Recherche avancée

Sur d’autres sites (9390)

• Convert mp3 to AAC with mpeg-2 container (FFMPEG)

  18 mars 2016, par jsurf

  I’m trying to convert an mp3 audio file to an AAC file with FFMPEG, and I need the audio to be wrapped in an MPEG-2 container.
  The resulting AAC file needs to be AAC-LC (Low Complexity), 1-channel, CBR mode, 44100 sample rate, and 48kb/s bitrate, so I use this command :

  ffmpeg -y -i input.mp3 -ar 44100 -ab 48k -acodec libfdk_aac -ac 1 output.aac

  But when I examine the ADTS headers, the audio file is always being wrapped in an MPEG-4 container. I have tried all the codecs listed here but I still end up with an mpeg-4 container wrapped around the audio : http://trac.ffmpeg.org/wiki/AACEncodingGuide.

  Here are the headers I get when examining the AAC output file :

  mpeg_type : ’MPEG4’,
  profile : 2,
  profile_name : ’AAC LC’,
  sample_freq : 44100,
  channel_config : 1,
  channels : 1,
  frame_length : 139,
  buffer_fullness : 157,
  number_of_frames : 1,
  frames_per_sec : 43.06640625

  Any ideas as to why ffmpeg wraps an mp4 container around the audio ? Can I get around this somehow ? Are there any other encoders I can try aside from FFMPEG ? I was giving FAAC encoder a shot and it gives me the proper encoding and ADTS headers, but alas it does not support mp3, only WAV.

• releases doc formating

  13 février 2013, par jonrohan

  m docs/releases.md
  

  releases doc formating

• How do I get duration of an In Memory Video in Python / Django ?

  19 juillet, par Lucas Tonon

  So I was successfully using the following code to get the duration of a saved video in Django.

  



  def get_video_length(file_path):
command = [
    'ffprobe',
    '-v',
    'error',
    '-show_entries',
    'format=duration',
    '-of',
    'default=noprint_wrappers=1:nokey=1',
    file_path
  ]

try:
    output = check_output( command, stderr=STDOUT ).decode()
except CalledProcessError as e:
    output = e.output.decode()

return output


  



  But now I need to get the duration of an uploaded file before saving it.
I have a serializer with a FileField and on validate method I should check the video duration.
For instance :

  



  class VideoSerializer(serializers.Serializer):
video = serializers.FileField(required=True, validators=[validate_media_extension, validate_video_duration])


  



  Then on validate_video_duration I needed to call some method like get_video_length, but I need an alternative to get the duration from the video in memory. The object that I have is an instance of InMemoryUploadedFile (https://docs.djangoproject.com/en/2.2/_modules/django/core/files/uploadedfile/)