Recherche avancée

Sur d’autres sites (7214)

• Video transcoding

  12 mai 2020, par avanjv

  I have successfully implemented video compression commands for android using FFmpeg with following command :

  



  ffmpeg -i input.mp4 -vf "scale=-1:height" -vcodec h264 -b:v 1000k -acodec mp3 output.mp4


  



  It reduces video file size substantially, though after compression video was not playing on some android devices, the issue was resolved by removing codec from the command

  



  ffmpeg -i input.mp4 -vf "scale=-1:height" -b:v 1000k output.mp4


  



  But the processing time is way too longer than expected.
I have found this official linkedin library for video transcoding
https://github.com/linkedin/LiTr

  



  Which can be used for changing resolution and/or bitrate of a video track(s). Has anyone used it ? I am new in this field, I couldn't figure out the methods to be used for scaling and adjusting bitrate of a video file for this lib (Litr). Any help with these methods ?

  


• ffmpeg is adding an extra new line into a box

  4 août 2017, par newbie123

  I’m overlaying weather data over my webcam stream. I put a background box filter, but the padding between the text and the box is uneven. There is "a new line" of extended box bellow the text.

  

  Why is that ? There are no empty lines in a text file I’m providing to ffmpeg. Here is my code for the ffmpeg :

  ffmpeg \
  
  -f lavfi -i anullsrc \
  
  -rtsp_transport tcp \
  
  -i "$SOURCE" \
  
  -vcodec libx264 -pix_fmt yuv420p -preset ultrafast -g 20 -b:v 1000k \
  
  -vf "drawtext="fontfile=${FONT}":textfile=${textfile}:x=5:y=55:reload=1: \
  
  fontcolor=white:fontsize=${FONTSIZE}:box=1:boxborderw=5:boxcolor=black@0.5" \
  
  -threads $THREADS -bufsize 512k \
  
  -f flv "$YOUTUBE_URL/$KEY"

  EDIT :

  I found out what the problem was. I was using printf "%s\n" "$variable1" "$variable2" to create a text file. Printf %s\n automatically prints each variable into a new line. The solution was to print the last variable without the new line. Code example :

  #!/bin/sh
  
  LC_CTYPE=en_US.utf8
  
  
  
  # Get APRS weather data from aprs.fi
  
  
  
  wxstation="S55MA-10"
  
  name="Juršče, Pivka"
  
  
  
  
  
  # Basic weather data
  
  temp="$(wget -q https://aprs.fi/weather/a/${wxstation} -O - | grep Temperature | egrep '[-+]?([0-9]*\.[0-9]+|[0-9]+)' -o)"
  
  humidity="$(wget -q https://aprs.fi/weather/a/${wxstation} -O - | grep Humidity | egrep '[-+]?([0-9]*\.[0-9]+|[0-9]+)' -o)"
  
  wind="$(wget -q https://aprs.fi/weather/a/${wxstation} -O - | grep Wind | egrep '[-+]?([0-9]*\.[0-9]+|[0-9]+)' -o | sed -n -e 2p)"
  
  rain="$(wget -q https://aprs.fi/weather/a/${wxstation} -O - | grep Rain | egrep '[-+]?([0-9]*\.[0-9]+|[0-9]+)' -o | sed -n -e 1p)"
  
  
  
  # Telemetry
  
  radioactivity="$(wget -q https://aprs.fi/telemetry/a/${wxstation} -O - | grep Radioactivity | egrep '[-+]?([0-9]*\.[0-9]+|[0-9]+)' -o | sed -n -e 5p)"
  
  
  
  printf "%s\n" "$name" "Temperature: ${temp}\°C" "Humidity: ${humidity}\%" "Wind: ${wind} m/s" "Rain: ${rain} mm/h"
  
  printf "Radioactivity: ${radioactivity} uSv/h"

• Revision 66845 : Un blog et puis c’est tout

  16 octobre 2012, par cedric@… — Log

  Un blog et puis c’est tout