X-Git-Url: https://git.nihav.org/?a=blobdiff_plain;f=nihav-core%2Fsrc%2Fio%2Fcodebook.rs;h=6ea3b1ee5ea4ff65df5700d02368a2d021d0f786;hb=6f2630992fe340ad1a122ec10c649f756e478185;hp=5b8259368986c74e5bef2069d190a4bb6c46c9cd;hpb=a4bd770744815a85f56861af67945c6925866023;p=nihav.git diff --git a/nihav-core/src/io/codebook.rs b/nihav-core/src/io/codebook.rs index 5b82593..6ea3b1e 100644 --- a/nihav-core/src/io/codebook.rs +++ b/nihav-core/src/io/codebook.rs @@ -16,7 +16,7 @@ //! ShortCodebookDesc { code: 0b01, bits: 2 }, //! ShortCodebookDesc { code: 0b1, bits: 1 }); //! let mut cr = ShortCodebookDescReader::new(cb_desc); -//! let cb = Codebook::new(&mut cr, CodebookMode::LSB).unwrap(); +//! let cb = Codebook::new(&mut cr, CodebookMode::MSB).unwrap(); //! ``` //! //! Create a codebook using more flexible [`TableCodebookDescReader`] approach. @@ -83,6 +83,7 @@ pub type CodebookResult = Result; /// This should be used to create a list of codeword definitions for [`FullCodebookDescReader`]. /// /// [`FullCodebookDescReader`]: ./struct.FullCodebookDescReader.html +#[derive(Clone,Copy)] pub struct FullCodebookDesc { /// Codeword bits. pub code: u32, @@ -97,6 +98,7 @@ pub struct FullCodebookDesc { /// This should be used to create a list of codeword definitions for [`ShortCodebookDescReader`]. /// /// [`ShortCodebookDescReader`]: ./struct.ShortCodebookDescReader.html +#[derive(Clone,Copy)] pub struct ShortCodebookDesc { /// Codeword bits. pub code: u32, @@ -111,6 +113,7 @@ pub struct ShortCodebookDesc { /// /// [`ShortCodebookDescReader`]: ./struct.ShortCodebookDescReader.html /// [`TableCodebookDescReader`]: ./struct.TableCodebookDescReader.html +#[allow(clippy::len_without_is_empty)] pub trait CodebookDescReader { /// Returns the codeword length for the provided index. fn bits(&mut self, idx: usize) -> u8; @@ -125,9 +128,9 @@ pub trait CodebookDescReader { /// The codebook structure for code reading. #[allow(dead_code)] pub struct Codebook { - table: Vec, - syms: Vec, - lut_bits: u8, + pub table: Vec, + pub syms: Vec, + pub lut_bits: u8, } /// Trait allowing bitreader to use codebook for decoding bit sequences. @@ -138,11 +141,11 @@ pub trait CodebookReader { fn read_cb(&mut self, cb: &Codebook) -> CodebookResult; } -const TABLE_FILL_VALUE: u32 = 0x7F; +pub const TABLE_FILL_VALUE: u32 = 0x7F; const MAX_LUT_BITS: u8 = 10; -fn fill_lut_msb(table: &mut Vec, off: usize, - code: u32, bits: u8, lut_bits: u8, symidx: u32, esc: bool) { +fn fill_lut_msb(table: &mut [u32], off: usize, + code: u32, bits: u8, lut_bits: u8, symidx: u32, esc: bool) -> CodebookResult<()> { if !esc { let fill_len = lut_bits - bits; let fill_size = 1 << fill_len; @@ -150,16 +153,19 @@ fn fill_lut_msb(table: &mut Vec, off: usize, let lut_value = (symidx << 8) | u32::from(bits); for j in 0..fill_size { let idx = (fill_code + j) as usize; + if table[idx + off] != TABLE_FILL_VALUE { return Err(CodebookError::InvalidCodebook); } table[idx + off] = lut_value; } } else { let idx = (code as usize) + off; + if table[idx] != TABLE_FILL_VALUE { return Err(CodebookError::InvalidCodebook); } table[idx] = (symidx << 8) | 0x80 | u32::from(bits); } + Ok(()) } -fn fill_lut_lsb(table: &mut Vec, off: usize, - code: u32, bits: u8, lut_bits: u8, symidx: u32, esc: bool) { +fn fill_lut_lsb(table: &mut [u32], off: usize, + code: u32, bits: u8, lut_bits: u8, symidx: u32, esc: bool) -> CodebookResult<()> { if !esc { let fill_len = lut_bits - bits; let fill_size = 1 << fill_len; @@ -167,21 +173,24 @@ fn fill_lut_lsb(table: &mut Vec, off: usize, let step = lut_bits - fill_len; for j in 0..fill_size { let idx = (fill_code + (j << step)) as usize; + if table[idx + off] != TABLE_FILL_VALUE { return Err(CodebookError::InvalidCodebook); } table[idx + off] = (symidx << 8) | u32::from(bits); } } else { let idx = (code as usize) + off; + if table[idx] != TABLE_FILL_VALUE { return Err(CodebookError::InvalidCodebook); } table[idx] = (symidx << 8) | 0x80 | u32::from(bits); } + Ok(()) } -fn fill_lut(table: &mut Vec, mode: CodebookMode, - off: usize, code: u32, bits: u8, lut_bits: u8, symidx: u32, esc: bool) -> bool { +fn fill_lut(table: &mut [u32], mode: CodebookMode, + off: usize, code: u32, bits: u8, lut_bits: u8, symidx: u32, esc: bool) -> CodebookResult { 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), + 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 + Ok(bits > lut_bits) } fn resize_table(table: &mut Vec, bits: u8) -> CodebookResult { @@ -252,7 +261,7 @@ fn build_esc_lut(table: &mut Vec, 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); + 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); @@ -266,7 +275,7 @@ fn build_esc_lut(table: &mut Vec, 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); + MAX_LUT_BITS, new_off, true)?; sec_bucket.offset = new_off as usize; } @@ -280,7 +289,7 @@ fn build_esc_lut(table: &mut Vec, impl Codebook { /// Constructs a new `Codebook` instance using provided codebook description and mode. - pub fn new(cb: &mut CodebookDescReader, mode: CodebookMode) -> CodebookResult { + pub fn new(cb: &mut dyn CodebookDescReader, mode: CodebookMode) -> CodebookResult { let mut maxbits = 0; let mut nnz = 0; let mut escape_list: EscapeCodes = HashMap::new(); @@ -320,7 +329,7 @@ impl Codebook { 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); + 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 { @@ -328,7 +337,7 @@ impl Codebook { 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); + fill_lut(&mut table, mode, 0, key, maxlen, MAX_LUT_BITS, new_off, true)?; bucket.offset = new_off as usize; } } @@ -337,7 +346,7 @@ impl Codebook { } for bucket in escape_list.values() { - build_esc_lut(&mut table, mode, &bucket)?; + build_esc_lut(&mut table, mode, bucket)?; } for i in 0..cb.len() { @@ -362,10 +371,10 @@ impl<'a, S: Copy> CodebookReader for BitReader<'a> { 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() { + let skip_bits = if esc { u32::from(lut_bits) } else { bits }; + if (skip_bits as isize) > self.left() { return Err(CodebookError::InvalidCode); } - let skip_bits = if esc { u32::from(lut_bits) } else { bits }; self.skip(skip_bits as u32).unwrap(); lut_bits = bits as u8; }