Newest 'ffmpeg' Questions - Stack Overflow

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• How to reset PTS for Stream

  8 juin 2017, par VMM2017

  I am trying reset pts on input stream and create new pts and publish stream to RTMP.

  ffmpeg -re -f lavfi -i "movie=${SOURCE}:s=0+1[out0][out1];[0:v]setpts=N/(FRAME_RATE*TB),[0:a]asetpts=N/(FRAME_RATE*TB)" \
         -r 24 -crf 20 \
         -c:v libx264 \
         -c:a aac -ar 44100 -ab 128k -ac 2 -strict -2 \
         -f flv ${DEST} 
  

  If I remove the setpts and asetpts filters them command works. But I need to setpts and asetpts at source before it is given to encoder.

  Please help.

• what is the FFMPEG alternative on ipage shared hosting to create video thumbnails

  8 juin 2017, par user3214617

  so ipage says they dont support FFMPEG on shared hosting and they could not suggest an alternative technology that works on their shared hosting. What is the FFMPEG alternative that works on iPage?

• How do I convert flac to wav on iOS ?

  8 juin 2017, par popctrl

  I have a file which is encoded with FLAC and I want to convert it to WAV.

  I have added this FFMpeg lib to my project and imported it.

  I see some code from this answer, but I am unclear on how to use it:

  #import "avformat.h"
  
  // Some code goes here
  
  /*
   *   avformat_open_input(AVFormatContext **ps, const char *filename, AVInputFormat *fmt, AVDictionary **options)
   */
  int openInputValue = avformat_open_input(&pFormatCtx, utf8FilePath, inputFormat, nil);
  NSLog(@"%s - %d # openInputValue = %d", __PRETTY_FUNCTION__, __LINE__, openInputValue);
  

  I currently have this code in a function which takes NSData holding the FLAC file. If avformat_open_input is the correct call, how do I set the variable? If it is not the correct call, what is?

  This question seems like a duplicate but it doesn't really have a good answer.

  Also note that I don't want a player. This file contains MQA so I need to run it through my own custom decoder.

• ffmpeg re-encoding is very slow in android

  8 juin 2017, par azim vaziri

  I want to create a movie from series of images with complex filter in Android. My command is:

   -loop 1 -t 5 -i input1.jpg
  
   -loop 1 -t 5 -i input2.jpg
  
   -loop 1 -t 5 -i input3.jpg
  
   -loop 1 -t 5 -i input4.jpg
  
   -filter_complex 
   [0:v]scale=640x640,setdar=16/9,fade=t=out:st=4:d=1[v0];
  
   [1:v]scale=640x640,setdar=16/9,fade=t=in:st=0:d=1,fade=t=out:st=4:d=1[v1];
  
   [2:v]scale=640x640,setdar=16/9,fade=t=in:st=0:d=1,fade=t=out:st=4:d=1[v2];
  
   [3:v]scale=640x640,setdar=16/9,fade=t=in:st=0:d=1,fade=t=out:st=4:d=1[v3];
  
   [v0][v1][v2]
   [v3]concat=n=4:v=1:a=0,drawbox=x=10:y=0:w=100:color=black@0.5:t=max,
  
   drawtext=fontfile=homa.ttf:text=title:fontcolor=white:fontsize=24:x=100:y=h-line_h-100,
  
   format=yuv420p[v]
  
   -preset ultrafast -map [v] out.mp4
  

  This code would concatenate four videos that created by four images and finally draw a box and text over final video.

  The speed of re-encoding is very slow. I tried some other options and all of them not useful:

  -thread 16
  -crf 18
  -preset ultrafast
  -strict -2
  

  Please help me, How can I speed up or simulate this command?

• Decode/decompress H.264 back into raw/original file format, then encode into H.265

  8 juin 2017, par clippertm

  I have some files encoded using the H.264 codec.

  There is a loss of quality when I convert them from H.264 to H.265.

  I imagine I should convert them back to raw/original file format, then encode them into H.265.

  Is it possible to decompress/decode H.264 into the original format (perhaps using FFMpeg)?

  Is it the best way to convert from H.264 to H.265 without quality loss?

  Thank you again for your help,