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• Concatenation and Transcoding of MPEG-TS files FFMPEG

  20 décembre 2020, par SquawkBirdies

  I have a DVR which records over-the-air TV and saves the recordings in the MPEG-TS format, splitting each episode across multiple files, each 500 MB in size.

  



  To simplify archiving, I have been trying to write a shell script to automate the process of concatenating the files together and transcoding them into a more common video format, like h.264.

  



  Here are the steps I have performed so far :

  



  

  • I wanted to make sure that the files I was getting were valid in the first place. To test this, each section was transcoded in Handbrake before being merged using ffmpeg's concat command. This worked, but was manual and added an annoying black frame between each section.

  


  • I wrote a shell script to find all the sections of an episode in a folder and put the file names into a text file that the concat demuxer could parse.

  


  • Tested this command :

  


  



  


  


  ffmpeg -hide_banner -f concat -i video_files_tmp.txt -c:v libx264 -pix_fmt yuv420p -c:a aac $2$OUTPUT_FILE_NAME

  


  


  




  During the transcode, this would throw many warnings and errors, such as "PES packet size mismatch". At some point, it would warn that more than 1,000 frame were skipped. When the output was played, it would skip frames and result in a file where the video froze partway through but the audio continued playing. I tried adding -vsync 0 to the output as well.

  



  

  • Then, tried splitting the concatenation and transcode into two steps :

  


  



  


  


  ffmpeg -hide_banner -f concat -i video_files_tmp.txt -c copy output_tmp.ts
ffmpeg -hide_banner -i output_tmp.ts -c:v libx265 -pix_fmt yuv420p -c:a aac $2$OUTPUT_FILE_NAME

  


  


  




  This did basically the same thing as before.

  



  

  • Tried using the libx265 encoder instead. Same result.

  


  • Then, I tried just playing the concatenated MPEG-TS file directly, which also would freeze at some point during the playback.

  


  



  I was wondering about what ffmpeg flags or options to set to get this working, or other options I could try ? Thanks !

  


• How to combine three ffmpeg commands into one ?

  26 juillet 2018, par Nane

  I am pretty confused that how to combine three ffmpeg commnads into one which also consists of two inputs.

  // rescale with certain dimension 
  
  ffmpeg -i front.mp4 -filter_complex scale=600:400 rescale.mp4
  
  
  
  //Attach to image
  
  ffmpeg -i 600800.jpg  -i rescale.mp4 -filter_complex "overlay=(W-w)/2:(H-h)/2" final.mp4
  
  
  
  // After Changed to specific even size Burn Subtitles with Draw Text
  
  ffmpeg -i final.mp4 -filter_complex "drawtext=fontfile=Lucida Grande.ttf:text='I am TEXT':fontsize=72:fontcolor=white:x=50:y=100,subtitles=sample.srt:force_style='Fontsize=22,OutlineColour=&H55000000,BorderStyle=3'" CheckMe.mp4

• can we use -vf and -filter:a with -filter_complex

  15 avril 2021, par Eswar T

  I want to combine some videos with some specific features like(video Speed, volume increase, resolution, rotation, framerate) of the final output of the video
We can do this process in 2 steps like

  


  Combine video

  


  ffmpeg -i test1.mp4 -i test2.mp4 -filter_complex [0:v:0][0:a:0][1:v:0][1:a:0]concat=n=2:v=1:a=1[outv][outa] -map [outv] -map [outa] output.mp4


  


  Then apply filters

  


  ffmpeg -i output.mp4 -filter:a volume=1.0,atempo=1.0 -vf transpose=2,setpts=1/1.0*PTS,scale=3840X2160,fps=30 final.mp4


  


  I can do it this way but is there any way to do it in 1 step

  


  thank you