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Diffstat (limited to 'vendor/image/src/codecs/webp/lossless.rs')
| -rw-r--r-- | vendor/image/src/codecs/webp/lossless.rs | 783 |
1 files changed, 0 insertions, 783 deletions
diff --git a/vendor/image/src/codecs/webp/lossless.rs b/vendor/image/src/codecs/webp/lossless.rs deleted file mode 100644 index 7271eda..0000000 --- a/vendor/image/src/codecs/webp/lossless.rs +++ /dev/null @@ -1,783 +0,0 @@ -//! Decoding of lossless WebP images -//! -//! [Lossless spec](https://developers.google.com/speed/webp/docs/webp_lossless_bitstream_specification) -//! - -use std::{ - convert::TryFrom, - convert::TryInto, - error, fmt, - io::Read, - ops::{AddAssign, Shl}, -}; - -use byteorder::ReadBytesExt; - -use crate::{error::DecodingError, ImageError, ImageFormat, ImageResult}; - -use super::huffman::HuffmanTree; -use super::lossless_transform::{add_pixels, TransformType}; - -const CODE_LENGTH_CODES: usize = 19; -const CODE_LENGTH_CODE_ORDER: [usize; CODE_LENGTH_CODES] = [ - 17, 18, 0, 1, 2, 3, 4, 5, 16, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, -]; - -#[rustfmt::skip] -const DISTANCE_MAP: [(i8, i8); 120] = [ - (0, 1), (1, 0), (1, 1), (-1, 1), (0, 2), (2, 0), (1, 2), (-1, 2), - (2, 1), (-2, 1), (2, 2), (-2, 2), (0, 3), (3, 0), (1, 3), (-1, 3), - (3, 1), (-3, 1), (2, 3), (-2, 3), (3, 2), (-3, 2), (0, 4), (4, 0), - (1, 4), (-1, 4), (4, 1), (-4, 1), (3, 3), (-3, 3), (2, 4), (-2, 4), - (4, 2), (-4, 2), (0, 5), (3, 4), (-3, 4), (4, 3), (-4, 3), (5, 0), - (1, 5), (-1, 5), (5, 1), (-5, 1), (2, 5), (-2, 5), (5, 2), (-5, 2), - (4, 4), (-4, 4), (3, 5), (-3, 5), (5, 3), (-5, 3), (0, 6), (6, 0), - (1, 6), (-1, 6), (6, 1), (-6, 1), (2, 6), (-2, 6), (6, 2), (-6, 2), - (4, 5), (-4, 5), (5, 4), (-5, 4), (3, 6), (-3, 6), (6, 3), (-6, 3), - (0, 7), (7, 0), (1, 7), (-1, 7), (5, 5), (-5, 5), (7, 1), (-7, 1), - (4, 6), (-4, 6), (6, 4), (-6, 4), (2, 7), (-2, 7), (7, 2), (-7, 2), - (3, 7), (-3, 7), (7, 3), (-7, 3), (5, 6), (-5, 6), (6, 5), (-6, 5), - (8, 0), (4, 7), (-4, 7), (7, 4), (-7, 4), (8, 1), (8, 2), (6, 6), - (-6, 6), (8, 3), (5, 7), (-5, 7), (7, 5), (-7, 5), (8, 4), (6, 7), - (-6, 7), (7, 6), (-7, 6), (8, 5), (7, 7), (-7, 7), (8, 6), (8, 7) -]; - -const GREEN: usize = 0; -const RED: usize = 1; -const BLUE: usize = 2; -const ALPHA: usize = 3; -const DIST: usize = 4; - -const HUFFMAN_CODES_PER_META_CODE: usize = 5; - -type HuffmanCodeGroup = [HuffmanTree; HUFFMAN_CODES_PER_META_CODE]; - -const ALPHABET_SIZE: [u16; HUFFMAN_CODES_PER_META_CODE] = [256 + 24, 256, 256, 256, 40]; - -#[inline] -pub(crate) fn subsample_size(size: u16, bits: u8) -> u16 { - ((u32::from(size) + (1u32 << bits) - 1) >> bits) - .try_into() - .unwrap() -} - -#[derive(Debug, Clone, Copy)] -pub(crate) enum DecoderError { - /// Signature of 0x2f not found - LosslessSignatureInvalid(u8), - /// Version Number must be 0 - VersionNumberInvalid(u8), - - /// - InvalidColorCacheBits(u8), - - HuffmanError, - - BitStreamError, - - TransformError, -} - -impl fmt::Display for DecoderError { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - match self { - DecoderError::LosslessSignatureInvalid(sig) => { - f.write_fmt(format_args!("Invalid lossless signature: {}", sig)) - } - DecoderError::VersionNumberInvalid(num) => { - f.write_fmt(format_args!("Invalid version number: {}", num)) - } - DecoderError::InvalidColorCacheBits(num) => f.write_fmt(format_args!( - "Invalid color cache(must be between 1-11): {}", - num - )), - DecoderError::HuffmanError => f.write_fmt(format_args!("Error building Huffman Tree")), - DecoderError::BitStreamError => { - f.write_fmt(format_args!("Error while reading bitstream")) - } - DecoderError::TransformError => { - f.write_fmt(format_args!("Error while reading or writing transforms")) - } - } - } -} - -impl From<DecoderError> for ImageError { - fn from(e: DecoderError) -> ImageError { - ImageError::Decoding(DecodingError::new(ImageFormat::WebP.into(), e)) - } -} - -impl error::Error for DecoderError {} - -const NUM_TRANSFORM_TYPES: usize = 4; - -//Decodes lossless WebP images -#[derive(Debug)] -pub(crate) struct LosslessDecoder<R> { - r: R, - bit_reader: BitReader, - frame: LosslessFrame, - transforms: [Option<TransformType>; NUM_TRANSFORM_TYPES], - transform_order: Vec<u8>, -} - -impl<R: Read> LosslessDecoder<R> { - /// Create a new decoder - pub(crate) fn new(r: R) -> LosslessDecoder<R> { - LosslessDecoder { - r, - bit_reader: BitReader::new(), - frame: Default::default(), - transforms: [None, None, None, None], - transform_order: Vec::new(), - } - } - - /// Reads the frame - pub(crate) fn decode_frame(&mut self) -> ImageResult<&LosslessFrame> { - let signature = self.r.read_u8()?; - - if signature != 0x2f { - return Err(DecoderError::LosslessSignatureInvalid(signature).into()); - } - - let mut buf = Vec::new(); - self.r.read_to_end(&mut buf)?; - self.bit_reader.init(buf); - - self.frame.width = self.bit_reader.read_bits::<u16>(14)? + 1; - self.frame.height = self.bit_reader.read_bits::<u16>(14)? + 1; - - let _alpha_used = self.bit_reader.read_bits::<u8>(1)?; - - let version_num = self.bit_reader.read_bits::<u8>(3)?; - - if version_num != 0 { - return Err(DecoderError::VersionNumberInvalid(version_num).into()); - } - - let mut data = self.decode_image_stream(self.frame.width, self.frame.height, true)?; - - for &trans_index in self.transform_order.iter().rev() { - let trans = self.transforms[usize::from(trans_index)].as_ref().unwrap(); - trans.apply_transform(&mut data, self.frame.width, self.frame.height)?; - } - - self.frame.buf = data; - Ok(&self.frame) - } - - //used for alpha data in extended decoding - pub(crate) fn decode_frame_implicit_dims( - &mut self, - width: u16, - height: u16, - ) -> ImageResult<&LosslessFrame> { - let mut buf = Vec::new(); - self.r.read_to_end(&mut buf)?; - self.bit_reader.init(buf); - - self.frame.width = width; - self.frame.height = height; - - let mut data = self.decode_image_stream(self.frame.width, self.frame.height, true)?; - - //transform_order is vector of indices(0-3) into transforms in order decoded - for &trans_index in self.transform_order.iter().rev() { - let trans = self.transforms[usize::from(trans_index)].as_ref().unwrap(); - trans.apply_transform(&mut data, self.frame.width, self.frame.height)?; - } - - self.frame.buf = data; - Ok(&self.frame) - } - - /// Reads Image data from the bitstream - /// Can be in any of the 5 roles described in the Specification - /// ARGB Image role has different behaviour to the other 4 - /// xsize and ysize describe the size of the blocks where each block has its own entropy code - fn decode_image_stream( - &mut self, - xsize: u16, - ysize: u16, - is_argb_img: bool, - ) -> ImageResult<Vec<u32>> { - let trans_xsize = if is_argb_img { - self.read_transforms()? - } else { - xsize - }; - - let color_cache_bits = self.read_color_cache()?; - - let color_cache = color_cache_bits.map(|bits| { - let size = 1 << bits; - let cache = vec![0u32; size]; - ColorCache { - color_cache_bits: bits, - color_cache: cache, - } - }); - - let huffman_info = self.read_huffman_codes(is_argb_img, trans_xsize, ysize, color_cache)?; - - //decode data - let data = self.decode_image_data(trans_xsize, ysize, huffman_info)?; - - Ok(data) - } - - /// Reads transforms and their data from the bitstream - fn read_transforms(&mut self) -> ImageResult<u16> { - let mut xsize = self.frame.width; - - while self.bit_reader.read_bits::<u8>(1)? == 1 { - let transform_type_val = self.bit_reader.read_bits::<u8>(2)?; - - if self.transforms[usize::from(transform_type_val)].is_some() { - //can only have one of each transform, error - return Err(DecoderError::TransformError.into()); - } - - self.transform_order.push(transform_type_val); - - let transform_type = match transform_type_val { - 0 => { - //predictor - - let size_bits = self.bit_reader.read_bits::<u8>(3)? + 2; - - let block_xsize = subsample_size(xsize, size_bits); - let block_ysize = subsample_size(self.frame.height, size_bits); - - let data = self.decode_image_stream(block_xsize, block_ysize, false)?; - - TransformType::PredictorTransform { - size_bits, - predictor_data: data, - } - } - 1 => { - //color transform - - let size_bits = self.bit_reader.read_bits::<u8>(3)? + 2; - - let block_xsize = subsample_size(xsize, size_bits); - let block_ysize = subsample_size(self.frame.height, size_bits); - - let data = self.decode_image_stream(block_xsize, block_ysize, false)?; - - TransformType::ColorTransform { - size_bits, - transform_data: data, - } - } - 2 => { - //subtract green - - TransformType::SubtractGreen - } - 3 => { - let color_table_size = self.bit_reader.read_bits::<u16>(8)? + 1; - - let mut color_map = self.decode_image_stream(color_table_size, 1, false)?; - - let bits = if color_table_size <= 2 { - 3 - } else if color_table_size <= 4 { - 2 - } else if color_table_size <= 16 { - 1 - } else { - 0 - }; - xsize = subsample_size(xsize, bits); - - Self::adjust_color_map(&mut color_map); - - TransformType::ColorIndexingTransform { - table_size: color_table_size, - table_data: color_map, - } - } - _ => unreachable!(), - }; - - self.transforms[usize::from(transform_type_val)] = Some(transform_type); - } - - Ok(xsize) - } - - /// Adjusts the color map since it's subtraction coded - fn adjust_color_map(color_map: &mut Vec<u32>) { - for i in 1..color_map.len() { - color_map[i] = add_pixels(color_map[i], color_map[i - 1]); - } - } - - /// Reads huffman codes associated with an image - fn read_huffman_codes( - &mut self, - read_meta: bool, - xsize: u16, - ysize: u16, - color_cache: Option<ColorCache>, - ) -> ImageResult<HuffmanInfo> { - let mut num_huff_groups = 1; - - let mut huffman_bits = 0; - let mut huffman_xsize = 1; - let mut huffman_ysize = 1; - let mut entropy_image = Vec::new(); - - if read_meta && self.bit_reader.read_bits::<u8>(1)? == 1 { - //meta huffman codes - huffman_bits = self.bit_reader.read_bits::<u8>(3)? + 2; - huffman_xsize = subsample_size(xsize, huffman_bits); - huffman_ysize = subsample_size(ysize, huffman_bits); - - entropy_image = self.decode_image_stream(huffman_xsize, huffman_ysize, false)?; - - for pixel in entropy_image.iter_mut() { - let meta_huff_code = (*pixel >> 8) & 0xffff; - - *pixel = meta_huff_code; - - if meta_huff_code >= num_huff_groups { - num_huff_groups = meta_huff_code + 1; - } - } - } - - let mut hufftree_groups = Vec::new(); - - for _i in 0..num_huff_groups { - let mut group: HuffmanCodeGroup = Default::default(); - for j in 0..HUFFMAN_CODES_PER_META_CODE { - let mut alphabet_size = ALPHABET_SIZE[j]; - if j == 0 { - if let Some(color_cache) = color_cache.as_ref() { - alphabet_size += 1 << color_cache.color_cache_bits; - } - } - - let tree = self.read_huffman_code(alphabet_size)?; - group[j] = tree; - } - hufftree_groups.push(group); - } - - let huffman_mask = if huffman_bits == 0 { - !0 - } else { - (1 << huffman_bits) - 1 - }; - - let info = HuffmanInfo { - xsize: huffman_xsize, - _ysize: huffman_ysize, - color_cache, - image: entropy_image, - bits: huffman_bits, - mask: huffman_mask, - huffman_code_groups: hufftree_groups, - }; - - Ok(info) - } - - /// Decodes and returns a single huffman tree - fn read_huffman_code(&mut self, alphabet_size: u16) -> ImageResult<HuffmanTree> { - let simple = self.bit_reader.read_bits::<u8>(1)? == 1; - - if simple { - let num_symbols = self.bit_reader.read_bits::<u8>(1)? + 1; - - let mut code_lengths = vec![u16::from(num_symbols - 1)]; - let mut codes = vec![0]; - let mut symbols = Vec::new(); - - let is_first_8bits = self.bit_reader.read_bits::<u8>(1)?; - symbols.push(self.bit_reader.read_bits::<u16>(1 + 7 * is_first_8bits)?); - - if num_symbols == 2 { - symbols.push(self.bit_reader.read_bits::<u16>(8)?); - code_lengths.push(1); - codes.push(1); - } - - HuffmanTree::build_explicit(code_lengths, codes, symbols) - } else { - let mut code_length_code_lengths = vec![0; CODE_LENGTH_CODES]; - - let num_code_lengths = 4 + self.bit_reader.read_bits::<usize>(4)?; - for i in 0..num_code_lengths { - code_length_code_lengths[CODE_LENGTH_CODE_ORDER[i]] = - self.bit_reader.read_bits(3)?; - } - - let new_code_lengths = - self.read_huffman_code_lengths(code_length_code_lengths, alphabet_size)?; - - HuffmanTree::build_implicit(new_code_lengths) - } - } - - /// Reads huffman code lengths - fn read_huffman_code_lengths( - &mut self, - code_length_code_lengths: Vec<u16>, - num_symbols: u16, - ) -> ImageResult<Vec<u16>> { - let table = HuffmanTree::build_implicit(code_length_code_lengths)?; - - let mut max_symbol = if self.bit_reader.read_bits::<u8>(1)? == 1 { - let length_nbits = 2 + 2 * self.bit_reader.read_bits::<u8>(3)?; - 2 + self.bit_reader.read_bits::<u16>(length_nbits)? - } else { - num_symbols - }; - - let mut code_lengths = vec![0; usize::from(num_symbols)]; - let mut prev_code_len = 8; //default code length - - let mut symbol = 0; - while symbol < num_symbols { - if max_symbol == 0 { - break; - } - max_symbol -= 1; - - let code_len = table.read_symbol(&mut self.bit_reader)?; - - if code_len < 16 { - code_lengths[usize::from(symbol)] = code_len; - symbol += 1; - if code_len != 0 { - prev_code_len = code_len; - } - } else { - let use_prev = code_len == 16; - let slot = code_len - 16; - let extra_bits = match slot { - 0 => 2, - 1 => 3, - 2 => 7, - _ => return Err(DecoderError::BitStreamError.into()), - }; - let repeat_offset = match slot { - 0 | 1 => 3, - 2 => 11, - _ => return Err(DecoderError::BitStreamError.into()), - }; - - let mut repeat = self.bit_reader.read_bits::<u16>(extra_bits)? + repeat_offset; - - if symbol + repeat > num_symbols { - return Err(DecoderError::BitStreamError.into()); - } else { - let length = if use_prev { prev_code_len } else { 0 }; - while repeat > 0 { - repeat -= 1; - code_lengths[usize::from(symbol)] = length; - symbol += 1; - } - } - } - } - - Ok(code_lengths) - } - - /// Decodes the image data using the huffman trees and either of the 3 methods of decoding - fn decode_image_data( - &mut self, - width: u16, - height: u16, - mut huffman_info: HuffmanInfo, - ) -> ImageResult<Vec<u32>> { - let num_values = usize::from(width) * usize::from(height); - let mut data = vec![0; num_values]; - - let huff_index = huffman_info.get_huff_index(0, 0); - let mut tree = &huffman_info.huffman_code_groups[huff_index]; - let mut last_cached = 0; - let mut index = 0; - let mut x = 0; - let mut y = 0; - while index < num_values { - if (x & huffman_info.mask) == 0 { - let index = huffman_info.get_huff_index(x, y); - tree = &huffman_info.huffman_code_groups[index]; - } - - let code = tree[GREEN].read_symbol(&mut self.bit_reader)?; - - //check code - if code < 256 { - //literal, so just use huffman codes and read as argb - let red = tree[RED].read_symbol(&mut self.bit_reader)?; - let blue = tree[BLUE].read_symbol(&mut self.bit_reader)?; - let alpha = tree[ALPHA].read_symbol(&mut self.bit_reader)?; - - data[index] = (u32::from(alpha) << 24) - + (u32::from(red) << 16) - + (u32::from(code) << 8) - + u32::from(blue); - - index += 1; - x += 1; - if x >= width { - x = 0; - y += 1; - } - } else if code < 256 + 24 { - //backward reference, so go back and use that to add image data - let length_symbol = code - 256; - let length = Self::get_copy_distance(&mut self.bit_reader, length_symbol)?; - - let dist_symbol = tree[DIST].read_symbol(&mut self.bit_reader)?; - let dist_code = Self::get_copy_distance(&mut self.bit_reader, dist_symbol)?; - let dist = Self::plane_code_to_distance(width, dist_code); - - if index < dist || num_values - index < length { - return Err(DecoderError::BitStreamError.into()); - } - - for i in 0..length { - data[index + i] = data[index + i - dist]; - } - index += length; - x += u16::try_from(length).unwrap(); - while x >= width { - x -= width; - y += 1; - } - if index < num_values { - let index = huffman_info.get_huff_index(x, y); - tree = &huffman_info.huffman_code_groups[index]; - } - } else { - //color cache, so use previously stored pixels to get this pixel - let key = code - 256 - 24; - - if let Some(color_cache) = huffman_info.color_cache.as_mut() { - //cache old colors - while last_cached < index { - color_cache.insert(data[last_cached]); - last_cached += 1; - } - data[index] = color_cache.lookup(key.into())?; - } else { - return Err(DecoderError::BitStreamError.into()); - } - index += 1; - x += 1; - if x >= width { - x = 0; - y += 1; - } - } - } - - Ok(data) - } - - /// Reads color cache data from the bitstream - fn read_color_cache(&mut self) -> ImageResult<Option<u8>> { - if self.bit_reader.read_bits::<u8>(1)? == 1 { - let code_bits = self.bit_reader.read_bits::<u8>(4)?; - - if !(1..=11).contains(&code_bits) { - return Err(DecoderError::InvalidColorCacheBits(code_bits).into()); - } - - Ok(Some(code_bits)) - } else { - Ok(None) - } - } - - /// Gets the copy distance from the prefix code and bitstream - fn get_copy_distance(bit_reader: &mut BitReader, prefix_code: u16) -> ImageResult<usize> { - if prefix_code < 4 { - return Ok(usize::from(prefix_code + 1)); - } - let extra_bits: u8 = ((prefix_code - 2) >> 1).try_into().unwrap(); - let offset = (2 + (usize::from(prefix_code) & 1)) << extra_bits; - - Ok(offset + bit_reader.read_bits::<usize>(extra_bits)? + 1) - } - - /// Gets distance to pixel - fn plane_code_to_distance(xsize: u16, plane_code: usize) -> usize { - if plane_code > 120 { - plane_code - 120 - } else { - let (xoffset, yoffset) = DISTANCE_MAP[plane_code - 1]; - - let dist = i32::from(xoffset) + i32::from(yoffset) * i32::from(xsize); - if dist < 1 { - return 1; - } - dist.try_into().unwrap() - } - } -} - -#[derive(Debug, Clone)] -struct HuffmanInfo { - xsize: u16, - _ysize: u16, - color_cache: Option<ColorCache>, - image: Vec<u32>, - bits: u8, - mask: u16, - huffman_code_groups: Vec<HuffmanCodeGroup>, -} - -impl HuffmanInfo { - fn get_huff_index(&self, x: u16, y: u16) -> usize { - if self.bits == 0 { - return 0; - } - let position = usize::from((y >> self.bits) * self.xsize + (x >> self.bits)); - let meta_huff_code: usize = self.image[position].try_into().unwrap(); - meta_huff_code - } -} - -#[derive(Debug, Clone)] -struct ColorCache { - color_cache_bits: u8, - color_cache: Vec<u32>, -} - -impl ColorCache { - fn insert(&mut self, color: u32) { - let index = (0x1e35a7bdu32.overflowing_mul(color).0) >> (32 - self.color_cache_bits); - self.color_cache[index as usize] = color; - } - - fn lookup(&self, index: usize) -> ImageResult<u32> { - match self.color_cache.get(index) { - Some(&value) => Ok(value), - None => Err(DecoderError::BitStreamError.into()), - } - } -} - -#[derive(Debug, Clone)] -pub(crate) struct BitReader { - buf: Vec<u8>, - index: usize, - bit_count: u8, -} - -impl BitReader { - fn new() -> BitReader { - BitReader { - buf: Vec::new(), - index: 0, - bit_count: 0, - } - } - - fn init(&mut self, buf: Vec<u8>) { - self.buf = buf; - } - - pub(crate) fn read_bits<T>(&mut self, num: u8) -> ImageResult<T> - where - T: num_traits::Unsigned + Shl<u8, Output = T> + AddAssign<T> + From<bool>, - { - let mut value: T = T::zero(); - - for i in 0..num { - if self.buf.len() <= self.index { - return Err(DecoderError::BitStreamError.into()); - } - let bit_true = self.buf[self.index] & (1 << self.bit_count) != 0; - value += T::from(bit_true) << i; - self.bit_count = if self.bit_count == 7 { - self.index += 1; - 0 - } else { - self.bit_count + 1 - }; - } - - Ok(value) - } -} - -#[derive(Debug, Clone, Default)] -pub(crate) struct LosslessFrame { - pub(crate) width: u16, - pub(crate) height: u16, - - pub(crate) buf: Vec<u32>, -} - -impl LosslessFrame { - /// Fills a buffer by converting from argb to rgba - pub(crate) fn fill_rgba(&self, buf: &mut [u8]) { - for (&argb_val, chunk) in self.buf.iter().zip(buf.chunks_exact_mut(4)) { - chunk[0] = ((argb_val >> 16) & 0xff).try_into().unwrap(); - chunk[1] = ((argb_val >> 8) & 0xff).try_into().unwrap(); - chunk[2] = (argb_val & 0xff).try_into().unwrap(); - chunk[3] = ((argb_val >> 24) & 0xff).try_into().unwrap(); - } - } - - /// Get buffer size from the image - pub(crate) fn get_buf_size(&self) -> usize { - usize::from(self.width) * usize::from(self.height) * 4 - } - - /// Fills a buffer with just the green values from the lossless decoding - /// Used in extended alpha decoding - pub(crate) fn fill_green(&self, buf: &mut [u8]) { - for (&argb_val, buf_value) in self.buf.iter().zip(buf.iter_mut()) { - *buf_value = ((argb_val >> 8) & 0xff).try_into().unwrap(); - } - } -} - -#[cfg(test)] -mod test { - - use super::BitReader; - - #[test] - fn bit_read_test() { - let mut bit_reader = BitReader::new(); - - //10011100 01000001 11100001 - let buf = vec![0x9C, 0x41, 0xE1]; - - bit_reader.init(buf); - - assert_eq!(bit_reader.read_bits::<u8>(3).unwrap(), 4); //100 - assert_eq!(bit_reader.read_bits::<u8>(2).unwrap(), 3); //11 - assert_eq!(bit_reader.read_bits::<u8>(6).unwrap(), 12); //001100 - assert_eq!(bit_reader.read_bits::<u16>(10).unwrap(), 40); //0000101000 - assert_eq!(bit_reader.read_bits::<u8>(3).unwrap(), 7); //111 - } - - #[test] - fn bit_read_error_test() { - let mut bit_reader = BitReader::new(); - - //01101010 - let buf = vec![0x6A]; - - bit_reader.init(buf); - - assert_eq!(bit_reader.read_bits::<u8>(3).unwrap(), 2); //010 - assert_eq!(bit_reader.read_bits::<u8>(5).unwrap(), 13); //01101 - assert!(bit_reader.read_bits::<u8>(4).is_err()); //error - } -} |