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• How can I add subtitles to FFMPEG live streaming ?

  23 février 2016, par Andrey Pietrov

  Is it possible to add any kind of subtitles(closed captions) to ffmpeg live stream of any format ?

• Python & OpenCV - VideoCapture.read() always returns false

  21 août 2017, par Julen

  I need to extract frames from a video at a given time, and I’m using OpenCV for it. I’m using Linux Mint 18.1, but it must also run on Ubuntu.

  This code example is not working for me :

  import cv2
  
  
  
  print('making screenshot from {0}'.format('/tmp/big_buck_bunny_720p_5mb.mp4'))
  
  
  
  cap = cv2.VideoCapture(video_path)
  
  cap.set(cv2.CAP_PROP_POS_MSEC,1000)
  
  ret,frame = cap.read()
  
  print(ret)                      # This is false
  
  cv2.imwrite("image.jpg", frame) # Creates an empty file

  (I’ve checked that the path of the video is correct and that the file is not corrupted).

  I have installed the Python OpenCV 3.3.0 version :

  >>> import cv2
  
  >>> cv2.__version__
  
  '3.3.0'

  I’ve compiled and installed the source for OpenCV (with the WITH_FFMPEG=ON option) :

  git clone https://github.com/Itseez/opencv.git /tmp/opencv-3                                                                                                                                                                                
  
  /tmp/opencv-3                                                                                                                                                                                                                            
  
  mkdir -p release                                                                                                                                                                                                                            
  
  cd release                                                                                                                                                                                                                                  
  
  cmake -D WITH_FFMPEG=ON -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local ..                                                                                                                                                   
  
  make                                                                                                                                                                                                                                        
  
  sudo make install     

  The output of ffmpeg -version is the following :

  ffmpeg version 2.8.11-0ubuntu0.16.04.1 Copyright (c) 2000-2017 the FFmpeg developers
  
  built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.4) 20160609
  
  configuration: --prefix=/usr --extra-version=0ubuntu0.16.04.1 --build-suffix=-ffmpeg --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --cc=cc --cxx=g++ --enable-gpl --enable-shared --disable-stripping --disable-decoder=libopenjpeg --disable-decoder=libschroedinger --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librtmp --enable-libschroedinger --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzvbi --enable-openal --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzmq --enable-frei0r --enable-libx264 --enable-libopencv
  
  libavutil      54. 31.100 / 54. 31.100
  
  libavcodec     56. 60.100 / 56. 60.100
  
  libavformat    56. 40.101 / 56. 40.101
  
  libavdevice    56.  4.100 / 56.  4.100
  
  libavfilter     5. 40.101 /  5. 40.101
  
  libavresample   2.  1.  0 /  2.  1.  0
  
  libswscale      3.  1.101 /  3.  1.101
  
  libswresample   1.  2.101 /  1.  2.101
  
  libpostproc    53.  3.100 / 53.  3.100

  What am I missing ?

• Django api returns Gif as JPG despite a function to add it as video

  7 septembre 2023, par Earthling

  I'm trying to upload a .gif to my django 3.2 api. I have already ran troubleshoots through Postman and came to the conclusion that my flutter app sends it as a .gif and it gets returned as a .jpg. The problem is on the backend. Here is my relevant code which checks for file_meme subtype and then the function should convert the incoming .gif to a video :

  


  


  


  def add_media(self, file, order=None):
    check_can_add_media(post=self)

    is_in_memory_file = isinstance(file, InMemoryUploadedFile) or isinstance(file, SimpleUploadedFile)

    if is_in_memory_file:
        file_mime = magic.from_buffer(file.read())
    elif isinstance(file, TemporaryUploadedFile):
        file_mime = magic.from_file(file.temporary_file_path())
    else:
        file_mime = magic.from_file(file.name)

    check_mimetype_is_supported_media_mimetypes(file_mime)
    # Mime check moved pointer
    file.seek(0)

    file_mime_types = file_mime.split('/')

    file_mime_type = file_mime_types[0]
    file_mime_subtype = file_mime_types[1]

    temp_files_to_close = []

    if file_mime_subtype == 'gif':
                if is_in_memory_file:
                    file = write_in_memory_file_to_disk(file)

                temp_dir = tempfile.gettempdir()
                converted_gif_file_name = os.path.join(temp_dir, str(uuid.uuid4()) + '.mp4')

                ff = ffmpy.FFmpeg(
                    inputs={file.temporary_file_path() if hasattr(file, 'temporary_file_path') else file.name: None},
                    outputs={converted_gif_file_name: None})
                ff.run()
                converted_gif_file = open(converted_gif_file_name, 'rb')
                temp_files_to_close.append(converted_gif_file)
                file = File(file=converted_gif_file)
                file_mime_type = 'video'

            has_other_media = self.media.exists()
    
    if file_mime_type == 'image':
        post_image = self._add_media_image(image=file, order=order)
        if not has_other_media:
            self.media_width = post_image.width
            self.media_height = post_image.height
            self.media_thumbnail = file

    elif file_mime_type == 'video':
        post_video = self._add_media_video(video=file, order=order)
        if not has_other_media:
            self.media_width = post_video.width
            self.media_height = post_video.height
            self.media_thumbnail = post_video.thumbnail.file
    else:
        raise ValidationError(
            _('Unsupported media file type')
        )

    for file_to_close in temp_files_to_close:
        file_to_close.close()
            
            
    self.save()        

  


  


  



  def _add_media_image(self, image, order):
    return PostImage.create_post_media_image(image=image, post_id=self.pk, order=order)

def _add_media_video(self, video, order):
    return PostVideo.create_post_media_video(file=video, post_id=self.pk, order=order)


@classmethod
    def create_post_media_image(cls, image, post_id, order):
        hash = sha256sum(file=image.file)
        post_image = cls.objects.create(image=image, post_id=post_id, hash=hash, thumbnail=image)
        PostMedia.create_post_media(type=PostMedia.MEDIA_TYPE_IMAGE,
                                    content_object=post_image,
                                    post_id=post_id, order=order)
        return post_image


@classmethod
    def create_post_media_video(cls, file, post_id, order):
        hash = sha256sum(file=file.file)
        video_backend = get_backend()

        if isinstance(file, InMemoryUploadedFile):
            # If its in memory, doing read shouldn't be an issue as the file should be small.
            in_disk_file = write_in_memory_file_to_disk(file)
            thumbnail_path = video_backend.get_thumbnail(video_path=in_disk_file.name, at_time=0.0)
        else:
            thumbnail_path = video_backend.get_thumbnail(video_path=file.file.name, at_time=0.0)

        with open(thumbnail_path, 'rb+') as thumbnail_file:
            post_video = cls.objects.create(file=file, post_id=post_id, hash=hash, thumbnail=File(thumbnail_file), )
        PostMedia.create_post_media(type=PostMedia.MEDIA_TYPE_VIDEO,
                                    content_object=post_video,
                                    post_id=post_id, order=order)
        return post_video
        
    


  


  I'm not sure where the problem is. From my limited understanding, it is taking only the first frame of the .gif and uploading it as an image.