Hi folks! New to the forum, but not to ffmpegx. Just finally stumped. I've been using the "join" tool off and on for a couple years with never any trouble, but now I've come to a dead end.
I have two halves of a video. One is 699.2meg, the other 700.7meg. When dropped in Source, both are recognized as AVI, mpeg4, yuv420p, 640x272, AC3, 48000 hz, stereo, 192kbps. For both, the audio and video are perfectly in sync. After using the "join" tool, though, the audio ends up almost a full second "early", right from the beginning and straight through to end.
I've tried using the standard conversion to AVI-DivX that is the ffmpegx default conversion, and both convert perfectly ... but again using join on the newly converted files the result is out of sync.
Showing the movie properties in Quicktime shows the video and audio tracks on part 1 to be 1:25:58:64 and 1:25:58:66 respectively, and for part 2 to be 1:17:58:12 and 1:17:58:18. The joined file shows 2:43:56:68 and 2:43:56:50. With discrepancies of only a couple hundredths of a second this would not seem to be the problem.
I thought maybe I'd separate the video and audio, join them separately, and then re-add the audio. So I dropped the first half into source and un-checked "encode audio" on the audio screen ... but the resulting file still had the audio in it ... ??? I tried playing with some of the bit rates, but at this point it seems I'm just shooting in the dark.
So, any clues as to what I can try next? Seems it shouldn't be this hard just to join two halves into a whole!
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Thanks for your detailed description. It rules out some possible causes. But I'm afraid I do not have a sure fix for this problem.
If you have QuickTime Pro (/w Perian), you could try joining (pasting the second part at the end of the first part) there. Save as .mov. Then convert the .mov to AVI-DivX. Perhaps the QuickTime architecture does something that keeps the sync. -
OK, no stranger to QTP or Perian either. Opened the two in QTP, copied #2, pasted at the end of #1, saved as self contained movie. I now have a .mov with the info:
Video Track ID 1, DivX 4.1.2, duration 2:43:56:97, Frame Rate 25
Sound Track ID 2, MPEG Layer 3, duration 2:43:57:50
and it's in sync beginning to end.
When I dropped this resulting .mov back onto ffmpegx, it showed the video recognized as "mgeg4 yuv420p" and the audio recognized as "mp2 48000 Hz". I ran it through the default AVI DivX encoder and this time the first half of the resulting video is perfectly in sync, but the second half of the resulting .avi has the audio late by about a half second. I checked the left and right sides of the cut point (around 1:20:00:00 and 1:30:00:00) and the sync issue is definitely limited to "part 2" now, even though it is not out of sync in the .mov. I suppose I can just leave it as a .mov.
For that matter, is there any reason I cannot just change the .mov extension to .avi and leave it at that without re-running it through ffmpegx? I tried it and it still opens happily in Quicktime, mplayer, and VLC. When I pasted Part2.avi at the end of Part1.avi in QTP and saved the resulting file, there did not seem to be any "conversion" or "flattening" that took place. QTP just saved it with a .mov in the normal amount of time it would take to File->Duplicate something 1.3gig in size. What's in a "shell" if the interior is still DivX and MP3? Is the .move extension just a Quicktime placebo? Anyone know? -
Both AVI and MOV are "container" formats (essentially file specifications). Within these containers can reside media encoded with a wide variety of different video and audio codecs. So, what's the difference? It's actually Windows vs. Mac, essentially. These container formats achieve similar ends, but they are not the same. It's like Word vs. WordPerfect. Similar things targeted to solve similar problems, but not the same.
Just because VLC can recognize a file means very little, actually, since VLC is written to be very tolerant of errors, Frankenstein hybrid formats, etc. So, playability in VLC should not be taken as any sort of proof of compatibility, say, or standards compliance.
That said, here's something to try in order to solve your problem. Since QT seems to get the sync right, be sure to select "decode with QT" in your conversion. If you've already done so, and still get a sync error, then I'm confused, but post back, and someone can walk you through a troubleshooting/solution procedure. -
Originally Posted by RedDwarph
Originally Posted by RedDwarph
Originally Posted by RedDwarph
Originally Posted by RedDwarph -
First, you can try with D-Vision which offers two different joining methods (avimerge and mencoder).
You may also have a look to avidemux which can append .avi files one to another, then export the resulting file to a new .avi with audio/video direct stream copy.
If you have Quicktime Pro, instead of exporting as a ".mov" file as case suggested, you may try the free "Save as .avi" component provided with MPEGStreamclip, which alloaws .avi audio/video stream copy with Quicktime.Jean-Philippe Schuck
Un générique, un autre jour, le blog sur les génériques de dessins animés -
The trouble with the join is that there is probably a audio delay
in the 2nd half of the movie. This is getting to be pretty regular
now. I usually drop my files into avi mux and click on the audio
to find out if there is a delay and most of the time there ia a delay
in the 2nd clip. You'll need to use an audio editor, extract the
audio file add x amount of silence x being the ms delay avi mux
shows you then mux it back into the file. -
Originally Posted by tomlee59Originally Posted by case
I'll try a couple other ffmpeg codecs that include the decode with QT option first, then jpschuck's suggestions next and see how that turns out.
fastman: I have Audacity and was prepared to go this route, but was hoping first that I was missing something obvious to more experienced user (e.g. "tick the encode with quicktime box"). Most of my experience is with audio, so I know how to pad, stretch, and shrink if needed.
Thank you all for being so friendly and helpful. I will post again as soon as I have tried a couple more things. -
Originally Posted by jpschuck
Originally Posted by jpschuck
Originally Posted by jpschuck
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