Recherche avancée

Sur d’autres sites (4008)

• Metadict in ffmpeg does not have rotate information

  14 juillet 2022, par Lucky Sunda

  My aim is to extract frames out of a video but many times the frames are inverted. This is happening because "VideoCapture" in cv2 does read the rotate flag data present in the video metadata. I am running it on mac and installed "ffmpeg" package (5.0.1) using brew package manager. This is my code to check rotation present in a video using ffmpeg.

  


  import ffmpeg 
import cv2   
import pprint 
pp = pprint.PrettyPrinter(depth=4)
def check_rotation(path_video_file):
    # this returns meta-data of the video file in form of a dictionary
    meta_dict = ffmpeg.probe(path_video_file)
    pp.pprint(meta_dict)

    # from the dictionary, meta_dict['streams'][0]['tags']['rotate'] is the key
    # we are looking for
    rotateCode = None
    if int(meta_dict['streams'][0]['tags']['rotate']) == 90:
        rotateCode = cv2.ROTATE_90_CLOCKWISE
    elif int(meta_dict['streams'][0]['tags']['rotate']) == 180:
        rotateCode = cv2.ROTATE_180
    elif int(meta_dict['streams'][0]['tags']['rotate']) == 270:
        rotateCode = cv2.ROTATE_90_COUNTERCLOCKWISE

    return rotateCode



  


  Here the meta_dict is supposed to have information about the rotation but it is not there.
printing out meta_dict gives :

  


  {'format': {'bit_rate': '18498544',
            'duration': '3.584000',
            'filename': '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': '8287348',
            'start_time': '0.000000',
            'tags': {'com.android.version': '11',
                     'compatible_brands': 'isommp42',
                     'creation_time': '2021-12-08T10:56:57.000000Z',
                     'major_brand': 'mp42',
                     'minor_version': '0'}},
 'streams': [{'avg_frame_rate': '990000/34997',
              'bit_rate': '18804651',
              'bits_per_raw_sample': '8',
              'chroma_location': 'left',
              'closed_captions': 0,
              'codec_long_name': 'H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10',
              'codec_name': 'h264',
              'codec_tag': '0x31637661',
              'codec_tag_string': 'avc1',
              'codec_type': 'video',
              'coded_height': 1080,
              'coded_width': 1920,
              'color_primaries': 'bt470bg',
              'color_range': 'pc',
              'color_space': 'bt470bg',
              'color_transfer': 'smpte170m',
              'display_aspect_ratio': '16:9',
              'disposition': {'attached_pic': 0,
                              'captions': 0,
                              'clean_effects': 0,
                              'comment': 0,
                              'default': 1,
                              'dependent': 0,
                              'descriptions': 0,
                              'dub': 0,
                              'forced': 0,
                              'hearing_impaired': 0,
                              'karaoke': 0,
                              'lyrics': 0,
                              'metadata': 0,
                              'original': 0,
                              'still_image': 0,
                              'timed_thumbnails': 0,
                              'visual_impaired': 0},
              'duration': '3.499700',
              'duration_ts': 314973,
              'extradata_size': 35,
              'field_order': 'progressive',
              'film_grain': 0,
              'has_b_frames': 0,
              'height': 1080,
              'id': '0x1',
              'index': 0,
              'is_avc': 'true',
              'level': 40,
              'nal_length_size': '4',
              'nb_frames': '99',
              'pix_fmt': 'yuvj420p',
              'profile': 'High',
              'r_frame_rate': '120/1',
              'refs': 1,
              'sample_aspect_ratio': '1:1',
              'side_data_list': [{...}],
              'start_pts': 3168,
              'start_time': '0.035200',
              'tags': {'creation_time': '2021-12-08T10:56:57.000000Z',
                       'handler_name': 'VideoHandle',
                       'language': 'eng',
                       'vendor_id': '[0][0][0][0]'},
              'time_base': '1/90000',
              'width': 1920},
             {'avg_frame_rate': '0/0',
              'bit_rate': '128986',
              '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_type': 'audio',
              'disposition': {'attached_pic': 0,
                              'captions': 0,
                              'clean_effects': 0,
                              'comment': 0,
                              'default': 1,
                              'dependent': 0,
                              'descriptions': 0,
                              'dub': 0,
                              'forced': 0,
                              'hearing_impaired': 0,
                              'karaoke': 0,
                              'lyrics': 0,
                              'metadata': 0,
                              'original': 0,
                              'still_image': 0,
                              'timed_thumbnails': 0,
                              'visual_impaired': 0},
              'duration': '3.584000',
              'duration_ts': 172032,
              'extradata_size': 2,
              'id': '0x2',
              'index': 1,
              'nb_frames': '168',
              'profile': 'LC',
              'r_frame_rate': '0/0',
              'sample_fmt': 'fltp',
              'sample_rate': '48000',
              'start_pts': 0,
              'start_time': '0.000000',
              'tags': {'creation_time': '2021-12-08T10:56:57.000000Z',
                       'handler_name': 'SoundHandle',
                       'language': 'eng',
                       'vendor_id': '[0][0][0][0]'},
              'time_base': '1/48000'}]}


  


  Can someone please help me to find if rotation is present in a video ?

  


• Convert mkv to mp4

  7 juin 2021, par KalemKutu

  I have a video file input.mkv
It contains 2 audios and only 1 substring.

  


  I want to convert it in mp4 with same quality.
It should contain same : 2 audios and 1 substring.

  


  I tried :

  


  ffmpeg -i input.mkv -map 0:v:0 -map 0:a:0 -map 0:a:1 -map 0:s:0 -c copy output.mp4

  


  I got an error message :

  


      Could not find tag for codec subrip in stream #3, codec not currently supported in container
Could not write header for output file #0 (incorrect codec parameters ?): Invalid argument
Error initializing output stream 0:3 -- 


  


  .

  


  I tried also

  


  ffmpeg -i input.mkv -c copy -c:s mov_text output.mp4

  


  But this line converts audio=1 and substitle=1, but NO audio 2.

  


  Anyone who can help me ?

  


  Thanks,
Kalem

  


  PS : I am using mac version of ffmpeg downloaded on "2021-06-05"

  


• Image generated by System.Drawing.Image is 10x larger than original file

  13 mai 2021, par Ninbura

  I've written a Powershell script that extracts one frame from a dshow capture device using FFmpeg, and then copies the output image from a file to my clipboard :

  


  $screenshot = [System.Drawing.Image]::FromFile((Get-Item -Path $outputFilePath))
[System.Windows.Forms.Clipboard]::SetImage($screenshot)
$screenshot.Dispose()


  


  The original file is a 1MB JPEG, but the image in my clipboard is an 11MB PNG. When I go to paste this file into something like Discord the file size is too large, unless you have Discord Nitro.

  


  Is there any way to avoid this file size inflation while using [System.Drawing.Image]::FromFile() ?

  


  Here's an easy test template :

  


  Add-Type -AssemblyName System.Drawing
Add-Type -AssemblyName System.Windows.Forms

$screenshot = [System.Drawing.Image]::FromFile((Get-Item -Path "Path to picture"))
[System.Windows.Forms.Clipboard]::SetImage($screenshot)
$screenshot.Dispose()


  


  Edit 2021/05/13 :

  


  Interestingly, it's starting to seem like this is a limitation of copying an image to a clipboard. I decided to dig deeper and see if the image size was increasing when I drew the image with System.Drawing.Image or when I pushed it in my clipboard with System.Windwos.Forms.Clipboard. If I save the image before putting it my clipboard like so, it retains the original file size, even if I change the extension to png :

  


  Add-Type -AssemblyName System.Drawing
Add-Type -AssemblyName System.Windows.Forms

$screenshot = [System.Drawing.Image]::FromFile((Get-Item -Path "C:\Users\gabri\Pictures\FFScreenshots\2021-05-12 19-04-26.845.jpeg"))
$screenshot.Save("C:\Users\gabri\Pictures\FFScreenshots\test.jpeg") # test.png makes no difference
$screenshot.Dispose()


  


  So it would seem that the image grows exponentially in size specifically when I push it to my clipboard. I verified this by simply uploading an image to Discord, copying it to my clipboard (click image > Open original > right click and copy result), and uploading it again. Sure enough, the new image pasted from my clipboard was around 10x the size of the original image (1MB vs 12MB). I wondered if this was a "limitation" of Windows so I ran the same test on Ubuntu 20.04. Uploaded an image to Discord, copied the image to my clipboard, and uploaded it again. Once again the image was about 10x larger, though slightly smaller than then when I uploaded the image from my clipboard on my Windows machine (11.4MB VS 12MB). Just to make sure this wasn't limited to Discord, I ran the same test with Gmail in-browser on both operating systems, same result.

  


  Alas, there appears to be something happening when you copy an image to a clipboard that drastically increases file size. One thing's for sure, whatever's happening is definitely over my head.