// Table B.1
#[derive(Clone, Copy, Debug, PartialEq)]
// Note: Established names.
#[allow(clippy::upper_case_acronyms)]
pub enum Marker {
/// Start Of Frame markers
///
/// - SOF(0): Baseline DCT (Huffman coding)
/// - SOF(1): Extended sequential DCT (Huffman coding)
/// - SOF(2): Progressive DCT (Huffman coding)
/// - SOF(3): Lossless (sequential) (Huffman coding)
/// - SOF(5): Differential sequential DCT (Huffman coding)
/// - SOF(6): Differential progressive DCT (Huffman coding)
/// - SOF(7): Differential lossless (sequential) (Huffman coding)
/// - SOF(9): Extended sequential DCT (arithmetic coding)
/// - SOF(10): Progressive DCT (arithmetic coding)
/// - SOF(11): Lossless (sequential) (arithmetic coding)
/// - SOF(13): Differential sequential DCT (arithmetic coding)
/// - SOF(14): Differential progressive DCT (arithmetic coding)
/// - SOF(15): Differential lossless (sequential) (arithmetic coding)
SOF(u8),
/// Reserved for JPEG extensions
JPG,
/// Define Huffman table(s)
DHT,
/// Define arithmetic coding conditioning(s)
DAC,
/// Restart with modulo 8 count `m`
RST(u8),
/// Start of image
SOI,
/// End of image
EOI,
/// Start of scan
SOS,
/// Define quantization table(s)
DQT,
/// Define number of lines
DNL,
/// Define restart interval
DRI,
/// Define hierarchical progression
DHP,
/// Expand reference component(s)
EXP,
/// Reserved for application segments
APP(u8),
/// Reserved for JPEG extensions
JPGn(u8),
/// Comment
COM,
/// For temporary private use in arithmetic coding
TEM,
/// Reserved
RES,
}
impl Marker {
pub fn has_length(self) -> bool {
use self::Marker::*;
! matches!(self, RST(..) | SOI | EOI | TEM)
}
pub fn from_u8(n: u8) -> Option<Marker> {
use self::Marker::*;
match n {
0x00 => None, // Byte stuffing
0x01 => Some(TEM),
0x02 ..= 0xBF => Some(RES),
0xC0 => Some(SOF(0)),
0xC1 => Some(SOF(1)),
0xC2 => Some(SOF(2)),
0xC3 => Some(SOF(3)),
0xC4 => Some(DHT),
0xC5 => Some(SOF(5)),
0xC6 => Some(SOF(6)),
0xC7 => Some(SOF(7)),
0xC8 => Some(JPG),
0xC9 => Some(SOF(9)),
0xCA => Some(SOF(10)),
0xCB => Some(SOF(11)),
0xCC => Some(DAC),
0xCD => Some(SOF(13)),
0xCE => Some(SOF(14)),
0xCF => Some(SOF(15)),
0xD0 => Some(RST(0)),
0xD1 => Some(RST(1)),
0xD2 => Some(RST(2)),
0xD3 => Some(RST(3)),
0xD4 => Some(RST(4)),
0xD5 => Some(RST(5)),
0xD6 => Some(RST(6)),
0xD7 => Some(RST(7)),
0xD8 => Some(SOI),
0xD9 => Some(EOI),
0xDA => Some(SOS),
0xDB => Some(DQT),
0xDC => Some(DNL),
0xDD => Some(DRI),
0xDE => Some(DHP),
0xDF => Some(EXP),
0xE0 => Some(APP(0)),
0xE1 => Some(APP(1)),
0xE2 => Some(APP(2)),
0xE3 => Some(APP(3)),
0xE4 => Some(APP(4)),
0xE5 => Some(APP(5)),
0xE6 => Some(APP(6)),
0xE7 => Some(APP(7)),
0xE8 => Some(APP(8)),
0xE9 => Some(APP(9)),
0xEA => Some(APP(10)),
0xEB => Some(APP(11)),
0xEC => Some(APP(12)),
0xED => Some(APP(13)),
0xEE => Some(APP(14)),
0xEF => Some(APP(15)),
0xF0 => Some(JPGn(0)),
0xF1 => Some(JPGn(1)),
0xF2 => Some(JPGn(2)),
0xF3 => Some(JPGn(3)),
0xF4 => Some(JPGn(4)),
0xF5 => Some(JPGn(5)),
0xF6 => Some(JPGn(6)),
0xF7 => Some(JPGn(7)),
0xF8 => Some(JPGn(8)),
0xF9 => Some(JPGn(9)),
0xFA => Some(JPGn(10)),
0xFB => Some(JPGn(11)),
0xFC => Some(JPGn(12)),
0xFD => Some(JPGn(13)),
0xFE => Some(COM),
0xFF => None, // Fill byte
}
}
}