/usr/lib/python2.7/dist-packages/webm/yuv.py is in python-webm 0.2.2-2.1.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 | # -*- coding: utf-8 -*-
"""
Copyright (c) 2011, Daniele Esposti <expo@expobrain.net>
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
* The name of the contributors may be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
"""
from handlers import BitmapHandler
"""
Porting of the YUVtoRGB converter code from the Chromium project. See
third_party/libwebp/yuv.c and /third_party/libwebp/yuv.h files for the original
source code.
"""
# -----------------------------------------------------------------------------
# Internal functions
# -----------------------------------------------------------------------------
# YUV conversion constants
YUV_FIX = 16 # fixed-point precision
YUV_RANGE_MIN = -227 # min value of r/g/b output
YUV_RANGE_MAX = 256 + 226 # max value of r/g/b output
YUV_HALF = 1 << (YUV_FIX - 1)
VP8kVToR = [0] * 256
VP8kUToB = [0] * 256
VP8kVToG = [0] * 256
VP8kUToG = [0] * 256
VP8kClip = [0] * (YUV_RANGE_MAX - YUV_RANGE_MIN)
def _init_yuv_module():
"""
Initialise the YUVtoRGB lookup tables
"""
for i in xrange(256):
VP8kVToR[i] = (89858 * (i - 128) + YUV_HALF) >> YUV_FIX
VP8kUToG[i] = -22014 * (i - 128) + YUV_HALF
VP8kVToG[i] = -45773 * (i - 128)
VP8kUToB[i] = (113618 * (i - 128) + YUV_HALF) >> YUV_FIX
for i in xrange(YUV_RANGE_MIN, YUV_RANGE_MAX):
k = ((i - 16) * 76283 + YUV_HALF) >> YUV_FIX
k = 0 if k < 0 else 255 if k > 255 else k
VP8kClip[i - YUV_RANGE_MIN] = k
# Initialise YUVtoRGB lookup table on module loading
_init_yuv_module()
def _decode_YUV_image(image):
"""
Decode the given image in YUV format to a RGB byte array
:param image: The image in YUV format to be decoded
:type image: BitmapHandler
:rtype: bytearray
"""
rgb_bitmap = bytearray()
for h in xrange(image.height):
for w in xrange(image.width):
# Get luma
i = h * image.stride + w
y = image.bitmap[i]
# WORKAROUND:
# This is a workaround for YUV to RGB decoding to have a useful
# grayscale image from the YUV data.
# Remove this when the correct YUV to color RGB function is
# found.
rgb_bitmap.extend((y, y, y))
# # Get chrominance
# i = h * image.uv_stride + int(w/2)
#
# if w % 2:
# u = image.u_bitmap[i] & 0b1111
# v = image.v_bitmap[i] & 0b1111
# else:
# u = image.u_bitmap[i] >> 4
# v = image.v_bitmap[i] >> 4
#
# # Calculate RGB values
# r_off = VP8kVToR[v]
# g_off = (VP8kVToG[v] + VP8kUToG[u]) >> YUV_FIX
# b_off = VP8kUToB[u]
#
# rgb_bitmap.append( VP8kClip[y + r_off - YUV_RANGE_MIN] )
# rgb_bitmap.append( VP8kClip[y + g_off - YUV_RANGE_MIN] )
# rgb_bitmap.append( VP8kClip[y + b_off - YUV_RANGE_MIN] )
# End
return rgb_bitmap
# -----------------------------------------------------------------------------
# Public functions
# -----------------------------------------------------------------------------
def YUVtoRGB(image):
"""
Convert the given WebP image instance from a YUV format to an RGB format
:param image: The WebP image in YUV format
:type image: BitmapHandler
:rtype: BitmapHandler
"""
return BitmapHandler(
_decode_YUV_image(image), BitmapHandler.RGB,
image.width, image.height, image.width * 3
)
def YUVtoRGBA(image):
"""
Convert the given WebP image instance form YUV format to RGBA format
:param image: The WebP image in YUV format
:type image: BitmapHandler
:rtype: BitmapHandler
"""
rgb_bitmap = _decode_YUV_image(image)
rgba_bitmap = bytearray()
for i in xrange(len(rgb_bitmap) / 3):
i *= 3
rgba_bitmap.append(rgb_bitmap[i])
rgba_bitmap.append(rgb_bitmap[i + 1])
rgba_bitmap.append(rgb_bitmap[i + 2])
rgba_bitmap.append(0xff)
# Return the BitmapHandler in RGB format
return BitmapHandler(
rgba_bitmap, BitmapHandler.RGBA,
image.width, image.height, image.width * 4
)
def YUVtoBGR(image):
"""
Convert the given WebP image instance form YUV format to BGR format
:param image: The WebP image in YUV format
:type image: BitmapHandler
:rtype: BitmapHandler
"""
rgb_bitmap = _decode_YUV_image(image)
bgr_bitmap = bytearray()
for i in xrange(len(rgb_bitmap) / 3):
i *= 3
bgr_bitmap.append(rgb_bitmap[i + 2])
bgr_bitmap.append(rgb_bitmap[i + 1])
bgr_bitmap.append(rgb_bitmap[i])
# Return the BitmapHandler in BGR format
return BitmapHandler(
bgr_bitmap, BitmapHandler.BGR,
image.width, image.height, image.width * 3
)
def YUVtoBGRA(image):
"""
Convert the given WebP image instance form YUV format to BGRA format
:param image: The WebP image in YUV format
:type image: BitmapHandler
:rtype: BitmapHandler
"""
rgb_bitmap = _decode_YUV_image(image)
bgra_bitmap = bytearray()
for i in xrange(len(rgb_bitmap) / 3):
i *= 3
bgra_bitmap.append(rgb_bitmap[i + 2])
bgra_bitmap.append(rgb_bitmap[i + 1])
bgra_bitmap.append(rgb_bitmap[i])
bgra_bitmap.append(0xff)
# Return the BitmapHandler in BGRA format
return BitmapHandler(
bgra_bitmap, BitmapHandler.BGRA,
image.width, image.height, image.width * 4
)
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