7 replies to this topic

[AlanBrownOne]

I just converted two different avi files to iPod m4v's and found that the audio track was out of sync with the video track on the converted files.  I tried again, this time taking one of the avi's and converting it to H.264 mov file and experienced the same thing.  The original avi files were each 1.2 gb.  

I love the convenience and speed of your software, but the conversions are of no use to me this way.

Suggestions?  Ideas on what is going wrong?

Thanks for any help you can offer.

--Alan

[Brian Dunning]

Same thing happened to me, converting an MP4 file. By the end of the movie the sound was as much as 2 minutes behind the picture.

[tsantee]

Same thing happened to me, converting an MP4 file. By the end of the movie the sound was as much as 2 minutes behind the picture.

I'm willing to look into this if you'll tell me the resolution and frame rate of the source video and if it is NTSC or PAL. Same goes for the letterboxing but I need to know I'm working with a file that is no different in its specs than the one you are using.

Something else that might be useful is how does Crunch describe the specs for the export when you have Automatic selected? I'm wondering if you chose 24 fps instead of 29.97 fps in the Custom settings if that will fix the audio sync issue. Also, the widescreen video output probably should be 720x404 or 640x360 if the source is standard definition.

Edited by tsantee, 11 May 2007 - 04:03 PM.

[AlanBrownOne]

I'm willing to look into this if you'll tell me the resolution and frame rate of the source video and if it is NTSC or PAL. Same goes for the letterboxing but I need to know I'm working with a file that is no different in its specs than the one you are using.

The frame rate is 29.97, original size:  640x480, NTSC, 16-bit Integer (Little Endian), Stereo, 48 kHz, data rate: 30.28mbits/sec.

Hope this is the information that will help you figure it out.  Thank you for your help.  It is greatly appreciated

--Alan

[tsantee]

I believe I've solved the audio sync issue.

For reasons that are beyond my comprehension, Crunch speeds up the video when the source is some (or all) MP4 files and the output is the Automatic Apple TV choice (which is H.264, 720x480, 29.97 fps for the samples I used). The audio finishes on time but the video gets ahead and finishes too early. What I did was go to the Custom setting and chose 24 fps instead. This kept the audio and video in sync.

I don't understand why. The source I used is a DivX video that I encoded awhile ago with Toast. It is 29.97 fps and was encoded from an MPEG 2 file that also was originally 29.97 fps. None of this ever was 24 fps.

Meanwhile, an MPEG 2 video that is 24 fps kept the audio in sync using the Crunch default of 29.97 fps. So far I haven't experienced any audio sync issues when converting from a VIDEO_TS of a MPEG 2 source.

Based on my limited testing so far I suggest DivX and other MP4 videos should use a custom encoding setting of 24 fps when encoded in H.264 with Crunch and probably with Popcorn and Toast as well. Hopefully others will test this and report here what they learn.

[AlanBrownOne]

That worked!!!  Thank you so much for figuring it out.  24 fps kept the audio and video in sync.

[old man and the sea]

That worked!!!  Thank you so much for figuring it out.  24 fps kept the audio and video in sync.

Thanks tsantee - same problem; your fix worked for me too.

Cheers

[TXCraig]

I'm having the same problem also. I have changed the setting also to 24 to see if that helps. I had hoped paying Roxio for software that I could easily find a few freeware products out there would give me a better quality product. I was also looking for somehting that was easy to use.  The very first AVI file i try to convert messes up the audio! It was quite a let down.

I have a brand new Mac Book Pro with 4 GB or RAM in it.. it take FOREVER to convert the files also. One 30 min program takes about 20 mins to convert! Not what I was expecting either....

So far I'm not impressed at all with this product.


*** UPDATE - Changing the setting to 24 corrected the audio problem for me also. Now I have to redo 7 hours worth of conversions.....

Edited by TXCraig, 08 July 2007 - 06:46 AM.