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• Converting avi to mp4 : audio is out of sync

  17 octobre 2011, par M.S

  I'm using ffmpeg to convert a video from avi to mp4. The audio / video in the output mp4 are out of sync. I researched and found the following link, which suggests that this is an issue with newer builds of ffmpeg:

  http://forum.videohelp.com/threads/320342-Audio-out-of-sync-problem-with-FFMPEG-encoding-MP4-%28h-264-AAC%29?p=1983858&viewfull=1#post1983858

  I tried build 18715 as suggested and indeed the a/v is in sync. I thought I'd just use this build, but I then realized that the output file size is much larger (about a third more). Any idea why? Bandwidth is currently a major concern in my application.

  I'm trying to either solve the sync problem with the latest build or figure out how to reduce the size of the file with the older build. Any suggestions?

  EDIT: The command I use for the conversion:

  ffmpeg -i test.avi -vb 100k -ab 48k -r 20 test.mp4

  This is a very low res and quite static video and the low bitrate is adequate (and isn't a cause for any problem when not using mp4).

• compile ffmpeg on stand redhat

  17 octobre 2011, par Raoul

  I'm working on a redhat server which isn't connected to the internet, so I can't download things directly onto the server. I can transfer them via SCP from another server.

  Is there a step by step guide to compiling ffmpeg for redhat?

• Best way to load in a video and to grab images using c++

  17 octobre 2011, par Seb

  I am looking for a fast way to load in a video file and to create images from them at certain intervals ( every second, every minute, every hour, etc.).

  I tried using DirectShow, but it just ran too slow for me to start the video file and move to a certain location to get data and to save it out to an image. Even if I disabled the reference clock. Tried OpenCV, but it has trouble opening the AVI file unless I know the exact codec information. So if I know a way to get the codec information out from OpenCV I may give it another shot. I tried to use FFMPEG, but I don't have as much control over it as well as I would wish.

  Any advice would be greatly appreciated. This is being developed on a Windows box since it has to be hosted on a Windows box.

• I'm running ffmpeg but when i compile it it shows this error on cygwin

  16 octobre 2011, par Bryan G

  I want to know or do u have a sample project how to compile ffmpeg on android thank you

• FFMPEG permission in windows wamp

  15 octobre 2011, par shababhsiddique

  I am trying to build a video sharing site using drupal 6. One of the modules i am using is ffmpeg , it requires me to set a ffmpeg binary file location . I downloaded ffmpeg from here

  http://ffmpeg.arrozcru.org/autobuilds/ffmpeg/mingw32/static/

  I placed it on C:\ffmpeg\bin\ffmpeg.exe and gave this path with the slashes changed to /

  it got the encoders information .. but i cant test it. It shows a message like

  Fmpeg failed to create an output file. This could be due to permission problems or an error from the encoding settings.

  I found that i need permission. How do i set permission? i am using wamp on windows. Please help urgent.