0e901b2f84
Add methods to MediaFile to calculate the duration, frame count, and frame rate of animated GIFs, PNGs, Ugoiras, and videos. Some considerations: * It's possible to have a GIF or PNG that's technically animated but just has one frame. These are treated as non-animated images. * It's possible to have an animated GIF that has an unspecified frame rate. In this case we assume the frame rate is 10 FPS; this is browser dependent and may not be correct. * Animated GIFs, PNGs, and Ugoiras all support variable frame rates. Technically, each frame has a separate delay, and the delays can be different frame-to-frame. We report only the average frame rate. * Getting the duration of an APNG is surprisingly hard. Most tools don't have good support for APNGs since it's a rare and non-standardized format. The best we can do is get the frame count using ExifTool and the frame rate using ffprobe, then calculate the duration from that.
32 lines
665 B
Ruby
32 lines
665 B
Ruby
# A MediaFile for a webm or mp4 video. Uses ffmpeg to generate preview
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# thumbnails.
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#
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# @see https://github.com/streamio/streamio-ffmpeg
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class MediaFile::Video < MediaFile
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delegate :duration, :frame_count, :frame_rate, :has_audio?, to: :video
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def dimensions
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[video.width, video.height]
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end
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def preview(max_width, max_height)
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preview_frame.preview(max_width, max_height)
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end
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def crop(max_width, max_height)
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preview_frame.crop(max_width, max_height)
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end
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private
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def video
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FFmpeg.new(file)
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end
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def preview_frame
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video.smart_video_preview
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end
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memoize :video, :preview_frame, :dimensions, :duration, :has_audio?
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end
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