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• Revision 35436 : Petites pétouilles en passant par là (écriture aux dernières normes ...

  22 février 2010, par marcimat@… — Log

  Petites pétouilles en passant par là (écriture aux dernières normes ISO)…

• ffmpeg split_by_silence output flac have broken metadata [duplicate]

  20 mars 2023, par Martin

  Input flac File : https://file.io/D1EXEgJ0OtgM

  


  I have a shell script split_by_silence.sh which takes an input audio file, detects split points where silence (or very low volume audio) occurs, and then splits the audio file using ffmpeg into the individual split point segments.

  


  So if 10 split points = 11 audio files exported.

  


  When I run it on an mp3, it produces 11 files (as expected with my input file) and each file has correct length metadata.

  


  But when ffmpeg splits a flac file, the metadata output for 'length' is broken

  


  I've tried following the closest question, marked as a duplicate, here :
Cutting FLAC using ffmpeg does not change timestamps accordingly

  


  By adding a step to re-encode my flac file in ffmpeg :

  


  ffmpeg -i full.flac -ss 0 -t 2241 fixed.flac

  


  Which I'm not sure if is working, but outputs a fixed.flac file. Which when I run with my split command :

  


  ffmpeg -i "inputFile.flac" -c copy -map 0 -f segment -segment_times "22,441,5567,1122,etc..." "%d_output.flac"

  


  The output files still have broken flac 'length' metadata, like you can see in my image, even though when opened in audacity, the file does have a real length. ffmpeg just encoded the wrong value ?

  


  

  


  This is my current ffmpeg version :

  


  $ ffmpeg
ffmpeg version 4.4.2-0ubuntu0.22.04.1 Copyright (c) 2000-2021 the FFmpeg developers
  built with gcc 11 (Ubuntu 11.2.0-19ubuntu1)


  


  And here is my .sh file I run with

  


  $ ./split_by_silence.sh

  


  # -----------------------
# SPLIT BY SILENCE
# Requirements:
#    ffmpeg
#    $ apt-get install bc
# How To Run:
# $ ./split_by_silence.sh "full_lowq.flac" %03d_output.flac

# output title format
OUTPUTTITLE="%d_output.flac"
# input audio filepath
IN="/mnt/c/Users/marti/Documents/projects/split_by_silence2/full.flac"
# output audio filepath
OUTPUTFILEPATH="/mnt/c/Users/marti/Documents/projects/split_by_silence2"
# ffmpeg option: split input audio based on this silencedetect value
SD_PARAMS="-11dB"
MIN_FRAGMENT_DURATION=120 # split option: minimum fragment duration
export MIN_FRAGMENT_DURATION

# -----------------------
# step: ffmpeg
# goal: get comma separated list of split points (use ffmpeg to determine points where audio is at SD_PARAMS [-18db] )

echo "_______________________"
echo "Determining split points..."
SPLITS=$(
    ffmpeg -v warning -i "$IN" -af silencedetect="$SD_PARAMS",ametadata=mode=print:file=-:key=lavfi.silence_start -vn -sn  -f s16le  -y /dev/null \
    | grep lavfi.silence_start= \
    | cut -f 2-2 -d= \
    | perl -ne '
        our $prev;
        INIT { $prev = 0.0; }
        chomp;
        if (($_ - $prev) >= $ENV{MIN_FRAGMENT_DURATION}) {
            print "$_,";
            $prev = $_;
        }
    ' \
    | sed 's!,$!!'
)
echo "split points list= $SPLITS"

# add '5.5' to each split\
IFS=',' read -ra SPLITS_ARRAY <<< "$SPLITS"
for i in "${!SPLITS_ARRAY[@]}"; do
  SPLITS_ARRAY[i]=$(echo "${SPLITS_ARRAY[i]}+5.5" | bc)
done

SPLITS=$(IFS=','; echo "${SPLITS_ARRAY[*]}")
echo "SPLITS=$SPLITS"

# using the split points list, calculate how many output audio files will be created 
num=0
res="${SPLITS//[^,]}"
CHARCOUNT="${#res}"
num=$((CHARCOUNT + 2))
echo "_______________________"
echo "Exporting $num tracks with ffmpeg"

ffmpeg -i "$IN" -c copy -map 0 -f segment -segment_times "$SPLITS" "$OUTPUTFILEPATH/$OUTPUTTITLE"

echo "Done."

echo "------------------------------------------------"
echo "$num TRACKS EXPORTED"


  


  I think this is an open defect ?
https://trac.ffmpeg.org/ticket/4905

  


• ffmpeg drawtext on ubuntu : ffmpeg does not change text location [closed]

  10 juin 2024, par Wolf Wolf

  I am designing a video editor bot for Telegram. I want to use ffmpeg
and I need a text to be placed on the video and change the place of
the text randomly every few seconds.

  


  There is an example on the site itself.

  


  I used the following command :

  


     ffmpeg -i
   "/home/editor/downloads/video_2023-07-10_17-53-05_7375753324605210932.mp4"
   -filter:v drawtext="fontsize=30:fontfile=/usr/share/hellotext=hellotext/share/World':
   x=if(eq(mod(t\,30)\,0)\,rand(0\,(w-text_w))\,x):y=if(eq(mod (t\,30
   )\, 0)\,rand(0\,(h-text_h))\,y)" -codec:v libx264 -codec:a copy
   -preset slow -crf 18 -y output.mp4


  


  This command executes and even the text is placed on the video, now
the problem is that it doesn't change the location of the text. I
tested this before and it worked fine, but now it doesn't run
properly.