revc 0.1.3

Rust Essential Video Coding (MPEG-5 EVC)
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
161
162
163
164

use crate::api::*;
use crate::tracer::*;

/* Bitstream structure for encoder */
#[derive(Default)]
pub(crate) struct EvceBsw {
    /* buffer */
    code: u32,
    /* bits left in buffer */
    leftbits: isize,
    /* buffer */
    pub(crate) pkt: Option<Packet>,
    /* trace */
    pub(crate) tracer: Option<Tracer>,
}

impl EvceBsw {
    /* is bitstream byte aligned? */
    #[inline]
    pub(crate) fn IS_BYTE_ALIGN(&self) -> bool {
        (self.leftbits & 0x7) == 0
    }

    /* get number of byte written */
    #[inline]
    pub(crate) fn GET_WRITE_BYTE(&self) -> usize {
        if let Some(pkt) = &self.pkt {
            pkt.data.len()
        } else {
            0
        }
    }

    /* number of bytes to be sunk */
    #[inline]
    pub(crate) fn GET_SINK_BYTE(&self) -> u32 {
        ((32 - self.leftbits + 7) >> 3) as u32
    }

    fn flush(&mut self) {
        let mut bytes = self.GET_SINK_BYTE();

        while bytes != 0 {
            if let Some(pkt) = &mut self.pkt {
                pkt.data.push(((self.code >> 24) & 0xFF) as u8);
            }
            self.code <<= 8;
            bytes -= 1;
        }

        self.leftbits = 32;
    }

    pub(crate) fn init(&mut self) {
        self.code = 0;
        self.leftbits = 32;
        self.pkt = Some(Packet {
            data: Vec::with_capacity(1024), // 1K?
            ts: 0,
        });
        self.tracer = None;
    }

    pub(crate) fn deinit(&mut self) {
        self.flush();
    }

    pub(crate) fn write_nalu_size(&mut self) {
        let size = self.GET_WRITE_BYTE() - 4;

        if let Some(pkt) = &mut self.pkt {
            pkt.data[0] = (size & 0x000000ff) as u8; //TBC(@Chernyak): is there a better way?
            pkt.data[1] = ((size & 0x0000ff00) >> 8) as u8;
            pkt.data[2] = ((size & 0x00ff0000) >> 16) as u8;
            pkt.data[3] = ((size & 0xff000000) >> 24) as u8;
        }
    }

    pub(crate) fn write1(&mut self, val: u32, name: Option<&str>) {
        if let Some(name) = name {
            EVC_TRACE(&mut self.tracer, name);
            EVC_TRACE(&mut self.tracer, " ");
            EVC_TRACE(&mut self.tracer, val);
            EVC_TRACE(&mut self.tracer, " \n");
        }

        self.leftbits -= 1;
        self.code |= ((val & 0x1) << self.leftbits);

        if self.leftbits == 0 {
            //evc_assert_rv(bs->cur <= bs->end, -1);
            self.flush();

            self.code = 0;
            self.leftbits = 32;
        }
    }

    pub(crate) fn write(&mut self, mut val: u32, len: isize, name: Option<&str>) {
        assert!(len > 0);

        if let Some(name) = name {
            EVC_TRACE(&mut self.tracer, name);
            EVC_TRACE(&mut self.tracer, " ");
            EVC_TRACE(&mut self.tracer, val);
            EVC_TRACE(&mut self.tracer, " \n");
        }

        let leftbits = self.leftbits;
        val <<= (32 - len);
        if leftbits == 0 {
            // val >> 32 overflow panic in rust, but val == val >> 32 == val << 32 in C/C++
            self.code |= val;
        } else {
            self.code |= (val >> (32 - leftbits));
        }

        if len < leftbits {
            self.leftbits -= len;
        } else {
            //evc_assert_rv(bs->cur + 4 <= bs->end, -1);

            self.leftbits = 0;
            self.flush();
            self.code = if leftbits < 32 { val << leftbits } else { 0 };
            self.leftbits = 32 - (len - leftbits);
        }
    }

    pub(crate) fn write_ue(&mut self, val: u32, name: Option<&str>) {
        if let Some(name) = name {
            EVC_TRACE(&mut self.tracer, name);
            EVC_TRACE(&mut self.tracer, " ");
            EVC_TRACE(&mut self.tracer, val);
            EVC_TRACE(&mut self.tracer, " \n");
        }

        let mut nn = ((val + 1) >> 1);
        let mut len_i = 0;
        while len_i < 16 && nn != 0 {
            nn >>= 1;
            len_i += 1;
        }

        let info = val + 1 - (1 << len_i);
        let code = (1 << len_i) | ((info) & ((1 << len_i) - 1));

        let len_c = (len_i << 1) + 1;

        self.write(code, len_c, None);
    }

    pub(crate) fn write_se(&mut self, val: i32, name: Option<&str>) {
        if let Some(name) = name {
            EVC_TRACE(&mut self.tracer, name);
            EVC_TRACE(&mut self.tracer, " ");
            EVC_TRACE(&mut self.tracer, val);
            EVC_TRACE(&mut self.tracer, " \n");
        }

        let v = if val <= 0 { -val * 2 } else { val * 2 - 1 };
        self.write_ue(v as u32, None);
    }
}