Sync issues in FLV to MKV or AVI Remux

wst · 27th January 2009, 23:00

Hi all -

I'm trying to remux an FLV I grabbed off C-SPAN with Replay Media Catcher.

I used FLVExtract to get the audio, video, and timecode. I tried muxing to MKV with MKVMergeGUI, giving it A+V+Timecode, but the sync was way off. I also tried bringing the A+V into VirtualDub and setting the framerate to match the audio length, but had a similar sync issue.

The final output can be MOV, AVI, MKV, MP4 - I don't care - just not FLV, because I can't stream it to my TV. If you guys have any ideas, I'd surely appreciate it.

Here's the file:

http://rapidshare.com/files/19036466...0DFE7.flv.html
(about 100MB, FYI)

Thanks.

Kurtnoise · 28th January 2009, 17:49

Try this:

Code:

FFmpeg -i myfile.flv -vcodec copy -acodec copy output.mkv

wst · 29th January 2009, 21:20

Thanks Kurtnoise - that did indeed clear up the sync problem. (Though, not in MPC for some reason).

However, now there are these odd audio artifacts. It sounds like a "cutting out"-type sound - a garbled, high-pitched swoosh of MPEG noise is my best description. Should the audio be reencoded or processed in some way to fix that?

Thanks again,

Will

wst · 3rd February 2009, 23:14

I tried

Code:

FFmpeg -i "myfile.flv" -vcodec copy -acodec libmp3lame -ab 192kbps "output.mkv"

which fixed the audio glitches, but reintroduced the sync problem.

lovelove · 17th June 2011, 12:47

wst, have you been able to solve the sync problem?
If yes, could you please post the solution? thank you.

wst · 17th June 2011, 19:32

Sorry bro, I never figured it out. Maybe try some different settings on libmp3lame, or maybe a new version of ffmpeg...good luck!

27th January 2009, 23:00	#1 \| Link
wst Registered User Join Date: Aug 2008 Posts: 30	Sync issues in FLV to MKV or AVI Remux Hi all - I'm trying to remux an FLV I grabbed off C-SPAN with Replay Media Catcher. I used FLVExtract to get the audio, video, and timecode. I tried muxing to MKV with MKVMergeGUI, giving it A+V+Timecode, but the sync was way off. I also tried bringing the A+V into VirtualDub and setting the framerate to match the audio length, but had a similar sync issue. The final output can be MOV, AVI, MKV, MP4 - I don't care - just not FLV, because I can't stream it to my TV. If you guys have any ideas, I'd surely appreciate it. Here's the file: http://rapidshare.com/files/19036466...0DFE7.flv.html (about 100MB, FYI) Thanks.

28th January 2009, 17:49	#2 \| Link
Kurtnoise Swallowed in the Sea Join Date: Oct 2002 Location: Aix-en-Provence, France Posts: 5,191	Try this: Code: FFmpeg -i myfile.flv -vcodec copy -acodec copy output.mkv

3rd February 2009, 23:14	#4 \| Link
wst Registered User Join Date: Aug 2008 Posts: 30	I tried Code: FFmpeg -i "myfile.flv" -vcodec copy -acodec libmp3lame -ab 192kbps "output.mkv" which fixed the audio glitches, but reintroduced the sync problem.

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29th January 2009, 21:20	#3 \| Link
wst Registered User Join Date: Aug 2008 Posts: 30	Thanks Kurtnoise - that did indeed clear up the sync problem. (Though, not in MPC for some reason). However, now there are these odd audio artifacts. It sounds like a "cutting out"-type sound - a garbled, high-pitched swoosh of MPEG noise is my best description. Should the audio be reencoded or processed in some way to fix that? Thanks again, Will

17th June 2011, 12:47	#5 \| Link
lovelove Registered User Join Date: Mar 2010 Posts: 106	wst, have you been able to solve the sync problem? If yes, could you please post the solution? thank you.

17th June 2011, 19:32	#6 \| Link
wst Registered User Join Date: Aug 2008 Posts: 30	Sorry bro, I never figured it out. Maybe try some different settings on libmp3lame, or maybe a new version of ffmpeg...good luck!