Source File
	token.go

Belonging Package
	golang.org/x/image/vp8

// 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

// This file contains token probabilities for decoding DCT/WHT coefficients, as
// specified in chapter 13.

func (d *Decoder) parseTokenProb() {
	for i := range d.tokenProb {
		for j := range d.tokenProb[i] {
			for k := range d.tokenProb[i][j] {
				for l := range d.tokenProb[i][j][k] {
					if d.fp.readBit(tokenProbUpdateProb[i][j][k][l]) {
						d.tokenProb[i][j][k][l] = uint8(d.fp.readUint(uniformProb, 8))
					}
				}
			}
		}
	}
}

// The plane enumeration is specified in section 13.3.
const (
	planeY1WithY2 = iota
	planeY2
	planeUV
	planeY1SansY2
	nPlane
)

const (
	nBand    = 8
	nContext = 3
	nProb    = 11
)

// Token probability update probabilities are specified in section 13.4.
var tokenProbUpdateProb = [nPlane][nBand][nContext][nProb]uint8{
	{
		{
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{176, 246, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{223, 241, 252, 255, 255, 255, 255, 255, 255, 255, 255},
			{249, 253, 253, 255, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 244, 252, 255, 255, 255, 255, 255, 255, 255, 255},
			{234, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255},
			{253, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 246, 254, 255, 255, 255, 255, 255, 255, 255, 255},
			{239, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255},
			{254, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 248, 254, 255, 255, 255, 255, 255, 255, 255, 255},
			{251, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255},
			{251, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255},
			{254, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 254, 253, 255, 254, 255, 255, 255, 255, 255, 255},
			{250, 255, 254, 255, 254, 255, 255, 255, 255, 255, 255},
			{254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
		},
	},
	{
		{
			{217, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{225, 252, 241, 253, 255, 255, 254, 255, 255, 255, 255},
			{234, 250, 241, 250, 253, 255, 253, 254, 255, 255, 255},
		},
		{
			{255, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{223, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255},
			{238, 253, 254, 254, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 248, 254, 255, 255, 255, 255, 255, 255, 255, 255},
			{249, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 253, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{247, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255},
			{252, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255},
			{253, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 254, 253, 255, 255, 255, 255, 255, 255, 255, 255},
			{250, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
		},
	},
	{
		{
			{186, 251, 250, 255, 255, 255, 255, 255, 255, 255, 255},
			{234, 251, 244, 254, 255, 255, 255, 255, 255, 255, 255},
			{251, 251, 243, 253, 254, 255, 254, 255, 255, 255, 255},
		},
		{
			{255, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255},
			{236, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255},
			{251, 253, 253, 254, 254, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255},
			{254, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{254, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
		},
	},
	{
		{
			{248, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{250, 254, 252, 254, 255, 255, 255, 255, 255, 255, 255},
			{248, 254, 249, 253, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 253, 253, 255, 255, 255, 255, 255, 255, 255, 255},
			{246, 253, 253, 255, 255, 255, 255, 255, 255, 255, 255},
			{252, 254, 251, 254, 254, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 254, 252, 255, 255, 255, 255, 255, 255, 255, 255},
			{248, 254, 253, 255, 255, 255, 255, 255, 255, 255, 255},
			{253, 255, 254, 254, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 251, 254, 255, 255, 255, 255, 255, 255, 255, 255},
			{245, 251, 254, 255, 255, 255, 255, 255, 255, 255, 255},
			{253, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 251, 253, 255, 255, 255, 255, 255, 255, 255, 255},
			{252, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 252, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{249, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 255, 253, 255, 255, 255, 255, 255, 255, 255, 255},
			{250, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
		},
		{
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
			{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
		},
	},
}

// Default token probabilities are specified in section 13.5.
var defaultTokenProb = [nPlane][nBand][nContext][nProb]uint8{
	{
		{
			{128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128},
			{128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128},
			{128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128},
		},
		{
			{253, 136, 254, 255, 228, 219, 128, 128, 128, 128, 128},
			{189, 129, 242, 255, 227, 213, 255, 219, 128, 128, 128},
			{106, 126, 227, 252, 214, 209, 255, 255, 128, 128, 128},
		},
		{
			{1, 98, 248, 255, 236, 226, 255, 255, 128, 128, 128},
			{181, 133, 238, 254, 221, 234, 255, 154, 128, 128, 128},
			{78, 134, 202, 247, 198, 180, 255, 219, 128, 128, 128},
		},
		{
			{1, 185, 249, 255, 243, 255, 128, 128, 128, 128, 128},
			{184, 150, 247, 255, 236, 224, 128, 128, 128, 128, 128},
			{77, 110, 216, 255, 236, 230, 128, 128, 128, 128, 128},
		},
		{
			{1, 101, 251, 255, 241, 255, 128, 128, 128, 128, 128},
			{170, 139, 241, 252, 236, 209, 255, 255, 128, 128, 128},
			{37, 116, 196, 243, 228, 255, 255, 255, 128, 128, 128},
		},
		{
			{1, 204, 254, 255, 245, 255, 128, 128, 128, 128, 128},
			{207, 160, 250, 255, 238, 128, 128, 128, 128, 128, 128},
			{102, 103, 231, 255, 211, 171, 128, 128, 128, 128, 128},
		},
		{
			{1, 152, 252, 255, 240, 255, 128, 128, 128, 128, 128},
			{177, 135, 243, 255, 234, 225, 128, 128, 128, 128, 128},
			{80, 129, 211, 255, 194, 224, 128, 128, 128, 128, 128},
		},
		{
			{1, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128},
			{246, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128},
			{255, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128},
		},
	},
	{
		{
			{198, 35, 237, 223, 193, 187, 162, 160, 145, 155, 62},
			{131, 45, 198, 221, 172, 176, 220, 157, 252, 221, 1},
			{68, 47, 146, 208, 149, 167, 221, 162, 255, 223, 128},
		},
		{
			{1, 149, 241, 255, 221, 224, 255, 255, 128, 128, 128},
			{184, 141, 234, 253, 222, 220, 255, 199, 128, 128, 128},
			{81, 99, 181, 242, 176, 190, 249, 202, 255, 255, 128},
		},
		{
			{1, 129, 232, 253, 214, 197, 242, 196, 255, 255, 128},
			{99, 121, 210, 250, 201, 198, 255, 202, 128, 128, 128},
			{23, 91, 163, 242, 170, 187, 247, 210, 255, 255, 128},
		},
		{
			{1, 200, 246, 255, 234, 255, 128, 128, 128, 128, 128},
			{109, 178, 241, 255, 231, 245, 255, 255, 128, 128, 128},
			{44, 130, 201, 253, 205, 192, 255, 255, 128, 128, 128},
		},
		{
			{1, 132, 239, 251, 219, 209, 255, 165, 128, 128, 128},
			{94, 136, 225, 251, 218, 190, 255, 255, 128, 128, 128},
			{22, 100, 174, 245, 186, 161, 255, 199, 128, 128, 128},
		},
		{
			{1, 182, 249, 255, 232, 235, 128, 128, 128, 128, 128},
			{124, 143, 241, 255, 227, 234, 128, 128, 128, 128, 128},
			{35, 77, 181, 251, 193, 211, 255, 205, 128, 128, 128},
		},
		{
			{1, 157, 247, 255, 236, 231, 255, 255, 128, 128, 128},
			{121, 141, 235, 255, 225, 227, 255, 255, 128, 128, 128},
			{45, 99, 188, 251, 195, 217, 255, 224, 128, 128, 128},
		},
		{
			{1, 1, 251, 255, 213, 255, 128, 128, 128, 128, 128},
			{203, 1, 248, 255, 255, 128, 128, 128, 128, 128, 128},
			{137, 1, 177, 255, 224, 255, 128, 128, 128, 128, 128},
		},
	},
	{
		{
			{253, 9, 248, 251, 207, 208, 255, 192, 128, 128, 128},
			{175, 13, 224, 243, 193, 185, 249, 198, 255, 255, 128},
			{73, 17, 171, 221, 161, 179, 236, 167, 255, 234, 128},
		},
		{
			{1, 95, 247, 253, 212, 183, 255, 255, 128, 128, 128},
			{239, 90, 244, 250, 211, 209, 255, 255, 128, 128, 128},
			{155, 77, 195, 248, 188, 195, 255, 255, 128, 128, 128},
		},
		{
			{1, 24, 239, 251, 218, 219, 255, 205, 128, 128, 128},
			{201, 51, 219, 255, 196, 186, 128, 128, 128, 128, 128},
			{69, 46, 190, 239, 201, 218, 255, 228, 128, 128, 128},
		},
		{
			{1, 191, 251, 255, 255, 128, 128, 128, 128, 128, 128},
			{223, 165, 249, 255, 213, 255, 128, 128, 128, 128, 128},
			{141, 124, 248, 255, 255, 128, 128, 128, 128, 128, 128},
		},
		{
			{1, 16, 248, 255, 255, 128, 128, 128, 128, 128, 128},
			{190, 36, 230, 255, 236, 255, 128, 128, 128, 128, 128},
			{149, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128},
		},
		{
			{1, 226, 255, 128, 128, 128, 128, 128, 128, 128, 128},
			{247, 192, 255, 128, 128, 128, 128, 128, 128, 128, 128},
			{240, 128, 255, 128, 128, 128, 128, 128, 128, 128, 128},
		},
		{
			{1, 134, 252, 255, 255, 128, 128, 128, 128, 128, 128},
			{213, 62, 250, 255, 255, 128, 128, 128, 128, 128, 128},
			{55, 93, 255, 128, 128, 128, 128, 128, 128, 128, 128},
		},
		{
			{128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128},
			{128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128},
			{128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128},
		},
	},
	{
		{
			{202, 24, 213, 235, 186, 191, 220, 160, 240, 175, 255},
			{126, 38, 182, 232, 169, 184, 228, 174, 255, 187, 128},
			{61, 46, 138, 219, 151, 178, 240, 170, 255, 216, 128},
		},
		{
			{1, 112, 230, 250, 199, 191, 247, 159, 255, 255, 128},
			{166, 109, 228, 252, 211, 215, 255, 174, 128, 128, 128},
			{39, 77, 162, 232, 172, 180, 245, 178, 255, 255, 128},
		},
		{
			{1, 52, 220, 246, 198, 199, 249, 220, 255, 255, 128},
			{124, 74, 191, 243, 183, 193, 250, 221, 255, 255, 128},
			{24, 71, 130, 219, 154, 170, 243, 182, 255, 255, 128},
		},
		{
			{1, 182, 225, 249, 219, 240, 255, 224, 128, 128, 128},
			{149, 150, 226, 252, 216, 205, 255, 171, 128, 128, 128},
			{28, 108, 170, 242, 183, 194, 254, 223, 255, 255, 128},
		},
		{
			{1, 81, 230, 252, 204, 203, 255, 192, 128, 128, 128},
			{123, 102, 209, 247, 188, 196, 255, 233, 128, 128, 128},
			{20, 95, 153, 243, 164, 173, 255, 203, 128, 128, 128},
		},
		{
			{1, 222, 248, 255, 216, 213, 128, 128, 128, 128, 128},
			{168, 175, 246, 252, 235, 205, 255, 255, 128, 128, 128},
			{47, 116, 215, 255, 211, 212, 255, 255, 128, 128, 128},
		},
		{
			{1, 121, 236, 253, 212, 214, 255, 255, 128, 128, 128},
			{141, 84, 213, 252, 201, 202, 255, 219, 128, 128, 128},
			{42, 80, 160, 240, 162, 185, 255, 205, 128, 128, 128},
		},
		{
			{1, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128},
			{244, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128},
			{238, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128},
		},
	},
}

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