scuffle_mp4/boxes/types/
padb.rs

1use std::io;
2
3use byteorder::{BigEndian, ReadBytesExt, WriteBytesExt};
4use bytes::Bytes;
5
6use crate::boxes::header::{BoxHeader, FullBoxHeader};
7use crate::boxes::traits::BoxType;
8
9#[derive(Debug, Clone, PartialEq)]
10/// Padding bits box.
11/// ISO/IEC 14496-12:2022(E) - 8.7.6
12pub struct Padb {
13    pub header: FullBoxHeader,
14    pub samples: Vec<u8>,
15}
16
17impl BoxType for Padb {
18    const NAME: [u8; 4] = *b"padb";
19
20    fn demux(header: BoxHeader, data: Bytes) -> io::Result<Self> {
21        let mut reader = io::Cursor::new(data);
22
23        let header = FullBoxHeader::demux(header, &mut reader)?;
24
25        let sample_count = (reader.read_u32::<BigEndian>()?).div_ceil(2);
26        let mut samples = Vec::with_capacity(sample_count as usize);
27
28        for _ in 0..sample_count {
29            let byte = reader.read_u8()?;
30            samples.push(byte);
31        }
32
33        Ok(Self { header, samples })
34    }
35
36    fn primitive_size(&self) -> u64 {
37        let mut size = self.header.size();
38        size += 4; // sample_count
39        size + (self.samples.len() as u64) // samples
40    }
41
42    fn primitive_mux<T: io::Write>(&self, writer: &mut T) -> io::Result<()> {
43        self.header.mux(writer)?;
44
45        writer.write_u32::<BigEndian>((self.samples.len() as u32) * 2 - 1)?;
46
47        for byte in &self.samples {
48            writer.write_u8(*byte)?;
49        }
50
51        Ok(())
52    }
53
54    fn validate(&self) -> io::Result<()> {
55        if self.header.version != 0 {
56            return Err(io::Error::new(io::ErrorKind::InvalidData, "padb box version must be 0"));
57        }
58
59        if self.header.flags != 0 {
60            return Err(io::Error::new(io::ErrorKind::InvalidData, "padb box flags must be 0"));
61        }
62
63        Ok(())
64    }
65}
scuffle_mp4/boxes/types/padb.rs

scuffle_mp4/boxes/types/
padb.rs
