Solved: converting Flash Video(.FLV) file to AVI format without audio sync issues

Audio starts after first minute in the original Flash Video file whereas in the converted AVI it starts at the first second.

I tried using different converters like uRex video converter, HD Video Converter Factory Pro, Aiseesoft Total Media Converter to convert the FLV to AVI but all AVI files have the same issue. I even tried converting to different formats like WMV, MKV but the issue persists. Tried using Media Player Classic(http://sourceforge.net/projects/g...20Classic/) to fix the audio sync issue, but don't see a Play -> Audio -> Option where I could enter a value for Audio shift time.

How can I fix it?

I need to edit the Flash Video, but have to convert it to a format which Windows movie maker can edit.

Any suggestions would be appreciated.

I sometimes have this problem. A few times I used the trial version of Camtasia to record the FLV file as it plays on my screen and then publish it as an avi. This way there is no conversion process to screw up the audio sync. Works like a charm for me.

http://www.techsmith.com/camtasia.html

You can shift audio time in Media Player Classic by hitting + and - while the video is playing.

If you convert the video to AVI, you can adjust the audio in VirtualDub. Just load the AVI file into VirtualDub, go to Audio -> Interleaving and you have an option titled: "Delay Audio Track By" and you can place the offset value in there.

I've had this problem too with several flv files when converting them to something for my portable media player. I had to use either MP4 or wmv to prevent the audio sync issues.

As kakomu stated, VirtualDub is a good option as well. I've used it and if you can figure out all of the nuiances of it then you can do a lot with AVI files.

Try super

Quote from SuperChicken : I sometimes have this problem. A few times I used the trial version of Camtasia to record the FLV file as it plays on my screen and then publish it as an avi. This way there is no conversion process to screw up the audio sync. Works like a charm for me. http://www.techsmith.com/camtasia.html

Thanks, I have Hypercam and will try that.

Quote from kakomu : You can shift audio time in Media Player Classic by hitting + and - while the video is playing.

Well, the Media Player Classic I got from http://sourceforge.net/projects/g...20Classic/ has an option in Play->Audio-Option and there Audio time shift in ms. I entered the duration I required and the file plays fine. But, when I save it, the saved AVI is like the original AVI(out of sync). So, only Media Player Classic can play the file correctly because that option is set. No other player like Windows media player or VLC can play it correctly.

Quote from kakomu : If you convert the video to AVI, you can adjust the audio in VirtualDub. Just load the AVI file into VirtualDub, go to Audio -> Interleaving and you have an option titled: "Delay Audio Track By" and you can place the offset value in there.

Tried Virtual Dub which told me it would take 45 mins and produce a 194GB file. The original FLV video was 99MB and the converted AVI(where audio is out of sync) was 422MB. I did not have 194 GB free space so I aborted. Does syncing a AVI file(of size 422MB) produce a 194GB file?

Thanks for your advice.

Quote from menace33 : I've had this problem too with several flv files when converting them to something for my portable media player. I had to use either MP4 or wmv to prevent the audio sync issues. Thanks, MP4, WMV and even MKV format have the same sync issues. As kakomu stated, VirtualDub is a good option as well. I've used it and if you can figure out all of the nuiances of it then you can do a lot with AVI files.

I guess I am missing something as when I tried to sync the audio using VirtualDub the projected AVI file was 194GB.

Quote from hanji1 : Try super

If you are talking about this http://download.cnet.com/Super-Vi...77613.html

it seems during the free 7 day trial only 50% conversion can be done.

Quote from p_s_92 : I guess I am missing something as when I tried to sync the audio using VirtualDub the projected AVI file was 194GB.

You need to Video | Compression and choose a codec for your audio/video file otherwise it'll be uncompressed data. Also go to Audio | Compression to choose an audio format for your audio that is interlaced with your video.

Quote from p_s_92 : Tried Virtual Dub which told me it would take 45 mins and produce a 194GB file. The original FLV video was 99MB and the converted AVI(where audio is out of sync) was 422MB. I did not have 194 GB free space so I aborted. Does syncing a AVI file(of size 422MB) produce a 194GB file? Thanks for your advice.

Quote from menace33 : You need to Video | Compression and choose a codec for your audio/video file otherwise it'll be uncompressed data. Also go to Audio | Compression to choose an audio format for your audio that is interlaced with your video.

That's because VirtualDub is trying to recompress the video (and possibly the audio). If you go to the Video menu and select Direct Stream Copy and go to the Audio menu and select Direct Stream Copy, it will create a new AVI file with the exact same (not recompressed) audio and video.

Quote from kakomu : That's because VirtualDub is trying to recompress the video (and possibly the audio). If you go to the Video menu and select Direct Stream Copy and go to the Audio menu and select Direct Stream Copy, it will create a new AVI file with the exact same (not recompressed) audio and video.

Oh ok sweet tip. I've not used VDub in 10 years and I guess then I was going about it the hard way.

Quote from p_s_92 : If you are talking about this http://download.cnet.com/Super-Vi...77613.html it seems during the free 7 day trial only 50% conversion can be done.

No I was talking about "SUPER [erightsoft.com]" when I said super. The download link is a bit tricky to find. Avoid the ad link. It takes a couple of webpages to get to the actual link. Once you find the real one you'll know..

Or just try this link it might work.

Quote from kakomu : That's because VirtualDub is trying to recompress the video (and possibly the audio). If you go to the Video menu and select Direct Stream Copy and go to the Audio menu and select Direct Stream Copy, it will create a new AVI file with the exact same (not recompressed) audio and video.

Thanks, but now the converted AVI is lagging in video in the later part. The recording is of a speaker discussing powerpoint slides. When the speaker is talking about slide 16, the video is at slide 14. It seems as if the audio is slowly accelerating because at slide 1,2 3,4.5 the audio and video are aligned.

When i opened the AVI file to add the audio delay, I got a message that "Variable Bitrate audio detected which is non-standard in AVI. You may encounter sync errors up to 0ms when attempting to extract WAV files or playing in some players. If this is a problem, use Full Processing to decompress or recompress the audio."

I used Full Processing mode for audio, but that did not fix it.

Using Full processing mode for video would mean producing a 194GB output file.

What else can I try?

Quote from p_s_92 : Thanks, but now the converted AVI is lagging in video in the later part. The recording is of a speaker discussing powerpoint slides. When the speaker is talking about slide 16, the video is at slide 14. It seems as if the audio is slowly accelerating because at slide 1,2 3,4.5 the audio and video are aligned. When i opened the AVI file to add the audio delay, I got a message that "Variable Bitrate audio detected which is non-standard in AVI. You may encounter sync errors up to 0ms when attempting to extract WAV files or playing in some players. If this is a problem, use Full Processing to decompress or recompress the audio." I used Full Processing mode for audio, but that did not fix it. Using Full processing mode for video would mean producing a 194GB output file. What else can I try?

Full processing of either the audio or video isn't going to fix the issue of desync.

Seems to me the problem is probably that the flash video and the AVI you made from the flash video are running at different frame rates. The original flash video may be running at faster frame rate than the AVI you just made (e.g. the Flash video may be running a 29.97 and the AVI may be running at 25 fps).