chinwagsocial/app/lib/video_metadata_extractor.rb
Claire 166f6e4b50
Fix some media attachments being converted with too high framerates (#17619)
Video files with variable framerates are converted to constant framerate videos
and the output framerate picked by ffmpeg is based on the original file's
container framerate (which can be different from the average framerate).

This means that an input video with variable framerate with about 30 frames per
second on average, but a maximum of 120 fps will be converted to a constant 120
fps file, which won't be processed by other Mastodon servers.

This commit changes it so that input files with VFR and a maximum framerate
above the framerate threshold are converted to VFR files with the maximum frame
rate enforced.
2022-02-22 17:11:22 +01:00

55 lines
1.8 KiB
Ruby

# frozen_string_literal: true
class VideoMetadataExtractor
attr_reader :duration, :bitrate, :video_codec, :audio_codec,
:colorspace, :width, :height, :frame_rate, :r_frame_rate
def initialize(path)
@path = path
@metadata = Oj.load(ffmpeg_command_output, mode: :strict, symbol_keys: true)
parse_metadata
rescue Terrapin::ExitStatusError, Oj::ParseError
@invalid = true
rescue Terrapin::CommandNotFoundError
raise Paperclip::Errors::CommandNotFoundError, 'Could not run the `ffprobe` command. Please install ffmpeg.'
end
def valid?
!@invalid
end
private
def ffmpeg_command_output
command = Terrapin::CommandLine.new('ffprobe', '-i :path -print_format :format -show_format -show_streams -show_error -loglevel :loglevel')
command.run(path: @path, format: 'json', loglevel: 'fatal')
end
def parse_metadata
if @metadata.key?(:format)
@duration = @metadata[:format][:duration].to_f
@bitrate = @metadata[:format][:bit_rate].to_i
end
if @metadata.key?(:streams)
video_streams = @metadata[:streams].select { |stream| stream[:codec_type] == 'video' }
audio_streams = @metadata[:streams].select { |stream| stream[:codec_type] == 'audio' }
if (video_stream = video_streams.first)
@video_codec = video_stream[:codec_name]
@colorspace = video_stream[:pix_fmt]
@width = video_stream[:width]
@height = video_stream[:height]
@frame_rate = video_stream[:avg_frame_rate] == '0/0' ? nil : Rational(video_stream[:avg_frame_rate])
@r_frame_rate = video_stream[:r_frame_rate] == '0/0' ? nil : Rational(video_stream[:r_frame_rate])
end
if (audio_stream = audio_streams.first)
@audio_codec = audio_stream[:codec_name]
end
end
@invalid = true if @metadata.key?(:error)
end
end