flowly_mp4/mp4box/
mehd.rs

1use byteorder::{BigEndian, WriteBytesExt};
2use serde::Serialize;
3use std::io::Write;
4
5use crate::mp4box::*;
6
7#[derive(Debug, Clone, PartialEq, Eq, Serialize, Default)]
8pub struct MehdBox {
9    pub version: u8,
10    pub flags: u32,
11    pub fragment_duration: u64,
12}
13
14impl MehdBox {
15    pub fn get_type(&self) -> BoxType {
16        BoxType::MehdBox
17    }
18
19    pub fn get_size(&self) -> u64 {
20        let mut size = HEADER_SIZE + HEADER_EXT_SIZE;
21
22        if self.version == 1 {
23            size += 8;
24        } else if self.version == 0 {
25            size += 4;
26        }
27        size
28    }
29}
30
31impl Mp4Box for MehdBox {
32    const TYPE: BoxType = BoxType::MehdBox;
33
34    fn box_size(&self) -> u64 {
35        self.get_size()
36    }
37
38    fn to_json(&self) -> Result<String, Error> {
39        Ok(serde_json::to_string(&self).unwrap())
40    }
41
42    fn summary(&self) -> Result<String, Error> {
43        let s = format!("fragment_duration={}", self.fragment_duration);
44        Ok(s)
45    }
46}
47
48impl BlockReader for MehdBox {
49    fn read_block<'a>(reader: &mut impl Reader<'a>) -> Result<Self, Error> {
50        let (version, flags) = read_box_header_ext(reader);
51
52        let fragment_duration = if version == 1 {
53            reader.get_u64()
54        } else if version == 0 {
55            reader.get_u32() as u64
56        } else {
57            return Err(Error::InvalidData("version must be 0 or 1"));
58        };
59
60        Ok(MehdBox {
61            version,
62            flags,
63            fragment_duration,
64        })
65    }
66
67    fn size_hint() -> usize {
68        8
69    }
70}
71
72impl<W: Write> WriteBox<&mut W> for MehdBox {
73    fn write_box(&self, writer: &mut W) -> Result<u64, Error> {
74        let size = self.box_size();
75        BoxHeader::new(Self::TYPE, size).write(writer)?;
76
77        write_box_header_ext(writer, self.version, self.flags)?;
78
79        if self.version == 1 {
80            writer.write_u64::<BigEndian>(self.fragment_duration)?;
81        } else if self.version == 0 {
82            writer.write_u32::<BigEndian>(self.fragment_duration as u32)?;
83        } else {
84            return Err(Error::InvalidData("version must be 0 or 1"));
85        }
86
87        Ok(size)
88    }
89}
90
91#[cfg(test)]
92mod tests {
93    use super::*;
94    use crate::mp4box::BoxHeader;
95
96    #[tokio::test]
97    async fn test_mehd32() {
98        let src_box = MehdBox {
99            version: 0,
100            flags: 0,
101            fragment_duration: 32,
102        };
103        let mut buf = Vec::new();
104        src_box.write_box(&mut buf).unwrap();
105        assert_eq!(buf.len(), src_box.box_size() as usize);
106
107        let mut reader = buf.as_slice();
108        let header = BoxHeader::read(&mut reader, &mut 0).await.unwrap().unwrap();
109        assert_eq!(header.kind, BoxType::MehdBox);
110        assert_eq!(src_box.box_size(), header.size);
111
112        let dst_box = MehdBox::read_block(&mut reader).unwrap();
113        assert_eq!(src_box, dst_box);
114    }
115
116    #[tokio::test]
117    async fn test_mehd64() {
118        let src_box = MehdBox {
119            version: 0,
120            flags: 0,
121            fragment_duration: 30439936,
122        };
123        let mut buf = Vec::new();
124        src_box.write_box(&mut buf).unwrap();
125        assert_eq!(buf.len(), src_box.box_size() as usize);
126
127        let mut reader = buf.as_slice();
128        let header = BoxHeader::read(&mut reader, &mut 0).await.unwrap().unwrap();
129        assert_eq!(header.kind, BoxType::MehdBox);
130        assert_eq!(src_box.box_size(), header.size);
131
132        let dst_box = MehdBox::read_block(&mut reader).unwrap();
133        assert_eq!(src_box, dst_box);
134    }
135}