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/*
This file is part of jellything (https://codeberg.org/metamuffin/jellything)
which is licensed under the GNU Affero General Public License (version 3); see /COPYING.
Copyright (C) 2025 metamuffin <metamuffin.org>
*/
use crate::{
read::ReadExt,
write::{vint_length, write_vint},
ReadValue, Result, WriteValue,
};
use std::io::{Cursor, Write};
#[derive(Debug, PartialEq, Clone, Copy)]
pub enum LacingType {
None,
Xiph,
FixedSize,
Ebml,
}
#[derive(Debug, PartialEq, Clone)]
pub struct Block {
pub track: u64,
pub flags: Flags,
pub timestamp_off: i16,
pub data: Vec<u8>,
}
#[derive(Debug, PartialEq, Clone)]
pub struct Flags(u8);
impl Flags {
pub fn keyframe(&self) -> bool {
self.0 & 0b10000000 != 0
}
pub fn lacing(&self) -> LacingType {
match self.0 & 0b00000110 {
0b000 => LacingType::None,
0b010 => LacingType::Xiph,
0b100 => LacingType::FixedSize,
0b110 => LacingType::Ebml,
_ => unreachable!(),
}
}
pub fn discardable(&self) -> bool {
self.0 & 0b00000001 != 0
}
pub fn invisible(&self) -> bool {
self.0 & 0b00001000 != 0
}
}
impl ReadValue for Block {
fn from_buf(buf: &[u8]) -> Result<Self> {
let (track, c) = Cursor::new(buf).read_vint_len()?;
let timestamp_off = i16::from_be_bytes(buf[c..c + 2].try_into().unwrap());
let flags = Flags(buf[c + 2]);
let data = Vec::from(&buf[c + 3..]);
Ok(Self {
track,
data,
flags,
timestamp_off,
})
}
}
impl WriteValue for Block {
fn write_to(&self, w: &mut impl Write) -> Result<()> {
write_vint(w, self.inner_len() as u64)?;
write_vint(w, self.track)?;
w.write_all(&self.timestamp_off.to_be_bytes())?;
w.write_all(&[self.flags.0])?;
w.write_all(&self.data)?;
Ok(())
}
fn size(&self) -> usize {
let il = self.inner_len();
vint_length(il as u64) + il
}
}
impl Block {
fn inner_len(&self) -> usize {
vint_length(self.track)
+ 2 // timestamp
+ 1 // flags
+ self.data.len()
}
}
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