8b3ab04724
Fix how the duration of videos and animated GIFs / PNGs is calculated. If we can't determine the duration from the file metadata, then play the entire video or animation back using FFmpeg and scrape the duration and frame count. This is necessary for things like WebM files where the duration metadata is optional, or animated GIFs and PNGs that don't have a duration field in the metadata, only a frame count and a sequence of frame delays.
103 lines
2.5 KiB
Ruby
103 lines
2.5 KiB
Ruby
# A MediaFile for a JPEG, PNG, or GIF file. Uses libvips for resizing images.
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#
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# @see https://github.com/libvips/ruby-vips
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# @see https://libvips.github.io/libvips/API/current
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class MediaFile::Image < MediaFile
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# http://jcupitt.github.io/libvips/API/current/VipsForeignSave.html#vips-jpegsave
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JPEG_OPTIONS = { Q: 90, background: 255, strip: true, interlace: true, optimize_coding: true }
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# http://jcupitt.github.io/libvips/API/current/libvips-resample.html#vips-thumbnail
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THUMBNAIL_OPTIONS = { size: :down, linear: false }
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CROP_OPTIONS = { crop: :attention, linear: false }
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def dimensions
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image.size
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rescue Vips::Error
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[0, 0]
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end
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def is_corrupt?
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image.stats
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false
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rescue Vips::Error
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true
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end
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def duration
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return nil if !is_animated?
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video.duration
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end
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def frame_count
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if file_ext == :gif
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image.get("n-pages")
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elsif file_ext == :png
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metadata.fetch("PNG:AnimationFrames", 1)
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else
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nil
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end
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end
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def frame_rate
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return nil if !is_animated? || frame_count.nil? || duration.nil? || duration == 0
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frame_count / duration
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end
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def channels
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image.bands
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end
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def colorspace
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image.interpretation
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end
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# @see https://github.com/jcupitt/libvips/wiki/HOWTO----Image-shrinking
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# @see http://jcupitt.github.io/libvips/API/current/Using-vipsthumbnail.md.html
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def preview(width, height)
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output_file = Tempfile.new(["image-preview", ".jpg"])
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resized_image = preview_frame.image.thumbnail_image(width, height: height, **THUMBNAIL_OPTIONS)
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resized_image.jpegsave(output_file.path, **JPEG_OPTIONS)
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MediaFile::Image.new(output_file)
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end
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def crop(width, height)
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output_file = Tempfile.new(["image-crop", ".jpg"])
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resized_image = preview_frame.image.thumbnail_image(width, height: height, **CROP_OPTIONS)
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resized_image.jpegsave(output_file.path, **JPEG_OPTIONS)
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MediaFile::Image.new(output_file)
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end
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def preview_frame
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if is_animated?
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FFmpeg.new(file).smart_video_preview
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else
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self
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end
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end
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def is_animated?
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frame_count.to_i > 1
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end
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def is_animated_gif?
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file_ext == :gif && is_animated?
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end
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def is_animated_png?
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file_ext == :png && is_animated?
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end
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# @return [Vips::Image] the Vips image object for the file
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def image
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Vips::Image.new_from_file(file.path, fail: true).autorot
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end
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def video
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FFmpeg.new(file)
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end
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memoize :image, :video, :dimensions, :is_corrupt?, :is_animated_gif?, :is_animated_png?
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end
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