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a4bd7707 KS |
1 | //! Codebook support for bitstream reader. |
2 | //! | |
3 | //! Codebook is a set of unique bit strings and values assigned to them. | |
4 | //! Since there are many ways to define codebook, this implementation employs [`CodebookDescReader`] trait to provide codebook generator with the codes. | |
5 | //! Please also pay attention to the codebook creation mode: if bitstream reader reads bits starting from most significant bit first then you should use [`MSB`] mode and [`LSB`] mode otherwise. | |
6 | //! | |
7 | //! # Examples | |
8 | //! | |
9 | //! Create a codebook from arrays with codeword descriptions: | |
10 | //! ``` | |
11 | //! use nihav_core::io::codebook::{ShortCodebookDesc, ShortCodebookDescReader, Codebook, CodebookMode}; | |
12 | //! | |
13 | //! let cb_desc: Vec<ShortCodebookDesc> = vec!( | |
14 | //! ShortCodebookDesc { code: 0b00, bits: 2 }, | |
15 | //! ShortCodebookDesc { code: 0, bits: 0 }, | |
16 | //! ShortCodebookDesc { code: 0b01, bits: 2 }, | |
17 | //! ShortCodebookDesc { code: 0b1, bits: 1 }); | |
18 | //! let mut cr = ShortCodebookDescReader::new(cb_desc); | |
19 | //! let cb = Codebook::new(&mut cr, CodebookMode::LSB).unwrap(); | |
20 | //! ``` | |
21 | //! | |
22 | //! Create a codebook using more flexible [`TableCodebookDescReader`] approach. | |
23 | //! This will create a codebook for the following set: `1` -> -2, `01` -> -1, `001` -> 0, `0001` -> 1, `00001` -> 2. | |
24 | //! ``` | |
25 | //! use nihav_core::io::codebook::{TableCodebookDescReader, Codebook, CodebookMode}; | |
26 | //! | |
27 | //! fn map_cb_index(index: usize) -> i16 { (index as i16) - 2 } | |
28 | //! const CB_BITS: [u8; 5] = [ 1, 2, 3, 4, 5 ]; | |
29 | //! const CB_CODES: [u8; 5] = [ 1, 1, 1, 1, 1 ]; | |
30 | //! | |
31 | //! let mut tcr = TableCodebookDescReader::new(&CB_CODES, &CB_BITS, map_cb_index); | |
32 | //! let cb = Codebook::new(&mut tcr, CodebookMode::MSB).unwrap(); | |
33 | //! ``` | |
34 | //! | |
35 | //! Read value using a codebook: | |
36 | //! ```no_run | |
37 | //! use nihav_core::io::bitreader::BitReader; | |
38 | //! use nihav_core::io::codebook::{Codebook, CodebookReader, CodebookMode}; | |
39 | //! # use nihav_core::io::codebook::{ShortCodebookDesc, ShortCodebookDescReader, CodebookDescReader, CodebookResult}; | |
40 | //! | |
41 | //! # fn foo(br: &mut BitReader) -> CodebookResult<()> { | |
42 | //! # let mut cr = ShortCodebookDescReader::new(vec![ShortCodebookDesc { code: 0b00, bits: 2 }]); | |
43 | //! let cb = Codebook::new(&mut cr, CodebookMode::MSB).unwrap(); | |
44 | //! let value = br.read_cb(&cb)?; | |
45 | //! # Ok(()) | |
46 | //! # } | |
47 | //! ``` | |
48 | //! | |
49 | //! [`MSB`]: ./enum.CodebookMode.html#variant.MSB | |
50 | //! [`LSB`]: ./enum.CodebookMode.html#variant.LSB | |
51 | //! [`CodebookDescReader`]: ./trait.CodebookDescReader.html | |
52 | //! [`TableCodebookDescReader`]: ./struct.TableCodebookDescReader.html | |
53 | ||
0ca65ffd KS |
54 | use std::collections::HashMap; |
55 | use std::cmp::{max, min}; | |
aca89041 | 56 | use super::bitreader::BitReader; |
4667915a | 57 | |
a4bd7707 | 58 | /// A list specifying general codebook operations errors. |
4667915a KS |
59 | #[derive(Debug)] |
60 | pub enum CodebookError { | |
a4bd7707 | 61 | /// Codebook description contains errors. |
4667915a | 62 | InvalidCodebook, |
a4bd7707 | 63 | /// Could not allocate memory for codebook. |
4667915a | 64 | MemoryError, |
a4bd7707 | 65 | /// Bitstream contains a sequence not present in codebook. |
4667915a KS |
66 | InvalidCode, |
67 | } | |
68 | ||
a4bd7707 | 69 | /// Codebook operation modes. |
0ca65ffd KS |
70 | #[derive(Debug, Copy, Clone)] |
71 | pub enum CodebookMode { | |
a4bd7707 | 72 | /// Codes in the codebook should be read most significant bit first. |
0ca65ffd | 73 | MSB, |
a4bd7707 | 74 | /// Codes in the codebook should be read least significant bit first. |
0ca65ffd KS |
75 | LSB, |
76 | } | |
77 | ||
a4bd7707 KS |
78 | /// A specialised `Result` type for codebook operations. |
79 | pub type CodebookResult<T> = Result<T, CodebookError>; | |
4667915a | 80 | |
a4bd7707 KS |
81 | /// Codebook description for `(code bits, code length, code value)` triplet. |
82 | /// | |
83 | /// This should be used to create a list of codeword definitions for [`FullCodebookDescReader`]. | |
84 | /// | |
85 | /// [`FullCodebookDescReader`]: ./struct.FullCodebookDescReader.html | |
fd47a9b6 | 86 | #[derive(Clone,Copy)] |
4667915a | 87 | pub struct FullCodebookDesc<S> { |
a4bd7707 | 88 | /// Codeword bits. |
9a62b981 | 89 | pub code: u32, |
a4bd7707 | 90 | /// Codeword length. |
9a62b981 | 91 | pub bits: u8, |
a4bd7707 | 92 | /// Codeword value (symbol). |
9a62b981 | 93 | pub sym: S, |
4667915a KS |
94 | } |
95 | ||
a4bd7707 KS |
96 | /// Codebook description for `(code bits, code length)` pair with array index being used as codeword value. |
97 | /// | |
98 | /// This should be used to create a list of codeword definitions for [`ShortCodebookDescReader`]. | |
99 | /// | |
100 | /// [`ShortCodebookDescReader`]: ./struct.ShortCodebookDescReader.html | |
fd47a9b6 | 101 | #[derive(Clone,Copy)] |
4667915a | 102 | pub struct ShortCodebookDesc { |
a4bd7707 | 103 | /// Codeword bits. |
9a62b981 | 104 | pub code: u32, |
a4bd7707 | 105 | /// Codeword length. |
9a62b981 | 106 | pub bits: u8, |
4667915a KS |
107 | } |
108 | ||
a4bd7707 KS |
109 | /// The interface for providing a list of codeword definitions to the codebook creator. |
110 | /// | |
111 | /// The structure implementing this trait should be able to provide the total number of defined codewords and their bits and values. [`ShortCodebookDescReader`] or [`TableCodebookDescReader`] are some examples of such implementation. | |
112 | /// Codeword definitions with zero length are ignored (those may be used to create sparse codebook definitions though). | |
113 | /// | |
114 | /// [`ShortCodebookDescReader`]: ./struct.ShortCodebookDescReader.html | |
115 | /// [`TableCodebookDescReader`]: ./struct.TableCodebookDescReader.html | |
4667915a | 116 | pub trait CodebookDescReader<S> { |
a4bd7707 | 117 | /// Returns the codeword length for the provided index. |
4667915a | 118 | fn bits(&mut self, idx: usize) -> u8; |
a4bd7707 | 119 | /// Returns the codeword bits for the provided index. |
4667915a | 120 | fn code(&mut self, idx: usize) -> u32; |
a4bd7707 | 121 | /// Returns the codeword value (aka codeword symbol) for the provided index. |
4667915a | 122 | fn sym (&mut self, idx: usize) -> S; |
a4bd7707 | 123 | /// Returns the total number of defined codewords. |
4667915a KS |
124 | fn len (&mut self) -> usize; |
125 | } | |
126 | ||
a4bd7707 | 127 | /// The codebook structure for code reading. |
4667915a KS |
128 | #[allow(dead_code)] |
129 | pub struct Codebook<S> { | |
130 | table: Vec<u32>, | |
131 | syms: Vec<S>, | |
132 | lut_bits: u8, | |
133 | } | |
134 | ||
a4bd7707 | 135 | /// Trait allowing bitreader to use codebook for decoding bit sequences. |
4667915a | 136 | pub trait CodebookReader<S> { |
a4bd7707 KS |
137 | /// Reads the codeword from the bitstream and returns its value (or [`InvalidCode`] on error). |
138 | /// | |
139 | /// [`InvalidCode`]: ./enum.CodebookError.html#variant.InvalidCode | |
4667915a KS |
140 | fn read_cb(&mut self, cb: &Codebook<S>) -> CodebookResult<S>; |
141 | } | |
142 | ||
0ca65ffd KS |
143 | const TABLE_FILL_VALUE: u32 = 0x7F; |
144 | const MAX_LUT_BITS: u8 = 10; | |
145 | ||
146 | fn fill_lut_msb(table: &mut Vec<u32>, off: usize, | |
147 | code: u32, bits: u8, lut_bits: u8, symidx: u32, esc: bool) { | |
148 | if !esc { | |
149 | let fill_len = lut_bits - bits; | |
150 | let fill_size = 1 << fill_len; | |
151 | let fill_code = code << (lut_bits - bits); | |
e243ceb4 | 152 | let lut_value = (symidx << 8) | u32::from(bits); |
0ca65ffd KS |
153 | for j in 0..fill_size { |
154 | let idx = (fill_code + j) as usize; | |
155 | table[idx + off] = lut_value; | |
156 | } | |
157 | } else { | |
158 | let idx = (code as usize) + off; | |
e243ceb4 | 159 | table[idx] = (symidx << 8) | 0x80 | u32::from(bits); |
0ca65ffd KS |
160 | } |
161 | } | |
162 | ||
163 | fn fill_lut_lsb(table: &mut Vec<u32>, off: usize, | |
164 | code: u32, bits: u8, lut_bits: u8, symidx: u32, esc: bool) { | |
165 | if !esc { | |
166 | let fill_len = lut_bits - bits; | |
167 | let fill_size = 1 << fill_len; | |
168 | let fill_code = code; | |
169 | let step = lut_bits - fill_len; | |
170 | for j in 0..fill_size { | |
171 | let idx = (fill_code + (j << step)) as usize; | |
e243ceb4 | 172 | table[idx + off] = (symidx << 8) | u32::from(bits); |
0ca65ffd KS |
173 | } |
174 | } else { | |
175 | let idx = (code as usize) + off; | |
e243ceb4 | 176 | table[idx] = (symidx << 8) | 0x80 | u32::from(bits); |
0ca65ffd KS |
177 | } |
178 | } | |
179 | ||
180 | fn fill_lut(table: &mut Vec<u32>, mode: CodebookMode, | |
181 | off: usize, code: u32, bits: u8, lut_bits: u8, symidx: u32, esc: bool) -> bool { | |
182 | match mode { | |
183 | CodebookMode::MSB => fill_lut_msb(table, off, code, bits, lut_bits, symidx, esc), | |
184 | CodebookMode::LSB => fill_lut_lsb(table, off, code, bits, lut_bits, symidx, esc), | |
185 | }; | |
186 | bits > lut_bits | |
187 | } | |
188 | ||
189 | fn resize_table(table: &mut Vec<u32>, bits: u8) -> CodebookResult<u32> { | |
190 | let add_size = (1 << bits) as usize; | |
191 | table.reserve(add_size); | |
192 | let cur_off = table.len() as u32; | |
193 | let new_size = table.len() + add_size; | |
194 | if table.capacity() < new_size { return Err(CodebookError::MemoryError); } | |
195 | table.resize(new_size, TABLE_FILL_VALUE); | |
196 | Ok(cur_off) | |
197 | } | |
198 | ||
199 | ||
200 | fn extract_lut_part(code: u32, bits: u8, lut_bits: u8, mode: CodebookMode) -> u32 { | |
201 | match mode { | |
202 | CodebookMode::MSB => code >> (bits - lut_bits), | |
203 | CodebookMode::LSB => code & ((1 << lut_bits) - 1), | |
204 | } | |
205 | } | |
206 | ||
207 | fn extract_esc_part(code: u32, bits: u8, lut_bits: u8, mode: CodebookMode) -> u32 { | |
208 | match mode { | |
209 | CodebookMode::MSB => code & ((1 << (bits - lut_bits)) - 1), | |
210 | CodebookMode::LSB => code >> lut_bits, | |
211 | } | |
212 | } | |
213 | ||
214 | #[derive(Clone,Copy)] | |
215 | struct Code { | |
216 | code: u32, | |
217 | bits: u8, | |
218 | idx: usize, | |
219 | } | |
220 | ||
221 | struct CodeBucket { | |
222 | maxlen: u8, | |
223 | offset: usize, | |
224 | codes: Vec<Code>, | |
225 | } | |
226 | ||
227 | impl CodeBucket { | |
228 | fn new() -> Self { | |
229 | CodeBucket { maxlen: 0, offset: 0, codes: Vec::new() } | |
230 | } | |
231 | fn add_code(&mut self, c: Code) { | |
232 | if c.bits > self.maxlen { self.maxlen = c.bits; } | |
233 | self.codes.push(c); | |
234 | } | |
235 | } | |
236 | ||
237 | type EscapeCodes = HashMap<u32, CodeBucket>; | |
238 | ||
239 | fn add_esc_code(cc: &mut EscapeCodes, key: u32, code: u32, bits: u8, idx: usize) { | |
e243ceb4 | 240 | cc.entry(key).or_insert_with(CodeBucket::new); |
0ca65ffd KS |
241 | let b = cc.get_mut(&key); |
242 | if let Some(bucket) = b { | |
e243ceb4 | 243 | bucket.add_code(Code {code, bits, idx }); |
0ca65ffd KS |
244 | } else { panic!("no bucket when expected!"); } |
245 | } | |
246 | ||
247 | fn build_esc_lut(table: &mut Vec<u32>, | |
248 | mode: CodebookMode, | |
249 | bucket: &CodeBucket) -> CodebookResult<()> { | |
250 | let mut escape_list: EscapeCodes = HashMap::new(); | |
251 | let maxlen = if bucket.maxlen > MAX_LUT_BITS { MAX_LUT_BITS } else { bucket.maxlen }; | |
252 | ||
253 | for code in &bucket.codes { | |
254 | let bits = code.bits; | |
26af5ca8 | 255 | if code.bits <= MAX_LUT_BITS { |
0ca65ffd KS |
256 | fill_lut(table, mode, bucket.offset, code.code, bits, |
257 | maxlen, code.idx as u32, false); | |
258 | } else { | |
259 | let ckey = extract_lut_part(code.code, bits, MAX_LUT_BITS, mode); | |
260 | let cval = extract_esc_part(code.code, bits, MAX_LUT_BITS, mode); | |
261 | add_esc_code(&mut escape_list, ckey, cval, bits - MAX_LUT_BITS, code.idx); | |
262 | } | |
263 | } | |
264 | ||
265 | let cur_offset = bucket.offset; | |
266 | for (ckey, sec_bucket) in &mut escape_list { | |
267 | let key = *ckey as u32; | |
268 | let maxlen = min(sec_bucket.maxlen, MAX_LUT_BITS); | |
269 | let new_off = resize_table(table, maxlen)?; | |
270 | fill_lut(table, mode, cur_offset, key, maxlen, | |
271 | MAX_LUT_BITS, new_off, true); | |
272 | sec_bucket.offset = new_off as usize; | |
273 | } | |
274 | ||
e243ceb4 | 275 | for sec_bucket in escape_list.values() { |
0ca65ffd KS |
276 | build_esc_lut(table, mode, sec_bucket)?; |
277 | } | |
1a151e53 | 278 | |
0ca65ffd KS |
279 | Ok(()) |
280 | } | |
281 | ||
4667915a | 282 | impl<S: Copy> Codebook<S> { |
0ca65ffd | 283 | |
a4bd7707 | 284 | /// Constructs a new `Codebook` instance using provided codebook description and mode. |
0ca65ffd | 285 | pub fn new(cb: &mut CodebookDescReader<S>, mode: CodebookMode) -> CodebookResult<Self> { |
4667915a KS |
286 | let mut maxbits = 0; |
287 | let mut nnz = 0; | |
0ca65ffd KS |
288 | let mut escape_list: EscapeCodes = HashMap::new(); |
289 | ||
290 | let mut symidx: usize = 0; | |
4667915a KS |
291 | for i in 0..cb.len() { |
292 | let bits = cb.bits(i); | |
26488721 | 293 | if bits > 0 { |
e243ceb4 | 294 | nnz += 1; |
26488721 KS |
295 | if cb.code(i) >= (1 << bits) { |
296 | return Err(CodebookError::InvalidCodebook); | |
297 | } | |
298 | } | |
0ca65ffd KS |
299 | maxbits = max(bits, maxbits); |
300 | if bits > MAX_LUT_BITS { | |
301 | let code = cb.code(i); | |
302 | let ckey = extract_lut_part(code, bits, MAX_LUT_BITS, mode); | |
303 | let cval = extract_esc_part(code, bits, MAX_LUT_BITS, mode); | |
304 | add_esc_code(&mut escape_list, ckey, cval, bits - MAX_LUT_BITS, symidx); | |
4667915a | 305 | } |
e243ceb4 | 306 | if bits > 0 { symidx += 1; } |
4667915a KS |
307 | } |
308 | if maxbits == 0 { return Err(CodebookError::InvalidCodebook); } | |
309 | ||
0ca65ffd KS |
310 | if maxbits > MAX_LUT_BITS { maxbits = MAX_LUT_BITS; } |
311 | ||
4667915a | 312 | let tab_len = 1 << maxbits; |
0ca65ffd KS |
313 | let mut table: Vec<u32> = Vec::with_capacity(tab_len); |
314 | let mut syms: Vec<S> = Vec::with_capacity(nnz); | |
4667915a | 315 | if table.capacity() < tab_len { return Err(CodebookError::MemoryError); } |
0ca65ffd KS |
316 | if syms.capacity() < nnz { return Err(CodebookError::MemoryError); } |
317 | table.resize(tab_len, TABLE_FILL_VALUE); | |
4667915a KS |
318 | |
319 | let mut symidx: u32 = 0; | |
320 | for i in 0..cb.len() { | |
321 | let bits = cb.bits(i); | |
0ca65ffd | 322 | let code = cb.code(i); |
4667915a | 323 | if bits == 0 { continue; } |
0ca65ffd KS |
324 | if bits <= MAX_LUT_BITS { |
325 | fill_lut(&mut table, mode, 0, code, bits, maxbits, symidx, false); | |
326 | } else { | |
327 | let ckey = extract_lut_part(code, bits, MAX_LUT_BITS, mode) as usize; | |
328 | if table[ckey] == TABLE_FILL_VALUE { | |
329 | let key = ckey as u32; | |
330 | if let Some(bucket) = escape_list.get_mut(&key) { | |
331 | let maxlen = min(bucket.maxlen, MAX_LUT_BITS); | |
332 | let new_off = resize_table(&mut table, maxlen)?; | |
333 | fill_lut(&mut table, mode, 0, key, maxlen, MAX_LUT_BITS, new_off, true); | |
334 | bucket.offset = new_off as usize; | |
335 | } | |
336 | } | |
4667915a | 337 | } |
e243ceb4 | 338 | symidx += 1; |
4667915a KS |
339 | } |
340 | ||
e243ceb4 | 341 | for bucket in escape_list.values() { |
0ca65ffd KS |
342 | build_esc_lut(&mut table, mode, &bucket)?; |
343 | } | |
344 | ||
4667915a KS |
345 | for i in 0..cb.len() { |
346 | if cb.bits(i) > 0 { | |
347 | syms.push(cb.sym(i)); | |
348 | } | |
349 | } | |
350 | ||
e243ceb4 | 351 | Ok(Codebook { table, syms, lut_bits: maxbits }) |
4667915a KS |
352 | } |
353 | } | |
354 | ||
355 | impl<'a, S: Copy> CodebookReader<S> for BitReader<'a> { | |
356 | #[allow(unused_variables)] | |
357 | fn read_cb(&mut self, cb: &Codebook<S>) -> CodebookResult<S> { | |
0ca65ffd KS |
358 | let mut esc = true; |
359 | let mut idx = 0; | |
360 | let mut lut_bits = cb.lut_bits; | |
361 | while esc { | |
362 | let lut_idx = (self.peek(lut_bits) as usize) + (idx as usize); | |
363 | if cb.table[lut_idx] == TABLE_FILL_VALUE { return Err(CodebookError::InvalidCode); } | |
364 | let bits = cb.table[lut_idx] & 0x7F; | |
365 | esc = (cb.table[lut_idx] & 0x80) != 0; | |
366 | idx = (cb.table[lut_idx] >> 8) as usize; | |
367 | if (bits as isize) > self.left() { | |
368 | return Err(CodebookError::InvalidCode); | |
369 | } | |
e243ceb4 KS |
370 | let skip_bits = if esc { u32::from(lut_bits) } else { bits }; |
371 | self.skip(skip_bits as u32).unwrap(); | |
0ca65ffd | 372 | lut_bits = bits as u8; |
4667915a | 373 | } |
0ca65ffd | 374 | Ok(cb.syms[idx]) |
4667915a KS |
375 | } |
376 | } | |
377 | ||
a4bd7707 | 378 | /// Codebook description that stores a list of codewords and their values. |
4667915a KS |
379 | pub struct FullCodebookDescReader<S> { |
380 | data: Vec<FullCodebookDesc<S>>, | |
381 | } | |
382 | ||
383 | impl<S> FullCodebookDescReader<S> { | |
a4bd7707 | 384 | /// Constructs a new `FullCodebookDescReader` instance. |
4667915a | 385 | pub fn new(data: Vec<FullCodebookDesc<S>>) -> Self { |
e243ceb4 | 386 | FullCodebookDescReader { data } |
4667915a KS |
387 | } |
388 | } | |
389 | ||
390 | impl<S: Copy> CodebookDescReader<S> for FullCodebookDescReader<S> { | |
391 | fn bits(&mut self, idx: usize) -> u8 { self.data[idx].bits } | |
392 | fn code(&mut self, idx: usize) -> u32 { self.data[idx].code } | |
393 | fn sym (&mut self, idx: usize) -> S { self.data[idx].sym } | |
394 | fn len(&mut self) -> usize { self.data.len() } | |
395 | } | |
396 | ||
a4bd7707 | 397 | /// Codebook description that stores a list of codewords and their value is equal to the index. |
4667915a KS |
398 | pub struct ShortCodebookDescReader { |
399 | data: Vec<ShortCodebookDesc>, | |
400 | } | |
401 | ||
402 | impl ShortCodebookDescReader { | |
a4bd7707 | 403 | /// Constructs a new `ShortCodebookDescReader` instance. |
4667915a | 404 | pub fn new(data: Vec<ShortCodebookDesc<>>) -> Self { |
e243ceb4 | 405 | ShortCodebookDescReader { data } |
4667915a KS |
406 | } |
407 | } | |
408 | ||
409 | impl CodebookDescReader<u32> for ShortCodebookDescReader { | |
410 | fn bits(&mut self, idx: usize) -> u8 { self.data[idx].bits } | |
411 | fn code(&mut self, idx: usize) -> u32 { self.data[idx].code } | |
412 | fn sym (&mut self, idx: usize) -> u32 { idx as u32 } | |
413 | fn len(&mut self) -> usize { self.data.len() } | |
414 | } | |
415 | ||
a4bd7707 | 416 | /// Flexible codebook description that uses two separate arrays for codeword bits and lengths and a function that maps codeword index into its symbol. |
db63f876 KS |
417 | pub struct TableCodebookDescReader<'a, CodeType:'static, IndexType:'static> { |
418 | bits: &'a [u8], | |
419 | codes: &'a [CodeType], | |
6465a946 KS |
420 | idx_map: fn(usize) -> IndexType, |
421 | } | |
422 | ||
db63f876 | 423 | impl<'a, CodeType, IndexType> TableCodebookDescReader<'a, CodeType, IndexType> { |
a4bd7707 | 424 | /// Constructs a new `TableCodebookDescReader` instance. |
db63f876 | 425 | pub fn new(codes: &'a [CodeType], bits: &'a [u8], idx_map: fn(usize) -> IndexType) -> Self { |
6465a946 KS |
426 | Self { bits, codes, idx_map } |
427 | } | |
428 | } | |
db63f876 | 429 | impl<'a, CodeType: Copy+Into<u32>, IndexType> CodebookDescReader<IndexType> for TableCodebookDescReader<'a, CodeType, IndexType> |
6465a946 KS |
430 | { |
431 | fn bits(&mut self, idx: usize) -> u8 { self.bits[idx] } | |
432 | fn code(&mut self, idx: usize) -> u32 { self.codes[idx].into() } | |
433 | fn sym (&mut self, idx: usize) -> IndexType { (self.idx_map)(idx) } | |
434 | fn len(&mut self) -> usize { self.bits.len() } | |
435 | } | |
436 | ||
4667915a KS |
437 | #[cfg(test)] |
438 | mod test { | |
439 | use super::*; | |
aca89041 | 440 | use crate::io::bitreader::*; |
4667915a KS |
441 | |
442 | #[test] | |
443 | fn test_cb() { | |
444 | const BITS: [u8; 2] = [0b01011011, 0b10111100]; | |
445 | let cb_desc: Vec<FullCodebookDesc<i8>> = vec!( | |
446 | FullCodebookDesc { code: 0b0, bits: 1, sym: 16 }, | |
447 | FullCodebookDesc { code: 0b10, bits: 2, sym: -3 }, | |
448 | FullCodebookDesc { code: 0b110, bits: 3, sym: 42 }, | |
449 | FullCodebookDesc { code: 0b1110, bits: 4, sym: -42 } | |
450 | ); | |
451 | let buf = &BITS; | |
fa90ccfb | 452 | let mut br = BitReader::new(buf, BitReaderMode::BE); |
4667915a | 453 | let mut cfr = FullCodebookDescReader::new(cb_desc); |
0ca65ffd | 454 | let cb = Codebook::new(&mut cfr, CodebookMode::MSB).unwrap(); |
4667915a KS |
455 | assert_eq!(br.read_cb(&cb).unwrap(), 16); |
456 | assert_eq!(br.read_cb(&cb).unwrap(), -3); | |
457 | assert_eq!(br.read_cb(&cb).unwrap(), 42); | |
458 | assert_eq!(br.read_cb(&cb).unwrap(), -42); | |
459 | let ret = br.read_cb(&cb); | |
460 | if let Err(e) = ret { | |
461 | assert_eq!(e as i32, CodebookError::InvalidCode as i32); | |
462 | } else { | |
463 | assert_eq!(0, 1); | |
464 | } | |
465 | ||
466 | let scb_desc: Vec<ShortCodebookDesc> = vec!( | |
467 | ShortCodebookDesc { code: 0b0, bits: 1 }, | |
468 | ShortCodebookDesc { code: 0, bits: 0 }, | |
469 | ShortCodebookDesc { code: 0b10, bits: 2 }, | |
470 | ShortCodebookDesc { code: 0, bits: 0 }, | |
471 | ShortCodebookDesc { code: 0, bits: 0 }, | |
472 | ShortCodebookDesc { code: 0b110, bits: 3 }, | |
473 | ShortCodebookDesc { code: 0, bits: 0 }, | |
0ca65ffd KS |
474 | ShortCodebookDesc { code: 0b11100, bits: 5 }, |
475 | ShortCodebookDesc { code: 0b11101, bits: 5 }, | |
476 | ShortCodebookDesc { code: 0b1111010, bits: 7 }, | |
477 | ShortCodebookDesc { code: 0b1111011, bits: 7 }, | |
478 | ShortCodebookDesc { code: 0b1111110, bits: 7 }, | |
479 | ShortCodebookDesc { code: 0b11111111, bits: 8 } | |
4667915a | 480 | ); |
fa90ccfb | 481 | let mut br2 = BitReader::new(buf, BitReaderMode::BE); |
4667915a | 482 | let mut cfr = ShortCodebookDescReader::new(scb_desc); |
0ca65ffd | 483 | let cb = Codebook::new(&mut cfr, CodebookMode::MSB).unwrap(); |
4667915a KS |
484 | assert_eq!(br2.read_cb(&cb).unwrap(), 0); |
485 | assert_eq!(br2.read_cb(&cb).unwrap(), 2); | |
486 | assert_eq!(br2.read_cb(&cb).unwrap(), 5); | |
0ca65ffd KS |
487 | assert_eq!(br2.read_cb(&cb).unwrap(), 8); |
488 | ||
06fd8c88 | 489 | assert_eq!(reverse_bits(0b0000_0101_1011_1011_1101_1111_0111_1111, 32), |
0ca65ffd KS |
490 | 0b1111_1110_1111_1011_1101_1101_1010_0000); |
491 | ||
492 | const BITS_LE: [u8; 3] = [0b11101111, 0b01110010, 0b01]; | |
493 | let buf = &BITS_LE; | |
494 | let scble_desc: Vec<ShortCodebookDesc> = vec!( | |
495 | ShortCodebookDesc { code: 0b00, bits: 2 }, | |
496 | ShortCodebookDesc { code: 0, bits: 0 }, | |
497 | ShortCodebookDesc { code: 0b01, bits: 2 }, | |
498 | ShortCodebookDesc { code: 0, bits: 0 }, | |
499 | ShortCodebookDesc { code: 0, bits: 0 }, | |
500 | ShortCodebookDesc { code: 0b011, bits: 3 }, | |
501 | ShortCodebookDesc { code: 0, bits: 0 }, | |
502 | ShortCodebookDesc { code: 0b10111, bits: 5 }, | |
503 | ShortCodebookDesc { code: 0b00111, bits: 5 }, | |
504 | ShortCodebookDesc { code: 0b0101111, bits: 7 }, | |
505 | ShortCodebookDesc { code: 0b0111111, bits: 7 }, | |
506 | ShortCodebookDesc { code: 0b1011101111, bits: 10 } | |
507 | ); | |
fa90ccfb | 508 | let mut brl = BitReader::new(buf, BitReaderMode::LE); |
0ca65ffd KS |
509 | let mut cfr = ShortCodebookDescReader::new(scble_desc); |
510 | let cb = Codebook::new(&mut cfr, CodebookMode::LSB).unwrap(); | |
511 | assert_eq!(brl.read_cb(&cb).unwrap(), 11); | |
512 | assert_eq!(brl.read_cb(&cb).unwrap(), 0); | |
513 | assert_eq!(brl.read_cb(&cb).unwrap(), 7); | |
514 | assert_eq!(brl.read_cb(&cb).unwrap(), 0); | |
4667915a KS |
515 | } |
516 | } |