsgExt;
32
33    fn decode_body_ext<B: Buf>(buf: &mut B, ext: EmsgExt) -> Result<Self> {
34        Ok(match ext.version {
35            EmsgVersion::V0 => Emsg {
36                scheme_id_uri: String::decode(buf)?,
37                value: String::decode(buf)?,
38                timescale: u32::decode(buf)?,
39                presentation_time: EmsgTimestamp::Relative(u32::decode(buf)?),
40                event_duration: u32::decode(buf)?,
41                id: u32::decode(buf)?,
42                message_data: Vec::decode(buf)?,
43            },
44            EmsgVersion::V1 => Emsg {
45                timescale: u32::decode(buf)?,
46                presentation_time: EmsgTimestamp::Absolute(u64::decode(buf)?),
47                event_duration: u32::decode(buf)?,
48                id: u32::decode(buf)?,
49                scheme_id_uri: String::decode(buf)?,
50                value: String::decode(buf)?,
51                message_data: Vec::decode(buf)?,
52            },
53        })
54    }
55
56    fn encode_body_ext<B: BufMut>(&self, buf: &mut B) -> Result<EmsgExt> {
57        Ok(match self.presentation_time {
58            EmsgTimestamp::Absolute(presentation_time) => {
59                self.timescale.encode(buf)?;
60                presentation_time.encode(buf)?;
61                self.event_duration.encode(buf)?;
62                self.id.encode(buf)?;
63                self.scheme_id_uri.as_str().encode(buf)?;
64                self.value.as_str().encode(buf)?;
65                self.message_data.encode(buf)?;
66
67                EmsgVersion::V1.into()
68            }
69            EmsgTimestamp::Relative(presentation_time) => {
70                self.scheme_id_uri.as_str().encode(buf)?;
71                self.value.as_str().encode(buf)?;
72                self.timescale.encode(buf)?;
73                presentation_time.encode(buf)?;
74                self.event_duration.encode(buf)?;
75                self.id.encode(buf)?;
76                self.message_data.encode(buf)?;
77
78                EmsgVersion::V0.into()
79            }
80        })
81    }
82}
83
84#[cfg(test)]
85mod tests {
86    use super::*;
87
88    #[test]
89    fn test_emsg_version0() {
90        let decoded = Emsg {
91            timescale: 48000,
92            event_duration: 200,
93            presentation_time: EmsgTimestamp::Relative(100),
94            id: 8,
95            scheme_id_uri: String::from("foo"),
96            value: String::from("foo"),
97            message_data: [1, 2, 3].into(),
98        };
99
100        let mut buf = Vec::new();
101        decoded.encode(&mut buf).unwrap();
102
103        let output = Emsg::decode(&mut buf.as_slice()).unwrap();
104        assert_eq!(decoded, output);
105    }
106
107    #[test]
108    fn test_emsg_version1() {
109        let decoded = Emsg {
110            presentation_time: EmsgTimestamp::Absolute(50000),
111            timescale: 48000,
112            event_duration: 200,
113            id: 8,
114            scheme_id_uri: String::from("foo"),
115            value: String::from("foo"),
116            message_data: [3, 2, 1].into(),
117        };
118
119        let mut buf = Vec::new();
120        decoded.encode(&mut buf).unwrap();
121
122        let output = Emsg::decode(&mut buf.as_slice()).unwrap();
123        assert_eq!(decoded, output);
124    }
125}
mp4_atom/emsg.rs

mp4_atom/
emsg.rs
