58 行
2.1 KiB
Ruby
58 行
2.1 KiB
Ruby
# frozen_string_literal: true
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class VideoMetadataExtractor
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attr_reader :duration, :bitrate, :video_codec, :audio_codec,
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:colorspace, :width, :height, :frame_rate, :r_frame_rate
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def initialize(path)
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@path = path
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@metadata = Oj.load(ffmpeg_command_output, mode: :strict, symbol_keys: true)
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parse_metadata
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rescue Terrapin::ExitStatusError, Oj::ParseError
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@invalid = true
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rescue Terrapin::CommandNotFoundError
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raise Paperclip::Errors::CommandNotFoundError, 'Could not run the `ffprobe` command. Please install ffmpeg.'
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end
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def valid?
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!@invalid
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end
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private
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def ffmpeg_command_output
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command = Terrapin::CommandLine.new('ffprobe', '-i :path -print_format :format -show_format -show_streams -show_error -loglevel :loglevel')
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command.run(path: @path, format: 'json', loglevel: 'fatal')
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end
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def parse_metadata
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if @metadata.key?(:format)
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@duration = @metadata[:format][:duration].to_f
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@bitrate = @metadata[:format][:bit_rate].to_i
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end
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if @metadata.key?(:streams)
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video_streams = @metadata[:streams].select { |stream| stream[:codec_type] == 'video' }
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audio_streams = @metadata[:streams].select { |stream| stream[:codec_type] == 'audio' }
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if (video_stream = video_streams.first)
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@video_codec = video_stream[:codec_name]
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@colorspace = video_stream[:pix_fmt]
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@width = video_stream[:width]
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@height = video_stream[:height]
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@frame_rate = video_stream[:avg_frame_rate] == '0/0' ? nil : Rational(video_stream[:avg_frame_rate])
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@r_frame_rate = video_stream[:r_frame_rate] == '0/0' ? nil : Rational(video_stream[:r_frame_rate])
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# For some video streams the frame_rate reported by `ffprobe` will be 0/0, but for these streams we
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# should use `r_frame_rate` instead. Video screencast generated by Gnome Screencast have this issue.
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@frame_rate ||= @r_frame_rate
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end
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if (audio_stream = audio_streams.first)
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@audio_codec = audio_stream[:codec_name]
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end
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end
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@invalid = true if @metadata.key?(:error)
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end
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end
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