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• Batch script calling its own name instead of files of a certain type ?

  27 juin 2020, par R. Elias

  cd %cd%
ffmpeg -i %cd%/%04d.png out.mp4


  



  A script with just this in it works completely fine and outputs exactly what I need it to, but :

  



  :: A simple script to convert a png or jpg image sequence to an         
mp4 file with ffmpeg
cls
@echo off
title PNG2MP4
color C
echo Ensure you have ffmpeg installed and setup in your environment variables or this script won't work.


:QUERY
echo This will convert all image files in the following directory to a single mp4, 
echo %cd%
echo are the files PNGs or JPEGs(PNG/P/JPG/J/CANCEL)?
set/p "ch=>"
if /I %ch%==PNG goto CONVERTPNG
if /I %ch%==P goto CONVERTPNG
if /I %ch%==JPG goto CONVERTJPG
if /I %ch%==J goto CONVERTJPG
if /I %ch%==CANCEL goto :eof
echo Invalid choice & goto QUERY

:CONVERTPNG
cd %cd%
ffmpeg -i %cd%/%04d.png out.mp4

:CONVERTJPG
cd %cd%
ffmpeg -i %cd%/%04d.jpg out.mp4


  



  This more complex version of the script fails, outputting :

  



  C:\tmp/img2mp4.bat4d.jpg: No such file or directory


  



  Why is it no longer calling the files that it did before and is there an easy fix for this ?

  


• what is the best way to IPC with FFMPEG On windows

  17 octobre 2018, par Evren Bingøl

  I have a client and a server code. I create ffmpeg process on
  both ends and use pipes to communicate with ffmpeg. I passed an RGB data and read HVec out , send that the client and do the opposite. basically I’m streaming HVec, The problem I have with the pipes is The buffer size are too small so I have to do a bunch of file read operations from the pipe . and it’s really slows me down. for example if I have to read 100 bytes , function reads 20 bytes. so I have to loop five times to read hundred bytes . of course these numbers are made up . actual data size I try to Read is 1080*1920*4=829400
  1 is writing to a socket and communicating via sockets a better choice.
  2 would name pipes work better ?

  I know third option is to use avcodec lib but I’m trying not to do that

• Use FFMPEG to export audios with gaps filled

  17 octobre 2018, par jcea

  I have a MKV file with gaps in the audio. That is, there are gaps in the MKV audio track timestamps. According to "ffmpeg", the AC3 audio length is 802 seconds, but when exporting the audio to WAV, the resulting file length is 801’53 seconds. That is, the "exported" audio is shorter.

  Triaging the issue with

  ffmpeg -i INPUT.mkv -af ashowinfo -map 0:2 -y -frames:a XXXX -f alaw /dev/null

  I can confirm that the length difference is consistent with gaps in the timestamps of the original audio frames. There are a handful of missing audio frames. I guess those are replaced by silence in the player.

  The command I use to export the audio is :

  ffmpeg -i INPUT.mkv -map 0:1 -ac 2 OUTPUT.wav

  My question is : How can I instruct FFMPEG to preserve the gaps in the original audio, zero (silence) filled ?. The WAV file duration should be the same than the original AC3 audio.

  Given my current workflow, I would rather prefer to not keep the original timestamps in the output file but generate a WAV with (tiny) silences instead. I could consider keeping timestamps if there is no other choice, but this could be quite a pain in my workflow.

  Advice ? Help ?

  Thanks a lot in advance !