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Contents
require 'delegate'
class FormatParser::DPXParser
include FormatParser::IOUtils
require_relative 'dpx_parser/dpx_structs'
BE_MAGIC = 'SDPX'
LE_MAGIC = BE_MAGIC.reverse
# There is no official MIME type for DPX, so we have
# to invent something useful. We will prefix it with x-
# to indicate that it is a vendor subtype
DPX_MIME_TYPE = 'image/x-dpx'
class ByteOrderHintIO < SimpleDelegator
def initialize(io, is_little_endian)
super(io)
@little_endian = is_little_endian
end
def le?
@little_endian
end
end
private_constant :ByteOrderHintIO
def likely_match?(filename)
filename =~ /\.dpx$/i
end
def call(io)
io = FormatParser::IOConstraint.new(io)
magic = safe_read(io, 4)
return unless [BE_MAGIC, LE_MAGIC].include?(magic)
io.seek(0)
dpx_structure = DPX.read_and_unpack(ByteOrderHintIO.new(io, magic == LE_MAGIC))
w = dpx_structure.fetch(:image).fetch(:pixels_per_line)
h = dpx_structure.fetch(:image).fetch(:lines_per_element)
display_w = w
display_h = h
pixel_aspect_w = dpx_structure.fetch(:orientation).fetch(:horizontal_pixel_aspect)
pixel_aspect_h = dpx_structure.fetch(:orientation).fetch(:vertical_pixel_aspect)
# Find display height and width based on aspect only if the file structure has pixel aspects
if pixel_aspect_h != 0 && pixel_aspect_w != 0
pixel_aspect = pixel_aspect_w / pixel_aspect_h.to_f
image_aspect = w / h.to_f * pixel_aspect
if image_aspect > 1
display_h = (display_w / image_aspect).round
else
display_w = (display_h * image_aspect).round
end
end
FormatParser::Image.new(
format: :dpx,
width_px: w,
height_px: h,
display_width_px: display_w,
display_height_px: display_h,
intrinsics: dpx_structure,
content_type: DPX_MIME_TYPE,
)
end
FormatParser.register_parser new, natures: :image, formats: :dpx
end
Version data entries
35 entries across 35 versions & 1 rubygems