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• swscale : add two spatially stable dithering methods

  23 mars 2014, par Øyvind Kolås

  swscale : add two spatially stable dithering methods
  Both of these dithering methods are from http://pippin.gimp.org/a_dither/ for
  
  GIF they can be considered better than bayer (provides more gray-levels), and
  
  spatial stability - often more than twice as good compression and less visual
  
  flicker than error diffusion methods (the methods also avoids error-shadow
  
  artifacts of diffusion dithers).
  These methods are similar to blue/green noise type dither masks ; but are
  
  simple enough to generate their mask on the fly. They are still research work
  
  in progress ; though more expensive to generate masks (which can be used in a
  
  LUT) like ’void and cluster’ and similar methods will yield superior results
  

  • [DH] doc/scaler.texi
  • [DH] libswscale/options.c
  • [DH] libswscale/output.c
  • [DH] libswscale/swscale_internal.h
  • [DH] libswscale/utils.c

• Lost video stream when streaming using FFmpeg and RTSP camera

  13 février 2019, par Vape

  on the Linux server, I have FFmpeg installed which streams video from Chinese low-cost IP camera to Twitch or Youtube server. After a few hours, the video is not visible but on the server side, the FFmpeg is still running and also the IP camera respond to the "ping" command.

  Here is the script I’m using :

  #
  
  # Camera IP
  
  #
  
  AQUARIUM_CAM_IP="192.168.123.102"
  
  
  
  
  
  #
  
  # Aquarium data file
  
  #
  
  AQUARIUM_DATA_FILE="/run/aquarium-cam/data.txt"
  
  
  
  
  
  #
  
  # FFmpeg parameters
  
  #
  
  FFMPEG_LOG_LEVEL=fatal
  
  
  
  # Bitrate (1000k = 1Mbit/s)  and  encoding speed (affects CPU)  and  number of CPU cores to use
  
  FFMPEG_VBR="1000k"
  
  FFMPEG_QUAL="ultrafast"
  
  FFMPEG_THREADS="1"
  
  
  
  # Streaming source
  
  FFMPEG_CAM_RTSP_SRC="rtsp://${AQUARIUM_CAM_IP}:554/user=admin&password=&channel=1&stream=0.sdp" # Camera source
  
  
  
  # Streaming destination
  
  FFMPEG_TWITCH_STREAM_URL_DST="rtmp://live-ber.twitch.tv/app"  # RTMP stream URL
  
  FFMPEG_TWITCH_KEY=""
  
  
  
  # Data overlay setup
  
  FFMPEG_TEXT_OVERLAY_FONT_PATH="OpenSans-Regular.ttf"
  
  FFMPEG_TEXT_OVERLAY_FONT_SIZE=25
  
  FFMPEG_TEXT_OVERLAY_OFFSET_X=5
  
  FFMPEG_TEXT_OVERLAY_OFFSET_Y=60
  
  FFMPEG_TEXT_OVERLAY_RELOAD=1
  
  FFMPEG_TEXT_OVERLAY_BOX="1"
  
  FFMPEG_TEXT_OVERLAY_BOX_BORDER_WIDTH="5"
  
  FFMPEG_TEXT_OVERLAY_BOX_COLOR="blue@0.5"

  the FFmpeg script :

   ffmpeg \
  
      -loglevel ${FFMPEG_LOG_LEVEL} -f lavfi -i anullsrc \
  
      -rtsp_transport tcp \
  
      -i "${FFMPEG_CAM_RTSP_SRC}" \
  
      -vcodec libx264 -pix_fmt yuv420p -preset ${FFMPEG_QUAL} -g 75 -b:v ${FFMPEG_VBR} \
  
      -vf "\
  
  drawtext=fontfile=${FFMPEG_TEXT_OVERLAY_FONT_PATH}:textfile=${AQUARIUM_DATA_FILE}:\
  
  x=${FFMPEG_TEXT_OVERLAY_OFFSET_X}:y=${FFMPEG_TEXT_OVERLAY_OFFSET_X}:\
  
  reload=${FFMPEG_TEXT_OVERLAY_RELOAD}: \
  
  fontcolor=white:fontsize=${FFMPEG_TEXT_OVERLAY_FONT_SIZE}:\
  
  box=${FFMPEG_TEXT_OVERLAY_BOX}:boxborderw=${FFMPEG_TEXT_OVERLAY_BOX_BORDER_WIDTH}:\
  
  boxcolor=${FFMPEG_TEXT_OVERLAY_BOX_COLOR}"\
  
      -threads ${FFMPEG_THREADS} -bufsize 512k \
  
      -f flv "${FFMPEG_TWITCH_STREAM_URL_DST}/${FFMPEG_TWITCH_KEY}"

  The other strange thing is that when the FFmpeg start and the stream begin the CPU utilization is about 30% in the case when there is no stream but the FFmpeg is still alive the CPU utilization is below 20% or less.

  Any Idea how to resolve this kind of problem ?
  Has FFmpeg some option to terminate if there is no "stream" or if it has lost a connection with a camera ?

• How to optimize FFMPEG/ Chromacast video ?

  5 août 2021, par Hasan

  Re-broadcast a live broadcast by chromecasting it. The code below delays 5 seconds.

  


  Server I use :
https://instances.vantage.sh/?selected=c5.2xlarge

  


  Can you help me optimize the code ?

  


  chromakey.sh

  


  
# Combine two files using a chromakey effects
filter_complex(){
  local videoWith="${1:-1920}"  # Video Size
  local videoHeight="${2:-1080}"  # Video Size
  local key="${3:-00FF00}"      # Colorkey colour - default vaue is 0000FF or green
  local colorSim="${4:-0.2}"    # Colorkey similarity level - default value is 0.2
  local colorBlend="${5:-0.1}"  # Colorkey blending level - default value is 0.1

  # Update color variable according to user input
  # This makes the matching case insensitive
  if [[ $3 =~ ^[0-9A-F]{6}$ ]]; then
    key=$3
  elif [[ $(tr "[:upper:]" "[:lower:]" <<<"$1")  = "blue" ]]; then
    key="0000FF"
  elif [[ $(tr "[:upper:]" "[:lower:]" <<<"$1")  = "green" ]]; then
    key="00FF00"
  elif [[ $(tr "[:upper:]" "[:lower:]" <<<"$1")  = "red" ]]; then
    key="FF0000"
  elif [[ $(tr "[:upper:]" "[:lower:]" <<<"$1")  = "purple" ]]; then
    key="0000FF"
  elif [[ $(tr "[:upper:]" "[:lower:]" <<<"$1")  = "orange" ]]; then
    key="ff9900"
  elif [[ $(tr "[:upper:]" "[:lower:]" <<<"$1")  = "yellow" ]]; then
    key="FFFF00"
  fi

  
  filterString="[1:v]scale=$videoWith x $videoHeight,chromakey=0 x $key:$colorSim:$colorBlend[ckout];[0:v]scale=(iw*sar)*max($videoWith/(iw*sar)\,$videoHeight/ih):ih*max($videoWith/(iw*sar)\,$videoHeight/ih), crop=$videoWith:$videoHeight[bg];[bg][ckout]overlay[out]"
  
  printf '%s%s%s%s%s' $filterString
}

ffmpeg -re -stream_loop -1 -i "${1}" -i "${2}" -preset ultrafast -filter_complex "$(filter_complex "${@:4}")" -map '[out]' -c:v libx264 -f flv "${3}"


  


  Usage : ./chromakey.sh mask.mp4 http://example.com/live/broadcast_orj rtmp ://example.com/live/broadcast_greenscreen 1920 1080 green 0.1 0.2