Recherche avancée

Sur d’autres sites (14923)

• ffmpeg extracts only part of 1 audio stream from .ts file

  6 juillet 2020, par Shakalakah

  Here is what ffprobe input.ts shows :

  


    libavutil     56. 55.100 / 56. 55.100
  libavcodec    58. 93.100 / 58. 93.100
  libavformat       58. 47.100 / 58. 47.100
  libavdevice       58. 11.100 / 58. 11.100
  libavfilter         7. 86.100 /  7. 86.100
  libswscale          5.  8.100 /  5.  8.100
  libswresample       3.  8.100 /  3.  8.100
  libpostproc       55.  8.100 / 55.  8.100
Input #0, mpegts, from 'D:\Downloads\TEST\audio.ts':
  Duration: 02:22:29.67, start: 0.000000, bitrate: 51 kb/s
  Program 1
    Stream #0:0[0x101]: Audio: aac (LC) ([15][0][0][0] / 0x000F), 48000 Hz, stereo, fltp, 83 kb/s


  


  So the length of .ts file is 2h:22m:29.67s and looks like it contains only audio (AAC) : when i open it in Windows Media Player i can jump to any position within the 2h:22m range and hear sound playing, and there is no video on the screen. This makes me think the extracted audio will also be of 2h:22m length, but i get only a 51m:14s file.

  I tried the following commands :

  1) ffmpeg -i input.ts -vn -acodec copy outputaudio.aac

  2) ffmpeg -i input.ts -map 0:v -map 0:a -c copy outputaudio.aac (as far as i understood this is "extract ALL audiotracks" command)

  3) ffmpeg -i input.ts -ss 00:00:00 -t 02:22:29.6 -q:a 0 -map a outputaudio.aac (to force extraction to the full length, i.e. 2h:22m)

  4) ffmpeg -i input.ts -map 0:a outputaudio.aac -map 0:v outputonlyvideo.avi (i heard this is an alternative way to force extraction of full-length audio through simultaneous extraction of video. Though looks like my .ts has no video, i decided to try this command too and got an error message : Stream map '0:v' matches no streams)

  What am i doing wrong ? Which alternative commands can i try ?

  Is it possible, that the real length of audio stream is 51m:14s only ? But why i can listen to all 2h:22m length in Windows Media Player - could 51m:14s piece be somehow looped inside .ts to create an impression of 2h:22m length ?

  


• download part youtube video with ffmpeg ?

  1er août 2020, par testoflow

  I can't get this right
  
ffmpeg works well so can you help me ?

  


  #I can't get this right

  


  #!/bin/bash
var=$(xclip -o)

if [ -z $var ]; then  
    echo 'copia url a descargar al portapapeles'  
fi  

printf "(1) download part of video without audio\n"
printf "(2) download part of audio\n"
echo
echo -n 'opcion: '
read opcion
case $opcion in
    "1") c=$(youtube-dl -g $var | awk '{ if(NR==1) print $0 }' | sed 's/^/"/;s/$/"/')  && echo -n 'start time: ' && read segundos && echo -n 'duration: ' && read duration &&  ffmpeg -i $c -ss $segundos -t $duration probe.mp4;;  
    "2") b=$(youtube-dl -g $var | awk '{ if(NR==2) print $0 }' | sed 's/^/"/;s/$/"/')  && echo $b && ffmpeg -ss 0 -i $b  -t 10 probe.mp3;;  
esac  


  


• How to stream only a part of a video without downloading the whole thing ?

  11 mai 2024, par Abbas

  I am building a YouTube video trimmer, and currently, it takes the YouTube video ID, downloads the whole video from the server (Even it is like 10 hours long), and then it trims it according to user's inputted timeframe using ffmpeg.

  


  Now the problem with this is that it takes so much time to download the whole video even if we want a small piece of it hence it is highly impractical.

  


  I was thinking to implement something like an HTML5 video player does when you seek the video forward. It just jumps to the part where you seek-ed to without downloading the part you skipped over. How can I only download a part of a video file from a server in form of a buffer and then generate an already trimmed video file from that ? I don't know if that is even possible on the server-side, but video players do it on the client-side.