av-codec 0.1.0

Multimedia format decoding and encoding
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160

use std::collections::HashMap;

use crate::data::packet::Packet;
use crate::data::frame::ArcFrame;

use crate::error::*;
pub use crate::common::CodecList;

pub trait Decoder : Send {
    // TODO support codec configuration using set_option
    // fn open(&mut self) -> Result<()>;
    fn set_extradata(&mut self, extra: &[u8]);
    fn send_packet(&mut self, pkt: &Packet) -> Result<()>;
    fn receive_frame(&mut self) -> Result<ArcFrame>;
    fn configure(&mut self) -> Result<()>;
    fn flush(&mut self) -> Result<()>;
}

#[derive(Debug)]
pub struct Descr {
    pub codec: &'static str,
    pub name: &'static str,
    pub desc: &'static str,
    pub mime: &'static str,
    // TODO more fields regarding capabilities
}

pub struct Context {
    dec: Box<dyn Decoder>,
    // TODO: Queue up packets/frames
}

impl Context {
    // TODO: More constructors
    pub fn by_name(codecs: &Codecs, name: &str) -> Option<Context> {
        if let Some(builder) = codecs.by_name(name) {
            let dec = builder.create();
            Some(Context { dec: dec })
        } else {
            None
        }
    }
    pub fn set_extradata(&mut self, extra: &[u8]) {
        self.dec.set_extradata(extra);
    }
    pub fn send_packet(&mut self, pkt: &Packet) -> Result<()> {
        self.dec.send_packet(pkt)
    }
    pub fn receive_frame(&mut self) -> Result<ArcFrame> {
        self.dec.receive_frame()
    }
    pub fn configure(&mut self) -> Result<()> {
        self.dec.configure()
    }

    pub fn flush(&mut self) -> Result<()> {
        self.dec.flush()
    }
}

pub trait Descriptor {
    fn create(&self) -> Box<dyn Decoder>;
    fn describe<'a>(&'a self) -> &'a Descr;
}

pub struct Codecs {
    list: HashMap<&'static str, Vec<&'static dyn Descriptor>>
}

impl CodecList for Codecs {
    type D = dyn Descriptor;

    fn new() -> Codecs {
        Codecs { list: HashMap::new() }
    }

    // TODO more lookup functions
    fn by_name(&self, name: &str) -> Option<&'static Self::D> {
        if let Some(descs) = self.list.get(name) {
            Some(descs[0])
        } else {
            None
        }
    }

    fn append(&mut self, desc: &'static Self::D) {
        let codec_name = desc.describe().codec;

        self.list.entry(codec_name).or_insert(Vec::new()).push(desc);
    }
}

#[cfg(test)]
mod test {
    use super::*;

    mod dummy {
        use super::super::*;
        use std::sync::Arc;
        use crate::data::pixel::Formaton;

        struct Dec {
            state: usize,
            format: Option<Arc<Formaton>>
        }

        pub struct Des {
            descr: Descr,
        }

        impl Descriptor for Des {
            fn create(&self) -> Box<dyn Decoder> {
                Box::new(Dec { state: 0, format: None })
            }
            fn describe<'a>(&'a self) -> &'a Descr {
                &self.descr
            }
        }

        impl Decoder for Dec {
            fn configure(&mut self) -> Result<()> {
                Ok(())
            }
            fn set_extradata(&mut self, extra: &[u8]) {
                if extra.len() > 4 {
                    self.state = 42;
                } else {
                    self.state = 12;
                }
            }
            fn send_packet(&mut self, _packet: &Packet) -> Result<()> {
                self.state += 1;
                Ok(())
            }
            fn receive_frame(&mut self) -> Result<ArcFrame> {
                unimplemented!()
            }
            fn flush(&mut self) -> Result<()> {
                Ok(())
            }
        }

        pub const DUMMY_DESCR: &Des = &Des {
            descr: Descr {
                codec: "dummy",
                name: "dummy",
                desc: "Dummy encoder",
                mime: "x-application/dummy",
            }
        };
    }
    use self::dummy::DUMMY_DESCR;

    #[test]
    fn lookup() {
        let codecs = Codecs::from_list(&[DUMMY_DESCR]);

        let _dec = codecs.by_name("dummy").unwrap();
    }
}