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• Calculate VMAF score while encoding a video with FFmpeg

  31 octobre 2024, par user8071576

  I have an ffmpeg version built with VMAF library. I can use it to calculate the VMAF scores of a distorted video against a reference video using commands like this :

  


  ffmpeg -i distorted.mp4 -i original.mp4 -filter_complex "[0:v]scale=640:480:flags=bicubic[main];[main][1:v]libvmaf=model_path=model/vmaf_v0.6.1.json:log_path=log.json" -f null -


  


  Now, I remember there was a way to get VMAF scores while performing regular ffmpeg encoding. How can I do that at the same time ?

  


  I want to encode a video like this, while also calulate the VMAF of the output file :

  


  ffmpeg -i original.mp4 -crf 27 -s 640x480 out.mp4


  


• Python : Extracting device and lens information from video metadata

  14 mai 2023, par cat_got_my_tongue

  I am interested in extracting device and lens information from videos. Specifically, make and model of the device and the focal length. I was able to do this successfully for still images using the exifread module and extract a whole bunch of very useful information :

  


  image type      : MPO
Image ImageDescription: Shot with DxO ONE
Image Make: DxO
Image Model: DxO ONE
Image Orientation: Horizontal (normal)
Image XResolution: 300
Image YResolution: 300
Image ResolutionUnit: Pixels/Inch
Image Software: V3.0.0 (2b448a1aee) APP:1.0
Image DateTime: 2022:04:05 14:53:45
Image YCbCrCoefficients: [299/1000, 587/1000, 57/500]
Image YCbCrPositioning: Centered
Image ExifOffset: 158
Thumbnail Compression: JPEG (old-style)
Thumbnail XResolution: 300
Thumbnail YResolution: 300
Thumbnail ResolutionUnit: Pixels/Inch
Thumbnail JPEGInterchangeFormat: 7156
Thumbnail JPEGInterchangeFormatLength: 24886
EXIF ExposureTime: 1/3
EXIF FNumber: 8
EXIF ExposureProgram: Aperture Priority
EXIF ISOSpeedRatings: 100
EXIF SensitivityType: ISO Speed
EXIF ISOSpeed: 100
EXIF ExifVersion: 0221
EXIF DateTimeOriginal: 2022:04:05 14:53:45
EXIF DateTimeDigitized: 2022:04:05 14:53:45
EXIF ComponentsConfiguration: CrCbY
EXIF CompressedBitsPerPixel: 3249571/608175
EXIF ExposureBiasValue: 0
EXIF MaxApertureValue: 212/125
EXIF SubjectDistance: 39/125
EXIF MeteringMode: MultiSpot
EXIF LightSource: Unknown
EXIF Flash: Flash did not fire
EXIF FocalLength: 1187/100
EXIF SubjectArea: [2703, 1802, 675, 450]
EXIF MakerNote: [68, 88, 79, 32, 79, 78, 69, 0, 12, 0, 0, 0, 21, 0, 3, 0, 5, 0, 2, 0, ... ]
EXIF SubSecTime: 046
EXIF SubSecTimeOriginal: 046
EXIF SubSecTimeDigitized: 046
EXIF FlashPixVersion: 0100
EXIF ColorSpace: sRGB
EXIF ExifImageWidth: 5406
EXIF ExifImageLength: 3604
Interoperability InteroperabilityIndex: R98
Interoperability InteroperabilityVersion: [48, 49, 48, 48]
EXIF InteroperabilityOffset: 596
EXIF FileSource: Digital Camera
EXIF ExposureMode: Auto Exposure
EXIF WhiteBalance: Auto
EXIF DigitalZoomRatio: 1
EXIF FocalLengthIn35mmFilm: 32
EXIF SceneCaptureType: Standard
EXIF ImageUniqueID: C01A1709306530020220405185345046
EXIF BodySerialNumber: C01A1709306530


  


  Unfortunately, I have been unable to extract this kind of info from videos so far.

  


  This is what I have tried so far, with the ffmpeg module :

  


  import ffmpeg
from pprint import pprint

test_video = "my_video.mp4"
pprint(ffmpeg.probe(test_video)["streams"])


  


  And the output I get contains a lot of info but nothing related to the device or lens, which is what I am looking for :

  


  [{'avg_frame_rate': '30/1',
  'bit_rate': '1736871',
  'bits_per_raw_sample': '8',
  'chroma_location': 'left',
  'codec_long_name': 'H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10',
  'codec_name': 'h264',
  'codec_tag': '0x31637661',
  'codec_tag_string': 'avc1',
  'codec_time_base': '1/60',
  'codec_type': 'video',
  'coded_height': 1088,
  'coded_width': 1920,
  'display_aspect_ratio': '16:9',
  'disposition': {'attached_pic': 0,
                  'clean_effects': 0,
                  'comment': 0,
                  'default': 1,
                  'dub': 0,
                  'forced': 0,
                  'hearing_impaired': 0,
                  'karaoke': 0,
                  'lyrics': 0,
                  'original': 0,
                  'timed_thumbnails': 0,
                  'visual_impaired': 0},
  'duration': '20.800000',
  'duration_ts': 624000,
  'has_b_frames': 0,
  'height': 1080,
  'index': 0,
  'is_avc': 'true',
  'level': 40,
  'nal_length_size': '4',
  'nb_frames': '624',
  'pix_fmt': 'yuv420p',
  'profile': 'Constrained Baseline',
  'r_frame_rate': '30/1',
  'refs': 1,
  'sample_aspect_ratio': '1:1',
  'start_pts': 0,
  'start_time': '0.000000',
  'tags': {'creation_time': '2021-05-08T13:23:20.000000Z',
           'encoder': 'AVC Coding',
           'handler_name': 'VideoHandler',
           'language': 'und'},
  'time_base': '1/30000',
  'width': 1920},
 {'avg_frame_rate': '0/0',
  'bit_rate': '79858',
  'bits_per_sample': 0,
  'channel_layout': 'stereo',
  'channels': 2,
  'codec_long_name': 'AAC (Advanced Audio Coding)',
  'codec_name': 'aac',
  'codec_tag': '0x6134706d',
  'codec_tag_string': 'mp4a',
  'codec_time_base': '1/48000',
  'codec_type': 'audio',
  'disposition': {'attached_pic': 0,
                  'clean_effects': 0,
                  'comment': 0,
                  'default': 1,
                  'dub': 0,
                  'forced': 0,
                  'hearing_impaired': 0,
                  'karaoke': 0,
                  'lyrics': 0,
                  'original': 0,
                  'timed_thumbnails': 0,
                  'visual_impaired': 0},
  'duration': '20.864000',
  'duration_ts': 1001472,
  'index': 1,
  'max_bit_rate': '128000',
  'nb_frames': '978',
  'profile': 'LC',
  'r_frame_rate': '0/0',
  'sample_fmt': 'fltp',
  'sample_rate': '48000',
  'start_pts': 0,
  'start_time': '0.000000',
  'tags': {'creation_time': '2021-05-08T13:23:20.000000Z',
           'handler_name': 'SoundHandler',
           'language': 'und'},
  'time_base': '1/48000'}]


  


  Are these pieces of info available for videos ? Should I be using a different package ?

  


  Thanks.

  


  Edit :

  


  pprint(ffmpeg.probe(test_video)["format"]) gives

  


  {'bit_rate': '1815244',
 'duration': '20.864000',
 'filename': 'my_video.mp4',
 'format_long_name': 'QuickTime / MOV',
 'format_name': 'mov,mp4,m4a,3gp,3g2,mj2',
 'nb_programs': 0,
 'nb_streams': 2,
 'probe_score': 100,
 'size': '4734158',
 'start_time': '0.000000',
 'tags': {'artist': 'Microsoft Game DVR',
          'compatible_brands': 'mp41isom',
          'creation_time': '2021-05-08T12:12:33.000000Z',
          'major_brand': 'mp42',
          'minor_version': '0',
          'title': 'Snipping Tool'}}


  


• Way to bypass video upload when testing using Rspec

  1er mars 2014, par Justin

  I'm testing a page on my app that shows videos. I'm trying to speed up the test by bypassing the video upload process or another way ??

  Maybe I'm using FactoryGirl incorrectly for file uploads..

  Using FactoryGirl, I'm creating the video with

  FactoryGirl.define do
  
   factory :video do
  
    user_id 1
  
    type "Live"
  
    title "FooBar"
  
    description "Foo bar is the description"
  
    video { fixture_file_upload(Rails.root.join('spec', 'files', 'concert.mov'), 'video/mp4') }
  
   end
  
  end

  And in the request's spec I'm describing the videos as :

  describe "videos page" do
  
  
  
    let(:user) { FactoryGirl.create(:user) }
  
    let!(:video1) { FactoryGirl.create(:video) }
  
  
  
    before { visit user_video_path(user) }
  
  
  
    it { should have_title(user.name) }
  
    it { should have_content(user.name) }
  
  
  
    describe "videos" do
  
      it { should have_content(video1.description) }
  
    end
  
  end

  Now, everytime I run the test for this page it goes through the file upload process which takes more time. I'm also using FFmpeg

  **video.rb (video model)**
  
  
  
  validates :video, presence: true
  
  has_attached_file :video, :styles => {
  
                                        :medium => { :geometry => "640x480", :format => 'mp4' },
  
                                        :thumb => { :geometry => "470x290#", :format => 'jpg', :time => 10 }
  
                                       }, 
  
                            :processors => [:ffmpeg]

  What this does when I test the page is the CLI goes through the video upload process like it would if you were uploading the video and watching your local server.