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• Anomalie #4729 : problème d’affichage dans la colone date

  16 avril 2021

  En fait quel est le problème ?

  Parce que "2019-W16" ça veut dire Semaine 16 de 2019…
  C’est ça qui te gène ?

  C’est un format de date normalisé aussi.
  https://en.wikipedia.org/wiki/ISO_week_date

• Python : mp3 to wave.open(f,'r') through ffmpeg pipe

  7 avril 2015, par user2754098

  I’m trying to decode mp3 to wav using ffmpeg :

  import alsaaudio
  
  import wave
  
  from subprocess import Popen, PIPE
  
  
  
  with open('filename.mp3', 'rb') as infile:
  
      p=Popen(['ffmpeg', '-i', '-', '-f', 'wav', '-'], stdin=infile, stdout=PIPE)
  
      ...

  Next i want redirect data from p.stdout.read() to wave.open(file, r) to use readframes(n) and other methods. But i cannot because ’file’ in wave.open(file,’r’) can be only name of file or an open file pointer.

      ...
  
      file = wave.open(p.stdout.read(),'r')
  
      card='default'
  
      device=alsaaudio.PCM(card=card)
  
      device.setchannels(file.getnchannels())
  
      device.setrate(file.getframerate())
  
      device.setformat(alsaaudio.PCM_FORMAT_S16_LE)
  
      device.setsetperiodsize(320)
  
      data = file.readframes(320)
  
      while data:
  
          device.write(data)
  
          data = file.readframes(320)

  I got :

  TypeError: file() argument 1 must be encoded string without NULL bytes, not str

  So is it possible to handle data from p.stdout.read() by wave.open() ?
  Making temporary .wav file isn’t solution.

  Sorry for my english.
  Thanks.

• How to overlay images sequence from pipe over a video stream with ffmpeg ?

  7 juin 2018, par Dotan Simha

  I’m trying to figure out an issue with ffmpeg.
  I have the following installation :
   DeckLink Mini Recorder Card (for HDMI input)
   DeckLink Mini Monitor Card (for HDMI output)

  I’ve successfully managed to take the HDMI input from the Decklink card and output is as-is to the output card with the following command :

  ffmpeg -f decklink -video_input hdmi -raw_format yuv422p10 -i "DeckLink Mini Recorder" -f decklink -pix_fmt uyvy422 "DeckLink Mini Monitor"

  I tried to add a complex-filter to add an overlay of an image, with the following command, and it works :

  ffmpeg -f decklink -video_input hdmi -raw_format yuv422p10 -i "DeckLink Mini Recorder" -i ./tools/bin/windows/2.png -y -filter_complex "[0:1][1:0]overlay=10:10" -f decklink -pix_fmt uyvy422 "DeckLink Mini Monitor"

  I’m getting a realtime feed from the decklink recorder, the image is added to the stream, and it outputs it to the output HDMI card. Everything seems to work.

  Now I tried to change the static image path to use stdin (pipe:0), and I have a tool that constantly streaming PNG images to stdout :

  ffmpeg -f decklink -video_input hdmi -raw_format yuv422p10 -i "DeckLink Mini Recorder" -i pipe:0 -y -filter_complex "[0:1][1:0]overlay=10:10" -f decklink -pix_fmt uyvy422 "DeckLink Mini Monitor"

  The result that i’m getting on the output HDMI card is a static image, of the first frame.
  The output of ffmpeg also changes now, and it looks like it stuck of the first-second of the stream :

  ```
  frame= 30 fps=7.4 q=-0.0 size=N/A time=00:00:01.00 bitrate=N/A speed=0.247x

  frames : 30,
  currentFps : 7,
  currentKbps : NaN,
  targetSize : NaN,
  timemark : ’00:00:01.00’
  ```

  It just remains on 00:00:01.00 and never changes.

  I tried to find the issue, and did the following :

  • Tried to stream Decklink Recorder -> static png file overlay -> Decklink Monitor = IS WORKS

  • Tried to stream static png file -> Decklink Monitor = IS WORKS

  • Tried to stream pipe:0 (PNG files) -> Decklink Monitor = IS WORKS

  • Tried to stream Decklink Recorder -> pipe:0 (PNG files overlay) -> RAW AVI file IS WORKS

  The only issue is with :
   Tried to stream Decklink Recorder -> pipe:0 (PNG files) overlay -> Decklink Monitor DOES NOT WORK

  I suspect that Decklink output is more strict, and my pipe:0 with the PNG images is not stable, and the combination of both causes it to freeze.

  Any idea how to solve it ? :(

  Thanks !