mp4_atom/moov/trak/mdia/minf/stbl/stsd/
av01.rs

1use crate::coding::{Decode, Encode};
2use crate::{Any, Atom, Buf, BufMut, DecodeMaybe, Error, FourCC, Result};
3
4use super::{Btrt, Colr, Pasp, Taic, Visual};
5
6#[derive(Debug, Clone, PartialEq, Eq, Default)]
7#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
8pub struct Av01 {
9    pub visual: Visual,
10    pub av1c: Av1c,
11    pub btrt: Option<Btrt>,
12    pub colr: Option<Colr>,
13    pub pasp: Option<Pasp>,
14    pub taic: Option<Taic>,
15}
16
17impl Atom for Av01 {
18    const KIND: FourCC = FourCC::new(b"av01");
19
20    fn decode_body<B: Buf>(buf: &mut B) -> Result<Self> {
21        let visual = Visual::decode(buf)?;
22
23        let mut av1c = None;
24        let mut btrt = None;
25        let mut colr = None;
26        let mut pasp = None;
27        let mut taic = None;
28        while let Some(atom) = Any::decode_maybe(buf)? {
29            match atom {
30                Any::Av1c(atom) => av1c = atom.into(),
31                Any::Btrt(atom) => btrt = atom.into(),
32                Any::Colr(atom) => colr = atom.into(),
33                Any::Pasp(atom) => pasp = atom.into(),
34                Any::Taic(atom) => taic = atom.into(),
35                _ => tracing::warn!("unknown atom: {:?}", atom),
36            }
37        }
38
39        Ok(Av01 {
40            visual,
41            av1c: av1c.ok_or(Error::MissingBox(Av1c::KIND))?,
42            btrt,
43            colr,
44            pasp,
45            taic,
46        })
47    }
48
49    fn encode_body<B: BufMut>(&self, buf: &mut B) -> Result<()> {
50        self.visual.encode(buf)?;
51        self.av1c.encode(buf)?;
52        if self.btrt.is_some() {
53            self.btrt.encode(buf)?;
54        }
55        if self.colr.is_some() {
56            self.colr.encode(buf)?;
57        }
58        if self.pasp.is_some() {
59            self.pasp.encode(buf)?;
60        }
61        if self.taic.is_some() {
62            self.taic.encode(buf)?;
63        }
64
65        Ok(())
66    }
67}
68
69// https://aomediacodec.github.io/av1-isobmff/#av1codecconfigurationbox-section
70#[derive(Debug, Clone, PartialEq, Eq, Default)]
71#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
72pub struct Av1c {
73    pub seq_profile: u8,
74    pub seq_level_idx_0: u8,
75    pub seq_tier_0: bool,
76    pub high_bitdepth: bool,
77    pub twelve_bit: bool,
78    pub monochrome: bool,
79    pub chroma_subsampling_x: bool,
80    pub chroma_subsampling_y: bool,
81    pub chroma_sample_position: u8, // 0..3
82    pub initial_presentation_delay: Option<u8>,
83    pub config_obus: Vec<u8>,
84}
85
86impl Atom for Av1c {
87    const KIND: FourCC = FourCC::new(b"av1C");
88
89    fn decode_body<B: Buf>(buf: &mut B) -> Result<Self> {
90        let version = u8::decode(buf)?;
91        if version != 0b1000_0001 {
92            return Err(Error::UnknownVersion(version));
93        }
94
95        let v = u8::decode(buf)?;
96        let seq_profile = v >> 5;
97        let seq_level_idx_0 = v & 0b11111;
98
99        let v = u8::decode(buf)?;
100        let seq_tier_0 = (v >> 7) == 1;
101        let high_bitdepth = ((v >> 6) & 0b1) == 1;
102        let twelve_bit = ((v >> 5) & 0b1) == 1;
103        let monochrome = ((v >> 4) & 0b1) == 1;
104        let chroma_subsampling_x = ((v >> 3) & 0b1) == 1;
105        let chroma_subsampling_y = ((v >> 2) & 0b1) == 1;
106        let chroma_sample_position = v & 0b11;
107
108        let v = u8::decode(buf)?;
109        let reserved = v >> 5;
110        if reserved != 0 {
111            return Err(Error::Reserved);
112        }
113
114        let initial_presentation_delay_present = (v >> 4) & 0b1;
115        let initial_presentation_delay_minus_one = v & 0b1111;
116
117        let initial_presentation_delay = if initial_presentation_delay_present == 1 {
118            Some(initial_presentation_delay_minus_one + 1)
119        } else {
120            if initial_presentation_delay_minus_one != 0 {
121                return Err(Error::Reserved);
122            }
123
124            None
125        };
126
127        let config_obus = Vec::decode(buf)?;
128
129        Ok(Self {
130            seq_profile,
131            seq_level_idx_0,
132            seq_tier_0,
133            high_bitdepth,
134            twelve_bit,
135            monochrome,
136            chroma_subsampling_x,
137            chroma_subsampling_y,
138            chroma_sample_position,
139            initial_presentation_delay,
140            config_obus,
141        })
142    }
143
144    fn encode_body<B: BufMut>(&self, buf: &mut B) -> Result<()> {
145        0b1000_0001_u8.encode(buf)?;
146        ((self.seq_profile << 5) | self.seq_level_idx_0).encode(buf)?;
147
148        (((self.seq_tier_0 as u8) << 7)
149            | ((self.high_bitdepth as u8) << 6)
150            | ((self.twelve_bit as u8) << 5)
151            | ((self.monochrome as u8) << 4)
152            | ((self.chroma_subsampling_x as u8) << 3)
153            | ((self.chroma_subsampling_y as u8) << 2)
154            | self.chroma_sample_position)
155            .encode(buf)?;
156
157        if let Some(initial_presentation_delay) = self.initial_presentation_delay {
158            ((initial_presentation_delay - 1) | 0b0001_0000).encode(buf)?;
159        } else {
160            0b0000_0000_u8.encode(buf)?;
161        }
162
163        self.config_obus.encode(buf)?;
164
165        Ok(())
166    }
167}