mp4_atom/moov/trak/mdia/minf/stbl/
stsz.rs

1use crate::*;
2
3#[derive(Debug, Clone, PartialEq, Eq)]
4#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
5pub enum StszSamples {
6    Identical { count: u32, size: u32 },
7    Different { sizes: Vec<u32> },
8}
9
10impl Default for StszSamples {
11    fn default() -> Self {
12        StszSamples::Different { sizes: vec![] }
13    }
14}
15
16/// Sample Size Box (stsz)
17///
18/// Lists the size of each sample in the track.
19#[derive(Debug, Clone, PartialEq, Eq, Default)]
20#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
21pub struct Stsz {
22    pub samples: StszSamples,
23}
24
25impl AtomExt for Stsz {
26    type Ext = ();
27
28    const KIND_EXT: FourCC = FourCC::new(b"stsz");
29
30    fn decode_body_ext<B: Buf>(buf: &mut B, _ext: ()) -> Result<Self> {
31        let size = u32::decode(buf)?;
32        let count = u32::decode(buf)?;
33
34        let samples = match size {
35            0 => {
36                let mut sizes = Vec::with_capacity(count.min(1024) as usize);
37                for _ in 0..count {
38                    sizes.push(u32::decode(buf)?)
39                }
40                StszSamples::Different { sizes }
41            }
42            size => StszSamples::Identical { count, size },
43        };
44
45        Ok(Stsz { samples })
46    }
47
48    fn encode_body_ext<B: BufMut>(&self, buf: &mut B) -> Result<()> {
49        match self.samples {
50            StszSamples::Identical { count, size } => {
51                size.encode(buf)?;
52                count.encode(buf)?;
53            }
54            StszSamples::Different { ref sizes } => {
55                0u32.encode(buf)?;
56                (sizes.len() as u32).encode(buf)?;
57
58                for size in sizes {
59                    size.encode(buf)?;
60                }
61            }
62        }
63
64        Ok(())
65    }
66}
67
68#[cfg(test)]
69mod tests {
70    use super::*;
71
72    #[test]
73    fn test_stsz_same_size() {
74        let expected = Stsz {
75            samples: StszSamples::Identical {
76                count: 4,
77                size: 1165,
78            },
79        };
80        let mut buf = Vec::new();
81        expected.encode(&mut buf).unwrap();
82
83        let mut buf = buf.as_ref();
84        let decoded = Stsz::decode(&mut buf).unwrap();
85        assert_eq!(decoded, expected);
86    }
87
88    #[test]
89    fn test_stsz_many_sizes() {
90        let expected = Stsz {
91            samples: StszSamples::Different {
92                sizes: vec![1165, 11, 11, 8545, 10126, 10866, 9643, 9351, 7730],
93            },
94        };
95        let mut buf = Vec::new();
96        expected.encode(&mut buf).unwrap();
97
98        let mut buf = buf.as_ref();
99        let decoded = Stsz::decode(&mut buf).unwrap();
100        assert_eq!(decoded, expected);
101    }
102}
mp4_atom/moov/trak/mdia/minf/stbl/stsz.rs

mp4_atom/moov/trak/mdia/minf/stbl/
stsz.rs
