VideoHelp Forum

Our website is made possible by displaying online advertisements to our visitors. Consider supporting us by disable your adblocker or Try ConvertXtoDVD and convert all your movies to DVD. Free trial ! :)
+ Reply to Thread
Results 1 to 4 of 4
Thread
  1. I know that i can extract the streams from the MP4, covert the audio and then create another MP4 from those streams. But i was wonderign if there is a way to do this in a more automated fashion. Such as a command for ffmpeg that i could maybe run as a batch command? The problem i have is that i have many MP4s that i need to do this with, so doing each one manually is an extremely time consuming process.
    Quote Quote  
  2. Member racer-x's Avatar
    Join Date
    Mar 2003
    Location
    3rd Rock from the Sun
    Search Comp PM
    Bad idea.....

    Mp4 should use aac not ac3.
    Got my retirement plans all set. Looks like I only have to work another 5 years after I die........
    Quote Quote  
  3. I'm a MEGA Super Moderator Baldrick's Avatar
    Join Date
    Aug 2000
    Location
    Sweden
    Search Comp PM
    See https://forum.videohelp.com/threads/356314-How-to-batch-convert-multiplex-any-files-with-ffmpeg

    and the batch something like
    Code:
    for %%a in ("*.mp4") do ffmpeg -i "%%a" -c:v copy -c:a ac3 -b:a 224k "newfiles\%%~na.mp4"
    pause
    224k is the audio bitrate.

    But why do you need ac3?
    Quote Quote  
  4. Originally Posted by racer-x View Post
    Bad idea.....

    Mp4 should use aac not ac3.
    The files won't be staying as MP4, they will be converted to blu rays. The reason for needing the change in audio is due to a problem i found occuring over and over. When trying to author a blu from the MP4 files as is, i always end up with audio sync issues. I did however find a work around for this. Which is to extract tge streams, convert the audio and the create an MP4 again. That MP4 when converted to blu has no audio sync issue.
    Quote Quote