+++ /dev/null
-use io::bitreader::BitReader;
-
-#[derive(Debug)]
-pub enum CodebookError {
- InvalidCodebook,
- MemoryError,
- InvalidCode,
-}
-
-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>;
-}
-
-impl<S: Copy> Codebook<S> {
-//todo allow add escapes
- pub fn new(cb: &mut CodebookDescReader<S>) -> CodebookResult<Self> {
- let mut maxbits = 0;
- let mut nnz = 0;
- for i in 0..cb.len() {
- let bits = cb.bits(i);
- if bits > 0 { nnz = nnz + 1; }
- if bits > maxbits {
- maxbits = bits;
- }
- }
- if maxbits == 0 { return Err(CodebookError::InvalidCodebook); }
-
- let mut table: Vec<u32> = Vec::new();
- let mut syms: Vec<S> = Vec::new();
- let tab_len = 1 << maxbits;
- table.reserve(tab_len);
- if table.capacity() < tab_len { return Err(CodebookError::MemoryError); }
- table.resize(tab_len, 0xFF);
- syms.reserve(nnz);
- if syms.capacity() < nnz { return Err(CodebookError::MemoryError); }
-
- let mut symidx: u32 = 0;
- for i in 0..cb.len() {
- let bits = cb.bits(i);
- if bits == 0 { continue; }
- let code = cb.code(i) << (maxbits - bits);
- let fill_len = 1 << (maxbits - bits);
- for j in 0..fill_len {
- let idx = (code + j) as usize;
- table[idx] = (symidx << 8) | (bits as u32);
- }
- symidx = symidx + 1;
- }
-
- 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 lut_idx = self.peek(cb.lut_bits) as usize;
- let bits = cb.table[lut_idx] & 0xFF;
- let idx = (cb.table[lut_idx] >> 8) as usize;
- if bits == 0xFF || (bits as isize) > self.left() {
- return Err(CodebookError::InvalidCode);
- }
- if let Err(_) = self.skip(bits) {}
- let sym = cb.syms[idx];
- return Ok(sym)
- }
-}
-
-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).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: 0b1110, bits: 4 }
- );
- let mut br2 = BitReader::new(buf, buf.len(), BitReaderMode::BE);
- let mut cfr = ShortCodebookDescReader::new(scb_desc);
- let cb = Codebook::new(&mut cfr).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(), 7);
- }
-}
projects / nihav.git / blobdiff