From 14bb08c1df8db9ec6c8a05520d4eee67971235d9 Mon Sep 17 00:00:00 2001 From: Dimitri Sokolyuk Date: Thu, 27 Sep 2018 20:03:23 +0200 Subject: mod tidy --- vendor/golang.org/x/image/vp8/partition.go | 129 ----------------------------- 1 file changed, 129 deletions(-) delete mode 100644 vendor/golang.org/x/image/vp8/partition.go (limited to 'vendor/golang.org/x/image/vp8/partition.go') diff --git a/vendor/golang.org/x/image/vp8/partition.go b/vendor/golang.org/x/image/vp8/partition.go deleted file mode 100644 index 72288bd..0000000 --- a/vendor/golang.org/x/image/vp8/partition.go +++ /dev/null @@ -1,129 +0,0 @@ -// Copyright 2011 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package vp8 - -// Each VP8 frame consists of between 2 and 9 bitstream partitions. -// Each partition is byte-aligned and is independently arithmetic-encoded. -// -// This file implements decoding a partition's bitstream, as specified in -// chapter 7. The implementation follows libwebp's approach instead of the -// specification's reference C implementation. For example, we use a look-up -// table instead of a for loop to recalibrate the encoded range. - -var ( - lutShift = [127]uint8{ - 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4, - 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, - 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, - 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, - 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, - 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, - 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, - 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, - } - lutRangeM1 = [127]uint8{ - 127, - 127, 191, - 127, 159, 191, 223, - 127, 143, 159, 175, 191, 207, 223, 239, - 127, 135, 143, 151, 159, 167, 175, 183, 191, 199, 207, 215, 223, 231, 239, 247, - 127, 131, 135, 139, 143, 147, 151, 155, 159, 163, 167, 171, 175, 179, 183, 187, - 191, 195, 199, 203, 207, 211, 215, 219, 223, 227, 231, 235, 239, 243, 247, 251, - 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, - 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, - 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, - 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, - } -) - -// uniformProb represents a 50% probability that the next bit is 0. -const uniformProb = 128 - -// partition holds arithmetic-coded bits. -type partition struct { - // buf is the input bytes. - buf []byte - // r is how many of buf's bytes have been consumed. - r int - // rangeM1 is range minus 1, where range is in the arithmetic coding sense, - // not the Go language sense. - rangeM1 uint32 - // bits and nBits hold those bits shifted out of buf but not yet consumed. - bits uint32 - nBits uint8 - // unexpectedEOF tells whether we tried to read past buf. - unexpectedEOF bool -} - -// init initializes the partition. -func (p *partition) init(buf []byte) { - p.buf = buf - p.r = 0 - p.rangeM1 = 254 - p.bits = 0 - p.nBits = 0 - p.unexpectedEOF = false -} - -// readBit returns the next bit. -func (p *partition) readBit(prob uint8) bool { - if p.nBits < 8 { - if p.r >= len(p.buf) { - p.unexpectedEOF = true - return false - } - // Expression split for 386 compiler. - x := uint32(p.buf[p.r]) - p.bits |= x << (8 - p.nBits) - p.r++ - p.nBits += 8 - } - split := (p.rangeM1*uint32(prob))>>8 + 1 - bit := p.bits >= split<<8 - if bit { - p.rangeM1 -= split - p.bits -= split << 8 - } else { - p.rangeM1 = split - 1 - } - if p.rangeM1 < 127 { - shift := lutShift[p.rangeM1] - p.rangeM1 = uint32(lutRangeM1[p.rangeM1]) - p.bits <<= shift - p.nBits -= shift - } - return bit -} - -// readUint returns the next n-bit unsigned integer. -func (p *partition) readUint(prob, n uint8) uint32 { - var u uint32 - for n > 0 { - n-- - if p.readBit(prob) { - u |= 1 << n - } - } - return u -} - -// readInt returns the next n-bit signed integer. -func (p *partition) readInt(prob, n uint8) int32 { - u := p.readUint(prob, n) - b := p.readBit(prob) - if b { - return -int32(u) - } - return int32(u) -} - -// readOptionalInt returns the next n-bit signed integer in an encoding -// where the likely result is zero. -func (p *partition) readOptionalInt(prob, n uint8) int32 { - if !p.readBit(prob) { - return 0 - } - return p.readInt(prob, n) -} -- cgit v1.2.3