mastodon-glitch/lib/paperclip/blurhash_transcoder.rb

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# frozen_string_literal: true
module Paperclip
class BlurhashTranscoder < Paperclip::Processor
def make
return @file unless options[:style] == :small || options[:blurhash]
width, height, data = blurhash_params
# Guard against segfaults if data has unexpected size
raise RangeError("Invalid image data size (expected #{width * height * 3}, got #{data.size})") if data.size != width * height * 3 # TODO: should probably be another exception type
attachment.instance.blurhash = Blurhash.encode(width, height, data, **(options[:blurhash] || {}))
@file
rescue Vips::Error => e
raise Paperclip::Error, "Error while generating blurhash for #{@basename}: #{e}"
end
private
def blurhash_params
if Rails.configuration.x.use_vips
image = Vips::Image.thumbnail(@file.path, 100)
[image.width, image.height, image.colourspace(:srgb).extract_band(0, n: 3).to_a.flatten]
else
pixels = convert(':source -depth 8 RGB:-', source: File.expand_path(@file.path)).unpack('C*')
geometry = options.fetch(:file_geometry_parser).from_file(@file)
[geometry.width, geometry.height, pixels]
end
end
end
end