mastodon-glitch/lib/paperclip/vips_lazy_thumbnail.rb

142 lines
5.6 KiB
Ruby

# frozen_string_literal: true
module Paperclip
class LazyThumbnail < Paperclip::Processor
GIF_MAX_FPS = 60
GIF_MAX_FRAMES = 3000
GIF_PALETTE_COLORS = 32
ALLOWED_FIELDS = %w(
icc-profile-data
).freeze
class PixelGeometryParser
def self.parse(current_geometry, pixels)
width = Math.sqrt(pixels * (current_geometry.width.to_f / current_geometry.height)).round.to_i
height = Math.sqrt(pixels * (current_geometry.height.to_f / current_geometry.width)).round.to_i
Paperclip::Geometry.new(width, height)
end
end
def initialize(file, options = {}, attachment = nil)
super
@crop = options[:geometry].to_s[-1, 1] == '#'
@current_geometry = options.fetch(:file_geometry_parser, Geometry).from_file(@file)
@target_geometry = options[:pixels] ? PixelGeometryParser.parse(@current_geometry, options[:pixels]) : options.fetch(:string_geometry_parser, Geometry).parse(options[:geometry].to_s)
@format = options[:format]
@current_format = File.extname(@file.path)
@basename = File.basename(@file.path, @current_format)
correct_current_format!
end
def make
return File.open(@file.path) unless needs_convert?
dst = TempfileFactory.new.generate([@basename, @format ? ".#{@format}" : @current_format].join)
if preserve_animation?
if @target_geometry.nil? || (@current_geometry.width <= @target_geometry.width && @current_geometry.height <= @target_geometry.height)
target_width = 'iw'
target_height = 'ih'
else
scale = [@target_geometry.width.to_f / @current_geometry.width, @target_geometry.height.to_f / @current_geometry.height].min
target_width = (@current_geometry.width * scale).round
target_height = (@current_geometry.height * scale).round
end
# The only situation where we use crop on GIFs is cropping them to a square
# aspect ratio, such as for avatars, so this is the only special case we
# implement. If cropping ever becomes necessary for other situations, this will
# need to be expanded.
crop_width = crop_height = [target_width, target_height].min if @target_geometry&.square?
filter = begin
if @crop
"scale=#{target_width}:#{target_height}:force_original_aspect_ratio=increase,crop=#{crop_width}:#{crop_height}"
else
"scale=#{target_width}:#{target_height}:force_original_aspect_ratio=decrease"
end
end
command = Terrapin::CommandLine.new(Rails.configuration.x.ffmpeg_binary, '-nostdin -i :source -map_metadata -1 -fpsmax :max_fps -frames:v :max_frames -filter_complex :filter -y :destination', logger: Paperclip.logger)
command.run({ source: @file.path, filter: "#{filter},split[a][b];[a]palettegen=max_colors=#{GIF_PALETTE_COLORS}[p];[b][p]paletteuse=dither=bayer", max_fps: GIF_MAX_FPS, max_frames: GIF_MAX_FRAMES, destination: dst.path })
else
transformed_image.write_to_file(dst.path, **save_options)
end
dst
rescue Vips::Error, Terrapin::ExitStatusError => e
raise Paperclip::Error, "Error while optimizing #{@basename}: #{e}"
rescue Terrapin::CommandNotFoundError
raise Paperclip::Errors::CommandNotFoundError, 'Could not run the `ffmpeg` command. Please install ffmpeg.'
end
private
def correct_current_format!
# If the attachment was uploaded through a base64 payload, the tempfile
# will not have a file extension. It could also have the wrong file extension,
# depending on what the uploaded file was named. We correct for this in the final
# file name, which is however not yet physically in place on the temp file, so we
# need to use it here. Mind that this only reliably works if this processor is
# the first in line and we're working with the original, unmodified file.
@current_format = File.extname(attachment.instance_read(:file_name))
end
def transformed_image
# libvips has some optimizations for resizing an image on load. If we don't need to
# resize the image, we have to load it a different way.
if @target_geometry.nil?
Vips::Image.new_from_file(preserve_animation? ? "#{@file.path}[n=-1]" : @file.path, access: :sequential).copy.mutate do |mutable|
(mutable.get_fields - ALLOWED_FIELDS).each do |field|
mutable.remove!(field)
end
end
else
Vips::Image.thumbnail(@file.path, @target_geometry.width, height: @target_geometry.height, **thumbnail_options).mutate do |mutable|
(mutable.get_fields - ALLOWED_FIELDS).each do |field|
mutable.remove!(field)
end
end
end
end
def thumbnail_options
@crop ? { crop: :centre } : { size: :down }
end
def save_options
case @format
when 'jpg'
{ Q: 90, interlace: true }
else
{}
end
end
def preserve_animation?
@format == 'gif' || (@format.blank? && @current_format == '.gif')
end
def needs_convert?
needs_different_geometry? || needs_different_format? || needs_metadata_stripping?
end
def needs_different_geometry?
(options[:geometry] && @current_geometry.width != @target_geometry.width && @current_geometry.height != @target_geometry.height) ||
(options[:pixels] && @current_geometry.width * @current_geometry.height > options[:pixels])
end
def needs_different_format?
@format.present? && @current_format != ".#{@format}"
end
def needs_metadata_stripping?
@attachment.instance.respond_to?(:local?) && @attachment.instance.local?
end
end
end