FLV file with severe lip sync issue

[neftv]

Hi all,
I downloaded a Flash video program from a site in Greece. It's a 1 hour and 28 min program. I know they are in PAL and USA (where I am at) is NTSC and it appears that the file is in pal at 25 fps. However, when I play the flash file in Real Player or Flash player on my PC about halfway into the program its start to have lip sync issues and by the time its at the end the program the lip sync is so severe that its a real problem. I want to burn this program so that I can make a DVD out of it but even when I transcode to AVI the lip sync issue is so bad that when I put the file in a edit software and I offset the audio to video to match it somewhere along the time line I end up missing video frames and it will skip at a certain point multiple times. Has anyone dealt with severe lip sync issues like this and how to deal with it? Thank you in advance.

[DereX888]

Bad encoding case. Many longer FLVs go out of sync, even the ones on sites that "specialize" in FLVs only (like youtube).

Demultiplex audio and video streams and if youre lucky the videostream might be MPEG already; if not - encode it to a format thats easy to work with, encode audio to WAVE, then fix synch issue(s).

Week or so ago I was encoding this
http://www.youtube.com/watch?v=N9qXAO53ohg
trailer in "HD" for my bro, it had desynch too. Easy to fix.

[hech54]

I know they are in PAL and USA (where I am at) is NTSC and it appears that the file is in pal at 25 fps. However, when I play the flash file in Real Player or Flash player on my PC

Just for future reference....computers don't care about PAL or NTSC format....only
televisions and related equipment care about such things.

[poisondeathray]

Can you try another player e.g. kmplayer or smplayer ? still sync issues?

Make sure you rule out the simple cases of frame rate mismatch/ and file length mismatch first. (the fix would be just to either shrink/expand the audio or change the video fps to effectively shrink/expand to match the audio). But it sounds like you have multiple sync point issues.

If the original .flv file has sync issues you have problems. You will probably have to cut + process it in segments, and sync up each segment - very tedious to do. It takes hours to do, adjusting the framerate, and shifting the audio delay. Avidemux is a good tool to do this. Also check if the extracted streams are in sync with flvextract

If the original .flv is in sync, and only re-encoding efforts cause sync issues it is likely the .flv is variable frame rate. In this case you could use flvextract, which will extract the audio & video & generate a timecodes sheet. You use a v2 timecodes to v1 timecodes converter and examine if they are different frame rate changes at different times. VFR is not supported by DVD-video, only a few containers support it (mkv, mp4, wmv), so you have to make a hybrid framerate MPEG2 which is difficult to do. There are links on this following page which explain how to do this: http://avisynth.org/mediawiki/VFR

[neftv]

I am using flvextract. I have the video and audio in the timeline. About the middle part of the piece I am discovering slient audio where there suppose to be talking like one second. I am going to cut it out now and see how that goes. geez this is a nightmare but it will be worth it because it's an important piece.