[nihav.git] / src / io / codebook.rs

use std::collections::HashMap;
use std::cmp::{max, min};
use io::bitreader::BitReader;

#[derive(Debug)]
pub enum CodebookError {
    InvalidCodebook,
    MemoryError,
    InvalidCode,
}

#[derive(Debug, Copy, Clone)]
pub enum CodebookMode {
    MSB,
    LSB,
}

type CodebookResult<T> = Result<T, CodebookError>;

pub struct FullCodebookDesc<S> {
    code: u32,
    bits: u8,
    sym:  S,
}

pub struct ShortCodebookDesc {
    code: u32,
    bits: u8,
}

pub trait CodebookDescReader<S> {
    fn bits(&mut self, idx: usize) -> u8;
    fn code(&mut self, idx: usize) -> u32;
    fn sym (&mut self, idx: usize) -> S;
    fn len (&mut self)             -> usize;
}

#[allow(dead_code)]
pub struct Codebook<S> {
    table: Vec<u32>,
    syms:  Vec<S>,
    lut_bits: u8,
}

pub trait CodebookReader<S> {
    fn read_cb(&mut self, cb: &Codebook<S>) -> CodebookResult<S>;
}

pub fn reverse_bits(inval: u32) -> u32 {
    const REV_TAB: [u8; 16] = [
        0b0000, 0b1000, 0b0100, 0b1100, 0b0010, 0b1010, 0b0110, 0b1110,
        0b0001, 0b1001, 0b0101, 0b1101, 0b0011, 0b1011, 0b0111, 0b1111,
    ];

    let mut ret = 0;
    let mut val = inval;
    for _ in 0..8 {
        ret = (ret << 4) | (REV_TAB[(val & 0xF) as usize] as u32);
        val = val >> 4;
    }
    ret
}

const TABLE_FILL_VALUE: u32 = 0x7F;
const MAX_LUT_BITS: u8 = 10;

fn fill_lut_msb(table: &mut Vec<u32>, off: usize,
                code: u32, bits: u8, lut_bits: u8, symidx: u32, esc: bool) {
    if !esc {
        let fill_len  = lut_bits - bits;
        let fill_size = 1 << fill_len;
        let fill_code = code << (lut_bits - bits);
        let lut_value = (symidx << 8) | (bits as u32);
        for j in 0..fill_size {
            let idx = (fill_code + j) as usize;
            table[idx + off] = lut_value;
        }
    } else {
        let idx = (code as usize) + off;
        table[idx] = (symidx << 8) | 0x80 | (bits as u32);
    }
}

fn fill_lut_lsb(table: &mut Vec<u32>, off: usize,
                code: u32, bits: u8, lut_bits: u8, symidx: u32, esc: bool) {
    if !esc {
        let fill_len  = lut_bits - bits;
        let fill_size = 1 << fill_len;
        let fill_code = code;
        let step = lut_bits - fill_len;
        for j in 0..fill_size {
            let idx = (fill_code + (j << step)) as usize;
            table[idx + off] = (symidx << 8) | (bits as u32);
        }
    } else {
        let idx = (code as usize) + off;
        table[idx] = (symidx << 8) | 0x80 | (bits as u32);
    }
}

fn fill_lut(table: &mut Vec<u32>, mode: CodebookMode,
            off: usize, code: u32, bits: u8, lut_bits: u8, symidx: u32, esc: bool) -> bool {
    match mode {
        CodebookMode::MSB => fill_lut_msb(table, off, code, bits, lut_bits, symidx, esc),
        CodebookMode::LSB => fill_lut_lsb(table, off, code, bits, lut_bits, symidx, esc),
    };
    bits > lut_bits
}

fn resize_table(table: &mut Vec<u32>, bits: u8) -> CodebookResult<u32> {
    let add_size = (1 << bits) as usize;
    table.reserve(add_size);
    let cur_off = table.len() as u32;
    let new_size = table.len() + add_size;
    if table.capacity() < new_size { return Err(CodebookError::MemoryError); }
    table.resize(new_size, TABLE_FILL_VALUE);
    Ok(cur_off)
}


fn extract_lut_part(code: u32, bits: u8, lut_bits: u8, mode: CodebookMode) -> u32 {
    match mode {
        CodebookMode::MSB => code >> (bits - lut_bits),
        CodebookMode::LSB => code & ((1 << lut_bits) - 1),
    }
}

fn extract_esc_part(code: u32, bits: u8, lut_bits: u8, mode: CodebookMode) -> u32 {
    match mode {
        CodebookMode::MSB => code & ((1 << (bits - lut_bits)) - 1),
        CodebookMode::LSB => code >> lut_bits,
    }
}

#[derive(Clone,Copy)]
struct Code {
    code: u32,
    bits: u8,
    idx:  usize,
}

struct CodeBucket {
    maxlen: u8,
    offset: usize,
    codes:  Vec<Code>,
}

impl CodeBucket {
    fn new() -> Self {
        CodeBucket { maxlen: 0, offset: 0, codes: Vec::new() }
    }
    fn add_code(&mut self, c: Code) {
        if c.bits > self.maxlen { self.maxlen = c.bits; }
        self.codes.push(c);
    }
}

type EscapeCodes = HashMap<u32, CodeBucket>;

fn add_esc_code(cc: &mut EscapeCodes, key: u32, code: u32, bits: u8, idx: usize) {
    if !cc.contains_key(&key) { cc.insert(key, CodeBucket::new()); }
    let b = cc.get_mut(&key);
    if let Some(bucket) = b {
        bucket.add_code(Code {code: code, bits: bits, idx: idx });
    } else { panic!("no bucket when expected!"); }
}

fn build_esc_lut(table: &mut Vec<u32>,
                 mode: CodebookMode,
                 bucket: &CodeBucket) -> CodebookResult<()> {
    let mut escape_list: EscapeCodes = HashMap::new();
    let maxlen = if bucket.maxlen > MAX_LUT_BITS { MAX_LUT_BITS } else { bucket.maxlen };

    for code in &bucket.codes {
        let bits = code.bits;
        if code.bits < MAX_LUT_BITS {
            fill_lut(table, mode, bucket.offset, code.code, bits,
                     maxlen, code.idx as u32, false);
        } else {
            let ckey = extract_lut_part(code.code, bits, MAX_LUT_BITS, mode);
            let cval = extract_esc_part(code.code, bits, MAX_LUT_BITS, mode);
            add_esc_code(&mut escape_list, ckey, cval, bits - MAX_LUT_BITS, code.idx);
        }
    }

    let cur_offset = bucket.offset;
    for (ckey, sec_bucket) in &mut escape_list {
        let key = *ckey as u32;
        let maxlen = min(sec_bucket.maxlen, MAX_LUT_BITS);
        let new_off = resize_table(table, maxlen)?;
        fill_lut(table, mode, cur_offset, key, maxlen,
                 MAX_LUT_BITS, new_off, true);
        sec_bucket.offset = new_off as usize;
    }

    for (_, sec_bucket) in &escape_list {
        build_esc_lut(table, mode, sec_bucket)?;
    }
    
    Ok(())
}

impl<S: Copy> Codebook<S> {

    pub fn new(cb: &mut CodebookDescReader<S>, mode: CodebookMode) -> CodebookResult<Self> {
        let mut maxbits = 0;
        let mut nnz = 0;
        let mut escape_list: EscapeCodes = HashMap::new();

        let mut symidx: usize = 0;
        for i in 0..cb.len() {
            let bits = cb.bits(i);
            if bits > 0 { nnz = nnz + 1; }
            maxbits = max(bits, maxbits);
            if bits > MAX_LUT_BITS {
                let code = cb.code(i);
                let ckey = extract_lut_part(code, bits, MAX_LUT_BITS, mode);
                let cval = extract_esc_part(code, bits, MAX_LUT_BITS, mode);
                add_esc_code(&mut escape_list, ckey, cval, bits - MAX_LUT_BITS, symidx);
            }
            if bits > 0 { symidx = symidx + 1; }
        }
        if maxbits == 0 { return Err(CodebookError::InvalidCodebook); }

        if maxbits > MAX_LUT_BITS { maxbits = MAX_LUT_BITS; }

        let tab_len = 1 << maxbits;
        let mut table: Vec<u32> = Vec::with_capacity(tab_len);
        let mut syms:  Vec<S>   = Vec::with_capacity(nnz);
        if table.capacity() < tab_len { return Err(CodebookError::MemoryError); }
        if syms.capacity()  < nnz     { return Err(CodebookError::MemoryError); }
        table.resize(tab_len, TABLE_FILL_VALUE);

        let mut symidx: u32 = 0;
        for i in 0..cb.len() {
            let bits = cb.bits(i);
            let code = cb.code(i);
            if bits == 0 { continue; }
            if bits <= MAX_LUT_BITS {
                fill_lut(&mut table, mode, 0, code, bits, maxbits, symidx, false);
            } else {
                let ckey = extract_lut_part(code, bits, MAX_LUT_BITS, mode) as usize;
                if table[ckey] == TABLE_FILL_VALUE {
                    let key = ckey as u32;
                    if let Some(bucket) = escape_list.get_mut(&key) {
                        let maxlen = min(bucket.maxlen, MAX_LUT_BITS);
                        let new_off = resize_table(&mut table, maxlen)?;
                        fill_lut(&mut table, mode, 0, key, maxlen, MAX_LUT_BITS, new_off, true);
                        bucket.offset = new_off as usize;
                    }
                }
            }
            symidx = symidx + 1;
        }

        for (_, bucket) in &escape_list {
            build_esc_lut(&mut table, mode, &bucket)?;
        }

        for i in 0..cb.len() {
            if cb.bits(i) > 0 {
                syms.push(cb.sym(i));
            }
        }

        Ok(Codebook { table: table, syms: syms, lut_bits: maxbits })
    }
}

impl<'a, S: Copy> CodebookReader<S> for BitReader<'a> {
    #[allow(unused_variables)]
    fn read_cb(&mut self, cb: &Codebook<S>) -> CodebookResult<S> {
        let mut esc = true;
        let mut idx = 0;
        let mut lut_bits = cb.lut_bits;
        while esc {
            let lut_idx = (self.peek(lut_bits) as usize) + (idx as usize);
            if cb.table[lut_idx] == TABLE_FILL_VALUE { return Err(CodebookError::InvalidCode); }
            let bits = cb.table[lut_idx] & 0x7F;
            esc  = (cb.table[lut_idx] & 0x80) != 0;
            idx  = (cb.table[lut_idx] >> 8) as usize;
            if (bits as isize) > self.left() {
                return Err(CodebookError::InvalidCode);
            }
            let skip_bits = if esc { lut_bits as u32 } else { bits };
            if let Err(_) = self.skip(skip_bits as u32) {}
            lut_bits = bits as u8;
        }
        Ok(cb.syms[idx])
    }
}

pub struct FullCodebookDescReader<S> {
    data: Vec<FullCodebookDesc<S>>,
}

impl<S> FullCodebookDescReader<S> {
    pub fn new(data: Vec<FullCodebookDesc<S>>) -> Self {
        FullCodebookDescReader { data: data }
    }
}

impl<S: Copy> CodebookDescReader<S> for FullCodebookDescReader<S> {
    fn bits(&mut self, idx: usize) -> u8  { self.data[idx].bits }
    fn code(&mut self, idx: usize) -> u32 { self.data[idx].code }
    fn sym (&mut self, idx: usize) -> S   { self.data[idx].sym  }
    fn len(&mut self) -> usize { self.data.len() }
}

pub struct ShortCodebookDescReader {
    data: Vec<ShortCodebookDesc>,
}

impl ShortCodebookDescReader {
    pub fn new(data: Vec<ShortCodebookDesc<>>) -> Self {
        ShortCodebookDescReader { data: data }
    }
}

impl CodebookDescReader<u32> for ShortCodebookDescReader {
    fn bits(&mut self, idx: usize) -> u8  { self.data[idx].bits }
    fn code(&mut self, idx: usize) -> u32 { self.data[idx].code }
    fn sym (&mut self, idx: usize) -> u32 { idx as u32 }
    fn len(&mut self) -> usize { self.data.len() }
}

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

    #[test]
    fn test_cb() {
        const BITS: [u8; 2] = [0b01011011, 0b10111100];
        let cb_desc: Vec<FullCodebookDesc<i8>> = vec!(
            FullCodebookDesc { code: 0b0,    bits: 1, sym:  16 },
            FullCodebookDesc { code: 0b10,   bits: 2, sym:  -3 },
            FullCodebookDesc { code: 0b110,  bits: 3, sym:  42 },
            FullCodebookDesc { code: 0b1110, bits: 4, sym: -42 }
        );
        let buf = &BITS;
        let mut br = BitReader::new(buf, buf.len(), BitReaderMode::BE);
        let mut cfr = FullCodebookDescReader::new(cb_desc);
        let cb = Codebook::new(&mut cfr, CodebookMode::MSB).unwrap();
        assert_eq!(br.read_cb(&cb).unwrap(),  16);
        assert_eq!(br.read_cb(&cb).unwrap(),  -3);
        assert_eq!(br.read_cb(&cb).unwrap(),  42);
        assert_eq!(br.read_cb(&cb).unwrap(), -42);
        let ret = br.read_cb(&cb);
        if let Err(e) = ret {
            assert_eq!(e as i32, CodebookError::InvalidCode as i32);
        } else {
            assert_eq!(0, 1);
        }

        let scb_desc: Vec<ShortCodebookDesc> = vec!(
            ShortCodebookDesc { code: 0b0,    bits: 1 },
            ShortCodebookDesc { code: 0,      bits: 0 },
            ShortCodebookDesc { code: 0b10,   bits: 2 },
            ShortCodebookDesc { code: 0,      bits: 0 },
            ShortCodebookDesc { code: 0,      bits: 0 },
            ShortCodebookDesc { code: 0b110,  bits: 3 },
            ShortCodebookDesc { code: 0,      bits: 0 },
            ShortCodebookDesc { code: 0b11100, bits: 5 },
            ShortCodebookDesc { code: 0b11101, bits: 5 },
            ShortCodebookDesc { code: 0b1111010, bits: 7 },
            ShortCodebookDesc { code: 0b1111011, bits: 7 },
            ShortCodebookDesc { code: 0b1111110, bits: 7 },
            ShortCodebookDesc { code: 0b11111111, bits: 8 }
        );
        let mut br2 = BitReader::new(buf, buf.len(), BitReaderMode::BE);
        let mut cfr = ShortCodebookDescReader::new(scb_desc);
        let cb = Codebook::new(&mut cfr, CodebookMode::MSB).unwrap();
        assert_eq!(br2.read_cb(&cb).unwrap(), 0);
        assert_eq!(br2.read_cb(&cb).unwrap(), 2);
        assert_eq!(br2.read_cb(&cb).unwrap(), 5);
        assert_eq!(br2.read_cb(&cb).unwrap(), 8);

        assert_eq!(reverse_bits(0b0000_0101_1011_1011_1101_1111_0111_1111),
                                0b1111_1110_1111_1011_1101_1101_1010_0000);

        const BITS_LE: [u8; 3] = [0b11101111, 0b01110010, 0b01];
        let buf = &BITS_LE;
        let scble_desc: Vec<ShortCodebookDesc> = vec!(
            ShortCodebookDesc { code: 0b00,   bits: 2 },
            ShortCodebookDesc { code: 0,      bits: 0 },
            ShortCodebookDesc { code: 0b01,   bits: 2 },
            ShortCodebookDesc { code: 0,      bits: 0 },
            ShortCodebookDesc { code: 0,      bits: 0 },
            ShortCodebookDesc { code: 0b011,  bits: 3 },
            ShortCodebookDesc { code: 0,      bits: 0 },
            ShortCodebookDesc { code: 0b10111, bits: 5 },
            ShortCodebookDesc { code: 0b00111, bits: 5 },
            ShortCodebookDesc { code: 0b0101111, bits: 7 },
            ShortCodebookDesc { code: 0b0111111, bits: 7 },
            ShortCodebookDesc { code: 0b1011101111, bits: 10 }
        );
        let mut brl = BitReader::new(buf, buf.len(), BitReaderMode::LE);
        let mut cfr = ShortCodebookDescReader::new(scble_desc);
        let cb = Codebook::new(&mut cfr, CodebookMode::LSB).unwrap();
        assert_eq!(brl.read_cb(&cb).unwrap(), 11);
        assert_eq!(brl.read_cb(&cb).unwrap(), 0);
        assert_eq!(brl.read_cb(&cb).unwrap(), 7);
        assert_eq!(brl.read_cb(&cb).unwrap(), 0);
    }
}
Commit	Line	Data
0ca65ffd KS	1	use std::collections::HashMap;
0ca65ffd KS	2	use std::cmp::{max, min};
4667915a KS	3	use io::bitreader::BitReader;
	4
	5	#[derive(Debug)]
	6	pub enum CodebookError {
	7	InvalidCodebook,
	8	MemoryError,
	9	InvalidCode,
	10	}
	11
0ca65ffd KS	12	#[derive(Debug, Copy, Clone)]
	13	pub enum CodebookMode {
	14	MSB,
	15	LSB,
	16	}
	17
4667915a KS	18	type CodebookResult<T> = Result<T, CodebookError>;
	19
	20	pub struct FullCodebookDesc<S> {
	21	code: u32,
	22	bits: u8,
	23	sym: S,
	24	}
	25
	26	pub struct ShortCodebookDesc {
	27	code: u32,
	28	bits: u8,
	29	}
	30
	31	pub trait CodebookDescReader<S> {
	32	fn bits(&mut self, idx: usize) -> u8;
	33	fn code(&mut self, idx: usize) -> u32;
	34	fn sym (&mut self, idx: usize) -> S;
	35	fn len (&mut self) -> usize;
	36	}
	37
	38	#[allow(dead_code)]
	39	pub struct Codebook<S> {
	40	table: Vec<u32>,
	41	syms: Vec<S>,
	42	lut_bits: u8,
	43	}
	44
	45	pub trait CodebookReader<S> {
	46	fn read_cb(&mut self, cb: &Codebook<S>) -> CodebookResult<S>;
	47	}
	48
0ca65ffd KS	49	pub fn reverse_bits(inval: u32) -> u32 {
	50	const REV_TAB: [u8; 16] = [
	51	0b0000, 0b1000, 0b0100, 0b1100, 0b0010, 0b1010, 0b0110, 0b1110,
	52	0b0001, 0b1001, 0b0101, 0b1101, 0b0011, 0b1011, 0b0111, 0b1111,
	53	];
	54
	55	let mut ret = 0;
	56	let mut val = inval;
	57	for _ in 0..8 {
	58	ret = (ret << 4) \| (REV_TAB[(val & 0xF) as usize] as u32);
	59	val = val >> 4;
	60	}
	61	ret
	62	}
	63
	64	const TABLE_FILL_VALUE: u32 = 0x7F;
	65	const MAX_LUT_BITS: u8 = 10;
	66
	67	fn fill_lut_msb(table: &mut Vec<u32>, off: usize,
	68	code: u32, bits: u8, lut_bits: u8, symidx: u32, esc: bool) {
	69	if !esc {
	70	let fill_len = lut_bits - bits;
	71	let fill_size = 1 << fill_len;
	72	let fill_code = code << (lut_bits - bits);
	73	let lut_value = (symidx << 8) \| (bits as u32);
	74	for j in 0..fill_size {
	75	let idx = (fill_code + j) as usize;
	76	table[idx + off] = lut_value;
	77	}
	78	} else {
	79	let idx = (code as usize) + off;
	80	table[idx] = (symidx << 8) \| 0x80 \| (bits as u32);
	81	}
	82	}
	83
	84	fn fill_lut_lsb(table: &mut Vec<u32>, off: usize,
	85	code: u32, bits: u8, lut_bits: u8, symidx: u32, esc: bool) {
	86	if !esc {
	87	let fill_len = lut_bits - bits;
	88	let fill_size = 1 << fill_len;
	89	let fill_code = code;
	90	let step = lut_bits - fill_len;
	91	for j in 0..fill_size {
	92	let idx = (fill_code + (j << step)) as usize;
	93	table[idx + off] = (symidx << 8) \| (bits as u32);
	94	}
	95	} else {
	96	let idx = (code as usize) + off;
	97	table[idx] = (symidx << 8) \| 0x80 \| (bits as u32);
	98	}
	99	}
	100
	101	fn fill_lut(table: &mut Vec<u32>, mode: CodebookMode,
	102	off: usize, code: u32, bits: u8, lut_bits: u8, symidx: u32, esc: bool) -> bool {
	103	match mode {
	104	CodebookMode::MSB => fill_lut_msb(table, off, code, bits, lut_bits, symidx, esc),
	105	CodebookMode::LSB => fill_lut_lsb(table, off, code, bits, lut_bits, symidx, esc),
	106	};
	107	bits > lut_bits
	108	}
	109
	110	fn resize_table(table: &mut Vec<u32>, bits: u8) -> CodebookResult<u32> {
	111	let add_size = (1 << bits) as usize;
	112	table.reserve(add_size);
113	let cur_off = table.len() as u32;
114	let new_size = table.len() + add_size;
115	if table.capacity() < new_size { return Err(CodebookError::MemoryError); }
116	table.resize(new_size, TABLE_FILL_VALUE);
117	Ok(cur_off)
118	}
119
120
121	fn extract_lut_part(code: u32, bits: u8, lut_bits: u8, mode: CodebookMode) -> u32 {
122	match mode {
123	CodebookMode::MSB => code >> (bits - lut_bits),
124	CodebookMode::LSB => code & ((1 << lut_bits) - 1),
125	}
126	}
127
128	fn extract_esc_part(code: u32, bits: u8, lut_bits: u8, mode: CodebookMode) -> u32 {
129	match mode {
130	CodebookMode::MSB => code & ((1 << (bits - lut_bits)) - 1),
131	CodebookMode::LSB => code >> lut_bits,
132	}
133	}
134
135	#[derive(Clone,Copy)]
136	struct Code {
137	code: u32,
138	bits: u8,
139	idx: usize,
140	}
141
142	struct CodeBucket {
143	maxlen: u8,
144	offset: usize,
145	codes: Vec<Code>,
146	}
147
148	impl CodeBucket {
149	fn new() -> Self {
150	CodeBucket { maxlen: 0, offset: 0, codes: Vec::new() }
151	}
152	fn add_code(&mut self, c: Code) {
153	if c.bits > self.maxlen { self.maxlen = c.bits; }
154	self.codes.push(c);
155	}
156	}
157
158	type EscapeCodes = HashMap<u32, CodeBucket>;
159
160	fn add_esc_code(cc: &mut EscapeCodes, key: u32, code: u32, bits: u8, idx: usize) {
161	if !cc.contains_key(&key) { cc.insert(key, CodeBucket::new()); }
162	let b = cc.get_mut(&key);
163	if let Some(bucket) = b {
164	bucket.add_code(Code {code: code, bits: bits, idx: idx });
165	} else { panic!("no bucket when expected!"); }
166	}
167
168	fn build_esc_lut(table: &mut Vec<u32>,
169	mode: CodebookMode,
170	bucket: &CodeBucket) -> CodebookResult<()> {
171	let mut escape_list: EscapeCodes = HashMap::new();
172	let maxlen = if bucket.maxlen > MAX_LUT_BITS { MAX_LUT_BITS } else { bucket.maxlen };
173
174	for code in &bucket.codes {
175	let bits = code.bits;
176	if code.bits < MAX_LUT_BITS {
177	fill_lut(table, mode, bucket.offset, code.code, bits,
178	maxlen, code.idx as u32, false);
179	} else {
180	let ckey = extract_lut_part(code.code, bits, MAX_LUT_BITS, mode);
181	let cval = extract_esc_part(code.code, bits, MAX_LUT_BITS, mode);
182	add_esc_code(&mut escape_list, ckey, cval, bits - MAX_LUT_BITS, code.idx);
183	}
184	}
185
186	let cur_offset = bucket.offset;
187	for (ckey, sec_bucket) in &mut escape_list {
188	let key = *ckey as u32;
189	let maxlen = min(sec_bucket.maxlen, MAX_LUT_BITS);
190	let new_off = resize_table(table, maxlen)?;
191	fill_lut(table, mode, cur_offset, key, maxlen,
192	MAX_LUT_BITS, new_off, true);
193	sec_bucket.offset = new_off as usize;
194	}
195
196	for (_, sec_bucket) in &escape_list {
197	build_esc_lut(table, mode, sec_bucket)?;
198	}
199
200	Ok(())
201	}
202
4667915a	203	impl<S: Copy> Codebook<S> {
0ca65ffd KS	204
0ca65ffd KS	205	pub fn new(cb: &mut CodebookDescReader<S>, mode: CodebookMode) -> CodebookResult<Self> {
4667915a KS	206	let mut maxbits = 0;
4667915a KS	207	let mut nnz = 0;
0ca65ffd KS	208	let mut escape_list: EscapeCodes = HashMap::new();
	209
	210	let mut symidx: usize = 0;
4667915a KS	211	for i in 0..cb.len() {
	212	let bits = cb.bits(i);
	213	if bits > 0 { nnz = nnz + 1; }
0ca65ffd KS	214	maxbits = max(bits, maxbits);
	215	if bits > MAX_LUT_BITS {
	216	let code = cb.code(i);
	217	let ckey = extract_lut_part(code, bits, MAX_LUT_BITS, mode);
	218	let cval = extract_esc_part(code, bits, MAX_LUT_BITS, mode);
	219	add_esc_code(&mut escape_list, ckey, cval, bits - MAX_LUT_BITS, symidx);
4667915a	220	}
0ca65ffd	221	if bits > 0 { symidx = symidx + 1; }
4667915a KS	222	}
	223	if maxbits == 0 { return Err(CodebookError::InvalidCodebook); }
	224
0ca65ffd KS	225	if maxbits > MAX_LUT_BITS { maxbits = MAX_LUT_BITS; }
0ca65ffd KS	226
4667915a	227	let tab_len = 1 << maxbits;
0ca65ffd KS	228	let mut table: Vec<u32> = Vec::with_capacity(tab_len);
0ca65ffd KS	229	let mut syms: Vec<S> = Vec::with_capacity(nnz);
4667915a	230	if table.capacity() < tab_len { return Err(CodebookError::MemoryError); }
0ca65ffd KS	231	if syms.capacity() < nnz { return Err(CodebookError::MemoryError); }
0ca65ffd KS	232	table.resize(tab_len, TABLE_FILL_VALUE);
4667915a KS	233
	234	let mut symidx: u32 = 0;
	235	for i in 0..cb.len() {
	236	let bits = cb.bits(i);
0ca65ffd	237	let code = cb.code(i);
4667915a	238	if bits == 0 { continue; }
0ca65ffd KS	239	if bits <= MAX_LUT_BITS {
	240	fill_lut(&mut table, mode, 0, code, bits, maxbits, symidx, false);
	241	} else {
	242	let ckey = extract_lut_part(code, bits, MAX_LUT_BITS, mode) as usize;
	243	if table[ckey] == TABLE_FILL_VALUE {
	244	let key = ckey as u32;
	245	if let Some(bucket) = escape_list.get_mut(&key) {
	246	let maxlen = min(bucket.maxlen, MAX_LUT_BITS);
	247	let new_off = resize_table(&mut table, maxlen)?;
	248	fill_lut(&mut table, mode, 0, key, maxlen, MAX_LUT_BITS, new_off, true);
	249	bucket.offset = new_off as usize;
	250	}
	251	}
4667915a KS	252	}
	253	symidx = symidx + 1;
	254	}
	255
0ca65ffd KS	256	for (_, bucket) in &escape_list {
	257	build_esc_lut(&mut table, mode, &bucket)?;
	258	}
	259
4667915a KS	260	for i in 0..cb.len() {
	261	if cb.bits(i) > 0 {
	262	syms.push(cb.sym(i));
	263	}
	264	}
	265
	266	Ok(Codebook { table: table, syms: syms, lut_bits: maxbits })
	267	}
	268	}
	269
	270	impl<'a, S: Copy> CodebookReader<S> for BitReader<'a> {
	271	#[allow(unused_variables)]
	272	fn read_cb(&mut self, cb: &Codebook<S>) -> CodebookResult<S> {
0ca65ffd KS	273	let mut esc = true;
	274	let mut idx = 0;
	275	let mut lut_bits = cb.lut_bits;
	276	while esc {
	277	let lut_idx = (self.peek(lut_bits) as usize) + (idx as usize);
	278	if cb.table[lut_idx] == TABLE_FILL_VALUE { return Err(CodebookError::InvalidCode); }
	279	let bits = cb.table[lut_idx] & 0x7F;
	280	esc = (cb.table[lut_idx] & 0x80) != 0;
	281	idx = (cb.table[lut_idx] >> 8) as usize;
	282	if (bits as isize) > self.left() {
	283	return Err(CodebookError::InvalidCode);
	284	}
	285	let skip_bits = if esc { lut_bits as u32 } else { bits };
	286	if let Err(_) = self.skip(skip_bits as u32) {}
	287	lut_bits = bits as u8;
4667915a	288	}
0ca65ffd	289	Ok(cb.syms[idx])
4667915a KS	290	}
	291	}
	292
	293	pub struct FullCodebookDescReader<S> {
	294	data: Vec<FullCodebookDesc<S>>,
	295	}
	296
	297	impl<S> FullCodebookDescReader<S> {
	298	pub fn new(data: Vec<FullCodebookDesc<S>>) -> Self {
	299	FullCodebookDescReader { data: data }
	300	}
	301	}
	302
	303	impl<S: Copy> CodebookDescReader<S> for FullCodebookDescReader<S> {
	304	fn bits(&mut self, idx: usize) -> u8 { self.data[idx].bits }
	305	fn code(&mut self, idx: usize) -> u32 { self.data[idx].code }
	306	fn sym (&mut self, idx: usize) -> S { self.data[idx].sym }
	307	fn len(&mut self) -> usize { self.data.len() }
	308	}
	309
	310	pub struct ShortCodebookDescReader {
	311	data: Vec<ShortCodebookDesc>,
	312	}
	313
	314	impl ShortCodebookDescReader {
	315	pub fn new(data: Vec<ShortCodebookDesc<>>) -> Self {
	316	ShortCodebookDescReader { data: data }
	317	}
	318	}
	319
	320	impl CodebookDescReader<u32> for ShortCodebookDescReader {
	321	fn bits(&mut self, idx: usize) -> u8 { self.data[idx].bits }
	322	fn code(&mut self, idx: usize) -> u32 { self.data[idx].code }
	323	fn sym (&mut self, idx: usize) -> u32 { idx as u32 }
	324	fn len(&mut self) -> usize { self.data.len() }
	325	}
	326
	327	#[cfg(test)]
	328	mod test {
	329	use super::*;
	330	use io::bitreader::*;
	331
	332	#[test]
	333	fn test_cb() {
	334	const BITS: [u8; 2] = [0b01011011, 0b10111100];
	335	let cb_desc: Vec<FullCodebookDesc<i8>> = vec!(
	336	FullCodebookDesc { code: 0b0, bits: 1, sym: 16 },
	337	FullCodebookDesc { code: 0b10, bits: 2, sym: -3 },
	338	FullCodebookDesc { code: 0b110, bits: 3, sym: 42 },
	339	FullCodebookDesc { code: 0b1110, bits: 4, sym: -42 }
	340	);
	341	let buf = &BITS;
	342	let mut br = BitReader::new(buf, buf.len(), BitReaderMode::BE);
	343	let mut cfr = FullCodebookDescReader::new(cb_desc);
0ca65ffd	344	let cb = Codebook::new(&mut cfr, CodebookMode::MSB).unwrap();
4667915a KS	345	assert_eq!(br.read_cb(&cb).unwrap(), 16);
	346	assert_eq!(br.read_cb(&cb).unwrap(), -3);
	347	assert_eq!(br.read_cb(&cb).unwrap(), 42);
	348	assert_eq!(br.read_cb(&cb).unwrap(), -42);
	349	let ret = br.read_cb(&cb);
	350	if let Err(e) = ret {
	351	assert_eq!(e as i32, CodebookError::InvalidCode as i32);
	352	} else {
	353	assert_eq!(0, 1);
	354	}
	355
	356	let scb_desc: Vec<ShortCodebookDesc> = vec!(
	357	ShortCodebookDesc { code: 0b0, bits: 1 },
	358	ShortCodebookDesc { code: 0, bits: 0 },
	359	ShortCodebookDesc { code: 0b10, bits: 2 },
	360	ShortCodebookDesc { code: 0, bits: 0 },
	361	ShortCodebookDesc { code: 0, bits: 0 },
	362	ShortCodebookDesc { code: 0b110, bits: 3 },
	363	ShortCodebookDesc { code: 0, bits: 0 },
0ca65ffd KS	364	ShortCodebookDesc { code: 0b11100, bits: 5 },
	365	ShortCodebookDesc { code: 0b11101, bits: 5 },
	366	ShortCodebookDesc { code: 0b1111010, bits: 7 },
	367	ShortCodebookDesc { code: 0b1111011, bits: 7 },
	368	ShortCodebookDesc { code: 0b1111110, bits: 7 },
	369	ShortCodebookDesc { code: 0b11111111, bits: 8 }
4667915a KS	370	);
	371	let mut br2 = BitReader::new(buf, buf.len(), BitReaderMode::BE);
	372	let mut cfr = ShortCodebookDescReader::new(scb_desc);
0ca65ffd	373	let cb = Codebook::new(&mut cfr, CodebookMode::MSB).unwrap();
4667915a KS	374	assert_eq!(br2.read_cb(&cb).unwrap(), 0);
	375	assert_eq!(br2.read_cb(&cb).unwrap(), 2);
	376	assert_eq!(br2.read_cb(&cb).unwrap(), 5);
0ca65ffd KS	377	assert_eq!(br2.read_cb(&cb).unwrap(), 8);
	378
	379	assert_eq!(reverse_bits(0b0000_0101_1011_1011_1101_1111_0111_1111),
	380	0b1111_1110_1111_1011_1101_1101_1010_0000);
	381
	382	const BITS_LE: [u8; 3] = [0b11101111, 0b01110010, 0b01];
	383	let buf = &BITS_LE;
	384	let scble_desc: Vec<ShortCodebookDesc> = vec!(
	385	ShortCodebookDesc { code: 0b00, bits: 2 },
	386	ShortCodebookDesc { code: 0, bits: 0 },
	387	ShortCodebookDesc { code: 0b01, bits: 2 },
	388	ShortCodebookDesc { code: 0, bits: 0 },
	389	ShortCodebookDesc { code: 0, bits: 0 },
	390	ShortCodebookDesc { code: 0b011, bits: 3 },
	391	ShortCodebookDesc { code: 0, bits: 0 },
	392	ShortCodebookDesc { code: 0b10111, bits: 5 },
	393	ShortCodebookDesc { code: 0b00111, bits: 5 },
	394	ShortCodebookDesc { code: 0b0101111, bits: 7 },
	395	ShortCodebookDesc { code: 0b0111111, bits: 7 },
	396	ShortCodebookDesc { code: 0b1011101111, bits: 10 }
	397	);
	398	let mut brl = BitReader::new(buf, buf.len(), BitReaderMode::LE);
	399	let mut cfr = ShortCodebookDescReader::new(scble_desc);
	400	let cb = Codebook::new(&mut cfr, CodebookMode::LSB).unwrap();
	401	assert_eq!(brl.read_cb(&cb).unwrap(), 11);
	402	assert_eq!(brl.read_cb(&cb).unwrap(), 0);
	403	assert_eq!(brl.read_cb(&cb).unwrap(), 7);
	404	assert_eq!(brl.read_cb(&cb).unwrap(), 0);
4667915a KS	405	}
4667915a KS	406	}