Audio out of sync

tautitan · #1 (**permalink**) 5th Feb 2007, 12:09 pm

Hi

I am having trouble when trying to convert videos to play on my mp4 player. As far as I can tell it's a rockchip player with a 2.4" screen. When I convert a video to Xvid AVI format and transfer it to the player the audio is out of sync with the video after about 2-3 seconds, sometimes more, sometimes less. The weird thing is that the video plays perfectly on my laptop.

I am using the converter software that came with the player (AVConverter 1.0) but have tried all the different software under the sun I can think of to no avail.

I am assuming that the problem is that the software converts the video to 24 FPS, which is what my player supports and does nothing with the audio.

Any ideas guys?

Matt

lattesurf · #2 (**permalink**) 5th Feb 2007, 12:17 pm

tautitan , you might wanna try lowering the FPS to perhaps 16fps. Sometimes the sync problem is not too obvious at this rate.

tautitan · #3 (**permalink**) 5th Feb 2007, 12:32 pm

Hi

Thanks for the reply but encoding at 16FPS seems to make a the problem worse lol, leading me to believe that its not "dropping" audio as it does the video frames.

lattesurf · #4 (**permalink**) 5th Feb 2007, 12:47 pm

tautitan , which audio codec are you using for the avi format?

I noticed that with raw audio (ie .wav) the sync problem is lesser to none. Whilst with compressed audio (eg .mp3) the sync get worse.

tautitan · #5 (**permalink**) 5th Feb 2007, 1:02 pm

I'm fairly new to the whole video conversion thing bit I'm using Xvid for video and it's using MP2 for audio as per the xilisoft tutorial on this site. I am trying to convert from various formats includng MP4 and FLV.

http://cgi.ebay.co.uk/ws/eBayISAPI.d...MEWN:IT&ih=003

Thats my player if it helps.

tautitan · #6 (**permalink**) 5th Feb 2007, 1:40 pm

One addition, when i skip to a different part of the video the audio is fine again for about 2 seconds, at which point the audio begins to "drift" away from the video again. Is there any way to tell the audio file how many "frames" it should have so it synchronises properly with the video?

tadad1 · #7 (**permalink**) 5th Feb 2007, 3:42 pm

tautitan, If the video plays ok on your PC but lags on your player then it maybe that the video is encoded to high for your player to handle.
Be sure that you have a decent codec pack installed like K-Lite Mega Codec Pack.
Try lowering the audio bitrate settings and see if the problem improves.
What resolution are you encoding to 320x240?
Did the player come with a sample video if so could you upload it to www.uploaded.to and leave a link for download so I can see what settings it uses.

tautitan · #8 (**permalink**) 6th Feb 2007, 7:42 am

I have uploaded the video that came with my player to my blog which is at www.compublog.co.uk/defaultvideo.avi

I am fairly sure that this one is in sync but its not english so I really can't tell all that well lol.

tautitan · #9 (**permalink**) 6th Feb 2007, 12:14 pm

OK, OK I think I've got it sussed. I had to enable full stream audio processing in virtualdub to get it to sync the audio when it converted it to 24fps. I have no idea whether this is what made the difference but I have converted two previously unworking videos to have perfectly synced audio.

So here is the list of things I do to a wmv.

Once through Xilisoft MP4 Converter 3 to make it an AVI
Once through VirtualDub to convert it to 24FPS
Once through AvConverter 1.0 Presumably Giving It MP2 Audio

Anyways that sequence seems to work so I'm happy

Thanks to the guys who helped me figure this out.

Matt