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• lavc/h274 : transpose IDCT

  28 septembre 2023, par Niklas Haas

  lavc/h274 : transpose IDCT
  This is mathematically equivalent to what we were doing before, but
  
  gives subtly different results due to rounding (rows first vs columns
  
  first). Doing it this way makes our film grain database generation match
  
  reference implementation and now produces bit-exact outputs in my
  
  testing.
  Rename the transposed variables to be a bit less confusing.
  

  • [DH] libavcodec/h274.c

• MP4 to DASH using ffmpeg linux too slow

  16 mai 2022, par darox

  Currently, I'm working at a project that contains 2000 video mp4 files, and I need convert all of them in mpeg dash files.

  



  I have this script :

  



  MYDIR=$(dirname $(readlink -f ${BASH_SOURCE[0]}))
SAVEDIR=$(pwd)

# Check programs
if [ -z "$(which ffmpeg)" ]; then
    echo "Error: ffmpeg is not installed"
    exit 1
fi

if [ -z "$(which MP4Box)" ]; then
    echo "Error: MP4Box is not installed"
    exit 1
fi

cd "$MYDIR"

TARGET_FILES=$(find ./ -maxdepth 1 -type f \( -name "*.mov" -or -name "*.mp4" \))
for f in $TARGET_FILES
do
  fe=$(basename "$f") # fullname of the file
  f="${fe%.*}" # name without extension

  if [ ! -d "${f}" ]; then #if directory does not exist, convert
    echo "Converting \"$f\" to multi-bitrate video in MPEG-DASH"

    mkdir "${f}"

    ffmpeg -y -i "${fe}" -c:a aac -b:a 192k -vn "${f}_audio.m4a"


    ffmpeg -y -i "${fe}" -preset slow -tune film -vsync passthrough -write_tmcd 0 -an -c:v libx264 -x264opts 'keyint=25:min-keyint=25:no-scenecut' -crf 23 -maxrate 800k -bufsize 2000k -pix_fmt yuv420p -vf "scale=-2:720" -f mp4  "${f}_800.mp4"
    # static file for ios and old browsers and mobile safari
    ffmpeg -y -i "${fe}" -preset slow -tune film -movflags +faststart -vsync passthrough -write_tmcd 0 -c:a aac -b:a 160k -c:v libx264  -crf 23 -maxrate 1400 -bufsize 3000k -pix_fmt yuv420p -f mp4 "${f}/${f}.mp4"


    rm -f ffmpeg*log*
    # if audio stream does not exist, ignore it
    if [ -e "${f}_audio.m4a" ]; then
        MP4Box -dash-strict 2000 -rap -frag-rap  -bs-switching no -profile "dashavc264:live" "${f}_5000.mp4" "${f}_3000.mp4" "${f}_1500.mp4" "${f}_800.mp4" "${f}_400.mp4" "${f}_audio.m4a" -out "${f}/${f}.mpd"
        rm "${f}_5000.mp4" "${f}_3000.mp4" "${f}_1500.mp4" "${f}_800.mp4" "${f}_400.mp4" "${f}_audio.m4a"
    else
        MP4Box -dash-strict 2000 -rap -frag-rap  -bs-switching no -profile "dashavc264:live" "${f}_5000.mp4" "${f}_3000.mp4" "${f}_1500.mp4" "${f}_800.mp4" "${f}_400.mp4" -out "${f}/${f}.mpd"
        rm "${f}_5000.mp4" "${f}_3000.mp4" "${f}_1500.mp4" "${f}_800.mp4" "${f}_400.mp4" 
    fi
    # create a jpg for poster. Use imagemagick or just save the frame directly from ffmpeg is you don't have cjpeg installed.
    ffmpeg -i "${fe}" -ss 00:00:00 -vframes 1  -qscale:v 10 -n -f image2 - | cjpeg -progressive -quality 75 -outfile "${f}"/"${f}".jpg

    fi

done

cd "$SAVEDIR"


  



  This is working fine, but, taking a long time to convert only single file, I have intel 7 and a simple mp4 file take 30 min to be converted. How can I accelerate this process ? Must I change something in this script ?

  



  Thank you.

  


• ffplay : add support for interactive volume control

  27 septembre 2015, par Ganesh Ajjanagadde

  ffplay : add support for interactive volume control
  This is a feature heavily inspired by the mpv player. At the moment, methods
  
  for adjusting volume in ffplay are rather clumsy : either one needs to set it
  
  system-wide, or one needs to set it via the volume filter.
  This patch adds key bindings identical to the mpv defaults for muting/unmuting
  
  and increasing/decreasing the volume interactively without any introduction of
  
  external dependencies.
  TODO : doc update, possible mouse button bindings (mpv has this).
  Signed-off-by : Ganesh Ajjanagadde <gajjanagadde@gmail.com>
  
  Signed-off-by : Marton Balint <cus@passwd.hu>
  

  • [DH] ffplay.c