scuffle_mp4/boxes/types/
smhd.rs

use std::io;

use byteorder::{BigEndian, ReadBytesExt, WriteBytesExt};
use bytes::Bytes;
use fixed::types::extra::U8;
use fixed::FixedI16;

use crate::boxes::header::{BoxHeader, FullBoxHeader};
use crate::boxes::traits::BoxType;

#[derive(Debug, Clone, PartialEq)]
/// Sound Media Header Box
/// ISO/IEC 14496-12:2022(E) - 12.2.2
pub struct Smhd {
    pub header: FullBoxHeader,
    pub balance: FixedI16<U8>,
    pub reserved: u16,
}

impl Default for Smhd {
    fn default() -> Self {
        Self::new()
    }
}

impl Smhd {
    pub fn new() -> Self {
        Self {
            header: FullBoxHeader::new(Self::NAME, 0, 0),
            balance: FixedI16::<U8>::from_num(0),
            reserved: 0,
        }
    }
}

impl BoxType for Smhd {
    const NAME: [u8; 4] = *b"smhd";

    fn demux(header: BoxHeader, data: Bytes) -> io::Result<Self> {
        let mut reader = io::Cursor::new(data);

        let header = FullBoxHeader::demux(header, &mut reader)?;

        let balance = reader.read_i16::<BigEndian>()?;
        let reserved = reader.read_u16::<BigEndian>()?;

        Ok(Self {
            header,
            balance: FixedI16::from_bits(balance),
            reserved,
        })
    }

    fn primitive_size(&self) -> u64 {
        let size = self.header.size();
        let size = size + 2; // balance
                             // reserved
        size + 2
    }

    fn primitive_mux<T: io::Write>(&self, writer: &mut T) -> io::Result<()> {
        self.header.mux(writer)?;

        writer.write_i16::<BigEndian>(self.balance.to_bits())?;
        writer.write_u16::<BigEndian>(self.reserved)?;

        Ok(())
    }

    fn validate(&self) -> io::Result<()> {
        if self.header.version != 0 {
            return Err(io::Error::new(io::ErrorKind::InvalidData, "smhd version must be 0"));
        }

        if self.header.flags != 0 {
            return Err(io::Error::new(io::ErrorKind::InvalidData, "smhd flags must be 0"));
        }

        if self.reserved != 0 {
            return Err(io::Error::new(io::ErrorKind::InvalidData, "smhd reserved must be 0"));
        }

        Ok(())
    }
}
scuffle_mp4/boxes/types/smhd.rs

scuffle_mp4/boxes/types/
smhd.rs
