Avidemux - Audio sync problems before one even begins an edit. Why?

[Hilbert G]

I have .mpg files saved from TV by a PVR. These files play AOK in any player on my computer, VLC, MPC-HC etc.--the audio and video are in full sync as one would expect.

Now, all I want to do is to cut out ads or separate two adjacent programs using Avidemux 2.6 but it's become a drama. Just simply playing the video in Avidemux (without attempting any edit) the audio and video are way out of sync.

1. Can someone tell me in simple words why a video editor such as Avidemux cannot play a video in sync when simple players have absolutely no trouble syncing audio and video?

2. Is there some simple way to force Avidemux to play in sync without using (ticking) the Shift function? Why should I have to work out the delay (which I find quite difficult to do without a clapper etc., not to mention it's tedious and very time consuming) when obviously the file is already in sync in ways that players have no trouble with?

Please tell me whether Avidemux is just half-baked crud software or not (being free I suppose it is). If this software can't really be used without having a PhD in film editing then could someone tell me of editing software that's at least as smart as the average player.

P.S.: Avidemux is set to its install defaults (except the Output was changed to Mpeg-PS Muxer as recommended in the Wiki readme), but even so it made no difference if this change wasn't made.)

[smrpix]

Try something else then (a different tool.) Nobody's putting a gun to your head. It doesn't work with your files.

[hech54]

I have .mpg files saved from TV by a PVR. These files play AOK in any player on my computer, VLC, MPC-HC etc.--the audio and video are in full sync as one would expect.

Now, all I want to do is to cut out ads or separate two adjacent programs using Avidemux 2.6 but it's become a drama. Just simply playing the video in Avidemux (without attempting any edit) the audio and video are way out of sync.

1. Can someone tell me in simple words why a video editor such as Avidemux cannot play a video in sync when simple players have absolutely no trouble syncing audio and video?

2. Is there some simple way to force Avidemux to play in sync without using (ticking) the Shift function? Why should I have to work out the delay (which I find quite difficult to do without a clapper etc., not to mention it's tedious and very time consuming) when obviously the file is already in sync in ways that players have no trouble with?

Please tell me whether Avidemux is just half-baked crud software or not (being free I suppose it is). If this software can't really be used without having a PhD in film editing then could someone tell me of editing software that's at least as smart as the average player.

P.S.: Avidemux is set to its install defaults (except the Output was changed to Mpeg-PS Muxer as recommended in the Wiki readme), but even so it made no difference if this change wasn't made.)

Something is wacky with your original files. I use AviDemux(2.4.4) almost exclusively for simple MPEG2 cuts from all different types of sources and I never have the problem you describe above.
I also use AviDemux exclusively to REPLACE audio in MPEG2 files.
When my cheapo cable box was still working(Telefunken), the recordings I pulled from that thing displayed the same problems you describe above....ALL of the files I pulled from it.

[poisondeathray]

Sometimes newer builds introduce bugs. You can try an older version or some other free programs like mpg2cut2 . (I'm assuming your .mpg files are use MPEG2 compression, not something else like AVC, because .mpg just indicates mpeg2-program stream, and doesn't necessarily indicate what compression is used)

Video players can often skip over errors, and have speedup tricks to keep everything in sync. Editing requires a higher level of resiliency

Or try some payware like videoredo (it has a quickstream fix option if the stream is damaged) , or solveigmm video splitter

[hello_hello]

Try Video To Video Converter. It has a file splitter/joiner and commercial remover under the Tools menu.

[Hilbert G]

Try something else then (a different tool.) Nobody's putting a gun to your head. It doesn't work with your files.

If I was seriously into video editing I wouldn't muck about, I'd simply go to Adobe Premiere, ivsEdits etc. and I'm sure I wouldn't have a problem. But the fact is all I have to edit is a collection of old TV programs, most of which will be discarded after I sort them out.

The issue is why ALL the .mpg files that I've collected (about 80 files amounting to approx. a half terabyte) all play in sync and without problems across multiple players and across various different PCs as well as in the PVR's media player they were originally saved on but they do NOT sync by default on Avidemux 2.6.6 and 2.6.7. (At no time has there ever been any issues with these files until I loaded them into Avidemux.)

There are too many normal AOK working files that play fully in sync in every other environment than to just dismiss the problem. The questions is what is specifically different about the way Avidemux plays [and syncs] .mpg files that it cannot sync certain .mpg files unless it's done manually? (And clearly, from what others have said, not all .mpg files are a problem).

Either someone knows the answer and/or it's an unresolved bug. If so, perhaps the developers should be notified.

(BTW, in the past I've used other editors with some of these files and not had a problem. However these other editors are not on this PC but Avidemux is. Incidentally, those other editors were: Windows Movie Maker, ivsEdits and Shotcut--but Shotcut was useless for other reasons.)

[smrpix]

If so, perhaps the developers should be notified.

We're counting on you.

Try the free trial of TMPGenc Smart Renderer

[Steve(MS)]

Presuming there is nothing wrong with your files...which isn't a given....
When using Avidemux, cut only on the "I" frames.
This should keep the A/V in sync.
VideoRedo is a better choice but it is payware.

[jagabo]

The issue is why ALL the .mpg files that I've collected (about 80 files amounting to approx. a half terabyte) all play in sync and without problems across multiple players and across various different PCs as well as in the PVR's media player they were originally saved on but they do NOT sync by default on Avidemux 2.6.6 and 2.6.7. (At no time has there ever been any issues with these files until I loaded them into Avidemux.)

Avidemux is simply not a very robust program. It has problems with many files -- the files from your PVR included, apparently. Maybe if you send the authors samples of your files they'll fix the program. Probably not.

[Hilbert G]

If so, perhaps the developers should be notified.

We're counting on you.

Try the free trial of TMPGenc Smart Renderer

OK, we've not yet resolved my problem but we're nearer to a solution thanks to the feedback. It seems that Avidemux has a sync problem with some 'types' of .mpg files. As hech54 points out, they may be too wacky for Avidemux but OK for players, I guess but perhaps the default sync window is narrower than for most media players--my files being outside this range.

I can't imagine that I'm alone with this problem as PVRs (and their chipsets) are only made by a handful of manufacturers, thus presumably the chipset that outputs this .mpg file is pretty common (it may also be a BIOS/firmware issue, mismatched timing etc., in the PVR). I'll check/solve this as soon as I can get a different brand of PVR.

What I'll now do is to first get some .mpg files from a completely different source and try to edit them and see what happens. I'll also take poisondeathray's point and use an earlier version (the earliest I have is 2.5.6). I'll also reinstall the editors I used earlier and also try others suggested here.

I'll resolve the problem through a process of elimination, if necessary I'll send the developers a bug report.

[jagabo]

I can't imagine that I'm alone with this problem...

Which is why I said they probably won't fix the program.

Do what others have suggested: use a different program. Mpg2Cut2 maybe. VideoRedo will probably work but it's not free.

[hech54]

Create a small sample vid and upload it.....or drop one of the files into MediaInfo(careful installing MediaInfo) and post the text results.

[hech54]

If I was seriously into video editing I wouldn't muck about, I'd simply go to Adobe Premiere, ivsEdits etc.

Adobe Premier doesn't import MPEG very well from what I hear....and the free version of ivsEdits also doesn't import MPEG2 according to their website.

[Hilbert G]

If I was seriously into video editing I wouldn't muck about, I'd simply go to Adobe Premiere, ivsEdits etc.

Adobe Premier doesn't import MPEG very well from what I hear....and the free version of ivsEdits also doesn't import MPEG2 according to their website.

Wasn't the free ivsEdits but full version and it worked AOK, but it's installed on another machine. As it's not installed on this machine, and as the job doesn't warrant a high-end commercial product, I selected Avidemux for what I thought would be a quick and easy solution.

[Hilbert G]

Avidemux is simply not a very robust program. It has problems with many files -- the files from your PVR included, apparently. Maybe if you send the authors samples of your files they'll fix the program. Probably not.

Well, I wasn't aware of this, thanks for telling me. After reading all the ballyhoo about how wonderful it was, it sounded just right for what I thought would be the simplest of exercises.

Now that it's pretty certain that it's not finger trouble here, I'll test the files again on the other machine as soon as is practicable with software that I know works.

[Hilbert G]

Presuming there is nothing wrong with your files...which isn't a given....
When using Avidemux, cut only on the "I" frames.
This should keep the A/V in sync.
VideoRedo is a better choice but it is payware.

Understand that, but I'd not gotten that far. Just by loading the file it was out of sync.

[Hilbert G]

Presuming there is nothing wrong with your files...which isn't a given....
When using Avidemux, cut only on the "I" frames.
This should keep the A/V in sync.
VideoRedo is a better choice but it is payware.

OK I've downloaded the demo VideoRedo and tried it on my suspect files, and they work perfectly in VideoRedo without the slightest tweak.

Point proven, Avidemux 2.6 has significant bugs!

I'll try some of the suggestions from others as soon as I've a moment.

Thanks for the suggestion.

[Hilbert G]

Try Video To Video Converter. It has a file splitter/joiner and commercial remover under the Tools menu.

OK I've now also tried the demo of Video To Video Converter and it too works perfectly with these 'suss' files of mine.

Again, we've proved it. I've no doubt that Avidemux 2.6 is very buggy. Shame really, as it seemed to have potential as a free editor.

Thanks again.

I'll report this post to Avidemux and let them sort it from there.

[Hilbert G]

Here's an update on the new Avidemux 2.6.8. Essentially the problem isn't fixed. The best way to explain it is to provide a copy of my review post to Fileforum:


Hilbert

Reviewing 2.6.8 (Mar 13, 2014)

Well, despite Avidemux 2.6.8's long list of bug fixes, the TV/PVR .MPG audio sync bug is STILL NOT FIXED in this version (see my review for 2.6.7 below).

This is a truly serious bug in Avidemux, and a peculiar one at that. Peculiar, because I cannot find a single media player that actually plays these MPG files incorrectly in their unedited form! However, after the simplest Avidemux edit, they're all stuffed!

(That's to say media players such as MPC-HC, VLC, MPlayer, WMP, et al, play the files perfectly--i.e.: with absolutely NO audio/lip sync problem but AFTER they're edited with Avidemux all these players play them with the audio out of sync.)

[FYI, below is a MediaInfo's properties list of one of these MPG files.]

Yet, Avidemux 2.6.8--even in its 'player mode' (before any editing)--plays every one of these MPG files completely out of lip sync. The audio is out of sync by at least 350 to 500 ms (depending on file). This means that if one uses Avidemux, then even the simplest of edits has to be done manually using the offset, which is a real pain unless you've a clapper sync point (which is not often the case on TV/PVR programs).

Forget Avidemux, there's just far too much wrong with it!

(Buy a cheap program such as VideoRedo - http://www.videoredo.com/en/index.htm. It edits perfectly without a trace of out-of-sync audio on these MPEGs. Which also proves there's nothing essentially wrong with any of these MPEGs. )

________________

Typical MPEG file properties for files that Avidemux 2.6.x cannot audio sync:

General
Complete name : C:\AVI\TEST\000.mpg
Format : MPEG-PS
File size : 2.98 GiB
Duration : 1h 31mn
Overall bit rate mode : Variable
Overall bit rate : 4 668 Kbps

Video
ID : 224 (0xE0)
Format : MPEG Video
Format version : Version 2
Format profile : Main@Main
Format settings, BVOP : Yes
Format settings, Matrix : Custom
Format settings, GOP : Variable
Duration : 1h 31mn
Bit rate mode : Variable
Bit rate : 4 319 Kbps
Maximum bit rate : 10 000 Kbps
Width : 720 pixels
Height : 576 pixels
Display aspect ratio : 16:9
Frame rate : 25.000 fps
Standard : PAL
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Top Field First
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.417
Time code of first frame : 02:42:46:22
Time code source : Group of pictures header
Stream size : 2.76 GiB (93%)

Audio
ID : 192 (0xC0)
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 2
Duration : 1h 31mn
Bit rate mode : Constant
Bit rate : 256 Kbps
Channel(s) : 2 channels
Sampling rate : 48.0 KHz
Compression mode : Lossy
Delay relative to video : -393ms **
Stream size : 168 MiB (5%)

** Note the delayed audio.

[hech54]

Here's an update on the new Avidemux 2.6.8. Essentially the problem isn't fixed
Delay relative to video : -393ms **
Stream size : 168 MiB (5%)

** Note the delayed audio.

Note the delayed audio created by your PVR.
Your crusade against FREE software that works fine for tens of thousands of users worldwide, but doesn't work well on crap PVR files created by your device and my old Telefunken crapper is touching.
I look forward to reviewing HilbertDemux when it is released.

[Hilbert G]

"Your crusade against FREE software that works fine for tens of thousands of users worldwide..."


1. I have no crusade against free software. In fact, the commercial solution, VideoRedo, which I suggested actually came from another poster to this forum; I'd never used it before this (nor had I even heard of it—read previous posts). The fact that it and other commercial software work perfectly in this situation whereas Avidemux does not is simply a statement of fact.

2. Emotion won't get you anywhere, in fact it's counterproductive. Pretending Avidemux's bugs don't exist just because it's free software—and that somehow free software is immune from criticism—is about as stupid as doctor telling you that you've a potentially fatal disease and then completely ignoring the fact.

3. Here the obvious fact—the elephant in the room—which you are completely ignoring, is that ALL media players that I have tried have no problems playing and syncing audio and video perfectly with these files, whereas Avidemux DOES have problems when just acting as a media player. If Avidemux cannot act as a simple media player on files that are a non-issue for other players, then Avidemux has a serious fault—QED! Remember, at this point, we're just playing the file, not attempting to edit it!

(It's not my fault there's a fault, and shooting the messenger will not help.)

4. The concept of a HilbertDemux is ridiculous, the world is already awash with demuxers and we don't need any more. What Avidemux has to do is to make existing demuxers work for it.

5. Putting on one of my professional hats, I have to technically evaluate both commercial and free software and I can assure you that I often have to give very solid justifiable reasons why I've ruled out a piece of free software as unacceptable thus losing out to a commercial product. The reasons are obvious; my clients have to pay more if I rule out the free product. (BTW, evaluating Avidemux wasn't initially my idea, rather it was a client request.)

6. No one more than me would love free software to be truly effective competition for commercial software but, by and large, unfortunately it is not. To do so, a free software product has to be at least as good as its commercial counterpart and preferably better than it is—then we'd have proper competition which would force software standards up generally. From my years of examining why free software so often doesn't make the grade are:

(a) There just aren't sufficient commercial imperatives to ensure it succeeds, development is often a hobby-based activity and developers regularly lose interest. Hence the lack of development funds, thus lack of fixes, timely patches, etc., etc.

(b) Thus, because its development is often unreliable, similarly with support, it's not given much credence in the mainstream. Let me give an example: when I first had the problem with Avidemux, I looked to contact its developers (or someone closely associated with the project) for help but there was no one to contact! Clearly, Avidemux developers do not want the hoi polloi such as me contacting them. This is a huge disincentive for many users to use the product (and it sure tells me that Avidemux's developers are only mucking about with it at a hobby level).

(c) And probably the most significant point why most free software so often doesn't become mainstream is that its developers often have very different imperatives to those of its users (thus there's no commercial pressures to compel them to do otherwise, hence ultimately aliening users). Time and time again, one sees that the features users want are often NOT those of the development team. As the software is free, when users say 'can we have this?', developers so often ignore them or say 'no'—more often than not, they don't even bother to respond to requests. We see this repeatedly even in major software projects such as the Gimp, OpenOffice/LibreOffice etc.—even Linux, thus they're so often culled out in favour of even very mediocre commercial products (thus it's why we've 'second-rate' MS Office taking 90+ of the world's share by default).

Let's apply this logic to Avidemux for a moment (it may or may not be factual). Let's assume Avidemux's developers are not personally interested in editing variable bit rate interlaced MPG files then there's little incentive for them do anything about it. They won't bother to put in features that would fix the problem, nor will they put in debugging utilities that would help provide a fix, even if it leaves many users stranded by these features not working or not being installed. Nor is there any incentive to put in error messages to the effect that 'editing variable bit rate interlaced MPG files is not supported at this time'—thus leaving many hapless users to waste countless hours mucking about trying to get the program to work.

Of course, the quintessential example of this problem is OpenOffice/LibreOffice versus MS Office. Arguably—and this isn't just my assertion—MS Office is responsible for word-processing going nowhere in the last decade, but even so OpenOffice/LibreOffice make absolutely no attempt to push MS into developing a better more advanced Office. In fact, this free product is almost a decade behind its commercial rival in features etc.; ideally, the reverse would be true.

If you think what I'm saying is B/S then you don't spend much time at the users' coalface.

Perhaps your outburst is because you are an Avidemux developer in disguise. If so, then I'd urge you to do something about the program's problems. After all, I've given you the very best error message you could ever have—specifically the precise details of MPG files that do not work with Avidemux! That's half your battle done.

If you are not and only one of its fanbois, then you could crusade to have the product fixed.

Finally, make no mistake; if products such as Avidemux put themselves in the marketplace without stipulating any limiting specifications etc. (such as not working with certain type of MPG files), then they're absolutely fair game for criticism by people such as me. If for no other reasons than they're both misleading users and wasting their time.

[smrpix]

"Your crusade against FREE software that works fine for tens of thousands of users worldwide..."


1. I have no crusade against free software. In fact, the commercial solution, VideoRedo, which I suggested actually came from another poster to this forum; I'd never used it before this (nor had I even heard of it—read previous posts). The fact that it and other commercial software work perfectly in this situation whereas Avidemux does not is simply a statement of fact.

2. Emotion won't get you anywhere, in fact it's counterproductive. Pretending Avidemux's bugs don't exist just because it's free software—and that somehow free software is immune from criticism—is about as stupid as doctor telling you that you've a potentially fatal disease and then completely ignoring the fact.

3. Here the obvious fact—the elephant in the room—which you are completely ignoring, is that ALL media players that I have tried have no problems playing and syncing audio and video perfectly with these files, whereas Avidemux DOES have problems when just acting as a media player. If Avidemux cannot act as a simple media player on files that are a non-issue for other players, then Avidemux has a serious fault—QED! Remember, at this point, we're just playing the file, not attempting to edit it!

(It's not my fault there's a fault, and shooting the messenger will not help.)

4. The concept of a HilbertDemux is ridiculous, the world is already awash with demuxers and we don't need any more. What Avidemux has to do is to make existing demuxers work for it.

5. Putting on one of my professional hats, I have to technically evaluate both commercial and free software and I can assure you that I often have to give very solid justifiable reasons why I've ruled out a piece of free software as unacceptable thus losing out to a commercial product. The reasons are obvious; my clients have to pay more if I rule out the free product. (BTW, evaluating Avidemux wasn't initially my idea, rather it was a client request.)

6. No one more than me would love free software to be truly effective competition for commercial software but, by and large, unfortunately it is not. To do so, a free software product has to be at least as good as its commercial counterpart and preferably better than it is—then we'd have proper competition which would force software standards up generally. From my years of examining why free software so often doesn't make the grade are:

(a) There just aren't sufficient commercial imperatives to ensure it succeeds, development is often a hobby-based activity and developers regularly lose interest. Hence the lack of development funds, thus lack of fixes, timely patches, etc., etc.

(b) Thus, because its development is often unreliable, similarly with support, it's not given much credence in the mainstream. Let me give an example: when I first had the problem with Avidemux, I looked to contact its developers (or someone closely associated with the project) for help but there was no one to contact! Clearly, Avidemux developers do not want the hoi polloi such as me contacting them. This is a huge disincentive for many users to use the product (and it sure tells me that Avidemux's developers are only mucking about with it at a hobby level).

(c) And probably the most significant point why most free software so often doesn't become mainstream is that its developers often have very different imperatives to those of its users (thus there's no commercial pressures to compel them to do otherwise, hence ultimately aliening users). Time and time again, one sees that the features users want are often NOT those of the development team. As the software is free, when users say 'can we have this?', developers so often ignore them or say 'no'—more often than not, they don't even bother to respond to requests. We see this repeatedly even in major software projects such as the Gimp, OpenOffice/LibreOffice etc.—even Linux, thus they're so often culled out in favour of even very mediocre commercial products (thus it's why we've 'second-rate' MS Office taking 90+ of the world's share by default).

Let's apply this logic to Avidemux for a moment (it may or may not be factual). Let's assume Avidemux's developers are not personally interested in editing variable bit rate interlaced MPG files then there's little incentive for them do anything about it. They won't bother to put in features that would fix the problem, nor will they put in debugging utilities that would help provide a fix, even if it leaves many users stranded by these features not working or not being installed. Nor is there any incentive to put in error messages to the effect that 'editing variable bit rate interlaced MPG files is not supported at this time'—thus leaving many hapless users to waste countless hours time mucking about trying to get the program to work.

Of course, the quintessential example of this problem is OpenOffice/LibreOffice versus MS Office. Arguably—and this isn't just my assertion—MS Office is responsible for word-processing going nowhere in the last decade, but even so OpenOffice/LibreOffice make absolutely no attempt to push MS into developing a better more advanced Office. In fact, this free product is almost a decade behind its commercial rival in features etc.; ideally, the reverse would be true.

If you think what I'm saying is B/S then you don't spend much time at the users' coalface.

Perhaps your outburst is because you are an Avidemux developer in disguise. If so, then Id urge you to do something about the program's problems. After all, I've given you the very best error message you could ever have—specifically the precise details of MPG files that do not work with Avidemux! That's half your battle done.

If you are not and only one of its fanbois, then you could crusade to have the product fixed.

Finally, make no mistake; if products such as Avidemux put themselves in the marketplace without stipulating any limiting specifications etc. (such as not working with certain type of MPG files), then they're absolutely fair game for criticism by people such as me. If for no other reasons than they're both misleading users and wasting their time.

Please refer to my post #2, the first answer to your question.

[hech54]

If you are not and only one of its fanbois, then you could crusade to have the product fixed.

Why? It's free software that works perfectly for me. I already warned you about the goofy PVRs (mine included) that create files with incredibly ridiculous audio offset problems. THAT is your problem. You proved your own problem by posting the MediaInfo "info" from your bastard files.
When it comes time to replace and re-sync the audio in a video file, you'll be back to AviDemux. When it comes to to actually fix the audio sync of your files for some unforeseen future project with these PVR files....you'll be back to Avidemux. You can replace audio and re-sync existing audio without changing the quality of either the video or audio with Avidemux.
Keep banging your head against the wall....and have fun storming the castle.



.

[budwzr]

Most of us here use several different utilities because there is no universal 100% solution in editing.